Detecting and locating seismic events with using USArray as a large antenna
We design an earthquake detection and location algorithm that explores coherence and characteristic behavior of teleseismic waves recorded by a large-scale seismic network. The procedure consists of three steps. First, for every tested source location we construct a time-distance gather by computing...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-01-01
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| Series: | Advances in Geosciences |
| Online Access: | http://www.adv-geosci.net/40/27/2014/adgeo-40-27-2015.pdf |
| Summary: | We design an earthquake detection and location algorithm that explores
coherence and characteristic behavior of teleseismic waves recorded by a
large-scale seismic network. The procedure consists of three steps. First,
for every tested source location we construct a time-distance gather by
computing great-circle distances to all stations of the network and aligning
the signals respectively. Second, we use the constructed gather to compute a
Tau-P transform. For waves emitted by teleseismic sources, the amplitude of
this transform has a very characteristic behavior with maxima corresponding
to different seismic phases. Relative location of these maxima on the
time-slowness plane strongly depends on the distance to the earthquake. To
explore this dependence, in a third step, we convolve the Tau-P amplitude
with a time-slowness filter whose maxima are computed based on prediction of
a global travel-time calculator. As a result of this three-step procedure, we
obtain a function that characterizes a likelihood of occurrence of a seismic
event at a given position in space and time. We test the developed algorithm
by applying it to vertical-component records of USArray to locate a set of
earthquakes distributed around the Globe with magnitudes between 6.1 and 7.2. |
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| ISSN: | 1680-7340 1680-7359 |