Virtual array beamforming of GPS TEC observations of co-seismic ionospheric disturbances near the Geomagnetic South Pole triggered by teleseismic megathrusts
Abstract
We identified co-seismic ionospheric disturbances (CID) in Antarctica generated by the Rayleigh waves of the 2010 Maule and the 2011 Tohoku-Oki earthquakes analyzing TEC data with a modified beamforming technique. Beamforming in Antarctica, however, is not straightforward due to the effects of array deformation and atmospheric neutral wave-ionospheric plasma coupling. We take these effects into account and present a method to invert for the seismically generated acoustic wave using TEC observations. The back azimuths, speeds and waveforms obtained by the beamform are in excellent agreement with the hypothesis that the TEC signals are generated by the passage of Rayleigh waves from the Maule and Tohoku-Oki earthquakes. The Tohoku-Oki earthquake is ~12,500 km from Antarctica, making this the farthest observation of CIDs to date using GPS.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2015
- Bibcode:
- 2015AGUFMNH21C1833G
- Keywords:
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- 4341 Early warning systems;
- NATURAL HAZARDS;
- 6934 Ionospheric propagation;
- RADIO SCIENCE;
- 6969 Remote sensing;
- RADIO SCIENCE;
- 7223 Earthquake interaction;
- forecasting;
- and prediction;
- SEISMOLOGY