<http://schema.org/articleBody>
"  Imagine trying to hit a 20-inch hole in the ground while flying in an airplane and you might have some idea of what the scientists and engineers on the Japan Trench Fast Drilling Project (JFAST) had to deal with. Last year the 27-member team, representing 10 countries, spent weeks working 12-hour shifts around the clock to study the Japan Trench. It&amp;#039;s one of the deepest in the ocean, and the site where one day in March 2011, one of the earth&amp;#039;s plates dove under another and slid for 50 meters, triggering a magnitude-9 earthquake and devastating tsunami. These scientists were seeking an answer to what caused the plate to slip so far, the farthest distance ever recorded. To find out, they needed to reach the fault itself, dredge up rock samples, and bury instruments beneath the seafloor. And the best place to do that was underneath 7000 meters of ocean water.  Drilling at Depth Drilling through water is complicated, but not as difficult as drilling through rock. To reach the fault zone underneath Japan itself would mean drilling through many miles of solid Earth. Out at sea, the fault zone is much closer to the surface, about 800 meters (half a mile) below the sea floor.  In April of 2012, the team took a boat named Chikyu, designed and built by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), out about 155 miles due east of Sendai and parked it over the trench. The boat carried almost 5 miles of pipe in segments of about 10 meters long, which were stacked in vertical racks and clanged like wind chimes when the boat rocked in a storm.  In the bottom of Chikyu is an opening called the Moon Pool, and it was through this opening that engineers, with the help of robots about twice as tall as a human, twisted one piece of pipe into another, lowering the pipe piece by piece down to the ocean floor as the full length of the pipe came together.  They drilled three places overall: one to collect geophysical data, one to bring rock cores up to the surface, and one to install what the scientists call the observatory, essentially a rope with 55 sensors to measure the temperature of the fault zone in relation to the surrounding rock, which would reveal how much friction there had been between the two plates during the quake. Installing the observatory meant not only drilling a hole but then finding it again to insert the temperature sensors\u2014and coming back to the same spot nine months later to pick them up.  &amp;quot;A Wet Spaghetti Noodle&amp;quot; The first step is to install a 20-inch wellhead, which keeps the hole open to a depth of 30 meters. But once that&amp;#039;s done, the team needs to drag all the piping back up to the surface so it can install a drill bit, about 8 inches around, on the end. Then it lowers the whole assembly back into the water, where the engineers must find the wellhead again to continue drilling down past the fault.  The bottom of the pipe carried two underwater television cameras, along with some lights and sonar equipment, which allowed the team on board the boat to search for the hole opening via video. Although Chikyu has precise GPS location abilities, the long pipe sways in the ocean currents beneath the ship\u2014&amp;quot;like a wet spaghetti noodle,&amp;quot; Patrick Fulton, lead observatory scientist, said in a phone interview. Using the sonar and cameras, they tried to gauge their location, occasionally radioing up to the ship captain to move the boat a little bit this way or that as they zeroed in on the wellhead. &amp;quot;We will move along, and, hopefully, we see the wellhead, and once we see it we can make smaller moves and watch as the pipe swings above it,&amp;quot; Fulton said. &amp;quot;Right when we get above the hole someone yells, \u201A\u00C4\u00F2Now, now, now!&amp;#039; and then we drop it in and, hopefully, get into the hole.&amp;quot; The process of reentering can take an entire day, and it had to be done again to insert the observatory. &amp;quot;You&amp;#039;re trying to thread an 8-inch needle from 7 kilometers away,&amp;quot; says Emily Brodsky, another scientist on board and coauthor of one of the resulting papers. &amp;quot;And there is no motor on the bottom of the drill stem. The only motor&amp;#039;s at the top in your airplane, in your ship.&amp;quot; Problem Solving JFAST completed the deepest drilling ever accomplished, according to Nobu Eguchi, one of the project managers. (In 1978 the Deep Sea Drilling Project drilled into the Mariana Trench at a depth of 7049.5 meters, deeper than JFAST&amp;#039;s 6889.5 meters, but JFAST drilled much deeper into the seafloor, reaching a total depth of 7752.3 meters.) And along with any first comes challenges both expected and surprising.  The pipes weighed 350 tons, a significant weight to be dangling below any ship, which required a specially designed set of hydraulic clamps to hold them in place. The off-the-shelf temperature sensors had to be encased in titanium to protect them from the 11,000 pounds per square inch of pressure they&amp;#039;d experience at the bottom of the sea. Even something seemingly simple, like the cable needed to supply power to the lights and television cameras, caused unexpected troubles. No cables existed that were long enough, requiring a new one to be built specially for the expedition. But the spool around which it was wound wasn&amp;#039;t strong enough to handle it, creating kinks in the cable and disrupting transmissions. The team spent days throwing the cable overboard trying to straighten it. Eventually the cable failed, delaying the installation of the observatory.  &amp;amp;gt;  (Patrick Fulton/JAMSTEC) Wrapping Things Up Except for the cable and a few sonar transponders, everything worked like a charm. After installing the observatory inside the fault zone in July, the team headed home, leaving it to collect data until it could come back and reclaim it in February 2013. They retrieved their sensors with a remotely operated vehicle (ROV) called the KAIKO 7000-II, which could operate under a maximum of 7 kilometers (just over 4 miles) of water depth. &amp;quot;The retrieval was right at the technical limitations of what that ROV could do,&amp;quot; Brodsky says.  The February trip to find the hole was unsuccessful, stoking fears that a December earthquake had caused a landslide that covered the wellhead, burying the experiment forever. But when the team returned in April to calmer seas, it located the wellhead and deployed KAKIO to grab the edge of the observatory rope and haul it back up to the surface. Weak links had been built into the rope to allow it to break if a piece snagged, but ultimately all 55 sensors made it up to the surface. All of the effort culminated in the revelation that the temperature difference between the fault zone and the surrounding rock was just one third of a degree Celsius. Models had predicted that the difference would be closer to 2 degrees. The smaller difference meant friction between the plates had been unusually low, and that\u2014combined with the slippery clay pulled up by the coring\u2014told the scientists that the plates had been able to slide so disastrously far because the fault is exceedingly slick.  All thanks to science at 7000 meters deep. &amp;quot;But it was not at all trivial to make it happen,&amp;quot; Brodsky says. "^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.popularmechanics.com/science/a9853/how-scientists-drill-at-the-bottom-of-the-sea-16248335/>