Glacier Detachments: A New Hazard in a Warming World?

Related Articles

Related Articles

A startling event occurred deep in the remote interior of the United States’ largest national park.

A half-kilometer-long tongue of Alaska’s Flat Creek glacier suddenly broke off, unleashing a torrent of ice and rock that rushed 11 kilometers down a rugged mountain valley into the wilderness encompassed by Wrangell–St. Elias National Park and Preserve (https://www.nps.gov/wrst/index.htm).

After National Park Service geologist Michael Loso documented a similar event in the same location in 2015, he recruited Mylène Jacquemart, a Ph.D. student at the University of Colorado Boulder, to investigate. “We were aware of glacier detachments that had happened in Tibet, Russia, and Argentina, but started out thinking we were investigating a regular landslide,” says Jacquemart. “Then we noticed that the entire glacier was missing.”

The results, published in Geology, indicate the Alaskan detachments occurred at the height of the summer melt seasons and suggest these highly destructive events could occur more frequently in a warming world.

After National Park Service geologist Michael Loso conducted preliminary research that ruled out a seismic trigger for these events, he, Jacquemart, and other experts began a research project to investigate what had happened at Flat Creek. The team used a variety of tools, including satellite imagery, field measurements, digital elevation models, and meltwater modeling, to piece together the sequence of events. “This project was a real sleuthing challenge,” says Jacquemart, “and the pieces finally fell into place when we discovered the bulge on the Flat Creek glacier.”

Although the researchers were aware that an odd ice bulge existed on the glacier’s tongue prior to the first detachment in 2013, it wasn’t until they obtained 10-year-old, high-resolution satellite images and estimated that the bulge was an impressive 70 meters high that they began to understand its implications. “Our data indicate that the lowermost part of the glacier tongue was very thin, stagnant, and firmly frozen to the glacier bed,” Jacquemart says. “We believe this frozen tongue did two things: it blocked ice flowing down from higher on the glacier, forcing it to bulge; and it slowed meltwater drainage, allowing the water to pool under the glacier.” The resulting increase in subglacial water pressure, she says, eventually caused the glacier tongue to suddenly detach, resulting in two mass flows so large that they each buried about 3 square kilometers of 400-year-old forest.


Subscribe to more articles like this by following our Google Discovery feed - Click the follow button on your desktop or the star button on mobile. Subscribe

Glaciers are primarily disappearing as a result of their ice melting at a faster pace, says Jacquemart. “But the new insights we’re gaining from places like Flat Creek show that we also need to consider new processes we weren’t previously aware of.” Ultimately, says Jacquemart, scientists will need to develop a better understanding of these new processes and potentially reevaluate hazard assessments in mountain communities.

“Flat Creek is fortunately in a very remote place,” says Jacquemart, “but the detachments that occurred in Russia and Tibet claimed numerous lives.” Given that the mass flows produced by glacier detachments appear to travel quite far, she says, emergency planners also need to consider possible cascading hazards, such as the temporary damming of a river followed by the water’s release. “Suddenly, a remote event can have far-reaching impacts downstream,” says Jacquemart.

The similarity of the glacier detachments in Alaska with those that occurred in Tibet suggest that all of these events shared a common cause. Other detachments elsewhere in the world have also been recently discovered, says Jacquemart, suggesting that large-scale glacier detachments may be exacerbated by global warming. “We conclude that the meltwater produced by increasingly warmer summers has the potential to create unexpected consequences in the form of hazards that we didn’t previously know about”, says Jacquemart, “and that we are only just beginning to understand.”

Geological Society of America, The (GSA)

Header Image – View into the detachment zone: Flat Creek glacier used to occupy the central trough visible in the image. Within just a few years, the surrounding ice flowed into space previously filled by the glacier, masking the full extent of the damage left by the detachments. Wrangell–St. Elias National Park and Preserve. Image Credit : Mylène Jacquemart.

- Advertisement -

Download the HeritageDaily mobile application on iOS and Android

More on this topic

LATEST NEWS

Pella – Birthplace of Alexander The Great

Pella is an archaeological site and the historical capital of the ancient kingdom of Macedon.

New Argentine fossils uncover history of celebrated conifer group

Newly unearthed, surprisingly well-preserved conifer fossils from Patagonia, Argentina, show that an endangered and celebrated group of tropical West Pacific trees has roots in the ancient supercontinent that once comprised Australia, Antarctica and South America, according to an international team of researchers.

High-tech CT reveals ancient evolutionary adaptation of extinct crocodylomorphs

The tree of life is rich in examples of species that changed from living in water to a land-based existence.

Fish fossils become buried treasure

Rare metals crucial to green industries turn out to have a surprising origin. Ancient global climate change and certain kinds of undersea geology drove fish populations to specific locations.

Archaeologists Discover Viking Toilet in Denmark

Archaeologists excavating a settlement on the Stevns Peninsula in Denmark suggests they have discovered a toilet from the Viking Age.

Innovation by ancient farmers adds to biodiversity of the Amazon, study shows

Innovation by ancient farmers to improve soil fertility continues to have an impact on the biodiversity of the Amazon, a major new study shows.

Lost Shiva Temple Buried in Sand Discovered by Local Villagers

Villagers from the Perumallapadu village in the Pradesh’s Nellore district of India have unearthed the 300-year-old Temple of Nageswara Swamy on the banks of the Penna River.

Ma’rib – Capital of the Kingdom of Saba

Ma'rib is an archaeological site and former capital of the ancient kingdom of Saba in modern-day Ma'rib in Yemen

Giant Egg Discovered in Antarctica Belonged to Marine Reptile

A large fossil discovered in Antarctica by Chilean researchers in 2011 has been found to be a giant, soft-shell egg from 66 million years ago.

Archaeologists Find Evidence of Incest Among Irelands Early Elite at Newgrange Passage Tomb

Archaeologists working with Geneticists from the Trinity College Dublin have determined that a burial in the Newgrange passage tomb shows indications of first-degree incest.

Popular stories