How exactly is the "global average temperature" calculated and how reasonable is this method?

It is also quite striking for those of us who are not climate
scientist that the amount of warming we are talking about is on a
scale (0-2 C) that is much smaller than the temperature variation we
might experience during a time scale as short as a day or distance
scales as short as a few hundred of kilometers.

TLDR, but here goes:
There's a few factors to consider regarding the relatively tiny 2 degrees C and I'm not sure how to explain this without being long, but obviously you're correct, we hardly notice a 2 degree change ourselves.   But if you look at the total energy of Earth you can get a slightly better picture.
The numbers below are only approximations but should be close enough to give an idea of how the trapped heat plays in the Earth's atmosphere and oceans.
The sun shines on the Earth about 1.8x1017 Joules per second, or about 5.6x1024 Joules per year.   Source.   Remember that number, I'll reference it a few times.
The rough division is about 48% of that hits the surface, 23% is absorbed in the atmosphere, 29% is reflected back into space.  Source.  Now, because the Earth is in largely in a stable equilibrium where energy in roughly equals energy out, the Earth radiates about the equivalent of 71% of that 5.6x1024 Joules per year that the sun shines on it, the other 29% being reflected.
This will be obvious to some but I'll mention it anyway.   Global warming has nothing to do with the sun giving the Earth more energy.   It has to do with the Earth radiating less energy into space, at least until the Earth warms enough for a new equilibrium to re-stabilize the energy in = energy out.   Raising the concentration of greenhouse gas changes the equilibrium of heat transfer.   It's the same principal as putting on a sweater.
Using the same link as above, 59 of that 71% radiates from Earth's upper atmosphere and the remaining 12% from the surface.  For greenhouse gas driven climate change to work, the only way that can work is that the 59% needs to drop (OK, not the only way, you can also play with albedo).  But heat is trapped in the lower atmosphere, the upper atmosphere cools and the 59% drops a little lower.   Cloud cover and changes in Albedo such as snow cover, ocean cover and green vs desert are factors too, (the 29% mentioned above), but that gets enormously complicated, and beyond the scope of anything I can try to explain, so I'm going to ignore that for now and just look at the 59% of the 5.6x1024 Joules per year.
Thermal radiation increases at roughly the 4th power of the temperature, so if we use the average temperature on Earth at about 288 Kelvin and add 2 degrees to that, the radiation difference between 288 Kelvin and 290 Kelvin using the 4th power rule is a 2.8% increase, or an increase from 12% to 12.34% of the 5.6x1024.   To keep the energy balance consistent, when a new equilibrium is reached, the 59% drops to 58.66% with 0.34% being "new heat" due to the additional greenhouse gas.   This change presumably has already happened.  In fact, today, the heat balance is out of equilibrium which is why the Earth is warming.   The Earth is taking in more heat than it's giving back into space.
0.34% of 5.6x1024 = 1.9x1022 Joules.  By comparison, the combined energy use of all man-kind is about 1/40th of that, or about 5x1020th Joules.  Source.   So, from a human perspective it's an enormous amount of energy but to the something the size of the Earth it's quite small.   Needless to say, the 0.34% estimate is pretty rough, so take the numbers below with some flexibility, but they're also, at least somewhat in the range.
Second, we have to consider where the heat is going.   By most estimates, more than 90% of this goes into the oceans and about 90% or a bit more of the heat is going into the oceans with some melting ice, some going into the ground and melting tundra and only a small percentage going into the atmosphere where surface temperatures are calculated.
Source, Source and Source (The first mentions a very specific 93.4% into the oceans and 2.3 into the Atmosphere.   The last 2 mention "more than 90%" and "about 90%", so there might be some uncertainty on the precise ratio and I'm going to round up to 3%.   Feel free to re-run the numbers with 2.3%, 4%, whatever you like.
3% of 1.9x1022 = 5.8x1020  (not a typo, it's actually 1.93)
So the atmosphere, by rough estimates, adds about 5.8x1020 Joules of energy as a result of the increase in CO2.  So, to estimate the expected warming from that amount of energy:
The mass of the Atmosphere is about 5.1x1021 grams.  Source.
About 4.2 joules can heat 1 gram of water 1 degree C.  Source, and the specific heat of the atmosphere is about 1/4.1 that of water, Source.   Of ocean water, slightly lower, I'm going to estimate 1/4.0
so, doing the maths: (4.0/4.2)x(5.1x1021/5.8x1020), my roughest of calculations says that we'd need about 9 years of trapped heat to warm the atmosphere 1 degree C.   If we use skeptical sciences 2.3% number, that ups it to about 11.5 years, and both estimates are obviously too aggressive.  The observed surface temperature warming is closer to 1 degree every 40-50 years, give or take, though the warming on land is faster than the warming over water.   But my estimate can't help but be quite rough.  It excludes albedo and cloud formation entirely, which is important, but trying to calculate is hugely complex and far above my pay-grade.   It's difficult to calculate the effects of clouds on global warming even with super-computers.
Now, obviously ocean currents, dictate varying amounts of heat exchanged between the ocean and the atmosphere, so one year to the next can vary by significantly more than 1/9th of 1 degree, but that's movement of heat, not new heat added to the system.
Now if I calculate how long it would take to heat the oceans, and as I understand it, the deep oceans aren't warming, but the surface and sometimes called "mid-oceans" or mid-depth are warming, (articles here and here
Using the numbers above, for 1 mile deep using with the estimate of about 33 times the heat going into the oceans than into the atmosphere, reapplying the specific heat of water to atmosphere ratio of 4 to 1 and estimating the mass of 1 mile of ocean water equivalent to about 160 atmospheres, adjusting for 71% of surface cover, it comes to a rough estimate of 124 years for my very rough heat trapping estimate to warm 1 mile of oceans about 1 degree C.   I couldn't find any precise warming in the oceans, but 1 degree of warming, 1 mile deep in 124 years sounds roughly in the neighborhood of what the experts expect. (I think).
So, long story short, while local temperature can change significantly over different parts of the day, global average temperature isn't nearly so easily changed.  On a single day (using numbers above), the Earth gets 71% of 5.6x1024/365 or about 1.1x1022 joules, and an amount quite close to that radiates away from the earth every day too.   Based on my very rough estimate, the difference between heat the Earth takes in and heat the Earth radiates is about 0.3%.  On individual days you might get a fair bit bigger than a 0.3% difference, but there's still not enough heat added by 1 day of sunlight to significantly change the Earth's global average temperature.
Now, obviously, the Earth's surface warms measurably under daylight but that's because 48% of the suns energy reaches the surface directly and the heat is localized, and while 1/2 of the Earth's surface warms the other half cools, so it tends to average out.    There's insufficient energy in sunlight to make much change to global average temperature over a short period of time.
With that in mind, the 2 degrees that the IPCC discusses, which includes ocean heat trapping, is quite significant.    It more likely works out to about 3 degrees on land, 1.5 degrees over water, with rising oceans due to both thermal expansion and melting ice.   Warmer oceans means bigger hurricanes.   It's easy to say "2 degrees won't matter", but the models say it actually might.   It's a pretty significant variation.  It also takes quite a bit of time for the 40% increase in CO2 to create that much warming, which is why the projections of 2 degrees warming go out to about 2100.
Another way to point out lack of global temperature variation is to look at the charts for global average temperature.   while, I couldn't find any charts for daily variation of average global temperatures, I found some monthly variation charts here.  Source.   Assuming the monthly averages have gotten more accurate in recent decades, The average global temperature change month to month is about 0.13 degrees C over land and about 0.095 degrees C over oceans since 1980, with the largest month to month variation about 0.47 degrees C over land 0.36 over oceans.  There's probably some rounding errors in there, but there's clearly a degree of consistency to global average surface temperature and even more consistency to surface temperature over the oceans, and that's exactly what we should expect, having looked at the heat in and heat out.
Local affects are driven by circulation, but circulation is simply the moving of heat from one place to another.  Circulation isn't the creation of heat but the behavior of heat and differences in air pressures and it doesn't measurably add any heat to the system.
Corrections to my too long answer welcome.


Removing agricultural plastic film waste after 10+ years degradation

One issue that you've got is the area will be contaminated with fragments of plastic that are microscopic in size to large pieces and they will be at varying depths throughout the soil.

To most people that wouldn't be much of a problem, but for you, who wants to grow food with an organic certification it's going to be a major problem.

Setting fire to that land and burning the plastic with dried vegetation is not a option for you and your desired organic accreditation.

If you can't use the land for another purpose, such a site for new buildings, a parking lot for visitors, or a new roadway you may need to dig deeply to remove the affected soil, and more, and then import replacement soil from elsewhere.


It is best to recalculate all major oxide (including TiO2), trace elements are not important. No need to recalculate them.


How do 'greenhouse gases' let heat in, but not let it out?

In a nutshell:

The radiation that enters is shortwave radiation from the sun.  Solar radiation is dominated by visible (as well as UV and near infrared) radiation with a wavelength mostly between 0.2 µm and 2 µm.  This wavelength is determined by the temperature of the Sun, in the order of 6000 K.  For visible radiation (roughly between 0.4 µm and 0.7 µm), all the gases in the atmosphere are (almost completely) transparent.  Clouds do scatter this radiation so you can't see the Sun directly when it's cloudy, but they still let plenty of light through, so it's still light on a cloudy day (just less bright), although it does feel cooler.

The radiation that leaves is longwave radiation, also known as terrestrial radiation or (incorrectly) as thermal radiation.  For Earth, this is dominated by radiation with a wavelength of mostly between 4 µm and 40 µm.  This wavelength is determined by the temperature of the Earth, at around 290 K.  At these wavelengths, greenhouse gases are mostly opaque.  They absorb the radiation.  The greenhouse gases reradiate the absorbed heat, but in both directions (back to Earth AND up to higher layers in the atmosphere), and at a lower temperature.  The upward longwave radiation gets in turn absorbed by higher-up layers of greenhouse gases, et cetera, such that ultimately the layers of greenhouse gases that do radiate into space tend to be high up in the air (say at 240 K).  Thus, their overall effect is to radiate less heat into space than the Earth surface would in the absence of those gases.

The most important greenhouse gases are water vapour, carbon dioxide, and methane.

Source: gisgeography.com

Source: science of doom


The Further reading link brings you to The PERSIANN System Fine Resolution Precipitation Estimates Using PERSIANN-Cloud Classification System which shows that the data is merged with signals coming from both geostationary and polar/near polar satellites. My guess is that it's just banding in one of these datasets (probably from that second group of satelites).

I tried to look at raw image data from these satellites (to illustrate my assumption), but I bump into sites that are affected by the current US government shutdown, resulting in e.g. incorrect and expired CSS certificates.

If you can dig up these raw images in a later stage, you'll probably be able to map the width of those bands to the aperture of the satellite.


Is this ice cover real - and what circumstances are required to make it?

Yes, it is real. Whoever took the photo, congratulations on a very fine image.
I have never seen this texture on such a scale, but something similar can be achieved in the laboratory by creating a bubble membrane of pure super-cooled water and blowing a few dust nuclei onto the surface. A comparable geometry appears very rapidly. The size of the ice crystals are difficult to judge without any feature to give scale, but they seem to be exceptionally large trigonal terminations. We have all seen snowflakes of hexagonal symmetry, but under metastasble conditions with rapid crystal growth, stacking disorders tend to occur in the crystal lattice, yielding a trigonal rather than hexagonal symmetry. See, for example, The ice phases of water. This is an unusual polymorph of ice, and I cannot see how it could be achieved except through sudden seeding of very pure water. Perhaps stratified freshwater lakes, in still air, on a very cold night, with a surface of previously melted ice (i.e. pure water), and subject to a sudden windy gust of nucleation particles would provide the right conditions?


What is the furthest observable phenomenon from Earth that is Earth Science?

It appears the Earth's magnetotail, which is a part of its magnetosphere, is on the Earth's nightside; lengthwise exceeds 6,300,000 kilometers (3,900,000 miles); and is the furthest known observable feature of Earth.

I am unable to explain why is it commonly not included in the "spheres" of Earth Science.

Note: The gravitational pull of Earth in theory spans the known Universe, though it's unlikely to have any observable affect, unlike the Earth's magnetotail.


Why is relative sea-level falling in Hudson Bay?

The area is experiencing post-glacial isostatic rebound.

Much of Canada was covered in an extensive ice sheet in the last glacial period (the 'Ice Age'), from about 110 ka until 12 ka. The ice in the Hudson Bay area was among the last to melt:

A thick ice sheet depresses the crust (the lithosphere), making a small dent in the uppermost mantle (the asthenosphere) in the process. Well, not that small: p 375 in Gornitz (2009, Encyclopedia of Paleoclimatology and Ancient Environments) says it could be 800 m for a 3000 metre-thick ice sheet!

Since the asthenosphere is highly viscous, it takes a long time time for the depression to 'bounce' back up. This map from Natural Resources Canada shows the current rate:

Since global sea-level is currently rising at about 3 mm/a, a local uplift at this rate will break even. Anything more will result in relative sea-level fall, as we see in Hudson Bay (as well as in Scandinavia, the UK, Alaska, and elsewhere — this map is wonderful).

Interesting, for geologists anyway, is the sedimentological record this leaves. I love this example of raised beaches and a small delta experiencing forced regression on the shores of Hudson Bay:

Last thing — you asked:

  Would it make sense for it to recede at the level that it is
  receding with sources of freshwater relatively close?

Since Hudson Bay is connected to the world's ocean, mainly through Hudson Strait, the runoff into the Bay has no measurable effect on the water level.

Credit
Ice retreat map by TKostolany, licensed CC-BY-SA. Rebound map by NRCan, free of copyright. Google Maps image contains own credit.


How to de-stagger (or unstagger) WRF wind fields?

The simplest way I've found in Python is to use the getvar function with the 'ua,' 'va,' or 'wa' variables from the WRF-Python module. Alternatively, you can take the midpoint between the staggers.
Edit: For example, using the WRF-Python module, you can get the destaggered wind variables with the following code

import netcdf4 as nc
import wrf
f=nc.Dataset('example.nc')
u=wrf.getvar(f,'ua')
v=wrf.getvar(f,'va')
w=wrf.getvar(f,'wa')


Prevailing Winds: Is the speed relevant?

Part of the complication goes to two separate definitions for the word:

prevailing:

  To be frequent (Miriam-Webster)

The most frequent, the most occurring wind direction in your example, even if weak, is east.  So that would be the prevailing wind, as that's the definition we generally use in meteorology.

So don't think of it as

  Having superior power or influence (Dictionary.com)

as indeed, that'd become a bit more subjective of a concept.

Sometimes you may hear about the average direction (which would be east-northeast in your example).  So perhaps that's more what you're wishing for?  Of course if you have an east wind for half the day and a west wind for half the day, the average wind direction would be either north or south.  Or, if instead of treating direction and speed differently, you took the vector average... you'd have a mean windspeed of nothing!

Looks like this MathSE question fairly discusses some of the benefits and troubles with different methods of summarizing wind direction... which line up closely with the more general disparities of each of mean, median, and mode.

Alternatively, wind roses can be much more informative and enticing.  They give both an indication of the directions (by the length of the bars in each direction) and the intensity (color coded).  You can find things, such as: in Colorado Springs in May (as shown below), winds aren't from the southwest very often... but when they are, they tend to be fairly strong (whereas when winds are from about east, as is more common, they're typically quite light):

Looks like you can make some pretty snazzy/customizable recent wind rose plots of locations around the world at the Iowa Environmental Mesonet site.

But the take home is: in meteorology we typically define prevailing wind as simply the most common direction, with no consideration of the speed distribution.


Calculating Stream Flow from Rainfall Data

Calculating river flow from rainfall - evaporation is a simplification. Firstly you are assuming that you can accurately measure rainfall, then that theoretical estimates of evaporation are correct which, given how much land cover and vegetation vary, is unlikely.
Next consider the pathway from raindrop hitting the soil to the river. It's clearly not instantaneous. That raindrop can evaporate directly, run off over the ground surface or soak into soil. In the soil it can be taken up by vegetation or infiltrate and become groundwater recharge. Depending on soil and aquifer characteristics this introduces a delay in the conversion of rainfall to runoff. In the real world this delay could be weeks, months or even years. In your example it's also worth thinking about low temperatures. Is rain falling as rain or is it snow?
Thirdly consider how water can get diverted from its pathway to a river. Is water abstracted from the pathway (i.e. from an aquifer),  or from the river directly?  Conversely reservoirs may regulate flows, either up or down depending on management.


Is the cause of Old Faithful's bimodal distribution for eruption times straightforward?

First I would like to say this is not my area of expertise, so this should perhaps be a comment but I am not allowed yet to comment on this site.

In a simplistic view a geyser has heated water chamber with a column of water above it.  The water is heated above the normal boiling temperature but is kept liquid by the pressure of the water column above it.  When the water eventually starts to vaporize this reduces the pressure on the water in the chamber resulting in more rapid vaporization of the water in the chamber resulting in the eruption.

For Old Faithful assume two chambers, one chamber is lower than the other. If the temperatures in both chambers are high enough the vaporization in the upper chamber would also reduce the pressure in the lower chamber allowing it to vaporize resulting in both chambers emptying, resulting in a longer eruption.  Assuming the infill and heating rates are essentially constant then the time before the next eruption would take longer because both chambers are "empty".  On the other hand if the upper chamber vaporizes and but the lower one does not, either because it is not hot enough or the pressure hasn't dropped enough or back pressure from the upper chamber keeps the lower chamber liquid, then only the upper chamber will empty resulting in less time to infill and reheat.

Again not my area.


Does the position of the Earth's axis affect the position and shape of its continents?

This is an idea that we can consider "wild".
Or even better, untamed. Every then and now there are researchers trying to address the questions, but the proof have not been conclusive up to now (as far as I know).
If you have sufficient knowledge, you may try to go through this peer-reviewed paper
Riguzzi et al, (2009) Can Earth's rotation and tidal despinning drive plate tectonics?
https://www.sciencedirect.com/science/article/abs/pii/S0040195109003321#!
It has been cited 67 times, which is a small number, but not negligible.
I would say your question at the moment has only a possible answer: maybe.
But it is a good question and maybe someone can provide a better answer!


To my understanding, the question refers to studies which aim to estimate pollutant emission fluxes using satellite retrievals of atmospheric constituents. Mathematically, this means estimating the forcing term in an advection-diffusion-reaction system given a set of tracer observations.

How well you can localize the emissions depends on the pollutant: for something shortlived, like NO2, a given observation will be influenced by a relatively small area, while for a long-lived pollutant (say CO) the effective resolution would be much lower. For long-lived pollutants, the problem is not well posed and needs to be regularized in some way. Typically, instead of reconstructing the emission from a scratch, you try to just refine an existing emission inventory.

The issues you mention regarding model errors are real and certainly do introduce biases in any emission estimates based on satellite products. This is quite well understood by people working on the field, but the difficulty is in quantifying the errors that are due to model uncertainty.

  How to generate a relative precise relationship between satellite data
  and source emission in consideration of these doubts?

Opinions vary. In my experience, few scientists believe that satellite-based emissions could replace traditional emission inventories. On the other hand, for many areas and pollutants, the regular emission inventories also involve a lot of extrapolation. Ultimately, the question is whether the inverse modeling can deliver some useful added value compared to the existing inventories.


Hazard event predictions. Examples of predictions causing more harm than good

One example that you may be able to research is the configuration of the tailings storage at the Ranger Uranium Mine in Australia's Northern Territory. The choices they had were either to dig a pit for the tailings, or build a dam for the tailings. A pit would leak a certain amount of contaminants into the surrounding waterways in the Kakadu National Park, and be more susceptible to flooding, but be more resistant to a catastrophic event such as a tropical cyclone, as there is no wall for the high winds to destroy. A tailings dam would be resistant to flooding, and as the construction of a dam can include control over the materials used to line and seal the dam, it would also not continually release contaminants into the environment. However, the dam wall would be susceptible to catastrophic failure in the event of a tropical cyclone, releasing the entire contents of the tailings storage into the environment.

This situation highlights the wicked problem nature of environmental risk assessment. The choice was made in the end to build a dam, and the result of that choice could, at some point in time in the future, result in the escape of millions of tons of toxic and radioactive contaminants into an extremely sensitive waterway.


At the northern and southern ends of the Sea of Japan, there are only short stretches of very shallow sea separating Japan from the mainland. During the Ice Age which ended 12,000 years ago, sea levels were much lower than they are today. It is probable that during the last Ice Age there were land bridges connecting Japan to the mainland at these two points.


Are hot springs in non-volcanic areas radioactive?

The answer is contained within your own question. Virtually everything is radioactive, including your own body, the air you breathe, and everything you eat. The radioactivity is usually beta radiation (emission of energetic electrons), which is the least harmful form of radioactivity.

Radon gas, which is emitted from granite rocks containing uranium, sometimes builds up to dangerous levels in our homes and is an alpha emitter. Alpha radiation is very ionising and dangerous, but needs to be ingested into the body to cause serious harm.

The answer to your question, therefore, is yes, hot springs are radioactive, but so are cold springs. As hot springs are more likely to have passed through granite rocks, they are probably on average more radioactive than cold springs, but neither are radioactive enough to cause concern.

The radioactivity which is dangerous enough to cause concern is radon gas, which varies from place to place according to the underlying rocks. Maps of radon hotspots can be obtained from the internet. If you happen to live in a hotspot, you need to keep your house well ventilated, otherwise the radon will build up to dangerous levels, sometimes levels which would not be tolerated in a nuclear power station or research establishment.


How much of Earth's forested land is currently protected from logging/deforestation?

How much forested land is currently protected from
  logging/deforestation?

I doubt that could be answered with anything better than a rough guesstimate. We would first need to know how much land is OFFICIALLY/LEGALLY protected. Then we would have to subtract acreage to allow for illegal logging or general environmental destruction. There are also areas that aren't legally protected but nevertheless aren't logged simply because they're very remote, the terrain is too rugged, etc.

In addition, it's a moving target. Various governments around the world continually modify their environmental management policies and practices. A forest that's protected today might fall prey to a bribe from some giant oil company tomorrow.

  How much is currently at risk?

Again, that's very hard to answer. Forest destruction is an ongoing process around the world. Forests in the most remote regions are typically the safest, but they will become more vulnerable as surrounding forests are felled, new roads are built, more people move into these remote areas, etc.

Another factor to consider is war, or political corruption in general. So many governments have been destabilized (primarily by the U.S.), and so many governments are grappling with economic woes or fears of invasion. Not surprisingly, they're going to emphasize security and survival over the environment.

Of course, war itself can take a toll. Consider Vietnam, where the U.S. used Agent Orange indiscriminately. I believe the Soviets similarly wiped out much of Afghanistan's montane forests.

  How do tree plantations compare in overall size?

Are you asking how the land area that is devoted to tree plantations compares to the land area covered with wild forests?

Again, I don't know the answer, but please note that there are vast differences between plantations and wild forests. Plantations may be preferable to barren earth, but they don't begin to compare to "natural forests" in terms of biodiversity. Tree farms are to Nature what fast food is to cuisine.

I fear for Africa more than South America. The Amazon is obviously a cause for concern, but there is some political stability in South America, and there are environmental activists there.

In comparison, Africa appears to be lost. How many acres have been converted to genetically modified food? I've read about thousands of traditional African farmers being replaced by GMO, though there isn't much information on the subject.

Libya's destruction by NATO was an enormous blow for Africa (and the world). And for whatever it's worth, I believe Colonel Gaddafi was generally regarded as an environmentalist, at least in comparison to other African leaders. There have long been predictions that the next cold war will be fought between the U.S. and China over Africa's natural resources. In fact, the U.S. has troops stationed in just about every country in Africa, and I just read that China is building a military base there.

In summary, forest loss is a huge problem in South America, but there is at least some hope. I predict that it will be a much bigger problem in Africa in the long run.

  Furthermore, if the size of forested land on N. America, Asia, and
  Europe remains constant or grows, how much of that is due to tree
  plantations?

Once again I don't have a specific answer, but I can offer a good guess: Most of it. After all, native forests will continue to shrink, while tree farms will continue to multiply.

Sorry to be so negative. I actually believe there is hope, but things aren't going to change without a massive change agent.


When did the last rifting / break-up event occur?

Rifting is an ongoing process. At the moment, e.g. East Africa is rifting apart from the Nubian plate, we also see rifting of continental plates elsewhere, eg Rio Grande. New continents are being formed, but it doesn't happen on a human time scale. Modellers of future geography have a difficult task to decide what rifts that will stop and what rift that eventually will result in a new continent.

See yellow marked faults and rifts:

Madagascar is sometimes refereed to as the eight continent, not only of biogeographic reasons. It was rifting away from Africa and later India during mesozoic time, starting 160 Ma.

The last rifting that resulted in the present continents I can think about (probably the community can come up with a later event!), would be the North Atlantic breakup, that is still ongoing, but the last part of separation of present continents was the opening of the Fram Strait 16-10 Ma. This separated Greenland from the European plate and had a large impact on the Arctic Ocean conditions.


How does the act of producing animal feed from the leftovers of a process result in a negative carbon footprint?

Its only marketing, not a science equation... It's saying that their gin gives back CO$_2$ from other gin which uses fertiliser, and saves a bit of crop space for livestock food. Overall, any crops tend deprive a region of carbon sinks and biodiversity.
Cropland has reduced the worlds total CO$_2$ sinks by 50+ percent, so using 1 crop for 2 things saves CO$_2$ sinks, fertilizer and fossil fuel. Animal stock is intrinsically a climate change accelerator too, especially mammal stocks, which occupy forest space and produce methane and use forest space for hay bales and food crops. Saving surplus foods slightly reduces their impact, its reduces the CO$_2$ budget compared to non surplus feeds.


CO2 Storage, it's possible, but what about

It is possible and there are several demonstration projects running. In Europe, the carbfix project quotes a price of $24.8/ton for carbon sequestration. Geothermal power is used to pump the CO2 underground, so no energy from fossil fuel is required.

There are concerns about the available capacity for storage using these mechanisms, and the pumping process does trigger seismic activity (e.g. wikipedia).

It is likely that carbon buried in geological formations will be sequestered more reliably and for longer that carbon which is simply absorbed by trees ... but there is no guarantee on that there will not be some leakage.

Because of these concerns, and because generating electricity from sustainable sources is cheaper than burning fossil fuels and then trying to manage the pollution, the main focus of dealing with global warming should be reduction of fossil fuel use to near zero.

There may well still be a significant role for carbon sequestration in dealing with some CO2 emissions which are difficult to avoid.


When a tectonic plate subducts, does any of the subducted material melt, or is it just the mantle above the subducted slab that melts?

This is a very good question Inkenbrandt. It is quite common for even some graduate students to think that the majority of partial-melting comes from the slab: when it is the the mantle above the fore-arc, in the volcanic region, where most of the partial melting occurs.

Lets think about this mathematically: you say yourself that you realize that subduction hydrates the mantle, lowering the solidus and allowing for more partial melting, so what happens to the slab? Well it has to dehydrate, making it much harder to melt the slab. So to answer your question: Probably a very small amount in the upper mantle, but if you are a mantle plume believer, the partial melting of a slab provides a great mechanism to 1) displace hot mantle so it rises and 2) a source of meltable material.  The hydration of the mantle from subduction happens on a much much faster timescale than the melting of a subducted slab. In this paper, the authors provide a mechanism for the volcanism in Yellowstone that relies on two things: the Farallon plate being ripped apart by rapid mantle flow and the cut off piece of the subducted slab to melt. Geochemical data supports this, and it turns out this is a very important paper.

I hope this answers your question. In geodynamic models interested in examining the melting structure at subduction zones, we largely ignore slab melting unless we are specifically looking at it. For almost everything else, it seems to be pretty negligible.


The B1 and A2 referenced in the chloropleth maps are referring to the emissions scenarios that were presented alongside the IPCC's Third Assessment Report (TAR) in the Special Report on Emissions Scenarios (SRES). These scenarios referred to the rate, timelines, and total volume of carbon and other greenhouse emissions that might be realized by the end of the 21st century.

These were several scenarios (A2, A1B, B1, etc.) that were used with the aid of climate models to determine what the possible climate change impacts of pursuing "Business as Usual" (A2), to rapidly reducing emissions and stabilizing climate (B1). While some researchers still use these emissions scenarios and the climate models that were presented with them for some predictions, most climate scientists now refer to the more recent Fifth Assessment Report's (AR5) Representative Concentration Pathway Scenarios (RCP).

For more information: http://www.nature.com/nature/journal/v463/n7282/full/nature08823.html


Kalman - Data assimilation with external model

$M$ is the forward model you are using. It is the dynamical model used to solve whatever discrete equation evolves the field ($d?/dt=$).

The best way to start with data assimilation and understand its nomenclature is to read Ide et al. (1997). In their work, they explain it as:

  A discrete model for the evolution of an atmospheric, oceanic, or coupled system from time $t_i$ to time $t_{i+1}$ is governed by an equation

  $x^f(t_{i+1})=M_i[x^f(t_{i})]$,          (1)

  where $x$ and $M$ are the model's state vector and its corresponding dynamic operator, respectively. The state vector $x$ has dimension $n$. The dynamics $M$ of the model evolution (1) in a computer simulation or prediction is commonly nonlinear and deterministic, while the true geofluid might differ from (1) by random or systematic errors.

Ide, K., Courtier, P., Ghil, M., Lorenc, A.C., 1997. Unified notation
for data assimilation: operational, sequential and variational. J.
Met. Soc. Jpn. 75, 181– 189.


Why does the moon orbit the earth and not the sun instead?

The moon does orbit the sun but it also orbits the earth.  But your assertion that the earth's gravity is weaker than the sun's is not universally true.  If the sun's gravitational pull were greater than the earth's HERE on the earth, the sun would literally suck everything not attached to the earth's surface into itself.  Clearly that's not happening.
Remember that Newton's Law of Gravitation says that the force is inversely proportional to the SQUARE of the distance.  So while the sun does have a stronger gravitational pull, the distance that both we and the moon are at makes the earth's field dominate.


Is there conclusive evidence to refute an earlier oxygenation of the Earth's atmosphere?

The earliest photosynthetic marine organisms (cyanobacteria) are known to have been established by 3.8 billion years ago from the isotopic composition of sedimentary rocks. The earliest microfossils of such organisms are dated at 3.5 billion years. Therefore these photosynthetic micro-organisms were pumping oxygen into the ocean and into the atmosphere at least 1.1 billion years before the Great Oxygenation Event and more likely 1.6 billion. In that almost unimaginably long span of time, these organisms must have created staggering amounts of oxygen. Much of it was soon dissolved and dispersed in the surrounding ocean, but some must have leaked into the CO2 and N2 atmosphere.

It is impossible to believe that after a thousand million years of oxygen production, not enough had leaked into the atmosphere to give it a measurable amount, notwithstanding the fact that there was no one around at the time to measure it. Some oxygen had been mopped up by iron and other elements from the earliest days, but not enough to show up clearly in the stratigraphic record until the so-called Great Oxygenation Event. It defies common sense to say that there was a sudden explosion of oxygen production 2.4 billion years ago and no significant amount had leaked into the atmosphere well before then.

So the answer to your question is no, there is not conclusive evidence to refute an earlier oxygenation of Earth's atmosphere. The question is, to what extent did it happen, rather than whether it happened. In other words, what was the percentage of O2 in the earth's atmosphere at, say, 250 million years before the GOE? We may be sure it was far less than in today's atmosphere, but nevertheless a significant amount and (at the time) an easily measurable amount.


What is the intensity of terrestrial radiation?

Assuming your question is about how much of the sun's radiation hits the Earth's surface rather than just reaching the edge of the atmosphere ...

The amount of solar radiation that hit's the Earth's surface varies a lot, depending on weather conditions, time of day, day of the year, latitude, altitude, air quality ... It can be anywhere between 0 and ~$1200W/m^2$

There is a standard "full sun" solar intensity which is used as a benchmark for things like photovoltaics testing and calibration. That's $1000W/m^2$, with an atmospheric spectrum denoted by AM1.5


Is continental drift caused by lava pushing the seabed apart?

No, lava does not push the plates apart.

The mid-ocean ridge basalt is passively filling the space left by the plates moving apart. Plate motion is driven by gravity (image by Vic DiVenere at Columbia; see note below):

There are thought to be two main effects at play: ridge push, and slab pull. We don't know much about their relative importance, but it probably varies spatially (e.g. Ribeiro, 2012, Soft Plate and Impact Tectonics, Springer).

Ridge push happens not because the new lava is pushing, but because the ridge is high up. It's so high that in some places it sticks out of the water (e.g. Iceland). It's high because it's hot — but not from deep convection. A geophysical technique called seismic tomography suggests that the hot zone is relatively shallow. As the new plate cools, it thickens and sinks 'downhill', pushing the older plate ahead.

Slab pull is easier to imagine: a subducting plate, sinking into the asthenosphere (uppermost mantle), pulls the younger plate behind it. Not all margins are destructive, however, so slab pull does not operate everywhere. Indeed, the relative important of push and pull is debated.

You will sometimes see figures like this one, strongly implying that convection and plate motion are strongly coupled. The earth is a complex system so the processes are certainly related, but we don't understand the frictional forces (drag) at the lithosphere–asthenosphere boundary well (e.g. read this primer by DiVenere). These images, while prevalent, are an unhelpful over-simplification.

Note: I'm using DiVenere's copyrighted image under 'fair use' terms. Please replace it with an open version if you find one! (But not one with convection cells :)


Is there an index that evaluate how even temporal rainfall distribution is?

Try to read something about Köppen climate classification. This classification among other things tries to distinguish between rainy and dry season for many areas. So, scientist needs to know the distribution of precipitation. Another possibility could be indices described in this scientific article on the ResearchGate.


That is what lakes and ponds do , fill with silt. Serious earth moving equipment is needed to slow Mother Nature. Our community has recently removed some silt with draglines, bulldozers , trucks , etc. I don't know the cost but certainly significant . They concentrated on certain areas to facilitate flow as we have a dammed stream that made roughly a 300 and 100 acre lake and the costs of general silt removal would be overwhelming.  On the upside , bushes on a new island have become a egret rookery,


Is there any open source, stochastic rain forecast data available for the UK?

Well there is ensemble data that you can use. For the UK, you can probably use the ECMWF ensemble prediction system data or GEFS from the US NWS. Both are global models, so they can be extended beyond their respective centers.
These ensembles can be used as samples of the probability density function. Normally (pun unintended), with these types of ensembles, the pdf can be assumed to take the form of a Gaussian distribution per ensemble filters. Obviously, this is problematic, as it implies a probability that there is negative precipitation, which is unrealistic. However, if you want to be clever, you can probably fit a kernel to the data. Or you could choose your own distribution. The distribution that is most widely used is the Gamma distribution, though the Pearson distribution has been shown to perform well too. Perhaps using the Kolmogorov-Smirnov test could help you determine which distribution is best.


When and where is the atmospheric greenhouse effect strongest?

It is strongest in the arctics,most radiation from this area will be long wave infra red and long wave infra red is absorbed and reflected by the climate gases in the atmosphere.

A large part of the heat from the sun is reflected by snow and ice,But as the snow and ice melts more heat is absorbed by the water in the ocean the effect of this is larger in the arctic(floatng ice)than it is in the antarctic(more ice on land and takes longer to melt)

Link https://en.wikipedia.org/wiki/Infrared

At the areas closer to equator the heating is higher so a larger amount of the radiation will be at a shorter wavelenght,And a larger portion of this will escape to space and not be stoped by the atmosphere.

The equator will heat up less than the arctics simply as a result of the shorter wavelenght in infrared radiation.

The winters will warm faster than the summers in the arctics and this too is a result of the longwave infrared radiation in the winter and the shorter wavelenght(hot summer).

The nights do warm faster than the days too as a result of longwave radiation at night(colder)and shorter wavelenght in the day(hotter)

The earth will keep getting warmer until a new equiriblium is reached where incomming and outgoing heat will be in balance(if we stop the realease of greenhouse gasses today the earth will keep on getting hotter for atleast 50-100 years).


Which geological processes will destroy plastic?

Some simplifying assumptions

This is quite a broad and complex question to answer, so I'm going to simplify it shamelessly to make it a little more answerable.

Firstly, there are a huge number of different plastics with a huge variety of physical characteristics. You mention that you're interested in ‘the most common type of plastics’, so I'm going to ignore exotic, high-temperature specialist polymers.

Secondly, you specified that by ‘destroy’, you mean ‘chemically convert the plastic to a molecular form that is found in "nature"’. This could be tricky to guarantee completely: to be really sure you'd have to do a thorough analysis of all the molecular structures in the altered plastic, and make sure that none of them occur in nature. I'm going to reference research on pyrolysis of plastics which classifies end products as gas, wax, oil, and char, and assume that these products contain little or no material which couldn’t be found in nature.

Thirdly, I’m going to ignore metamorphic conditions other than temperature. Temperature will, I’m fairly sure, have the biggest effect on the breakdown of plastics. The chemical environment might make the plastic break down more quickly (by providing reactants), but I don’t think that it will make the plastic break down any more slowly than it would at the same temperature in an inert atmosphere or vacuum. I’ll also ignore any pressure effects.

Grades of metamorphism

Here’s a helpful diagram of metamorphic facies, temperatures, and pressures (source: Wikimedia).

The chart cuts off at 900°C, by which point the rock will generally be melting, putting it into the igneous rather than metamorphic category.

Effects of heating on common plastics

Fortunately for this question, efforts to dispose of waste plastic have led to a lot of research on the effects of heating. Williams and Williams (1997) is a particularly useful reference. They report the effects of heating a sample of mixed plastic waste (low- and high-density polyethylene, polypropylene, polystyrene, polyvinyl chloride, and polyurethane) in an inert nitrogen atmosphere at temperatures ranging from 500°C to 700°C. Here’s what they got out of it (yields are in percentages):

(I assume that there's a typo somewhere in the 650°C column, since it implies a 110.5% yield.) The yield is 78.91% at 550°C, so maybe we could expect some identifiable plastic residue (though probably no actual plastic) to remain at that point. By 600°C, there's already a 95.51% yield; unfortunately the missing char figures prevent us from quantifying the yield at higher temperatures, but it seems likely that we’d be approaching 100% by 700°C.

There are a few pages of analyses of the products, but they’re mainly focused on their suitability as fuels rather than whether they’re found in nature. Considering the wide variety of compounds found it crude oil, I think it’s plausible that all the plastic pyrolysis products have naturally occurring counterparts, but it would be a significant research project to establish this beyond all doubt.

Putting it together

Referencing the pyrolysis temperatures back to the metamorphic facies, it looks as though the amphibolite facies corresponds reasonably to the range over which common plastics are completely, or near-completely, decomposed by temperature. So, when the aliens land in a few million years and start investigating the Anthropocene, they might well find some of our old rubbish in prehnite-pumpellyite (P-P) facies rocks, but there won't be much to see in the granulites. Here are some examples of metamorphic rocks from those grades.

Liberty Gulch Broken Formation, a prehnite-pumpellyite facies metasandstone. Source: Raymond and Berro (2015).

Amphibolite facies (staurolite zone) metasediments from the Scottish Dalradian. Source: Dave Waters, Dalradian Metamorphism album.

Strongly deformed high- to medium-pressure pelitic granulites from the Qianlishan Complex. Source: Yin et al. (2014).

References

Loren A. Raymond, David A. Bero (2015). Sandstone-matrix mélanges, architectural subdivision, and geologic history of accretionary complexes: A sedimentological and structural perspective from the Franciscan Complex of Sonoma and Marin counties, California, USA. Geosphere, 11(4), pp. 1077–1110. doi: https://doi.org/10.1130/GES01137.1

E. A. Williams & P. T. Williams (1997). Analysis of products derived from the fast pyrolysis of plastic waste, Journal of Analytical and Applied Pyrolysis. 40-41, pp. 347-363.

Yin, C., Zhao, G., Wei, C., Sun, M., Guo, J., & Zhou, X. (2014). Metamorphism and partial melting of high-pressure pelitic granulites from the Qianlishan Complex: constraints on the tectonic evolution of the Khondalite Belt in the North China Craton. Precambrian Research, 242, pp. 172-186.


What's causing this high SO2 concentrations in Kazakhstan?

The source of SO2 is the smelter associated with the Jezkazgan (Zhezkazgan, Жезказган) copper mine, mined by Kaz Minerals. The complex also produces sulfuric acid.

If you check for the other atmospheric pollutants with ventusky.com, you will see associated particulate matter - PM 2.5 and PM 10.


There are two types of dust storms.

The first, a dust storm or "sandstorm", is associated with a synoptic scale feature (like a low pressure system).  Strong winds along air mass boundaries (i.e. cold front) create clouds of dust as sand, dust, or other particulates become suspended by turbulent eddies near the surface and aloft.

The second, the infamous "haboob" is associated with the cold pool of thunderstorms.  In the American desert southwest, during the summer monsoon, numerous thunderstorms develop. These thunderstorms produce rain or virga that cools the atmosphere beneath the thunderstorm as it evaporates.  Cool air sinks into what is known as a 'cold pool'. Cold pools generally strengthen as a thunderstorm decays.  Cold pools are air masses of cooler than environment air that spreads out like a pancake in all directions from beneath the thunderstorm.  These cold pools can create wind gust fronts between 40 and 70mph. Similar to larger dust storms, sand, dust or other particulates become suspended in the air and create the wall of dust.


What does geochemical data tell us about Earth's earliest palaeoclimatic conditions?

The first thing to note here is that the zircons you mention in your question are the only thing we have dating from the Hadean: no known Hadean continental or oceanic crust have been found to date. So, all informations come from these zircons.

What do they tell us?

The rare earth element (REE) composition of these zircons (and in particular the zoning of said REE inside the mineral) suggests that they formed in a magma derived from the melting of a continental crust (Wilde et al. 2001). Their high $\delta^{18}\mathrm{O}$ composition also indicates that the magma was at some point in contact with liquid water (also Wilde et al. 2001): both continents and oceans were present in the Hadean. The presence of liquid water already implies cooler temperature than what was previously thought (Valley et al. 2002).

With regards to climate per say, the Lithium composition (high concentration, light isotopes) of the zircons (Ushikobo et al. 2008) have been interpreted as evidence of an intense chemical continental weathering. This weathering could have several explanations but one possibility retained by Ushikobo et al. 2008 (see also Sleep 2010) is a CO2-rich atmosphere with surface temperatures above 50°C.

Sleep, 2010. The Hadean-Archaean Environment. Cold Spring Harbor Perspectives in Biology, 2: a002527.
Ushikobo, Kita, Cavosie, Wilde, Rudnick & Valley, 2008. Lithium in Jack Hills zircons: Evidence for extensive weathering of Earth's earliest crust. Earth and Planetary Science Letters, 272: 666-676.
Valley, Peck, King & Wilde, 2002. A cool early Earth. Geology, 30: 351-354.
Wilde, Valley, Peck & Graham, 2001. Evidence from detrital zircons for the
existence of continental crust and oceans on the Earth 4.4 Gyr ago. Nature, 409: 175-178.


Is it feasible to use depleted oil wells for geothermal production?

In most cases, probably not.

Oil could be considered a metamorphic mineral, formed by "gentle" heating. That is gently on a geological scale - still enough to burn your hands!

Geothermal systems work most efficiently with a large temperature difference (Third Law of Thermodynamics). As soon as the temperatures increase enough to be interesting from a geothermal perspective, you are quickly losing ("overcooking") the oil on a geological timescale.

Therefore most oil fields have had the heat applied in the past and it has since been removed.
However this does not discount the situation where an oil field is still technically "being made" and the hydrocarbons are still being heated, and we just happened to drill it at just the right time. Hence the "in most cases": You might find the odd field where it is practical.

An old field, especially gas ones, could be used for carbon sequestration though. The field has stored methane for 10s if not 100s million years, why not the heavier CO2 instead?


How are organic walled microfossils preserved in the fossil record?

Organic-walled microfossils (wether they be dinoflagellates, pollens, spores or "acritarchs")  all have in common to contain an organic compound known as sporopollenin (for the spores and pollens) or dinosporin (for dinoflagellates and, I believe, acritarchs as well). Both compounds have chemical and structural similarities but have appeared independently.

Those compound are incredibly resistant. To give you an idea, to collect siliceous microfossils we first dissolve the sediments with HCl (hydrochloric acid) to get rid of carbonate microfossils. Palynologists (who study such organic-walled microfossils) uses HF (hydrofluoric acid) to get rid of both carbonate and siliceous microfossils (e.g. Doher 1980). Sporopollenin therefore resist to HF, which has a pH of ca. 3. In addition to this, they are also unusually resistant to microbiological degradation (e. g. Gunnison & Alexander 1975).

They are however not resistant to oxydation, hence, probably, why we don't find more of them in the sediments. Additionally, to break sporopollenin walls (in order to study the inner side of those walls) ultrasound can be used (e. g. Lennie 1968).

"Organic-walled" doesn't mean no hard part, it just means no "mineral" hard part.

Sources:
Doher, I., 1980. Palynomorph preparation procedures currently used in the paleontology and stratigraphy laboratories, U.S. Geological Survey. Geological Survey circular, 830: 1-29.
Gunnison, D., Alexander, M., 1975. Basis for the resistance of several algae to microbial decomposition. Applied Microbiology, 29: 729-738.
Lennie, C. R., 1968. Palynological Techniques used in New Zealand. New Zealand Journal of Geology and Geophysics, 11: 1211-1221.

At the request of the OP, a little word on another group of organic-walled microfossil with a extensive, coherent Paleozoic fossil record: the Chitinozoans.

This enigmatic group was found by Eisenack (1931) and because of their resistance to acids & bases he thought they consisted of chitin, hence the name he gave them. However studies (Voss-Foucart & Jeuniaux 1972; Jacob et al. 2007) showed that they do not consist of chitin or any kind of chitin-like bioproduct but of a network of kerogen with aromatic compounds. The diagenetic path that lead to this chemical composition is however unknown, meaning that we know neither what was their chemical composition when those organisms (NB: we don't know as well what their biological affinities are, though metazoan eggs seem to be a popular hypothesis, see e.g. Paris & Nõlvak 1999) were alive nor how they preserved.

Additional sources:
Eisenack, A., 1931. Neue Mikrofossilien des baltischen Silurs I.
Palaeontologische Zeitschrift, 13: 74–118.
Jacob, J., et al., 2007. New insights into the chemical composition of chitinozoans. Organic Geochemistry, 36(10): 1782–1788.
Paris, F. & Nõlvak, J., 1999. Biological interpretation and paleobiodiversity of a cryptic fossil group: The “chitinozoan animal”. Geobios, 32(2): 315-324.
Voss-Foucart, M.F. & Jeuniaux, C., 1972. Lack of chitin in a sample of Ordovician chitinozoa. Journal of Paleontology, 46: 769–770.


Can living where magnets are abundant provide a mini-magnetoshere?

Near to the Earth's surface there are small variations in the Earth's magnetic field, but these don't play a role in providing the magnetosphere which protects the Earth from charged particles emanating chiefly from the solar wind.


Understanding timescales within the day period

Intra-daily scale variability is pointing to the circadian rhythms. the circadian rhythms are physical, mental, and behavioral changes that follow a "daily" cycle. They respond primarily to light and darkness in an organism's environment. It is not an accurate time scale, as the light and darkness are not a cycle itself, but it is commonly use on medicine. Google it. I will recommend this.

The Intra-tidal it is used for a few processes linked with the tides, but it is not "just" on daily basis as the tides have not a daily interval. Look there and there

Both timescales are usefull for whatever process linked to human (or animal) bodies and tides. But as scale times, they are not very useful.

Regarding predictions... which kind of predictions are you talking about?


Why is radiation and total precipitation not available in ERA Interim Reanalysis at step 0?

The ERA archive description document, Berrisford et al (2011) "The ERA-Interim archive Version 2.0", provides additional information about what is available.  It's less explicit on the why, but we can read between the lines a bit.

The archive consists of re-analyses of the system state at 00, 06, 12, and 18 UTC and re-forecasts out to 10 days initialised from those 00 and 12 UTC states.  Table 9 of that document lists the variables (including the ones that you're interested in) that are stored as accumulations since the start of the re-forecast.  They are stored every 3 hours for the first day of the forecast (steps 3, 6, 9, 12, 15, 18, 21, 24) less frequently thereafter (every 6 or 12 hours).

The variables are not stored for step 0 because their accumulations would be exactly zero.

Regarding using ERA Interim for model forcing, you might consider what Balsamo et al (2015) do for ERA Land forcing.  They use state variables from steps 3, 6, 9 and 12 and accumulations from steps 12, 15, 18 and 21 (see Fig 1 of that paper).  This inconsistency is because the fluxes (accumulations) are particularly prone to spin-up artefacts in the first few hours of the forecast.  The trade-off is that the states and the fluxes used in the forcing come from slightly different forecasts.


Why do gold deposits form only in certain areas of the earth?

I'll take the form of the question given by another person here and attempt to provide a different answer.

So what you are asking is: "How did gold become so concentrated in certain parts of the world?"

So yes, gold is all around but the concentration is too low to make extraction of it worthwhile. You need some process to take small amounts of gold from a large volume and turn it into large amounts of gold in a small volume where it is convenient to build a mining facility and get it from the Earth.

One of the most common process to concentrate gold is through the action of hydrothermal fluids. This is basically heated water flowing through the Earth's crust. Heated water with certain properties such as acidity (pH) or dissolved anions (think chlorine-rich seawater is more corrosive than your tap water) can dissolve solid gold and put it into solution. Just like regular water can dissolve table-salt or sugar and put it into solution.

So you have this hydrothermal fluid flowing through huge masses of rock (mountain-like, but underground) for a very long time, and when it goes up to the surface, it is channelled into thin conduits of fluid flow. During their ascent the conditions change (be it temperature or pH, etc.) and the water are not capable of carrying gold with them anymore. This results in the deposition of gold in that specific region.

I made an example, that I hope will help you understand this in a clearer way:

So in here you have rain water, entering the Earth in a large area and getting hotter as they descend down. It becomes possible for them to dissolve the gold from the large volume of rock.  But also, because the water (now steam or a supercritical fluid) are hot they start to ascend upwards, usually through a narrow zone. When they cool down again, gold forms as a solid. For example, gold associated with quartz veins commonly forms through this process.

Now, what happens if these gold-bearing quartz veins are exposed on the surface? They may erode by rain and snow and get concentrated in river beds. So you can either mine the original quartz vein or the nearby river bed.


Hurricanes can be viewed as having primary and secondary circulations. The primary circulation is what we see in satellite photos, comprising the winds and clouds that circle the low pressure zone at the center of the hurricane. The secondary circulation is a vast heat engine that provides the energy needed to sustain the primary circulation.

The low pressure cell at the center draws surface air toward the center, gathering moisture from the warm ocean along the way. This flow is more or less isothermal.
Humid air rises in the clouds around the center of the storm, releasing moisture along the way. This rise is more or less adiabatic.
The now dry air at the top of the troposphere flows outward and radiates energy into space. This flow is roughly isothermal.
Finally, the air falls in downdrafts at the outer edges of the storm. Like the updrafts near the eye wall, the flow in these downdrafts is more or less adiabatic. From here the cycle repeats.

This heat engine, powered by a hundred kelvin temperature difference between the warm oceans and the top of the troposphere, does a very nice job of locally cooling the Earth.


What is the motivation behind the choice of unglazed Porcelain as a Streak plate?

It's white, so the streak colour is obvious.
It's hard. Porcelain is made from aluminosilicates like sillimanite and mullite. Mohs hardness is around 7. Not many geological materials are harder than it, and streak is not a diagnostic feature for those that are harder.
It's rough (i.e. unglazed) so it's really good in breaking tiny fragments from the tested material, thus producing the streak.
It's cheap and widely available.


Does anyone know of a comprehensive listing of geostationary weather satellites?

The WMO OSCAR database is a list of all Earth observation satellites¹.  The resulting table can be sorted by orbit type, status (inactive/operation/planned), agency, and other aspects.  From their own description:

  This table shows all known past, current and future satellites for meteorological and earth observation purposes.It can be sorted by clicking on the column headers. The filter on the right allows to display only specific satellites.

A screenshot showing three GOES satellites and the scroll-bar on the right is shown below:

Note that OSCAR has a lot more capabilities than this.  For anything Earth-observation-from-space related, it is a superb resource.

¹Except classified (spy) satellites...


Which one is the correct concept of Continental Crust and Oceanic Crust?

Michael is correct. SIAL and SIMA are very vague and over-simplified summaries of the continental and oceanic crustal compositions. These terms may be OK for school introductions to geology, but you don't have to look far to find many exceptions. There are eroded and fragmented continental remnants, of nominally SIALic composition, in every ocean. Indeed, 100% oceanic crust may include small amounts of highly differentiated plagiogranite (technically SIALic in composition). Then there are bits of oceanic crust, called ophiolites (SIMA) incorporated into continental crust through processes of obduction and terrain accretion, not to mention the many flood basalt terrains (SIMA), which can occur on either continental or oceanic crust. Whether crust is oceanic or continental is a matter of overall rock density, composition and crustal thickness.


How to recharge ground water directly from river water

What you are asking about is called "Managed Aquifer Recharge" It has been successfully employed in some situations but depends greatly on the geology of the area. The aquifer needs to be relatively shallow with permeable sediments between it and the surface. If the sediments are not permeable (e.g. clay rich or solid rock) The water won't flow down to the aquifer in a reasonable time.

As one comment pointed out the water can be diverted into an artificial lake to drain slowly into the sediments. It also may be possible to form a lake by placing a dam on the river.


No, the atmosphere is not becoming thicker.

If anything at all, the atmosphere is getting thinner, but only on very long time scales.  Planet Earth very slowly loses parts of it atmosphere due to atmospheric escape, either to space or to the solid Earth.  Historical atmospheric pressure is hard to determine, but billions of years ago, it might have been much thicker than it is now, in particular with a lot more greenhouse gases.  One clue is the faint young sun paradox; we know there was liquid water at a time the solar output was 20% less, which would require so much greenhouse effect that the total atmospheric pressure must have been much higher.  But the jury is still out on that one.

The atmosphere is not becoming significantly denser, either.

The concentration of gases that we are adding to the atmosphere is typically measured in parts per million (ppm) or parts per billion (ppb).  The effect of adding to this is small compared to the natural variability in atmospheric surface pressure / density due to weather and other effects.

The atmosphere does not act like a lens.


How to determine ocean bottom depth for a data set consisting of longitude and latitude?

The easiest products that provides ocean bathymetry (bottom depth) is the one you mentioned: https://maps.ngdc.noaa.gov/viewers/bathymetry/. It provides bathymetry data from a plethora of surveys. If you click in the map at any location, you will get a decent estimate of the depth at that point. You can also extract the surveys and data that are available for any given location. You also get DEMs and Lidar data. You can define a bounding box or a polygon (Identify tab) and it will provide the links to the original data. The original data in areas where no recent surveys are available is usually either from ETOPO or GEBCO.

If you are interested in a specific area you can also use a region selector directly from  GEBCO (pick a box around all your points and extract the data that way).

You can also try NOAA electronic navigational charts.


Earth and moon have different mantle compositions. Is this a fatal flaw in the 'Giant Impact hypothesis'?

I highly recommend this blog article from the Planetary Society. It is from 2012 but I believe the science is still sound. The author herself, has received recognition for her contribution to communicating space science to the public (She has an asteroid named after her!!)

It doesn't address your question about if there is a flaw in the giant impact hypothesis through an isotopic analysis, but rather through a gravity anomaly analysis from the GRAIL Mission.

Isostasy, gravity, and the Moon: an explainer of the first results of the GRAIL mission. Written by Emily Lakdawalla, 11 December 2012

The article starts off by giving some information on how gravity anomalies are formed and measured, before delving into the main arguments.

In Summary (all mistakes are mine), using various analysis's of the gravity anomalies, resulting in 3 further scientific papers linked in the article, the GRAIL mission has determined that the Moon has a highly fractured and highly mixed crust. The crust is alot thinner than previously thought and in some places the crust is nearly or even 0 km deep, allowing mantle minerals to be exposed on the surface. The unexpected porous nature of the crust supports the Earth/Moon common origin, whereas before there was a mismatch in the assumed numbers giving some doubt to the giant impact hypothesis.

The article then finishes off by mentioning an existing theory on how the moon could have formed while still creating the observed features we can see today.

About halfway through the article, after discussing Airy and Pratt Isostasy, the article starts to mention the observed results. When looking at the Bouguer gravity of the Moon,

  Now, the Moon should have local, small-scale variations in crustal density due to local geology; the fact that the variations are small and smooth means (Zuber argued while presenting these results) that impact cratering has completely battered, bashed, fragmented, mixed, and remixed the upper couple of kilometers of the crust, totally homogenizing it. Previous maps of lunar gravity have not had high enough detail to see this beautiful match between topography and gravity; so this is a new GRAIL result.

a little further on discussing some more results about the density of the moon surface,

  There is one big very surprising thing about this map. The average density is 2550 kilograms per cubic meter. This is much, much lower than what has been assumed for lunar crust; in fact, it's lower than the density of granite. We know what the highlands crust is made of, we have samples of it: the density of the minerals that makes up the crust is around 2800-2900 kilograms per cubic meter. For the Moon's density to be so low, Wieczorek says, it must be very porous, fractured and busted up to give it about 12% void space, to a depth of several kilometers below the surface. This is an important GRAIL result. The mission has given us X-ray vision to see that the Moon's crust is absolutely shattered from the surface for thousands of meters down. In places where the crust is very thin, even the uppermost mantle may be fractured and porous.

Here is where the article starts discussing the mantle minerals, especially Olivine which you mentioned. (emphasis is mine)

  This map shows crustal thickness is near zero under a few of the impact basins (particularly Crisium and Moscoviense) and some of the deepest craters inside the south pole-Aitken basin (Humboldtianum, Apollo, and Poincaré). And the crust reaches a high of 60 kilometers on the farside. Kaguya compositional data support the GRAIL conclusions. There's evidence for the mantle mineral olivine being exposed in precisely those places where GRAIL sees the thinnest crust: Crisium, Moscoviense, and Humboldtianum.

  The average crustal thickness that Wieczorek and coworkers calculated, 34-43 kilometers, is much lower than has previously been assumed. Why is that important? Because when you work out the math to figure out what the bulk composition of the Moon is, given this thinner crust, you wind up with numbers for the abundance of aluminum that are a much better match to Earth's aluminum abundance than they were before. Previously, an apparent compositional mismatch had been a problem dogging the giant impact hypothesis for the Moon's formation. The GRAIL result makes for a compositional match.

Near the end of the article, The article mentions Sean Solomon's idea on how the moon could have formed.

  Andrews-Hanna pointed out that some theorists have predicted exactly this situation. The paper he cites was by Sean Solomon, principal investigator on the MESSENGER Mercury mission, who was trying to explain how Mercury could have wrinkle ridges caused by global contraction if the Moon does not.

  If you condense the Moon from a ring of debris orbiting Earth following a collision, the first nucleus of the Moon will actually be quite cold. As it grows, the increasing energy of the impacts of stuff onto the proto-Moon would make the Moon's mantle hotter than its deep interior; you could wind up with a cool, solid center surrounded by a hot, liquid mantle. The heat from the mantle would take time to propagate into the interior; as it did, the warming center of the Moon would expand, producing exactly the kind of global extensional stresses that could make this set of dikes. The model has this expansion happening at the correct time, too: before the Moon was 500 million years old, which would be before the end of the basin-forming impacts.

I hope I actually understood the article correctly and that it helped answer your question. Albeit through a different route.


Is oxygen spread equally on Earth's surface?

Vegetative photosynthesis does indeed have a significant effect upon atmospheric oxygen concentrations, as may be seen in the plots of the
Atmospheric Oxygen Research.

The strong seasonal variation in photosynthesis, particularly in high latitude northern hemisphere regions, results in an annual oxygen fluctuation of about 20 ppm (parts per million). Superimposed upon this is the 'dilution effect' of increasing carbon dioxide, mainly due to the burning of fossil fuels, such that we are effectively losing about 19 oxygen molecules per million every year. These effects are far less than the short-term fluctuations in available oxygen caused by the weather.
You are correct in saying that the mean oxygen concentration is about 21%. Compare this to the optimal breathing range, for humans, of 19.5 to 23.5% oxygen. People tend to lose consciousness at about 10% oxygen, and die of asphyxiation at about 5% or less.
The above data are for sea-level. At high mountain altitudes the oxygen can be as little as 12%, which is why it is so difficult to climb the highest Himalayan peaks.

Taking the long perspective, even at sea level there has been a a large variation in oxygen content in the atmosphere over the last 550 million years, varying between 10% and 35%.

Don't worry, the human physiology is more than capable of handling normal fluctuations and trends in the atmosphere's oxygen content. But here is  something which you might want to worry about: Suppose international efforts to curb greenhouse gas emissions are negated by continued human population growth? A worst-case scenario can be contemplated in which the global mean temperature rise attains, or even exceeds, 4.5 degrees Celsius during some time next century. In this case, at least a billion people, mainly in the tropics, will be subjected to extreme seasonal heat-stress. At the same time the cumulative effects of oxygen dilution in the atmosphere might become sufficiently high to exacerbate that heat-stress. This is a scenario that does have the potential to kill people.


Is there a 'standard size' for volcanic eruptions in terms of gas output?

There is no "standard volcano" or "standard volcanic eruption". However, to perform the calculation you want to do, you could use the "typical" of "average" volcanic eruption.

The characteristics of the "average" volcanic eruption can be found by calculating the average parameters of many volcanic eruptions. Such averages are not often reported, because the variability of volcanic eruption sizes and compositions is so large that averaging them doesn't makes much sense. But it does for your very particular application. So let's try to estimate how the "typical" volcanic eruption looks like:

Let's first figura out the typical volume of ejecta produced by a volcanic eruption: this is usually measured by the VEI (Volcanic Explosivity Index), and the formula to turn VEI into volume is

$\text{Ejecta volume}=10^{-4+\text{VEI}} \, \text{km}^3$

If we download NOAA's Significant Volcanic Eruption Database, it contains 646 recorded eruptions from 1750 to the present, and 498 of them have reported VEI values. Computing the volume ejected by each eruption (using the above formula) and taking the average we get that the "typical" eruption produces 3.2 km$^3$ of ejecta.

Using an average density of volcanic ejecta of 2 g/cm$^3$, this average volume corresponds to $6.4 \times 10^{12}$ g or 6,400,000 tons.

In typical magma, about 0.5% of its mass corresponds to gases, and for our "typical" mass that would corresponds to $3.2 \times 10^{10}$ g or 32,000 tons of gases in a "typical" volcanic eruption.

Now, about 7% of the gases corresponds to SO$_2$. That means that 0.035% of the mass of the ejecta is SO$_2$, and for our "typical" mass that would corresponds to
$2.24 \times 10^9$ g or 2,240 tons of SO$_2$ in a "typical" volcanic eruption.

As you will see if you follow my references, I've pulled the above figures from multiple sources with varying degrees of reliability. Therefore, if you want a more precise estimate you can search for more accurate and updated values and repeat the exercise.


Neither hurricanes nor tornadoes burn out because they get "too strong". Their strength is dependent on how supportive the atmospheric conditions are. If a hurricane stays in the same place for too long, moves over land, or moves over colder water, it will weaken. Likewise, a tornado will weaken if its parent storm moves into less favorable conditions and weakens.

All storms operate at "maximum strength" - they always are using all the energy that is available to them.


What were the geometric coordinates of the Chicxulub impactor 66 million years ago?

Sixty six million years ago the Chicxulub meteorite struck the Yucatan peninsular in the same place as the crater is today. The peninsular hasn't moved very far since then, though some of the continents have, India for example. South America was already well adrift from Africa. At the time, most of Yucatan was probably under a shallow sea, too shallow to slow the impact to any great extent. Struck at that speed (about 55 km per sec), water is as solid as stone, but 50 feet of stone would have done little to slow the speed of such a large bolide. The water and much of the rock beneath it was vaporised.


What is the current theory about the formation of Tibet?

Per yesterday's What-If,

  If you make a building too big, the top part is heavy and it squishes the bottom part.

In the context of Tibet, what this means is that rock has a yield strength: pile it up high enough and it will break (via earthquakes); and if you make a big enough pile, especially of continental material, then the concentrations of radiogenic isotopes will be high enough to significantly raise the temperature - and lower the strength - of the rock in question.

In the case of Tibet and the Himalaya, height increase is due to north-south shortening as the Indian plate impacts the Eurasian plate, i.e. the Tibetan plateau initially formed via exactly the same process as the Himalaya. In order to get an approximately stable height, this increase has to be balanced by decrease. The principle processes causing decrease in height in Tibet are:

east-west extension (see. e.g. Dewey et al. (1988), Tapponnier et al. (1986)), typically along strike-slip faults: this is clearly visible not only in geological maps but also in aerial/satellite photography
erosion rates increase as topography becomes higher, especially in areas of active mountain-building, in part through a change in which erosion processes are favoured

That the Tibetan plateau is of such uniform height corresponds neatly to calculations suggesting that this is the maximum possible height for such features if they are of typical crustal composition.


What tidal databases are available to be used as model boundary conditions?

The boundaries to coastal models are frequently forced using information on water level (or, less commonly, velocities) predicted from databases of tidal constituents. These databases may be global or regional, and typically they offer a grid of points with constituents available at any of these points.

The products listed below are all produced by global tide models informed by satellite altimetry. All will give water levels, and some will also give depth-averaged velocities. As with any global tide model, caution should be exercised when applying them in coastal and/or shallow water regions, as they are unlikely to have the resolution (of bathymetry or computational mesh) to resolve coastal effects.

OTIS

One source is the outputs of the Oregon State University Tidal Inversion Software (OTIS). OSU host a number of different data sets which are accessible from this page, along with the software required to extract constituents in FORTRAN or MATLAB. Both global and regional grids are available. The data here are based on TOPEX/POSEIDON satellite altimetry, combined through data assimilation techniques with a basic global tidal model and, in some cases, coastal tide gauges. The various grids have varying resolutions and varying numbers of tidal constituents.

DTU10

Another source is the DTU10 model from the Technical University of Denmark. This information is produced from a global tidal model combined with TOPEX/POSEIDON data and also Jason-1 and Jason-2 satellite altimetry. The model is described in a poster here. This model has a resolution of ${\frac{1}{8}}^{\circ}$ and includes twelve tidal constituents. Use of it is likely to be widespread in industry because it is included in the commercial modelling package MIKE by DHI.

FES2012

The newest dataset listed here is FES2012. More satellite data was used in its building than the other two models listed, and an improved model was used. The authors claim especially good performance in coastal and shelf regions.
Data are available on a ${\frac{1}{16}}^{\circ}$ grid with 32 tidal constituents.

NB: this description is based on the linked web page. I have not personally used this dataset yet.

Regional databases

In order to minimize the effect of applying a global tide model solution to coastal and/or shallow water regions, regional tidal databases are available. Some examples are:

As mentioned above, OTIS provides a number of regional databases around the world with varying resolution (from 1/12 to 1/60 degrees).
ADCIRC tidal databases: One encompasses the Western North Atlantic, Caribbean and Gulf of Mexico (up to 60W); and another one the Eastern Pacific (from Alaska to Mexico).
Many examples of local tidal model simulations are available for many specific locations, but the solutions are rarely available online.

Other sources of boundary data

All of the above data sources provide surface elevations from models. In the near future it may become feasible to produce velocity boundary conditions from land-based radar measurements of surface velocities in some areas.


Is there less precipitation (rain/snow) in cold weather than in warm weather?

In most of Western Europe, precipitation comes from westerly winds formed over the warm waters of the Gulf Stream current that flows from the Caribbean to Western Europe. That is a warm current, so these winds would be warmer and make your area warmer. Besides, as they come from a warm ocean they are moist and carry water vapor and make clouds. Low temperatures are usually caused by easterly/northerly winds originating in Siberia, these are cold and come from land. Cold winds cannot carry moisture and on top of that they travel over land rather than the ocean and are dry. So in most cases in European winter, relative warmth and precipitation go hand-in-hand.


If water on Earth came from meteorites, why doesn't Mars have substantial water?

First off, that's a conjecture regarding the origin of the Earth's water rather than a known fact. A few times a year or so, a new journal article will appear that argues that the Earth's water is primordial, then another arguing that it came from comets, then yet another arguing that it came from asteroids.

If the Earth's water is mostly primordial, most of it is over 4.5 billion years old. If it came from asteroids or comets that collided with the Earth after the Earth had formed, it's still very, very old. Regardless of the source, almost all of the Earth's water has been here for at least 3.8 billion years old, since the end of the late heavy bombardment.

The same would apply to Mars. It has had almost four billion years to lose its water. So has the Earth; some argue that the Earth, too, has lost a lot of water to space in those four billion years.

The key causes of the disparity is that the Earth is significantly more massive and has a magnetic field. Mars's essentially non-existent magnetic field means that water molecules in the atmosphere are more readily split into hydrogen and oxygen than are water molecules in the Earth's atmosphere. Mars's smaller gravitational field means the hydrogen produced by these events has a much greater chance of escaping before it re-forms water than on the Earth.

A very recent conjecture poses another possibility, which is that Mar's mantle is slightly different in composition than the Earth's, and this different composition enabled Mars's mantle rocks to absorb significantly more water than did the Earth's.


The hardness of minerals is diagnostic because the hardness is determined by the strength of bonds and the structure of the mineral lattice. Hardness is basically the stress required to create and grow extended lattice defects such as micro-fractures, stress twins, and dislocations.

Diamond, quartz, and framework silicates, such as feldspar, are hard because they have a three-dimensional lattice of covalently bonded atoms. Native metals are soft because they have close-packing lattices of metallic bonded atoms.

Hardness is an intrinsic property of a mineral like density or refractive index.


Is this series of earthquakes near Broome, Australia normal?

Are you confusing faults with tectonic plate boundaries?

Australia is in the middle of a tectonic plate, but there are countless faults within the plate, as within all the other plates. Each plate is stressed & eventually rock adjacent to some faults moves resulting in a intraplate earthquakes.

As the Geoscience Australia website states:

  Although Australia is not on the edge of a plate, the continent experiences earthquakes because the Indo-Australian plate is being pushed north and is colliding with the Eurasian, Philippine and Pacific plates. This causes the build up of mainly compressive stress in the interior of the Indo-Australian plate which is released during earthquakes.


How did the Rhine originally look like? (before human intervention)

It would help if you'd ask a more clear question -- it's a dynamic river system so it is literally changing its shape every second! The story over long time-scales can be found on Wikipedia: https://en.wikipedia.org/wiki/Rhine#Geologic_history . You can find some more detailed information with some overview maps (esp. Fig 3) here https://www.sedimentologie.uni-freiburg.de/staff/Preusser2008NJG.pdf .

In broad terms, the Rhine in its current state is due to two processes. First of all, the North Sea Basin, i.e., North-West Europe is sinking constantly, providing a great place for rivers to deposit sediments. This is why the Rhine ends up in the Netherlands, because the Rhine can deposit large amounts of sediment without silting up and blocking its own course. Second of all, the formation of the Alps caused a huge potential for sediment transport (realizing that all that rivers really do is transport water and sediment from high points to low points), and the Alpine orogeny furthermore caused the creation of the Rhine Graben. The Rhine thus found the perfect source (high Alpine mountains), channel (Rhine Graben) and deposition space (North Sea Basin).

The story over smaller time-scales also plays over smaller distances. The Rhine changed its course during glaciations for example, because the advancing ice caps pushed sand out in front of them (moraines), in the Netherlands this literally pushed the rivers into a more southern course. The story about these details goes on and on and on! If you have any specific questions, you may want to contact the Geological Survey of the Netherlands or Geological Survey of Germany, they have people who dedicate their lives to studying the past and the present Rhine!


Where can I find data for annual high and low temperatures?

You can find this data from NCDC.  You can find the data for Portland, OR here.  These are annual summaries (ancsum) and for Portland they have extreme minimum daily temperature (EMNT) and extreme maximum daily temperature (EMXT) dating back to 1910.  From the linked page you can request data in various formats and select the date range and the specific variables you want.  They will put together the requested data and email you with a link to download it.  Here is some example data from the dataset:

COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201301  55  23
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201302  61  30
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201303  77  29
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201304  78  36
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201305  85  40
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201306  97  49
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201307  92  53
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201308  91  57
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201309  95  47
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201310  74  32
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201311  60  24
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201312  57  12
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201401  58  25
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201402  58  19
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201403  69  32
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201404  83  39
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201405  91  42
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201406  85  48
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201407  99  54
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201408  99  54
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201409  94  51
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201410  85  47
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201411  63  26
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201412  64  21
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201501  60  24
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201502  64  32
COOP:356751 PORTLAND INTERNATIONAL AIRPORT OR US    201503  73  30

These are extreme max/min temperatures for each month, so for this station you have annual maximums of 97 F and 99 F for 2013 and 2014.  You have annual minimums of 12 F and 19 F for the same two years.  There are multiple stations and they have varying temporal coverage.  You can request this data for each of the cities that interest you.


Creating a general log sheet for CTD and ADCP for fieldwork

This answer might be a bit late but here are some common metadata variables that get recorded:

For a CTD:

Operator
Date and time
Start and end co-ordinates of station
Station Number
Sample depths (assuming you'll also be collecting water samples)

Here you can also record what the water samples are used for i.e. salinities, chemistry etc

Sea state
Vessel
File name

For the ADCP:

Start and end co-ordinates
Date and time
ADCP type
Set-up (sampling frequency, bin size)
Vessel
Operator
File name


I suspect that rather than an ice jam as suggested in the comments, that this was a consequence of sustained high winds that happened to be blowing in just the right direction, thereby blowing the waters away from the side of the bay to which the inlet / bayou / saltwater river is connected.

Negative storm surge can drain shallow bays, sometimes dropping sea level by several feet. This happened, for example, along the west coast of Florida prior to Hurricane Irma. (That negative storm surge became a positive storm surge when the winds shifted direction.) This happens with great regularity where I live. The bayous later today and tomorrow will be very, very low due to a cold front that is pushing through right now.


It does seem like it's impossible to know unless you have additional information. However, I think there is a hint in there. See this white halo around the intrusion? My guess (and I could be wrong here) is that it's not there for artistic reasons but rather it's there to provide a very strong hint.

My feeling that this is some kind of metamorphosed contact zone (or aureole), which transforms sedimentary rocks into their low pressure and high temperature metamorphic equivalents (shales to hornfels, limestone to marble, sandstone to quartzite, etc).

It's hard to see, but I think I can see (when zooming in ) some of the white halo extending into the bottom of layer A. That would mean A was present when E intruded, because you can't metamorphose something that's not there. Otherwise, the metamorphic aureole would be cut by layer A.

Again, I'm not sure because the image is low resolution. Maybe you should ask your teacher or if that's not possible try to figure out if you should already know about metamorphic contact zones in your stage of geological education.


The easiest way I can explain it is you haven thousands of different material joined in billions of ways with chunks of all different sizes, there are just too many varables for an accurate prediction. becuase earthquakes are caused by a slow build up of pressure it is impossible to predict exactly when it will break because the forces are not spread evenly and the material properties of the rock are not consistent.

look at material testing, if you have a uniform object under steady predictable force they can predict when it will break with some reliability usually within a few seconds. but across a geologic timescale that kind of accuracy would give you plus or minus thousands of years, and that is under perfect conditions, Add in the complexity of the plates make up and you get even more error. Worse with plates the force on them is not uniform there are several forces acting on it and they are not spread evenly.

to use your glass analogy, imagine a sheet of glass several yards in diameter, but this glass was poorly made its lumpy so the thickness varies by several inches and is full of bubble and impurities. now try to predict when it will break based on a a group of children randomly throwing pennies onto it. You know it will break eventually but predicting when and where is functionally impossible.


The effect of CO2 concentration on the pH of the ocean

Increasing CO2 concentration in the atmosphere is leading to an increasing concentration of dissolved CO2 in sea-water. The dissolved CO2 then reacts with the water to create carbonic acid, decreasing the pH as recognised in the question.

The solubility of CO2 in water does decrease with increasing temperatures, so the maximum amount of CO2 that can be dissolved is being decreased as global temperatures rise, but the oceans are not yet saturated. There is a some further discussion and references om this page by NASA: The Oceans Carbon Balance.

Should global temperatures reach a point at which the oceans are saturated and start to release CO2 that they have been absorbing since the start of the industrial revolution, there would be very serious consequences for us all. This is, naturally, the subject of much ongoing research, e.g. Ocean-Atmosphere CO2 Exchange.