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CISN: EEW Project

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EEW process chart: Click to view one-pager descriptions.

CISN EEW flow chart imagemap. Stations at UC Berkeley, USGS Menlo Park, and Caltech and USGS Pasadena feed into the waveform parameter pool, which feeds into event detection. Event detection processes under development are Multiple threshold event detection (VS-MTED), Application of real-time GPS to EEW, and Finite Fault Detector. Event detection processes in operation are the On-site, Elarms, and Virtual Seismologist algorithms. Event detection feeds into the CISN ShakeAlert Decision Module, which feeds into User Displays and the CISN testing center.

Each data center processes in real time the telemetered digital waveform data collected at various broadband, strong motion and borehole sites distributed throughout California. Critical waveform parameters are calculated from this data, then dumped in a statewide waveform parameter pool.

During event detection, CISN's EEW algorithms rapidly detect and characterize each event within seconds from event initiation. ShakeAlert implements a parallel array of EEW detection algorithms to provide the Decision Module with the best available data given the unique set of source parameters.

The Decision Module combines earthquake information feeds from each algorithm and delivers a "ShakeAlert" xml message about an earthquake in progress to subscribed users.

The ShakeAlert User Display (UD) receives the xml-messages from the Decision Module and displays their content in a simple and easily understandable way.

CISN Testing Center Software provides automated and interactive performance evaluations of ShakeAlert forecasts.

Earthquake Early Warning links:

For more information please contact

Waveform Parameter Pool. Click for a 1-pager
 description of WPlib, the waveform processing library. On-site. Click for a 1-pager description of the On-site 
algorithm. ElarmS. Click for a 1-pager description of the ElarmS Al
gorithm. Virtual Seismologist. Click for a 1-pager description of
 the virtual seismologist algorithm. Multiple Threshold Event Detection (VS-MTED). Click for 
a 1-pager description of the VS-MTED Application of Real-time GPS to EEW. Click for a 1-pager
 description of application of real-time GPS to EEW. Finite Fault Detector. Click for a 1-pager description o
f the Finite Fault Detector. CISN ShakeAlert Decision Module. Click for a 1-pager desc
ription of the Decision Module. CTC. Click for a one-pager description of the CISN Testing 
Center software UD. Click for a 1-pager description of the CISN ShakeAle
rt User Displays UD. Click for a 1-pager description of the CISN ShakeA
lert User Displays

California Integrated Seismic Network

CGS USGS OES Caltech UC Berkeley