The glaciers in the heart of the ice sheet could contribute as much as 3.4 meters to global sea level rise over the next several centuries.
Many individual glaciers are fed by the East and WestAntarctic Ice sheets. Over the past few decades, the WA IS has been decreasing at an accelerated rate. The Thwaites and Pine Island glaciers are vulnerable to global warming and are already contributing to sea level rise.
The rate of local sea level change has been measured by a new study led by the University of Maine.
The glaciers have retreated at a rate not seen in the last five thousand years. The Thwaites and Pine Island glaciers are capable of causing large rises in global sea level.
The glaciers were relatively stable during the past few millennia, but their current rate of retreat is raising global sea level, according to the co-author.
It's too late to stop the bleeding.
The paper is in a journal.
Seashells are searched.
The climate during the mid-Holocene period was warmer than it is today and sea levels were higher. The researchers wanted to study the fluctuations in sea level since the mid-Holocene, so they studied the remnants of old Antarctic beaches.
They looked at the seashells and penguin bones on the beaches using a technique called radiocarbon dating, which uses the radioactive decay of carbon locked in the shells and bones as a clock to tell us how long they've been sitting above sea level.
Heavy glaciers push down or load the Earth's surface when they sit on the land. After the glaciers' ice melt or "unloads", the land "bounces back" so that what used to be a beach is now higher than sea level. The water from the melting ice caused global sea levels to rise.
By knowing the exact age of the beaches, they were able to reconstruct the changes in sea level over time.
The researchers think that the fall in sea level was caused by ice loss just prior to that time. The pattern is consistent with stable glacier behavior.
The relative sea-level fall since the mid-Holocene was five times smaller than it is today. Recent rapid ice mass loss is the most probable reason for the large difference.
Existing global models of the dynamics between ice and the Earth's crust were compared to the results. The models did not accurately represent the sea-level rise history of the area. The study helps to make sense of the history of the region.
The simplest interpretation of their data is that the glaciers have been relatively stable since the mid-Holocene.
Professor Hall says that "relative sea-level change allows you to see large scale loading and unloading by ice." If glacier readvance resulted in crustal loading, it would slow the rate of relative sea-level fall or even cause submergence of the land below sea level
It's stopping the bleeding.
To better forecast the future fate of the ice sheet and its impact on global sea level, the International Thwaites Glacier Collaboration is the largest joint UK-US program of field science ever conducted in Antarctica.
The ice contains important clues. To solve these mysteries, the researchers will be drilling through the glacier ice to collect rock underneath, which may contain evidence for the current rate of melting.
More information: Scott Braddock, Relative sea-level data preclude major late Holocene ice-mass change in Pine Island Bay, Nature Geoscience (2022). DOI: 10.1038/s41561-022-00961-y. www.nature.com/articles/s41561-022-00961-y Journal information: Nature Geoscience
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