Teton range glacial ice may have persisted in a dormant state during early Holocene warming

November 18, 2020

A continuous 10,000-year record of alpine glacier fluctuations in Wyoming's Teton Range suggests that some glacial ice in the western U.S. persisted in a reduced, essentially dormant state during periods of early Holocene warming. The findings challenge the paradigm that all Rocky Mountain glaciers completely disappeared during these warm, dry conditions, instead indicating that they may have taken the form of smaller glaciers covered by debris or caked with rocks, which insulated the lingering ice from the heat. This insight may help scientists better understand how glaciers in the region may respond to future warming. "The long-term survival of glacial ice through warm conditions highlights the potential role of debris-covered glaciers and/or rock glaciers to continue providing ecosystem services into the future, despite unfavorable climatic conditions," says Darren Larsen, the lead author of the study. Retreating glaciers are a hallmark of modern climate change, but due to an incomplete glacial record, little is known about how western U.S. glaciers responded to temperature and precipitation changes thousands of years ago. To construct a continuous record, Larsen and colleagues sampled sediment cores from two lake basins in the Tetons - Delta Lake, a glacial lake basin that provided a complementary record of glacier activity, and other nearby lakes including Surprise Lake, a nonglacial lake basin that provided a record of climate variability. By using accelerator mass spectrometry radiocarbon dating, the researchers developed composite rock layer sequences that documented changes in the glaciers as they endured shifts in climate over ten millennia. While sediment flux and meltwater from the Teton Glacier appeared to decrease during a warm period between about 10,000 and 6,300 years ago, Delta Lake sediments maintained distinctly glacial characteristics that suggest glacial ice remained.

American Association for the Advancement of Science

Related Glaciers Articles from Brightsurf:

Rock debris protects glaciers from climate change more than previously known
A new study which provides a global estimate of rock cover on the Earth's glaciers has revealed that the expanse of rock debris on glaciers, a factor that has been ignored in models of glacier melt and sea level rise, could be significant.

New 'law' to explain how glaciers flow over soft ground
Addressing a major source of uncertainty in glacier-flow models, researchers present a new slip law to describe glaciers sliding on soft, deformable material.

Melting glaciers will challenge some salmon populations and benefit others
A new Simon Fraser University-led study looking at the effects that glacier retreat will have on western North American Pacific salmon predicts that while some salmon populations may struggle, others may benefit.

How the ocean is gnawing away at glaciers
The Greenland Ice Sheet is melting faster today than it did only a few years ago.

Last remaining glaciers in the Pacific will soon melt away
The last remaining tropical glaciers between the Himalayas and the Andes will disappear in the next decade -- and possibly sooner -- due to climate change, a new study has found.

Drones help map Iceland's disappearing glaciers
Dr. Kieran Baxter from the University of Dundee has created composite images that compare views from 1980s aerial surveys to modern-day photos captured with the help of state-of-the-art technology.

Disappearing Peruvian glaciers
It is common knowledge that glaciers are melting in most areas across the globe.

New insight into glaciers regulating global silicon cycling
A new review of silicon cycling in glacial environments, led by scientists from the University of Bristol, highlights the potential importance of glaciers in exporting silicon to downstream ecosystems.

Tidewater glaciers: Melting underwater far faster than previously estimated?
A tidewater glacier in Alaska is melting underwater at rates upwards of two orders of magnitude greater than what is currently estimated, sonar surveys reveal.

Asia's glaciers provide buffer against drought
A new study to assess the contribution that Asia's high mountain glaciers make to relieving water stress in the region is published this week (May 29, 2019) in the journal Nature.

Read More: Glaciers News and Glaciers Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.