Some marine fossils tiny distributed very widely on rock surfaces in the Transantarctic Mountains point to the possibility of a substantial rise in sea levels if global warming continues without being hold back, according to the conclusions reached in a new study.
This, led by geologist Reed Scherer, of Northern Illinois University in the United States, indicates that the massive ice sheet of East Antarctica has a history of instability that has appeared during former warm periods and that this layer could be prone to experience a notable drop and rockfall as a result of the action of global warming. The ice of East Antarctica is the largest icecap in the world and which has a major importance in the scenario of a potential rise in sea levels.
Evidence from new research comes from microscopic fossils of ocean creatures called diatoms.
For decades, the scientific community has lived a heated debate about how diatoms eventually incorporated into the “Sirio Group”, a series of glacial sedimentary rocks that have been exposed to air along the Transantarctic Mountains.
A section of the scientific community has been claiming that diatoms accumulated in a marine basin after the retreat of the ice and then, after a noticeable drop in temperatures that reactivated the proliferation of ice, were taken to the mountains growing glaciers. This interpretation suggests a dramatic retreat of the ice made between 3 and 4.5 million years ago, during the Pliocene warm periods.
But another part of the scientific community has been arguing that the ice has been stable for at least the last 5 million years, and that diatoms were carried by wind and deposited on older sediments.
The new study suggests that both sectors are partially right and partially wrong.
Using sophisticated climate and ice sheet models, Scherer and his colleagues have found that the latter experienced a series of setbacks and successive advances during warm periods Pliocene, but the decreases were not as large as some scientists had previously suggested.
These setbacks were enough other notables to expose bays in the subglacial basins Aurora and Wilkes, establishing an environment conducive to the production of copious amounts of diatoms conditions.
However, the decline reduced the weight of the ice, allowing previously submerged and filled with diatomaceous earth rise above sea level over the following millennia.
Cyclonic winds then placed in the air diatomaceous tufts, the wind finally laid along the Transantarctic Mountains.
The Antarctic ice cap contains most of the world’s freshwater. A substantial thaw, also associated with a notable drop of the ice sheet in the future, result in a significant rise in sea level, with devastating consequences for many coastal regions around the world.
Very warm during certain stages of the Pliocene, the sea level could have been up to 23 meters (75 feet) higher than today.
The increase in atmospheric carbon dioxide from burning fossil fuels has now reached a concentration of 400 parts per million, as high as that of the warmest stages of the Pliocene.
