The edge of iceberg B15A in the Ross Sea. Dr. Doug MacAyeal, University of Chicago Department of Geophysical Sciences, studies giant icebergs. He and his team have placed seven GPS and weather monitoring stations, and four seismometers on different icebergs to track them. He hopes to learn more about what causes icebergs to calve; how and why they drift; study what happens when the icebergs warm; and learn why they are producing previously unknown tremors that are picked up on seismometers as far away as Tahiti. For more information about these bergs, read the November 28, 2004, issue of the ANTARCTIC SUN at: http://www.polar.org/antsun/index.htm