Accounting for ice-earth feedbacks at finer scale suggests slower glacier retreat

April 25, 2019

Accounting for the way the Antarctic ice sheet interacts with the solid earth below - an important but previously poorly captured phenomena - reveals that ice sheet collapse events may be delayed for several decades, at this major ice structure. Specifically, this interaction at the so-called "grounding line" may slow the otherwise fast-moving retreat of the Thwaites Glacier, the largest glacier in this region. "For those concerned about potentially catastrophic sea level rise, the results ... can be taken as welcome news," says Eric J. Steig, in a related Perspective. "But it is important to recognize that [the authors] do not make a specific prediction about the magnitude of the West Antarctic contribution to sea level." The question of how quickly the Antarctic ice sheet will lose mass over the next few centuries - contributing to global sea level rise as it does - continues to motivate glaciological research in Antarctica. Recent work on the West Antarctica Ice Sheet (WAIS) has shown that an unexpectedly rapid rebound of areas of this sheet may help stabilize the WAIS against catastrophic collapse. This is based on the way in which, as glaciers retreat, the Earth's crust springs up, creating changes in the sea bed geometry in relation to the point where the glacier goes afloat to become an ice shelf (the grounding line). This process can prevent the steady retreat of the glacier, allowing it to ground. To date, numerical model simulations of this process have been used to assess it at relatively large spatial scales. Here, Eric Larour and colleagues focus on the feedbacks between glacier retreat and solid earth processes at finer resolution, using the Thwaites and Pine Island Glacier grounding lines as case studies. In a sensitivity experiment using model simulations, they find that by the year 2350, the grounding line retreat from the Thwaites Glacier is reduced by about 40%, compared to a scenario where fine-scale feedbacks aren't included. Too, the Thwaites Glacier's contribution to sea level rise is reduced by more than 25%. "...their results should be seen as a guide to the magnitude (and sign) of uncertainty in existing predictions, and as a roadmap for future research," says Steig.
-end-


American Association for the Advancement of Science

Related Sea Level Articles from Brightsurf:

Sea-level rise will have complex consequences
Rising sea levels will affect coasts and human societies in complex and unpredictable ways, according to a new study that examined 12,000 years in which a large island became a cluster of smaller ones.

From sea to shining sea: new survey reveals state-level opinions on climate change
A new report analyzing state-level opinions on climate change finds the majority of Americans believe in and want action on climate change--but factors like state politics and local climate play important roles.

UM researcher proposes sea-level rise global observing system
University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science researcher Shane Elipot proposes a new approach to monitoring global sea-level rise.

How much will polar ice sheets add to sea level rise?
Over 99% of terrestrial ice is bound up in the ice sheets covering Antarctic and Greenland.

Larger variability in sea level expected as Earth warms
A team of researchers from the University of Hawai'i (UH) at Mānoa School of Ocean and Earth Science and Technology (SOEST) identified a global tendency for future sea levels to become more variable as oceans warm this century due to increasing greenhouse gas emissions.

Sea-level rise could make rivers more likely to jump course
A new study shows that sea level rise will cause rivers to change course more frequently.

UCF study: Sea level rise impacts to Canaveral sea turtle nests will be substantial
The study examined loggerhead and green sea turtle nests to predict beach habitat loss at four national seashores by the year 2100.

Wetlands will keep up with sea level rise to offset climate change
Sediment accrual rates in coastal wetlands will outpace sea level rise, enabling wetlands to increase their capacity to sequester carbon, a study from the Marine Biological Laboratory, Woods Hole, shows.

How sea level rise affects birds in coastal forests
Saltwater intrusion changes coastal vegetation that provides bird habitat. Researchers found that the transition from forests to marshes along the North Carolina coast due to climate change could benefit some bird species of concern for conservation.

As sea level rises, wetlands crank up their carbon storage
Some wetlands perform better under pressure. A new Nature study revealed that when faced with sea-level rise, coastal wetlands respond by burying even more carbon in their soils.

Read More: Sea Level News and Sea Level 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.