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Group 2 – Seismology | Poster Abstracts
Future QuakeML development will include an extension for macroseismic information.
Furthermore, development on seismic inventory information, resource identifiers, and resource
metadata is under way.
Online resources: http://www.quakeml.org, http://www.quakepy.org
2-106
TIME-FREQUENCY MISFIT AND GOODNESS-OF-FIT CRITERIA FOR
QUANTITATIVE COMPARISON OF TIME SIGNALS Kristek J, Kristeková M, and Moczo
P
The time-frequency (TF) representation of a signal provides unique and complete information on
the signal and is a very good basis for signal analysis and thus also for quantitative comparison of
signals. This is especially true about the TF representation defined using the continuous wavelet
transform and progressive analyzing wavelet. The TF representation enables us to define
unambiguous TF envelope and phase of the signal at each (t,f) point, and, consequently, envelope
and phase differences at each (t,f) point. Having these it is possible to define a variety of the TF
misfit and goodness-of-fit criteria depending on the goal of the comparison. The misfit criteria
quantify the level of disagreement and are more suitable for relatively close signals. The goodnessof-fit
criteria allow looking for the level of agreement rather than details of disagreement between
the compared signals and are more suitable in case of larger differences between the signals.
Kristekova et al. (BSSA 2006) developed TF misfit criteria for quantitative comparison of one
component signals assuming one of them to be a reference. Here we develop a systematic theory of
the TF misfit and TF goodness-of-fit criteria for three-component time signals. We include the
locally and globally normalized criteria. We also include criteria in case when one of the two
compared signals can be considered a reference, and criteria in case when the comparison does not
allow viewing one signal as a reference.
We numerically illustrate applications of the misfit and goodness-of-fit criteria to practically
important cases.
The software package TF_MISFITS_GOF_CRITERIA developed by Kristekova et al. (2008) for
numerical computation of the TF misfit and goodness-of-fit criteria is available at
http://www.nuquake.eu/Computer_Codes/index.html.
2-107
DEPTH LOCALIZATION OF SEISMICITY ON STRIKE-SLIP FAULTS IN
CALIFORNIA Boutwell C, Powers PM, and Jordan TH
We investigate the distribution of earthquake ruptures in three separate dimensions along
California strike-slip faults. Previous work by Powers and Jordan (in prep.) shows that the average
rate of small earthquakes along California strike-slip faults obeys a power-law of the form R~(x^2
+ d^2)^(- ? /2), where the rate R is in events/km^2, x is the distance from a fault, ? is the decay rate
of seismicity, and d is the near-fault inner scale. However, they do not consider the depth
variability of earthquake hypocenters. We therefore perform a reconnaissance of their faultreferenced
data set to determine if there is significant on-fault versus off-fault variability in
earthquake depths. For each fault segment, we compute the depth variance in 4d km wide faultnormal
bins, centered on the fault. For particularly long fault segments, we take the average
variance over several shorter fault-parallel sub-segments. Results show interesting regional
variations. In southern California, on-fault earthquake hypocenters are strongly localized in depth,
2008 SCEC Annual Meeting | 199