Are we missing a crucial component of sea-level rise?

Computational modeling has been used to understand how melting ice inAntarctica will impact the planet's oceans. Basal thaw, a process in which the bed of the ice sheet thaws at the interface of the land and the miles-thick ice sheet above it, could have a similar effect.

Thwaites Glacier is one of the areas that could be poised to match some of the biggest contributors to sea-level rise if they thaw. The susceptible regions comprise an area greater than California and are located in the southern part of the world. The research was published in a journal.

"You can't assume that all of the frozen areas will stay frozen," said the senior study author. These regions may not be appreciated enough.

There are unusual suspects.

Recent theoretical work shows that a thaw can occur over a short timescale. The study co- authors used ice sheet models to test the hypotheses that the thaw could lead to ice loss. They found that thaw caused mass loss in regions of the ice sheet that are not usually associated with instability.

There isn't a lot of work looking at the start of thaw, where a little water at the bed can cause the ice to slide. We wanted to learn how big an effect thaw could have and what areas of the ice sheet were most vulnerable to it.

The researchers were able to model the temperature changes at the base of the ice sheet. The simulations show that the George V Land area would be most sensitive to thaw at their beds. The Wilkes Basin is comparable in size to the rapidly evolving and likely unstable Thwaites Glacier in West Antarctica and could become a leading sea-level contributor if thaw were to occur.

The whole community is focused on Thwaites right now. Some of the regions that are the usual suspects for big, impactful changes aren't the most provocative and impactful areas.

The temperature is important.

Information about the ice sheet is hard to come by. It's not known much about the land beneath the faade.

"Measuring the bed is a massive effort in these remote places, but you really need to pick the spot, and sometimes it takes years, and field camps, and special equipment to go do that." It is difficult and costly.

The physicists used the physics of how ice slides to fill in information gaps. The authors plan to use radar-based analysis approaches to study the temperature of the ice sheet bed.

"You need to know the regions where it's important, and that's the important part of the paper," he said. Does this matter to this person? Where would it matter? We hope this approach will give the community some priorities into where to look and why.

Do you mean sleeping giants?

Scientists don't know how long it will take to thaw the bed in the areas identified in the study. There is a chance that one person could be changing ocean conditions.

"Warm ocean water doesn't necessarily reach these East Antarctica regions as it does in parts of West Antarctica, but it's nearby, so there's potential that could change." It makes near-term thaw of the ice-sheet bed seem like a far easier switch to flip than we had thought.

The biggest uncertainty in sea-level rise projections is the contribution from processes that can shift the behavior of massive ice sheets, and measuring, understanding, and modeling the temperature at the base of ice sheets is important for understanding our future.

It will be necessary to take a closer look at the areas identified in the paper. Mass loss from the ice sheet is a process that the community needs to understand and start looking at, especially in vulnerable areas.

More information: Ice mass loss sensitivity to the Antarctic ice sheet basal thermal state, Nature Communications (2022). DOI: 10.1038/s41467-022-32632-2 Journal information: Nature Communications Citation: Are we missing a crucial component of sea-level rise? (2022, September 14) retrieved 14 September 2022 from https://phys.org/news/2022-09-crucial-component-sea-level.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.