There has been a decades-long dispute amongst researchers who study the history of the Antarctic Ice Sheet, and it revolves around the discrepancy between marine information from the Ross Sea and data gathered in the McMurdo Dry Valleys, an ice-free mountainous coastal area nearby to the Ross Sea. In one corner stands marine records from the seafloor that have shown that the Antarctic Ice Sheet has actually consistently shrunk to a smaller-than-modern size across the last 10 million years, and that the ice-covered Ross Sea was regularly open ocean. This suggests that the Antarctic Ice Sheet is sensitive to reasonably little CO2 and temperature fluctuations and declined during past warm periods.
Halberstadt examining marine sediment cores. Credit: UMass Amherst
In the other corner stands terrestrial research studies of ancient and well-preserved landforms in the McMurdo Dry Valleys that reveal that cold-desert conditions on land were maintained across the very same ten-million-year period, which has actually led some researchers to conclude that a steady Antarctic Ice Sheet has continued across several previous warm durations, and therefore might be less prone to climate warming than the marine data suggests.
Is the West Antarctic Ice Sheet delicate to a warming environment or not? Handling this argument is of planetary significance, given that the very same parts of the Antarctic Ice Sheet that collapsed in the past might raise future water level by 10 feet or more if they were to collapse in our own time.
Using a series of high-resolution environment and ice-sheet designs, Anna Ruth Halberstadt, who completed this research as part of her Ph.D. in geosciences at UMass Amherst, and her colleagues were able to reveal that it is completely possible for below-freezing temperature levels to exist in the McMurdo Dry Valleys even when the neighboring Ross Sea is totally ice totally free. “We can now state, ok, now we understand why these 2 sets of data appeared to be at chances,” states Halberstadt, the papers lead author.
Halberstadt and her team conducted a series of experiments using cutting edge environment and sea-ice models to reveal that the McMurdo Dry Valleys might definitely have actually stayed frozen, even throughout times when the ice sheet collapsed. Halberstadt states that “this work finally brings all of the geologic details nicely into line, and suggests that large parts of the Antarctic Ice Sheet might have collapsed under climatic situations similar to today.”
Reference: “Reconciling relentless sub-zero temperatures in the McMurdo Dry Valleys, Antarctica, with Neogene dynamic marine ice-sheet changes” by Anna Ruth W. Halberstadt, Douglas E. Kowalewski and Robert M. DeConto, 11 February 2022, Geology.DOI: 10.1130/ G49664.1.
Anna Ruth Halberstadt conducting field research study in Antarcticas McMurdo Dry Valleys. Credit: Anna Ruth Halberstadt
Inconsistency between marine and terrestrial information resolved; shows that ice sheets susceptible to small CO2 changes.
New research study led by the University of Massachusetts Amherst definitively resolves a long-standing disparity in the geologic record that pitted research studies of marine ice-sheet behavior versus those that rebuilded previous conditions on land. The research, released just recently in the journal Geology, and funded by the National Science Foundation and the National Environment Research Council, lends extra weight to evidence that the Antarctic Ice Sheet is delicate to small changes in CO2 levels and that, in the past, big parts of the ice sheet might have vanished under CO2 levels comparable to today.
There has actually been a decades-long dispute amongst researchers who study the history of the Antarctic Ice Sheet, and it revolves around the inconsistency in between marine information from the Ross Sea and data gathered in the McMurdo Dry Valleys, an ice-free mountainous seaside area nearby to the Ross Sea. In one corner stands marine records from the seafloor that have actually shown that the Antarctic Ice Sheet has consistently diminished to a smaller-than-modern size throughout the last 10 million years, which the ice-covered Ross Sea was occasionally open ocean. This suggests that the Antarctic Ice Sheet is delicate to reasonably little CO2 and temperature level changes and receded throughout previous warm durations.