World's Largest Ice Sheet, Its Response to Climate Change Analyzed Using Unique Rock Samples

By examining unique rock samples collected years back in Antarctica, researchers at the University of California, Santa Cruz, have discovered a remarkable record of the manner East Antarctic Ice Sheet is responding to climate change over a period of 100,000 years during the Late Pleistocene.

As specified in a Phys.org report, the East Antarctic Ice sheet is the largest ice mass in the world. Understanding how sensitive it is to climate change is critical for initiatives to project how much the sea level will rise as global temperatures rise. Recent studies have suggested may be more susceptible to ice loss compared previously thought.

The recently published study offers evidence of changes at the ice sheet's base over a large area in response to cyclic changes in climate during the Pleistocene.

Changes in Mineral Types Deposited at the Ice Sheet's Base

Such changes are reflected in the mineral types deposited at the base of the ice sheet. According to Terrence Blackburn, co-author of the study and associate professor of Earth and planetary sciences at UC Santa Cruz, one of the key results of this research is that the ice sheet was responding to temperature changes in the Southern Ocean.

Essentially, the warm water is consuming the edges of the ice sheet and is causing the ice to flow more rapidly, and that specific response is reaching deep into the heart of the ice sheet.

As specified in the study published in Nature Communications, the rock samples analyzed in the research comprise substituting layers of calcite and opal that formed as a mineral deposit at the ice sheet's base, recording cycling changes in the subglacial fluids' composition.

Driven by Changes in the Motion of the Streams

Gavin Piccione, the study's first author and a PhD candidate working with Blackburn at the UCSC explained that each layer in the samples gathered is a manifestation of change at the ice sheet's base driven by changes in the motion of the streams.

Moreover, by dating the layers, the study investigators discovered a striking correlation between the mineral deposit layers and the polar sea surface temperatures record from ice cores. The opal was deposited during cold periods, as well as the calcite during warm periods.

Professor of Earth and planetary sciences Slawek Tulaczyk from UCSC who has been investigating the ice sheets and glaciers' behavior for decades said, such climate oscillations are causing changes in ice sheet behavior such that the chemistry and hydrology76 underneath the ice sheet are changing.

Climate Cycles

The climate cycles matching the mineral layers are somewhat small fluctuations taking place every few thousand years within the more pronounced glacial-interglacial cycles that took place 100,000 years back or so throughout the Pleistocene.

The NUSC report specified that the glacial-interglacial cycles are driven mainly by changes in the orbit of Earth surrounding the sun.

The smaller millennial-scale climate cycles engage oscillation in polar temperatures driven by the weakening and strengthening of a major ocean current transporting massive amounts of heat northward through the Atlantic Ocean.

Tulaczyk explained that the new findings reveal the sensitivity of the Antarctic Ice Sheet to small, short-term climate fluctuations.

He elaborated that as essential as the Antarctic Ice Sheet is, it is accountable for close to 17 meters of sea level rise since the most recent glacial maximum, and a minimal amount is known about how it has responded to climate change.

Related information about the East Antarctic Ice sheet is shown on Al Jazeera English's YouTube video below:

Check out more news and information on Antarctica in Science Times.