Berkeley Lab geophysicist Susan Hubbard (Ph.D.’98 CEE) studies Arctic permafrost dynamics in Barrow, Alaska. (Photos courtesy the researchers)
Hubbard measures soil temperature and active layer depth with NGEE-Arctic lead investigator Stan Wullschleger from Oak Ridge National Laboratory. Researchers hit the ground with sledgehammers to produce and measure seismic waves, while a bear guard keeps watch. Hubbard also uses snowmobiles to pull geophysical sensors across the Arctic tundra. Berkeley Lab scientist Baptiste Dafflon collects electromagnetic data. Current is inserted into the ground by electrodes to provide information about the electrical resistivity of the subsurface. A camera suspended from a kite collects high-resolution aerial photographs of the landscape. Researchers use a variety of above- and below-ground data to study the complex relationships between land surface, active layer and permafrost. “It’s all white – the polar bears blend with the snow and the horizon,” says Hubbard.