Large, marine-calving glaciers have the ability not only to shrink rapidly in response to global warming, but to grow at a remarkable pace during periods of global cooling, according to University at Buffalo geologists working in Greenland.
The conclusion stems from new research on Jakobshavn Isbrae, a tongue of ice extending out to sea from Greenland's west coast. Through an analysis of adjacent lake sediments and plant fossils, the UB team determined that the glacier, which retreated about 40 kilometers inland between 1850 and 2010, expanded outward at a similar pace about 200 years ago, during a time of cooler temperatures known as the Little Ice Age.
A paper detailing the results is in press and available online in Quaternary Science Reviews, a top peer-reviewed journal in the field.
"We know that Jakobshavn Isbrae has retreated at this incredible rate in recent years, and our study suggests that it advanced that fast, also," said Jason Briner, the associate professor of geology who led the research. His team included master's and PhD students from UB and Brown University.
"Our results support growing evidence that calving glaciers are particularly sensitive to climate change," Briner added.
Jakobshavn Isbrae has been the focus of intense scientific interest because it is one of the world's fastest-flowing glacier, releasing enormous quantities of Greenland's ice into the ocean. Changes in the rate at which icebergs calve off from the glacier could influence global sea level rise.
The decline of Jakobshavn Isbrae between 1850 and 2010 has been well-documented through aerial photographs and satellite photographs by UB Associate Professor of Geology Bea Csatho, which show the ice shrinking rapidly from west to east along a narrow fjord.
To reconstruct the glacier's advance from east to west during earlier, cooler years, Briner and his colleagues examined sediment samples from Glacial Lake Morten and Iceboom Lake, two glacier-fed lakes that sit along the glacier's path of expansion.
As Jakobshavn Isbrae expanded seaward, it reached Glacial Lake Morten first, damming one side of the lake with ice and filling the basin, previously a tundra-covered valley, with meltwater.
To pinpoint the time in history when this happened, the researchers counted annual layers of overlying glacial sediments and used radiocarbon dating to analyze plant fossils at the lake bottom (the last vestiges of the old tundra). The team's conclusion: Glacial Lake Morten formed between 1795 and 1800.
An analysis of sediment layers from the bottom of Iceboom Lake showed that Jakobshavn Isbrae reached Iceboom lake about 20 or 25 years later, around 1820.
Jakobshavn Isbrae's rate of expansion from Glacial Lake Morten to Iceboom Lake, as documented by the UB team, matched the glacier's rate of retreat between those two points. (Aerial imagery shows Iceboom Lake draining around 1965 and Glacial Lake Morten draining between 1986 and 1991.)
Briner's research was funded by the National Science Foundation's Geography and Spatial Sciences Program.
The University at Buffalo is a premier research-intensive public university, a flagship institution in the State University of New York system and its largest and most comprehensive campus. UB's more than 28,000 students pursue their academic interests through more than 300 undergraduate, graduate and professional degree programs. Founded in 1846, the University at Buffalo is a member of the Association of American Universities.
Charlotte Hsu | EurekAlert!
Diving robots find Antarctic seas exhale surprising amounts of carbon dioxide in winter
16.08.2018 | National Science Foundation
Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide
15.08.2018 | University of Washington
There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.
The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
21.08.2018 | Materials Sciences
20.08.2018 | Information Technology
20.08.2018 | Life Sciences