The WAIS Divide is the ice flow divide on the
West Antarctic Ice Sheet
The Western Antarctic Ice Sheet (WAIS) is the segment of the Antarctic ice sheet, continental ice sheet that covers West Antarctica, the portion of Antarctica on the side of the Transantarctic Mountains that lies in the Western Hemisphere. The WAI ...
(WAIS) which is a linear boundary that separates the region where the ice flows to the
Ross Sea
The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who vi ...
, from the region where the ice flows to the
Weddell Sea
The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha ...
. It is similar to a continental hydrographic divide.
Ice core project
The WAIS Divide
ice core
An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains ic ...
project (West Antarctic Ice Sheet Divide ice core project) investigated past climate changes, ice sheet dynamics and cryobiology. The project was completed by the
United States Antarctic Program
The United States Antarctic Program (or USAP; formerly known as the United States Antarctic Research Program or USARP and the United States Antarctic Service or USAS) is an organization of the United States government which has presence in the A ...
(USAP) and was funded by the
National Science Foundation
The National Science Foundation (NSF) is an independent agency of the United States government that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National I ...
(NSF). The focus of the project was to develop records spanning the last ~ 80,000 years of the concentration of greenhouse gases in the atmosphere and
Antarctic climate
The climate of Antarctica is the coldest on Earth. The continent is also extremely dry (it is a desert), averaging of precipitation per year. Snow rarely melts on most parts of the continent, and, after being compressed, becomes the glacier ic ...
, and to do this with the highest possible time resolution. The project is best known for producing records of atmospheric carbon dioxide and methane with high time resolution and dating accuracy. This was accomplished by collecting and analyzing an ice core from a site named WAIS Divide (79.468° S 112.086° W) that is on the WAIS ice flow divide. This can cause confusion because the name "WAIS Divide" can refer to the WAIS Divide ice flow divide or the WAIS Divide drill site that is at a single spot on the ice flow divide.
Project history
![Antarctica WAIS Divide Field Camp 16](https://upload.wikimedia.org/wikipedia/commons/0/00/Antarctica_WAIS_Divide_Field_Camp_16.jpg)
Site selection started in 2000 with the goal of finding the best place meeting the following requirements.
* A site in Antarctica was needed because Greenland ice contains enough dust that post-depositional chemical reactions comprise the record of atmospheric carbon dioxide.
* A site with minimal horizontal ice flow was needed to avoid complications caused by different ice deposition locations for ice at different depths. This required drilling on an ice flow divide.
* A site with high annual ice accumulation and thick ice was needed to provide a high time resolution record extending ~80,000 years into the past. This required drilling in West Antarctica which has higher ice accumulation rates than East Antarctica.
* Other requirements included simple basal topography, avoiding the depth interval of brittle ice during the deglacial part of the record, and logistics considerations.
Site preparation started in the 2005/2006 season with the construction of the skiway, and a steel arch shelter for drilling and core processing. Camp logistics was provided by
Raytheon Polar Services Company and the air transport by the
New York Air National Guard
The New York Air National Guard (NY ANG) is the aerial militia of the State of New York, United States of America. It is, along with the New York Army National Guard, an element of the New York National Guard.
As state militia units, the units ...
using
LC-130
The Lockheed LC-130 is a ski-equipped United States Air Force variant of the C-130 Hercules used in the Arctic and Antarctic. Ten are currently in service with the 109th Airlift Wing of the New York Air National Guard.
Design and developme ...
aircraft.
The deep coring started in the 2006/2007 season using the Deep Ice Sheet Coring (DISC) drill developed and operated by the Ice Drilling Design and Operations group at the University of Wisconsin, Madison. The coring was stopped in December 2011 at a depth of 3,405 m, which is ~ 50 m above the bottom of the ice sheet. The last 50 m of ice was left in place to provide a barrier between the borehole and the pristine aqueous basal environment. The ice at the bottom of the hole fell as snow 67,748 years ago. In the 2012-2013 season additional core was collected in zones of high scientific interest. This was done by drilling through the side of the main bore hole and coring along a path nearly parallel to the main core.
The ice core was transported to the
National Ice Core Laboratory
The National Science Foundation Ice Core Facility (NSF-ICF), known as the National Ice Core Laboratory (NICL) before 2018, is the primary repository for ice cores collected by the United States. The facility is located at the Denver Federal Cente ...
in Denver, Colorado where it was sampled and portions were distributed to 33 institutions for analysis. The analysis included the physical, chemical and isotopic properties of the gases trapped in the ice, the soluble and insoluble material in the melted ice, and the water from the melted ice.
Results
![WAIS-Flag-and-Camp](https://upload.wikimedia.org/wikipedia/commons/b/bb/WAIS-Flag-and-Camp.jpeg)
The core was dated using two methods. The top was dated by counting annual layers to an age of 31,200 years ago. The bottom was dated using stratigraphic methods to an age of 67,748, years at the bottom of the core. The dating was more accurate than other Antarctic ice cores and enables a better understanding of the causes of previous climate changes. This information helps improve predictions of future climate changes.
The project developed information on:
*The origins of the
abrupt climate change
An abrupt climate change occurs when the climate system is forced to transition at a rate that is determined by the climate system energy-balance, and which is more rapid than the rate of change of the external forcing, though it may include sud ...
s that occurred during the last ice age.
*The role of variations in the earth's orbit on climate.
*The natural variations in atmospheric carbon dioxide and the influence of ocean circulation on these variations.
*The natural variations in
atmospheric methane
Atmospheric methane is the methane present in Earth's atmosphere. Atmospheric methane concentrations are of interest because it is one of the most potent greenhouse gases in Earth's atmosphere. Atmospheric methane is rising.
The 20-year glob ...
and the role of tropical wet lands and ice sheets on these variations.
Paleoceanography will publish a special edition that includes all WAIS Divide related AGU publications as April 2016.
Additional information, including a complete list of all the publications related to the project, is available at: http://waisdivide.unh.edu.
Outreach
*NOVA: Secrets Beneath the Ice; December 12, 2011.
*Wall Street Journal: Mining for Cold, Hard Facts; May 29, 2010.
*Art installation: WAIS Divide Reliquary, Anna McKee;
Nevada Museum of Art The Nevada Museum of Art, is an art museum in Reno, Nevada.
Located at 160 West Liberty Street in Reno, it is the only American Alliance of Museums (AAM) accredited art museum in the state of Nevada. The museum has chosen a thematic approach, placi ...
, 2016.
Project leadership
Leadership for the project was provided by the following people:
*
Kendrick Taylor
Kendrick Cashman Taylor, Jr. is a climate change researcher working with ice cores in Greenland and Antarctica. While a Research Professor at the Desert Research Institute in Reno, Nevada, he was the Chief Scientist for the Siple Dome and WAIS Divi ...
, Chief Scientist;
*Matthew Kippenhan, Logistics planning and execution;
*Jay Johnson: Head Driller;
*Mark Twickler: Science Coordination Office Manager;
*Julie Palais, National Science Foundation Program Manager
See also
*
Antarctic field camps
Many Antarctic research stations support satellite field camps which are, in general, seasonal camps. The type of field camp can vary – some are permanent structures used during the annual Antarctic summer, whereas others are little more than te ...
*
List of airports in Antarctica
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List
, 18/36Ice
, - valign=top
, Palmer SkiwayHeliport
,
, NZ12
,
, Anvers Island
,
, 01/19Snow
, - valign=top
, Patriot Hills Blue-Ice Runway
,
, SCPZ
,
, Ellsworth Mountains
,
, 24MIce
, - valign=top
, Pegasu ...
References
External links
WAIS Ice Core ProjectDeep Into WAIS Dividefro
The Antarctic SunOn the Linefro
The Antarctic Sun
{{Airports in Antarctica
United States Antarctic Program
Science and technology in Antarctica
Paleoclimatology