Jemma Wadham | |
|---|---|
 Jemma Wadham at the Arolla Glacier | |
| Nationality | Britain |
| Alma mater | MA University of Cambridge PhD University of Bristol |
| Awards | Philip Leverhulme Prize (2007) |
| Scientific career | |
| Fields | Glaciology |
| Institutions | University of Bristol |
| Website | https://www.jemmawadham.com/ |
Jemma L. Wadham is a British glacial biogeochemist.
Wadham completed her BA and MA in physical geography at Cambridge University. She then completed her PhD at the University of Bristol in 1998.
Wadham undertook a short post-doctoral research post at the University of Leeds before returning to the University of Bristol to take up a post at the Bristol Glaciology Centre. [1] [2]
Wadham researches glacial ecosystems and investigates their impact on biogeochemical processes. [3] [4] [5] She has worked in the polar regions, including the Antarctic [6] and the Greenland ice sheets. [7] This has led to more than 90 articles [8] and a textbook on Antarctic lakes. [9]
Wadham has been involved with the International Scientific Committee on Antarctic Research, the Scientific Committee on Antarctic Research (SCAR) and subglacial science in Antarctica. [10] She has served on the Lake Ellsworth Exploration Steering Committee and is a contributor to this subglacial lake exploration programme. [11]
In 2012, Wadham's team at the University of Bristol used computer models to predict the amount of trapped methane under ice sheets and discovered 400 billion metric tons of carbon beneath. [12] [13]
She is one of few women working on technology development for exploring subglacial lakes. [7] Her work in Greenland has advanced our understanding of the dynamics of ice sheets and their contribution to global biogeochemical cycles. [7] [5]
In 2022, Wadham and her collaborator Dr. Monica Winsborrow were awarded €15 million to direct the Centre for ice, Cryosphere, Carbon and Climate (iC3), a ten-year Norwegian Centre of Research Excellence funded by the Norwegian Research Council that will run from 2023-2033. [14] [15] iC3 will be located at the University of Tromsø.
She was awarded a Philip Leverhulme Prize in October 2007 for her international contribution to polar science. [16]
Lake Vostok is the largest of Antarctica's 675 known subglacial lakes. Lake Vostok is located at the southern Pole of Cold, beneath Russia's Vostok Station under the surface of the central East Antarctic Ice Sheet, which is at 3,488 m (11,444 ft) above mean sea level. The surface of this fresh water lake is approximately 4,000 m (13,100 ft) under the surface of the ice, which places it at approximately 500 m (1,600 ft) below sea level.
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than 50,000 km2 (19,000 sq mi). The only current ice sheets are the Antarctic ice sheet and the Greenland ice sheet. Ice sheets are bigger than ice shelves or alpine glaciers. Masses of ice covering less than 50,000 km2 are termed an ice cap. An ice cap will typically feed a series of glaciers around its periphery.
The Amundsen Sea is an arm of the Southern Ocean off Marie Byrd Land in western Antarctica. It lies between Cape Flying Fish to the east and Cape Dart on Siple Island to the west. Cape Flying Fish marks the boundary between the Amundsen Sea and the Bellingshausen Sea. West of Cape Dart there is no named marginal sea of the Southern Ocean between the Amundsen and Ross Seas. The Norwegian expedition of 1928–1929 under Captain Nils Larsen named the body of water for the Norwegian polar explorer Roald Amundsen while exploring this area in February 1929.
A subglacial lake is a lake that is found under a glacier, typically beneath an ice cap or ice sheet. Subglacial lakes form at the boundary between ice and the underlying bedrock, where liquid water can exist above the lower melting point of ice under high pressure. Over time, the overlying ice gradually melts at a rate of a few millimeters per year. Meltwater flows from regions of high to low hydraulic pressure under the ice and pools, creating a body of liquid water that can be isolated from the external environment for millions of years.
Pine Island Glacier (PIG) is a large ice stream, and the fastest melting glacier in Antarctica, responsible for about 25% of Antarctica's ice loss. The glacier ice streams flow west-northwest along the south side of the Hudson Mountains into Pine Island Bay, Amundsen Sea, Antarctica. It was mapped by the United States Geological Survey (USGS) from surveys and United States Navy (USN) air photos, 1960–66, and named by the Advisory Committee on Antarctic Names (US-ACAN) in association with Pine Island Bay.
Lake Ellsworth is a natural freshwater liquid subglacial lake located in West Antarctica under approximately 2.93–3.28 km (1.82–2.04 mi) of ice. It is approximately 14.7 km (9.1 mi) long and is estimated to be 156 m (512 ft) in max. depth. The lake is named after the American explorer Lincoln Ellsworth. The surface of the lake itself is located, approximately 3,379–4,528 feet (1,030–1,380 m) below mean sea level. Elevation of icecap covering, the lake: 1,900–1,925 m (6,234–6,316 ft) m.a.s.l.
The WAIS Divide is the ice flow divide on the West Antarctic Ice Sheet (WAIS) which is a linear boundary that separates the region where the ice flows to the Ross Sea, from the region where the ice flows to the Weddell Sea. It is similar to a continental hydrographic divide.
The East Antarctic Ice Sheet (EAIS) lies between 45° west and 168° east longitudinally. It was first formed around 34 million years ago, and it is the largest ice sheet on the entire planet, with far greater volume than the Greenland ice sheet or the West Antarctic Ice Sheet (WAIS), from which it is separated by the Transantarctic Mountains. The ice sheet is around 2.2 km (1.4 mi) thick on average and is 4,897 m (16,066 ft) at its thickest point. It is also home to the geographic South Pole, South Magnetic Pole and the Amundsen–Scott South Pole Station.
Arctic methane emissions contribute to a rise in methane concentrations in the atmosphere. Whilst the Arctic region is one of many natural sources of the greenhouse gas methane, there is nowadays also a human component to this due to the effects of climate change. In the Arctic, the main human-influenced sources of methane are thawing permafrost, Arctic sea ice melting, clathrate breakdown and Greenland ice sheet melting. This methane release results in a positive climate change feedback, as methane is a powerful greenhouse gas. When permafrost thaws due to global warming, large amounts of organic material can become available for methanogenesis and may therefore be released as methane.
Hercules Dome is a large ice dome between the Thiel Mountains and the Horlick Mountains in Antarctica. The feature was first mapped by the United States Geological Survey from U.S. Navy aerial photographs taken 1959–60. It was further delineated by the Scott Polar Research Institute – National Science Foundation – Technical University of Denmark airborne aerial radio echo sounding program, 1967–79, and named after the Lockheed LC-130 Hercules aircraft which was used on all echo sounding flights from 1969. The dome is notable for its unusually high number of subglacial lakes.
Andrey Petrovich Kapitsa was a Soviet and Russian geographer and Antarctic explorer, discoverer of Lake Vostok, the largest subglacial lake in Antarctica. He was a member of the Kapitsa family, a scientific dynasty in Russia.
There are hundreds of antarctic lakes in Antarctica. In 2018 researchers at the Alfred Wegener Institute for Polar and Marine Research published a study they claimed cast doubt on the earlier estimate that there were almost 400 subglacial antarctic lakes. Antarctica also has some relatively small regions that are clear of ice and snow, and there are some surface lakes in these regions. They called for on the ground seismic studies, or drilling, to determine a more reliable number.
Lake Whillans is a subglacial lake in Antarctica. The lake is located under the Whillans Ice Stream at the southeastern edge of the Ross Ice Shelf in the west of the continent. The lake surface is 800 m (2,600 ft) beneath the surface of the ice and the lake covers an estimated area of 60 km2 (20 sq mi). Lake depths measured thus far have been around 2 metres. Its temperature is −0.49 °C, below 0 °C because of the high pressure.
Helen Amanda Fricker is a glaciologist and professor at Scripps Institution of Oceanography at the University of California, San Diego where she is a director of the Scripps Polar Center. She won the 2010 Martha T. Muse Prize for Science and Policy in Antarctica.
Robin Elizabeth Bell is Palisades Geophysical Institute (PGI) Lamont Research Professor at Columbia University's Lamont–Doherty Earth Observatory and a past President of the American Geophysical Union (AGU), 2019–2021. Dr. Bell was influential in co-ordinating the 2007 International Polar Year and was the first woman to chair the National Academy of Sciences Polar Research Board. She has made numerous important discoveries with regard to subglacial lakes and ice sheet dynamics, and has a ridge, called Bell Buttress, in Antarctica named after her.
Trista Vick-Majors is an American Assistant Professor in Biological Sciences at Michigan Tech. She is an Antarctic biogeochemist and microbial ecologist, best known for her work showing that microorganisms are present under the Antarctic ice sheet.
Jill Ann Mikucki is an American microbiologist, educator and Antarctic researcher, best known for her work at Blood Falls demonstrating that microbes can grow below ice in the absence of sunlight. She is a leader of international teams studying ecosystems under the ice.
Martin J. Siegert is a British glaciologist, and Deputy Vice Chancellor (Cornwall) at the University of Exeter. He co-Chairs the Diversity in Polar Science Initiative, and has spoken about socio-economic inclusion in Polar Science and indeed broader society.
Mercer Subglacial Lake is a subglacial lake in Antarctica covered by a sheet of ice 1,067 m (3,501 ft) thick; the water below is hydraulically active, with water replacement times on the order of a decade from the Ross Sea. Studies suggest that Mercer Subglacial Lake as well as other subglacial lakes appear to be linked, with drainage events in one reservoir causing filling and follow-on drainage in adjacent lakes.
Salty subglacial lakes are controversially inferred from radar measurements to exist below the South Polar Layered Deposits (SPLD) in Ultimi Scopuli of Mars' southern ice cap. The idea of subglacial lakes due to basal melting at the polar ice caps on Mars was first hypothesized in the 1980s. For liquid water to persist below the SPLD, researchers propose that perchlorate is dissolved in the water, which lowers the freezing temperature, but other explanations such as saline ice or hydrous minerals have been offered. Challenges for explaining sufficiently warm conditions for liquid water to exist below the southern ice cap include low amounts of geothermal heating from the subsurface and overlying pressure from the ice. As a result, it is disputed whether radar detections of bright reflectors were instead caused by other materials such as saline ice or deposits of minerals such as clays. While lakes with salt concentrations 20 times that of the ocean pose challenges for life, potential subglacial lakes on Mars are of high interest for astrobiology because microbial ecosystems have been found in deep subglacial lakes on Earth, such as in Lake Whillans in Antarctica below 800 m of ice.
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