Researchers think they might have explained one of Antarctica's longest-ever-standing mysteries, but the study does not promise too well for the future of the ice-sheltered continent. At the center of the mystery is a collection of fossilized remains left behind by small, single-celled algae named diatoms. How these microscopic oceanic organisms got where they are now, the patronizing peaks of the Transantarctic Mountains has been the cause of debate for more than 30 years. Now, thanks a lot to a new computer model, scientists from across the United State have found signs to suggest that the diatoms found their high-altitude home because of a significant glacial retreat. And if it is occurred before, it could happen again.
A geologist from the Northern Illinois University, lead scientist Reed Scherer says, "Studies like this indicate that pretty intense changes in sea level can happen on human time periods. Earlier, there have been two leading theories for how the diatoms rose more than a mile above sea level in the Antarctic Ocean. The 'dynamicist' hypothesis proposes that they journeyed as glaciers collapsed during an early shift from a hotter to a cooler weather. For the moment, the 'stabilist' argument is that tough winds took the diatoms up to their current position.
Why does it matter? Well, the two theories take different views about whether the East Antarctic sheet crumbled or held strong during the Pliocene era, which lasted between 5.3 million and 2.6 million years ago when Earth was about 2 or 3 degrees Celsius warmer than it is now. If the stabilists are correct, then Antarctica's giant ice tables might be able to live a sharp temperature rise. But if the dynamicists are correct, this is much less possible, based on the Earth's behavior in the past. The new computer model, in fact, recommends that both sides are somewhat correct, discovering that both shifting glaciers and strong winds donated to the diatoms' movement. But to the level that ever-changing glaciers were responsible, it is all bad news, because if the East Antarctic area is as shifting as this model proposes, an important sea level rise could be possible in the future.
Scherer says, "What makes this type of discovery more important and related is the idea that as ice retreats, sea level rises. And so much of the globe's population lives close to the coastline."
The new modeling explains the climate conditions of the Pliocene time and what the scientists call "isostatic rebound", where surface mass rises as heavier surface ice vanishes. And it's that isostatic rebound that is important here, with retreating ice bringing dead diatoms to the land, from where they can then be carried further away by the wind.
A climate scientist from Pennsylvania State University, another member of the team, Richard Alley says, "This is another part of a jigsaw puzzle that the environment is rapidly placing together, and which seems to show that the ice layers are more delicate to warming than we had expected."
According to Scherer, we can moderate the level of this happening in the future by reducing carbon dioxide emissions, which can slow sea level rises controllable levels, even if it is now impossible to stop them totally.
The alternative, he says, is impossible. "Do we actually want to wait until no one can reject it anymore?"