We live on the planet’s cold surface, but the Earth is a solid body and the surface is continually deformed, split, wrinkled and ruptured by the roiling of warmer layers beneath it.
Much of West Antarctica is a basin that lies below sea level, although it is currently filled with ice, not water. West Antarctica was stretched and thinned as it moved away from East Antarctica, forming one of the world’s largest continental rift systems.
The topography of West Antarctica below the ice sheet as viewed from above, looking toward the Antarctic Peninsula. (image: Bedrock Consortium)
The contrast between the surface and the depth is nowhere starker — or more important — than in Antarctica. What is causing the mysterious line of volcanoes that emerge from the ice sheet there, and what does it mean for the future of the ice?
“Our understanding of what’s going on is really hampered because we can’t see the geology,” said Andrew Lloyd, a graduate student in earth and planetary sciences in Arts & Sciences at Washington University in St. Louis. “We have to turn to geophysical methods, such as seismology, to learn more.”
Lloyd helped deploy research seismometers across the West Antarctic Rift System and Marie Byrd Land in the austral summer of 2009-10. He then returned in late 2011 and snowmobiled more than 1,000 miles, living in a Scott tent, to recover the precious data.
The recordings the instruments made of the reverberations of distant earthquakes from January 2010 to January 2012 were used to create maps of seismic velocities beneath the rift valley. An analysis of the maps was published online in the Journal of Geophysical Research: Solid Earth on Nov. 12, 2015
Read the story in the SOURCE: The geography of Antarctica’s underside.