This new map allows scientists to determine the age of substantial swaths of the second biggest mass of ice on Earth, an area containing sufficient water to raise ocean levels by about 20 feet. “This new, substantial information volume records how the ice allows scientists to determine the age of substantial swaths of the second biggest mass of ice on Earth, an area containing sufficient water to raise ocean levels by about 20 feet.
“This new, substantial information volume records how the ice sheet evolved and how it is flowing these days,” stated Joe MacGregor, the study’s lead author, a glaciologist at The University of Texas at Austin Institute for Geophysics (UTIG), a unit of the Jackson School of Geosciences.
Greenland’s ice sheet has been losing mass for the duration of the past two decades, a phenomenon accelerated by warming temperatures. Scientists are studying ice from diverse climate periods in the past to far better comprehend how the ice sheet could respond in the future.
Ice cores supply one way of studying the distant past. These cylinders of ice drilled from the ice sheet hold proof of past snow accumulation and temperature and include impurities such as dust and volcanic ash compacted over hundreds of thousands of years. These layers are visible in ice cores and can be detected with ice-penetrating radar.
Ice-penetrating radar works by sending radar signals into the ice and recording the strength and return time of reflected signals. From these signals, scientists can detect the ice surface, sub-ice bedrock and layers inside the ice.
New techniques made use of in this study permitted scientists to efficiently pick out these layers in radar data. Prior studies had mapped internal layers, but not at the scale made possible by these newer, quicker techniques.
Another main issue in this study was the scope of Operation IceBridge’s measurements across Greenland, which incorporated flights that covered distances of tens of thousands of kilometers across the ice sheet.
“IceBridge surveyed previously unexplored components of the Greenland Ice Sheet and did it employing state-of-the-art CReSIS radars,” mentioned study co-author Mark Fahnestock, an IceBridge science group member and glaciologist from the Geophysical Institute at the University of Alaska Fairbanks (UAF-GI).
CReSIS is the Center for Remote Sensing of Ice Sheets, a National Science Foundation science and technologies center headquartered at the University of Kansas in Lawrence, Kansas.
IceBridge’s flight lines often intersect ice core websites exactly where other scientists have analyzed the ice’s chemical composition to map and date layers in the ice. These core information deliver a reference for radar measurements and present a way to calculate how much ice from a offered climate period exists across the ice sheet, one thing recognized as an age volume. Scientists are interested in knowing a lot more about ice from the Eemian period, a time from 115,000 to 130,000 years ago that was about as warm as nowadays. This new age volume offers the initially data-driven estimate of where Eemian ice may remain.
Comparing this age volume to very simple computer system models helped the study’s group improved understand the ice sheet’s history. Differences in the mapped and modeled age volumes point to previous modifications in ice flow or processes such as melting at the ice sheet’s base. This information and facts will be valuable for evaluating the much more sophisticated ice sheet models that are critical for projecting Greenland’s future contribution to sea-level rise.
“Prior to this study, a superior ice-sheet model was one that got its present thickness and surface speed right. Now, they will also be able to function on acquiring its history ideal, which is vital mainly because ice sheets have quite extended memories,” mentioned MacGregor.
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