Earthquake Early Warning

SCEC Earthquake Early Warning Activities

SCEC4 science plans emphasize the development and use of time-dependent seismic hazard analysis. SCEC is working to extend time-dependent seismic hazard analysis through application of EEW technologies.

CISN ShakeAlert System

SCEC is working with the California Integrated Seismic Network (CISN) in the development and evaluation of a prototype CISN EEW system.

CISN EEW Testing System Development

SCEC is working to developed automated CISN EEW performance evaluation system. This system, currently called the CISN Testing Center (CTC), is based on the testing framework developed on the SCEC CSEP project.

CISN EEW Station Lists

CISN provided the following list of stations used in current CISN EEW processing

• Northern CISN Station List
• Southern CISN Station List
• Combined CISN EEW Station List (KML Format)

Fig 1: California Station List with M8 Epicenter.

Example Observations from ShakeMap RSS for Event (M5.0 )

Fig 2: Plotting of ShakeMap observation data for Event in Southern California.

Fig 3: Plotting of ShakeMap observation data for Event in Southern California.

Authorized Data Source

The ShakeMap authorized data source may provide the observational data used to validate short term ground motion forecasts.

• ShakeMap Rss System

Test Event List 2010

   * catalog=ANSS
   * start_time=2010/06/01,00:00:00
   * end_time=2010/11/01,00:00:00
   * minimum_latitude=32.00
   * maximum_latitude=42.00
   * minimum_longitude=-122.00
   * maximum_longitude=-114.00
   * minimum_magnitude=4.0
   * maximum_magnitude=10
   * event_type=E 

Date       Time             Lat       Lon  Depth   Mag Magt  Nst Gap  Clo  RMS  SRC   Event ID
----------------------------------------------------------------------------------------------
2010/06/02 16:07:48.08  32.0560 -115.1967  10.00  4.30   ML   12          0.22  CI      14732212
2010/06/03 18:10:04.03  32.6952 -115.9142   5.11  4.10   ML   43          0.23  CI      14733516
2010/06/10 22:07:12.97  32.0305 -115.1072  10.00  4.14   ML    7          0.28  CI      10699845
2010/06/11 20:51:11.69  32.3900 -115.1818  15.00  4.26   ML   17          0.29  CI      10700429
2010/06/12 15:29:25.45  37.4527 -117.5194   5.87  4.54   ML   25  96   53 0.14  NN        312414
2010/06/13 03:08:57.09  33.3833 -116.4158  12.48  4.90   ML  125          0.26  CI      10701405
2010/06/13 03:09:20.36  33.3920 -116.3947   5.57  4.23   ML   44          0.32  CI      10701413
2010/06/14 07:02:26.97  32.1803 -115.3155  10.00  4.69   ML   11          0.20  CI      10703133
2010/06/15 04:26:58.48  32.7002 -115.9213   5.41  5.72   Mw   52          0.28  CI      14745580
2010/06/15 04:36:07.63  32.6792 -115.9242  12.48  4.11   ML   49          0.37  CI      14745636
2010/06/15 04:59:45.53  32.6995 -115.9500  10.69  4.61   ML   71          0.33  CI      14745932
2010/06/15 05:34:16.83  32.7088 -115.9563   5.52  4.35   ML   68          0.28  CI      14746172
2010/06/15 08:14:47.02  32.6880 -115.9108   3.77  4.15   ML   67          0.30  CI      14747396
2010/06/17 09:05:38.19  32.0748 -115.0040  10.00  4.13   ML    9          0.40  CI      10160722
2010/06/25 06:37:52.80  32.6188 -115.7947   6.44  4.17   ML   50          0.31  CI      10724149
2010/07/06 16:38:05.23  32.2180 -115.3462   1.51  4.27   ML   16          0.23  CI      14776012
2010/07/07 23:53:33.53  33.4205 -116.4887  13.97  5.43   Mw  144          0.27  CI      10736069
2010/07/20 21:48:29.98  40.0764 -119.6219  11.75  4.22   ML   33 245   23 0.10  NN        314044
2010/07/30 11:13:46.81  38.6220 -118.2116  11.14  4.24   ML   19 189   27 0.11  NN        314505
2010/08/06 17:39:31.67  33.9790 -116.4432   7.66  4.05   ML  122          0.18  CI      10771621
2010/08/24 21:43:39.96  32.3633 -115.4110  10.00  4.22   ML   21          0.30  CI      10785477
2010/08/29 15:53:43.42  32.1803 -115.2930  10.00  4.28   ML   15          0.22  CI      10788765
2010/09/14 10:52:18.00  32.0485 -115.1982  10.00  4.96   Mw   14          0.21  CI      10798005
2010/09/15 06:09:53.38  32.1647 -115.2467  13.79  4.79   ML   12          0.20  CI      10798845
2010/09/20 00:30:02.40  32.0262 -115.1083  10.00  4.75   Mw    9          0.22  CI      14844244
2010/09/30 08:37:35.93  37.1385 -117.3803   8.47  4.42   ML   24 144   21 0.23  NN        317359
2010/10/05 21:22:46.52  37.1526 -117.3758   9.21  4.14   ML   13 164   19 0.12  NN        318065

Earthquake Wave Travel Time Curves

Fig 4: Travel time curves show region for which no warnings are possible because of travel time and processing delays.

Ground Motion Intensity Scale

Fig 5: ShakeMap color scale shows instrumental intensity estimates or observations.

CTC Abstract for SCEC Annual Meeting 2010

Testing Regional-scale Ground Motion Estimates for the CISN ShakeAlert Project Philip Maechling, Maria Liukis, Thomas H. Jordan

Our SCEC research team has developed initial capabilities of the CISN Testing Center (CTC) as a part of the USGS-funded CISN ShakeAlert Project. The CTC is designed to compare regional-scale ground motion estimates, such as peak ground motion estimates, against observed ground motion data, for significant California Earthquakes. The CTC is designed to identify which ShakeAlert ground motion estimation methods produce the best fit to observed ground motions.

Scientific goals of the CTC include (a) development of consensus among SCEC researchers on meaningful measures of comparison between ground motion estimates and observations, (b) collection and analysis of ShakeAlert performance information, and (c) integration of standard Probabilistic Seismic Hazard Analysis (PSHA) terms and practices into EEW. The technical goal of the CTC is to develop an automated system that can comparing ground motion estimates against ground motion observations. The CTC system used the CSEP testing framework to automate the evaluation of CISN ShakeAlert rapid earthquake parameters including ground motion forecasts for each event.

As part of this year’s CTC development, we updated the CSEP Testing Framework to use the USGS ShakeMap RSS Feed as an authorized source of event-based ground motion observations. As ShakeAlert systems produces rapid ground motion estimates for significant California events, the CTC will evaluate those ShakeAlert ground motion estimates against CISN ground motion observation using goodness-of-fit algorithms defined by CISN scientific groups.

Our ShakeAlert ground motion forecast testing shares scientific and technical goals with several other SCEC activities including validation of attenuation relationships, synthetic ShakeMaps, velocity model and wave propagation model goodness of fit measures, and short term ground motion forecast testing. The CTC system is designed to support CISN ShakeAlert testing and to also be applicable for evaluation of other ground motion estimation methods.

EEW Graphics

Fig 6: JMA diagram showing EEW concepts and types of EEW system implementations.

Fig 7: JMA diagram showing potential users of EEW ground motion forecasts.

Fig 8: San Francisco Chronicle graphic showing EEW concepts in California.

Additional ShakeAlert Information

• CISN Home Page
• USGS ShakeAlert Press Release
• Caltech Seismo Lab
• U.C. Berkeley Seismo Lab
• USGS Pasadena Seismic Network Operations
• USGS Menlo Park Seismic Network Operations

Additional Information

• /export/data/cisneew/data_in - path to input data for current cisn testing

References

• Mustafa Erdik EEW Presentation (2006)
• Shin'ya TSUKADA EEW Presentation (2006)
• Maren Bose EEW Presentation (2009)