West Antarctic Ice Sheet Divide -- Earth's Climate History Hidden in Ice

Crazy 'bout ice cores

Last week, meteorologist Dan Satterfield and I presented about Antarctic science and our trip at the American Meteorological Society's (AMS) 38th Conference on Broadcast Meteorology in Miami. The slide show, videos, photos and content are all freely available online for use in education/outreach efforts or for your learning purposes (credit www.earthgauge.net).

Among other things we and another speaker, Joseph Souney, covered is the West Antarctic Ice Sheet (WAIS, pronounced 'wayss') Divide ice core drilling project. Joe works in the project's Science Coordination Office based out of the University of New Hampshire.

A back-lit snow pit showing annual layers of snowfall accumulation on the West Antarctic Ice Sheet over the past few years. The darker thick layers are winter snowfall, the lighter thick layers are summer snowfall. Photo by Julie Palais, courtesy of National Science Foundation.

Although Dan and I did not have a chance to visit the field site in January, we are both dedicated to spreading the word about this major study. I encourage you to learn more through the project's website and videos. In addition, I created a fact sheet fact sheet for distribution through Earth Gauge and at AMS. Here's the gist:

What is an ice core?
An ice core is a cylindrical sample of deep ice taken from Antarctica, Greenland or other locations in high mountain glaciers. Glaciologists retrieve cores in order to analyze gases from ancient air bubbles trapped within the ice, as well as [the ice itself], in order to understand Earth’s past climate ...

Analyzing the core
Scientists analyze gases from the air bubbles, such as carbon dioxide, methane and other greenhouse gases. In addition, they measure sea salt and trace elements such as lead trapped in the ice (in Greenland ice cores, lead has been a useful indication of human impact, since it is expelled by the burning of fossil fuels). They also measure hydrogen isotopes from melted ice to determine the atmospheric temperature at the time of snowfall, and oxygen isotopes to reveal humidity. This information is then entered into climate models to show the relationship between temperature and gases over thousands of years ...


The significance of the WAIS core
The WAIS Divide ice core has the highest time resolution of any core ever extracted on Earth. The study will provide the most detailed record of greenhouse gases -- including carbon dioxide -- ever measured for the past 100,000 years of Earth’s climate history. Scientists will be able to determine annual data for the past 40,000 years by analyzing the electrical properties and chemistry of the ice cores, which vary seasonally. They also date the cores by identifying volcanic ash layers from known eruptions (the photo above shows an ash layer in the left segment of a core; copyright Chaz Firestone) ...

Download the full document.

Other WAIS Divide materials from fellow Antarctic journalists:

• Unearthing Cold, Hard Facts by Robert Lee Hotz, published on May 29, 2010 in the Wall Street Journal (also check out the video)
• Icy Hunt for Old Air by Chaz Firestone, published on January 27, 2010 in the journal Nature (see accompanying photo gallery)

Dan is headed to the Arctic in a few weeks to cover another major ice core study, the North Greenland Eemian Ice Drilling (NEEM) project, which will provide reliable climate data for the past 120,000 years -- basically a Northern Hemisphere version of the WAIS core. After analyzing data from the WAIS Divide and NEEM cores, scientists will have a much better understanding of Earth's past -- and future -- climate.