Researchers have discovered that Greenlands ice sheet melted significantly as recently as 416,000 years ago, indicating its high level of sensitivity to environment modification. This melting resulted in a significant international sea-level rise, which combined with todays high CO2 levels, presents a severe danger to our future. Credit: Joshua Brown/UVM
Scientists report much of the Artic islands ice melted as recently as 416,000 years back, which has ramifications for sea-level rise.
Newly evaluated samples from below Greenlands huge ice sheet reveal the Arctic island was substantially greener as recently as 416,000 years back. This discovery challenges prior beliefs that Greenlands huge glacier, inhabiting approximately 80 percent of the 836,300-square-mile land mass, has been consistent for the last 2 and a half million years.
Ice Sheet Sensitivity to Climate Change
” Were finding the ice sheet is much more sensitive to environment change than we previously thought,” says Utah State University geoscientist Tammy Rittenour. “This is a foreboding wake-up call.”
Rittenour, with colleagues from the University of Vermont and fourteen other institutions, reports findings in the July 20, 2023, issue of the journal Science. Their research study is supported by the National Science Foundation.
In the Utah State University Luminescence Lab, graduate trainee Hawke Woznick utilizes screens to prepare sediment samples from Greenlands Camp Century for OSL dating. USU Geosciences Professor Tammy Rittenour and associates reported findings about the samples in the July 20, 2023, problem of the journal Science. Credit: USU/Levi Sim
Unstable Future of Greenlands Ice Sheet
A greener Greenland implies the islands formidable-appearing ice sheet– almost 2 miles thick in places– is not as steady as presumed.
” We had constantly assumed the ice sheet has actually remained about the very same for nearly 2.5 million years,” states Rittenour, professor in USUs Department of Geosciences. “But our examination shows it melted enough to allow the development of moss, shrubs, and buzzing pests during an interglacial duration called Marine Isotope Stage 11, between 424,000 to 374,000 years ago.”
The melting triggered at least 5 feet of sea-level increase around the world, she states. “Some of our design circumstances recommend sea levels approximately 20 feet greater than today.”
Utah State University Geosciences Professor Tammy Rittenour, imagined in July 2023 at Icelands Langjökull ice cap, studies the paleoclimatology of extreme environments throughout the globe. Credit: USU/Tammy Rittenour
The Alarm of Rising CO2 Levels
” It was an unusually long duration of warming with reasonably raised levels of carbon dioxide– CO2– in the atmosphere,” Rittenour states. “Whats worrying about this finding is todays CO2 levels are 1.5 times greater.”
Even if humans quickly stopped activities that add to greenhouse gas emissions, she says, “we d still have pumped up CO2 levels for hundreds, perhaps even thousands, of years to come.”
Thats an anxious realization, she says, with existing rates at which Greenlands ice sheet is thawing.
” And thats not taking Antarctica and other glacial areas into consideration,” Rittenour states. “The deglaciation has implications for the whole globe and is particularly sobering for our coastal mega-cities, where a lot of the worlds population resides.”
From Cold War Relics to Climate Science
The groups analysis is an extension of research study began a number of years ago, when the researchers happened upon samples collected from a remarkable, Cold War-era military job.
” In 1960, the U.S. Army launched a top-secret effort called Project Iceworm in northwestern Greenland to develop a network of mobile nuclear launch sites under the ice sheet,” Rittenour states. “As part of that project, they likewise invited researchers and engineers to carry out experiments in an extremely publicized cover project, referred to as Camp Century, to study the feasibility of working and bring out military missions under ice and in extreme-cold conditions.”
Opening The Past From Forgotten Samples
Hindered by brutal blizzards and unsteady ice conditions, Project Iceworms spacious underground bunker and tunnels were deserted in 1966. However sediment samples gathered at the bottom of a more than 4,000-foot-long ice core extracted from the website have actually yielded the surprising information about Greenlands not-so-distant geologic past.
The frozen soil samples from the base of the Camp Century ice core were forgotten in a freezer for years, until recently re-discovered.
” We have very few samples from listed below the Greenland ice sheet, since the majority of drilling objectives stop when they reach the base of the ice,” Rittenour says. “These re-discovered Camp Century sediments represent a distinct, pristine time pill of past conditions.”
Advancements in Science Technology
While the frozen soil beinged in a freezer for more than 60 years, science technology advanced. Rittenour, who is director of the USU Luminescence Laboratory, was welcomed to assist date the sediment.
” Because the samples remained mostly unblemished and frozen, I was able to use luminescence dating to determine the last time they were exposed to sunlight,” she says. “If scientists had taken a look at the sediments in the past, we could not have run any of the analyses we provided for this paper.”
Rittenour states todays investigative technologies allow researchers to boil down a great record of whats taken place in Greenland and other parts of the world.
” These once-lost, Cold War relics from a top-secret nuclear military base carved within the ice are continuing to inform their secrets, and forewarn us of the sensitivity of Earths climate,” she states. “If we can lose the far northwest portion of the Greenland ice sheet under natural conditions, then were treading harmful waters given present elevated greenhouse gas conditions.”
For more on this research:
Reference: “Deglaciation of northwestern Greenland throughout Marine Isotope Stage 11” by Andrew J. Christ, Tammy M. Rittenour, Paul R. Bierman, Benjamin A. Keisling, Paul C. Knutz, Tonny B. Thomsen, Nynke Keulen, Julie C. Fosdick, Sidney R. Hemming, Jean-Louis Tison, Pierre-Henri Blard, Jørgen P. Steffensen, Marc W. Caffee, Lee B. Corbett, Dorthe Dahl-Jensen, David P. Dethier, Alan J. Hidy, Nicolas Perdrial, Dorothy M. Peteet, Eric J. Steig and Elizabeth K. Thomas, 20 July 2023, Science.DOI: 10.1126/ science.ade4248.
Scientists have actually discovered that Greenlands ice sheet melted substantially as recently as 416,000 years ago, suggesting its high sensitivity to climate change. This melting resulted in a substantial worldwide sea-level rise, which combined with todays high CO2 levels, poses a serious danger to our future. Credit: Joshua Brown/UVM
In the Utah State University Luminescence Lab, graduate trainee Hawke Woznick utilizes screens to prepare sediment samples from Greenlands Camp Century for OSL dating. USU Geosciences Professor Tammy Rittenour and coworkers reported findings about the samples in the July 20, 2023, issue of the journal Science.
