Topic: "Recording the Aurora at Seismometers Across Alaska"
Speaker: Carl Tape, Seismologist, University of Alaska, Fairbanks
Across Alaska there are six all-sky cameras, 13 magnetometers, and >200 seismometers. The all-sky images and magnetometers have the same objective, which is to monitor space weather and improve our understanding of auroral activity, including the influence on magnetic fields in the ground. These variations in the magnetic field are also visible on seismometers, to the extent that during an auroral event, the long-period (40–800 s) waves recorded by a seismometer are magnetic field variations, not true ground motion. Although this is a problem--one that can be rectified with magnetic shielding at each seismometer site--it is also an opportunity because the present seismic array in Alaska is much broader than the coverage by magnetometers and all-sky cameras. Here we focus on three aurora events and document a direct link between aurora images in the night sky and seismometer recordings on ground. We also dive into the history of scientific discoveries in this realm, starting in 1716.
Carl Tape is a seismologist at the University of Alaska Fairbanks. He develops and applies techniques in computational and observational seismology to obtain better images of Earth's internal structure and to obtain better representations of earthquakes. Improved seismic images of the crust and mantle provide an important snapshot of a dynamic Earth, and they can be used for scenario earthquake simulations that help assess seismic hazard in earthquake-prone regions. Dr. Tape received his B.A. in physics and geology from Carleton College, a M.S. from Oxford University, and a Ph.D. from California Institute of Technology. He did postdoctoral research at Harvard University before starting as faculty at UAF in 2010.
Because of Physical Distancing our luncheons will be virtual until further notice.
DATE: Thursday, November 19, 2020 - Virtual Meeting Online TIME: Virtual doors open at 11:30 (Alaska Time), Announcements start at 11:45, Talk starts at 12:00 LOCATION: Your home. Cost: Free. Bring your lunch to your computer.