News Release 13-017
Antarctic Ice Core Contains Unrivaled Detail of Past Climate
WAIS Divide Core will allow for examination of annual snowfall for each of the past 30,000 years
February 5, 2013
B-roll of WAIS Divide operations in Antarctica is available by contacting Dena Headlee, firstname.lastname@example.org, (703) 292-7739
This material is available primarily for archival purposes. Telephone numbers or other contact information may be out of date; please see current contact information at media contacts.
A team of U.S. ice-coring scientists and engineers in Antarctica, funded by the National Science Foundation (NSF), has recovered from the ice sheet a record of past climate and greenhouse gases in the atmosphere that extends back 68,000 years.
Retrieved from the West Antarctic Ice Sheet (WAIS), the ice containing the record is known as the WAIS Divide ice core. The cylinders of ice that make up the core contain uniquely detailed information on past environmental conditions such as the atmospheric concentration of greenhouse gases, surface air temperature, wind patterns, the extent of sea ice around Antarctica, and the average temperature of the ocean.
Successfully retrieving the core is the culmination of an eight-year project to obtain a paleoclimate record from one of the remotest parts of the continent.
The ice containing the record was recovered at a field camp in the center of West Antarctica, 1,040 kilometers (650 miles) from the geographic South Pole, where the ice is more than 3,460 meters (two miles) thick. In the new WAIS Divide core each of the past 30,000 years of snowfall can be identified in individual layers of ice. By allowing an examination of past climate at an annual resolution, the record will help scientists understand why climate can change abruptly--in less than 10 years--and how climate could unfold in the coming century.
Other ice-coring projects have produced cores of lower temporal resolution, showing that the current level of atmospheric greenhouse gases, which is due to the burning of fossil fuels, is the highest in at least 800,000 years.The ice that is between 30,000 and 68,000 years old--while not containing records with annual resolution--contains a higher time resolution record than previous projects.
When snow falls at WAIS Divide, it rarely melts, but builds up in thick annual layers, which are compressed into ice by subsequent snowfall. Chemicals and gases in the atmosphere that are characteristic of environmental conditions when the snow fell are trapped in the ice. The age of the ice is determined by identifying the chemical difference between winter snow and summer snow, and counting the years is much like counting tree rings to determine how old a tree is.
Samples of the ice core will be distributed to more than 20 U.S. university and national laboratories that make the measurements. Most of the measurements are known to be indicative of global atmospheric conditions, not just of the conditions at the remote location where the ice was collected.
The information from the project will be used to test and improve the predictions of how the current human-caused increases in greenhouses gases (e.g., carbon dioxide, methane) are altering the earth's climate.
"The combination of being able to identify individual years and new analytical methods that were not available on previous projects will greatly improve our understanding of how past changes in greenhouse gases influenced the global climate," said Kendrick Taylor, of the Desert Research Institute, in Reno Nevada, and chief scientist for the WAIS Divide project.
He added that it will take another two years to complete the analysis of the ice and publish the results.
The WAIS Divide research project has taken eight field seasons to prepare the remote field camp and collect the core. The weather and the remoteness of the field site limit field operations to 60 days a year. The unique ice-coring drill was designed and operated by the Ice Drilling Design and Operations group at the University of Wisconsin, Madison, through a collaborative arrangement with the Ice Drilling Program Office.
In addition to collecting 3,405 meters (11,160 feet) of a 12.2-centimeter (4.8-inch) diameter ice core, a new directional-drilling procedure was developed that allowed the team to drill through the wall of the main hole and collect a total of 285 meters (936 feet) of additional core from five of the most scientifically interesting time periods. This enables replication of the results and expands the suite of measurements that can be made on the most interesting ice.
This is the first time anyone has ever taken additional ice core out of the side of the borehole without blocking access to the lower part of the main borehole. It's an engineering breakthrough that will allow us to look in great detail at the causes of abrupt climate change," said Jeff Severinghaus of the Scripps Institution of Oceanography, chief scientist for replicate coring.
The team stopped drilling 165 feet above where the ice contacts the rock below in order to avoid contaminating the water at the bottom of the ice, which has been isolated from the rest of the biosphere for at least 100,000 years.
NSF is responsible for the U.S. Antarctic Program, through which it manages all U.S. research, as well as all of the required logistical support, in Antarctica and in the Southern Ocean.
The Whillans Ice Stream Subglacial Research Drilling project (WISSARD), working at a different site in West Antarctica and also funded by NSF, is using a different drilling method and a different engineering team to cleanly sample a sub-glacial lake to investigate the biology of the lake. The WISSARD team recently announced that it had obtained samples of the lake bottom.
The first replicate core ever taken from the high side of an ice-core borehole is shown.
Credit and Larger Version
Peter West, NSF, (703) 292-7530, email: email@example.com
Justin Broglio, Desert Research Institute, (775) 673-7610, email: Justin.Broglio@dri.edu
David Sims, University of New Hampshire, (603) 862-5369, email: David.Sims@unh.edu
John Cramer, Dartmouth College, (603) 646-9130, email: firstname.lastname@example.org
Julie M. Palais, NSF, (703) 292-8033, email: email@example.com
The U.S. National Science Foundation propels the nation forward by advancing fundamental research in all fields of science and engineering. NSF supports research and people by providing facilities, instruments and funding to support their ingenuity and sustain the U.S. as a global leader in research and innovation. With a fiscal year 2023 budget of $9.5 billion, NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and institutions. Each year, NSF receives more than 40,000 competitive proposals and makes about 11,000 new awards. Those awards include support for cooperative research with industry, Arctic and Antarctic research and operations, and U.S. participation in international scientific efforts.
"Kulingana na taarifa ya ""Antarctic Ice Core"" ya mwaka 2013, ""WAIS Divide Core"" inatoa maelezo ya kina ya hali ya hewa ya zamani, na ""B-roll"" ya shughuli za WAIS Divide katika Antarctica inapatikana kwa kuwasiliana na Dena Headley, firstname.lastname@example.org, 70329739." Nambari za simu au habari nyingine za mawasiliano zinaweza kuwa zimepitwa na wakati; tafadhali angalia habari za mawasiliano za sasa kwenye mawasiliano ya vyombo vya habari. Timu ya wanasayansi na wahandisi wa barafu ya Marekani katika Antaktika, iliyofadhiliwa na Shirika la Sayansi la Kitaifa (NSF), imepata rekodi ya hali ya hewa ya zamani na gesi za chafu katika anga ya anga ambayo inaendelea nyuma ya miaka 68,000. "Kutokana na uchunguzi wa barafu ya West Antarctic Ice Sheet (WAIS), barafu iliyo na rekodi hiyo inajulikana kama ""WAIS Divide Ice Core.""" Silinda za barafu zinazofanyiza kiini cha barafu zina habari za kipekee za hali ya mazingira ya zamani kama vile mkusanyiko wa gesi za chafu, joto la hewa ya uso, mifumo ya upepo, kiwango cha barafu ya bahari karibu na Antaktika, na joto la wastani la bahari. Ufanisi wa kupata kiini cha mlipuko huo ni kilele cha mradi wa miaka minane wa kupata rekodi ya hali ya hewa ya kale kutoka kwa moja ya sehemu za mbali zaidi za bara. Barafu hiyo iligunduliwa katika kambi ya mashambani katikati ya Antaktika Magharibi, kilomita 1,040 kutoka Ncha ya Kusini, ambapo barafu ina unene wa mita 3,460. Katika sehemu ya msingi ya WAIS Divide, kila moja ya miaka 30,000 iliyopita ya theluji inaweza kutambuliwa katika tabaka za barafu. Kwa kuruhusu uchunguzi wa hali ya hewa ya zamani kwa azimio la kila mwaka, rekodi hiyo itasaidia wanasayansi kuelewa ni kwa nini hali ya hewa inaweza kubadilika ghafla - katika chini ya miaka 10 - na jinsi hali ya hewa inaweza kuenea katika karne ijayo. "Mipango mingine ya kuchimba barafu imetoa makundi ya gesi ya chafu ya hali ya chini, ikionyesha kuwa kiwango cha sasa cha gesi ya chafu ya angahewa, ambayo ni kwa sababu ya kuchoma mafuta ya mafuta, ni ya juu zaidi katika miaka ya 800,000, ""alisema." Wakati theluji inapopanda katika WAIS Divide, ni nadra kuyeyuka, lakini hujenga katika tabaka nene za kila mwaka, ambazo hufinyangwa katika barafu na theluji inayofuata. Kemikali na gesi zilizo katika angahewa ambazo ni sifa ya hali za mazingira wakati theluji ilipokuwa ikianguka zinashikiliwa katika barafu. Kwa mfano, umri wa barafu huamuliwa kwa kutambua tofauti ya kemikali kati ya theluji ya majira ya baridi kali na theluji ya majira ya joto, na kuhesabu miaka ni kama kuhesabu pete za miti ili kuamua umri wa mti. Sampuli za barafu hiyo zitapelekwa katika vyuo vikuu zaidi ya 20 nchini Marekani na maabara ya kitaifa. "Kama ilivyoelezwa, ""kiwango cha hewa cha dunia ni muhimu kwa hali ya hewa ya dunia, sio tu kwa hali ya eneo la mbali ambapo barafu ilikusanywa.""" Taarifa kutoka kwa mradi huo itatumika kupima na kuboresha utabiri wa jinsi ongezeko la sasa la gesi za chafu (kwa mfano, kaboni dioksidi, methane) zinazosababisha binadamu zinavyobadilisha hali ya hewa ya dunia. "Uwezo wa kutambua miaka ya moja kwa moja na mbinu mpya za uchambuzi ambazo hazikupatikana katika miradi ya awali utaongeza sana uelewa wetu wa jinsi mabadiliko ya zamani ya gesi za chafu yalivyoathiri hali ya hewa ya ulimwengu, ""alisema Kendrick Taylor, wa Taasisi ya Utafiti wa Jangwa huko Reno, Nevada, na mwanasayansi mkuu wa mradi wa WAIS Divide." Aliongeza kwamba itachukua miaka mingine miwili kukamilisha uchambuzi wa barafu na kuchapisha matokeo. Kwa mujibu wa ripoti ya WAIS, imepangwa kufanya kazi kwa muda wa miezi nane ili kuandaa kambi ya mashambani na kukusanya vipande vya mawe. Hali ya hewa na ukosefu wa upatikanaji wa vifaa vya ujenzi wa uwanja wa ndege huathiri shughuli za uwanja wa ndege kwa siku 60 kwa mwaka. Drill hii ya kipekee ya kuchimba barafu ilitengenezwa na kuendeshwa na kikundi cha Ubunifu na Uendeshaji wa Drilling ya Barafu katika Chuo Kikuu cha Wisconsin, Madison, kupitia mpango wa ushirikiano na Ofisi ya Programu ya Drilling ya Barafu. Pamoja na kukusanya mita 3,405 za kiini cha barafu cha kipenyo cha sentimeta 12,2, utaratibu mpya wa kuchimba uliruhusiwa kupenya ukuta wa shimo kuu na kukusanya jumla ya mita 285 za kiini cha ziada kutoka vipindi vitano vya wakati vinavyovutia zaidi kisayansi. Hii inawezesha replication ya matokeo na kupanua seti ya vipimo ambayo inaweza kufanywa juu ya barafu ya kuvutia zaidi. Hii ni mara ya kwanza kwa mtu yeyote kuchukua barafu ya ziada nje ya shimo la kuchimba bila kuzuia upatikanaji wa sehemu ya chini ya shimo kuu. "Hii ni mafanikio ya uhandisi ambayo itaturuhusu kuangalia kwa undani sana sababu za mabadiliko ya hali ya hewa ya ghafla, ""alisema Jeff Severinghaus wa Taasisi ya Scripps ya Oceanography, mwanasayansi mkuu wa replicate coring." Watafiti hao waliacha kuchimba kwenye eneo la juu la barafu ili kuepuka kuchafua maji yaliyo chini ya barafu, ambayo yametengwa na sehemu nyingine ya dunia kwa miaka 100,000 hivi. NSF ni mtendaji wa Programu ya Antarctic ya Marekani, ambayo inasimamia utafiti wote wa Marekani, pamoja na msaada wote wa vifaa unaohitajika katika Antarctica na Bahari ya Kusini. Mradi wa Whelan Ice Stream Subglacial Research Drilling (WISSARD) unafanya kazi katika eneo tofauti katika Antaktika Magharibi na pia unafadhiliwa na NSF, kwa kutumia mbinu tofauti ya kuchimba na timu tofauti ya uhandisi kuchukua sampuli safi ya ziwa la chini ya barafu ili kuchunguza biolojia ya ziwa. Timu ya WISSARD hivi karibuni ilitangaza kwamba ilikuwa imepata sampuli za chini ya ziwa hilo. Kiini cha kwanza cha kuiga kilichowahi kuchukuliwa kutoka upande wa juu wa shimo la barafu linaonyeshwa. "Kama ilivyoelezwa katika makala ya ""Kutoka kwa Utafiti wa Utafiti wa Uchawi"" (Justin Broglia, Desert Research Institute, 775-73-366), ""Utafiti wa Utafiti wa Uchawi"" (David Broglia, Desert Research Institute, 775-76-367), ""Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti wa Utafiti." NSF inasaidia utafiti na watu kwa kutoa vifaa, vyombo na fedha kusaidia ubunifu wao na kudumisha Marekani kama kiongozi wa kimataifa katika utafiti na uvumbuzi. Kwa bajeti ya mwaka wa kifedha wa 2023 ya $ 9.5 bilioni, fedha za NSF zinafikia majimbo yote 50 kupitia ruzuku kwa karibu vyuo vikuu 2,000, vyuo vikuu na taasisi. Kila mwaka, NSF hupokea zaidi ya mapendekezo ya ushindani 40,000 na hufanya tuzo mpya za karibu 11,000. Tuzo hizo ni pamoja na msaada kwa ajili ya utafiti wa ushirikiano na viwanda, utafiti wa Arctic na Antarctic na shughuli, na ushiriki wa Marekani katika juhudi za kimataifa za kisayansi.