Annual Meeting - SCEC.org

SCEC Research Accomplishments | Report
A “Workshop on Satellite Observations and Earthquake Predictability” was held in July 2011. This workshop brought together
two separate communities that are active in attempting to understand how and whether it is possible to predict earthquakes.
One is a group of space scientists involved in making satellite-based observations of anomalous electromagnetic and thermal
signals that may be associated with earthquakes. The other consists of earthquake scientists involved in making seismological
and geodetic observations, many of whom are involved with SCEC. These communities have had insufficient communication
or collaboration, and bringing them together may
help each understand better each other’s data and
perspectives.
References
McGuire, J. J. (2008), Seismic Cycles and Earthquake
Predictability on East Pacific Rise Transform
Faults, Bull. Seis. Soc. Am., 98(3), 1067-1084, doi:
10.1785/0120070154.
Ground-Motion Prediction
The primary goal of the Ground-Motion Prediction
focus group is to develop and implement physicsbased
simulation methodologies that can predict
earthquake strong-motion waveforms over the
frequency range 0-10 Hz. At frequencies less than 1
Hz, the methodologies deterministically predict the
amplitude, phase and waveform of earthquake
ground motions using fully three-dimensional
representations of Earth structure, as well as
dynamic or dynamically compatible kinematic
representations of fault rupture. At higher
frequencies (1-10 Hz), the methodologies predict the
main character of the amplitude, phase and
waveform of the motions using a combination of
deterministic and stochastic representations of fault
rupture and wave propagation.
Rupture characterization plays a vital role in
ground-motion prediction and significant progress
has been made in the development of more realistic
implementations of dynamic and dynamically
compatible kinematic representations of fault
rupture within ground-motion simulations.
Verification (comparison against theoretical
predictions) and validation (comparison against
observations) of the simulation methodologies
continues to be an important component of this focus
group with the goal being to develop robust and
transparent simulation capabilities that incorporate
consistent and accurate representations of the
earthquake source and three-dimensional velocity
structure. The products of the Ground-Motion
Prediction group are designed to have direct
application to seismic hazard analysis, both in terms
of characterizing expected ground motions in future
Figure 61. Examples of Green's functions derived from abient noise analysis
(black) and synthetic ones from the SCEC CVM 4.0 (lower traces) and the
model revised using full waveform tomography (CVM4SI2). The map shows
the epicenter (start) and CMT solution (red beachball) of the Chino Hills
earthquake and the inter-station paths (green lines) for the Green's functions.
Figure 62. Three component (transverse: top, radial: middle, vertical:
bottom) Green's functions for three paths within the waveguide (A-C) and
one outside the waveguide (D). The Green's functions relatively impulsive
for the path outside the waveguide, whereas the Green's functions contain
long duration reverberations for paths within the waveguide, supporting its
presence in the SCEC Community Velocity Model.
2011 SCEC Annual Meeting | 81