Tuesday, January 27, 2015

[IPRNmail] UC Santa Cruz scientists drill through ice into a new Antarctic world


UC Santa Cruz scientists drill through ice into a new Antarctic world

WWW.nta-cruz-scientists-drill-through-ice-into-a-new-antarctic-world


SANTA CRUZ >> Early in January, a jet of hot water broke through the last meter of ice in Antarctica’s largest ice shelf, opening a passageway into an unknown world.

The jet was from a specially designed hot water drill, controlled by scientists half a mile above. Thus began a 10-day rush to gather as much data as possible before the hole in the ice froze shut, said Slawek Tulaczyk, a UC Santa Cruz professor and the project’s lead glaciologist.

This is the first time humans have accessed an ice shelf’s “grounding zone,†a region crucial to understanding the effects of climate change on Antarctic ice.

The Ross Ice Shelf is a slab of ice about the size of Texas that extends from Antarctica more than 500 miles over the open ocean. Where the ice separates from the Antarctic land mass, there is a wedge of water known as the “grounding zone†between the ice and the sea floor.

Scientists believe that warm ocean currents are melting ice shelves from underneath and pushing grounding zones inland, Tulaczyk said. But until now, no one has taken measurements from the point where water, earth, and ice all meet.

When the researchers sent down a robot with a camera Jan. 16, they were amazed to see fish, crustaceans and other complex animals. The sliver of water, just 10 meters deep, between the ice and the sea floor, receives few nutrients and no sunlight, Tulaczyk said.

Confident they would find only microscopic life in this harsh environment, the team did not even recruit anyone who studies larger life forms.

“It seems to be a place that has quite a vibrant ecosystem, and that is surprising,†Tulaczyk said.

The current expedition is part of the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project, a collaboration of investigators at several institutions. In previous years, WISSARD has drilled into parts of the ice sheet that rest directly on bedrock in order to study how ice flows toward the ocean, said Dan Sampson, an instrumentation engineer at UCSC who designs and builds instruments for the project.

This year, the team drilled two holes through nearly 2,500 feet of ice to reach liquid water.

The larger hole, about two feet in diameter, allowed the researchers to lower and retrieve bulky instruments and collect samples of sediment, Tulaczyk said. The smaller hole was for a string of instruments from UCSC that will remain in the ice after the hole closes, broadcasting measurements about factors such as tilt, pressure and temperature. A few of the instruments have failed, but that, said Sampson, is to be expected.

“We instrumented the heck out of that hole,†said Sampson. “It would have been awesome if everything worked perfectly, but any data we get is going to be incredible.â€

The data will help researchers understand how warm ocean water is eating away at Antarctic ice, and it may help them predict future rises in sea level, Tulaczyk said.

“We are shining a light on the very processes that will determine how sea levels will change in the future, in a place where it’s really really difficult to access and study,†Tulaczyk said. “We’ve managed to shine that light there for the first time.â€

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Shramik Maruti Patil
Research Scholar,
Antarctic Science Division,
National Centre For Antarctic and Ocean Research
Earth System Sciences Organisation (ESSO)
Ministry of Earth Science (MoES)
Headland Sada,
Vasco-Da-Gama,
Goa-403804
India

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