SZO Seminar Notes - April 8, 2015: Integrated analyses for monitoring and rapid source modeling of earthquakes and tsunamis

Discussion leader: Brendan Crowell

Papers:Koketsu, K.,Y. Yokota, N. Nishimura, Y. Yagi, S. Miyazaki, K. Satake, Y. Fujii, H. Miyake, S. Sakai, Y. Yamanaka, T. Okada (2011), A unified source model for the 2011 Tohoku earthquake, Earth and Planet. Sci. Letts., 310, 480-487.

Melgar, D. and Y. Bock (2015), Kinematic earthquake source inversion and tsunami runup prediction with regional geophysical data, J. Geophys. Res., in press.

Brendan presented a long list of geodetic and seismic instrumentation that records and transmits in real-time.  Each type measures some different characteristic of the deformation field, with different resolution and accuracy.  The benefits and limitations of many of these were summarized and discussed.  Examples of the sensitivity, resolution and accuracy of fault slip models achievable with which the different data types were presented.

Most systems that operate in near real-time currently are set up to detect and characterize earthquakes, rather than more general deformation transients.

Examples of methods being tested for earthquake early warning were shown.  The benefit of combining seismic and geodetic data for large earthquakes has been clearly demonstrated.  This led to some discussion of whether earthquakes were deterministic, but debate was cut short because it was considered a likely digression requiring more in depth thought and discussion.

We concluded with a discussion of what the inherent limits of GPS, with the experts in the room concluding that it may be possible to reduced errors by half (to perhaps 50 mm - for single epoch measurements?), but the huge distances between the satellites and Earth’s surface implicitly made greater accuracy impossible.