September 8, 2017 M8.1 Earthquake 87km SW of Pijijiapan, Mexico Data Event Response
Written by David Phillips & Beth Bartel
8 September 2017
Event Summary
A Mw 8.1 earthquake occurred at 04:49:21 UTC (11:49:21 pm 7/9 local) on September 8, 2017, 87km SW of Pijijiapan, Mexico. For more information, see the USGS Earthquake Hazards Program event page.
UNAVCO Response
GPS Data
In response to the M8.1 earthquake 87km SW of Pijijiapan, Mexico, on 2017-09-08, UNAVCO and UNAM-Geofisica have initiated the acquisition of high-rate (1 Hz and/or 5 Hz) GPS/GNSS data from stations within ~1200 km of the epicenter. A map of potentially available high rate GPS/GNSS stations is shown in Figure 2; please note that actual availability of high rate data will depend on the status of each station, TBD. Some of these stations provide high rate data on a regular basis; any currently available high rate data can be downloaded now from the UNAVCO ftp site either directly (ftp://data-out.unavco.org/pub/highrate/) or via the UNAVCO Data Archive Interface (DAI).
Tom Herring (MIT), the GAGE GPS Analysis Center Coordinator (ACC), has estimated preliminary coseismic offsets associated with the M8.1 Pijijiapan, Mexico earthquake. Individual station offsets are tabulated in a “rapid" event (*.EVT) file available from the UNAVCO ftp site [ftp://data-out.unavco.org/pub/products/event/
pbo_170908_0450_eq40_coseis_rapid.evt]. The horizontal displacements in this event file are plotted in Figure 12. As more data become available, the ACC will also produce a “final” offset solution as well as offsets estimated from Kalman filter time series analyses. Final and Kalman filter offset files will be added to the event file ftp site: ftp://data-out.unavco.org/pub/products/event.
Borehole Strainmeter Data
UNAVCO has produced a fully processed 1-sps borehole strainmeter (BSM) dataset spanning the time period of this event, available from the PBO borehole strainmeter event response page under 20170908_Mexico.
Details regarding available high rate GPS/GNSS data, as well as other data products, will be updated here as this data response evolves.
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Figure 1. USGS ShakeMap for the September 8, 2017 Mw 8.1 event near Pijijiapan, Mexico. (Figure from USGS.)...Read more » -
Figure 2. Map showing continuous GPS/GNSS stations with recently available data for PBO/TLALOCNet/COCONet and local networks, near the epicenter (yellow star) of the September 8, 2017 Mw 8.1 event near Pijijiapan,...Read more » -
Figure 3. Shear strains recorded by PBO borehole strainmeters generated by the September 8, 2017 Chiapas, Mexico earthquake. Vertical red line indicates event origin time. (Figure by Kathleen Hodgkinson, UNAVCO)...Read more » -
Figure 4. Vector displacements of GPS stations based on two days of data after the September 8, 2017 Chiapas, Mexico earthquake, compared to the median position of the stations from the previous 10 days. Significant...Read more » -
Figure 5. UNAVCO and UNAM staff working at TLALOCNET GPS-met station TNPJ on the SSN seismic bunker at Pijijiapan, Chiapas....Read more » -
Figure 6. UNAVCO and UNAM staff at TLALOCNET GPS-met station TNPJ on the SSN seismic bunker at Pijijiapan, Chiapas....Read more » -
Figure 7. Motions from the September 8, 2017 Chiapas, Mexico earthquake as recorded in real-time GPS data streams from stations in the region. Stations shown are part of the TLALOCNET and COCONet GPS/GNSS-met networks,...Read more » -
Figure 8. The Mw8.1 earthquake of 2017-09-08 04:49:21 UTC located 87km SW of Pijijiapan, Mexico was felt in Lake Yellowstone over 3,500 km away. Shown here is data from a UNAVCO-operated lake gauge at Grant in...Read more » -
Figure 9. Preliminary slip inversion calculated by inverting the static offsets from the Nevada Geodetic Laboratory jointly with 4 tide gauges and 1 DART buoy, and assuming an 80 degree dipping normal fault as modeled...Read more » -
Figure 10. Locations of tide gauges and DART buoy used in the slip inversion in Figure 9, with the projection of the hypocenter and rupture plan determined by the Servicio Seismológico Nacional (Mexico). (Provided...Read more » -
Figure 11. Fits from the inversion in Figure 9 to the data from stations shown in Figure 10. Numbers are peak values; black traces are observations, red traces are modeled. (From Diego Melgar, University of Oregon)...Read more » -
Figure 12. Preliminary horizontal GPS displacements from GPS sites near the M8.1 Pijijiapan, Mexico earthquake on 2017-09-08. These “rapid” coseismic offsets were estimated from analyzing a short span of...Read more » -
Figure 13. Coseismic interferogram from the Chiapas earthquake generated by the ARIA system showing the “wrapped” fringes (2.8 cm each). The data was acquired on 7 and 13 September 2017. The map includes the...Read more » -
Figure 14. Sentinel-1 interferogram image after phase unwrapping from the Chiapas earthquake generated by the ARIA system. For ARIA products, including a kmz of the interferogram, go to...Read more » -
![A GNSS point source centroid moment tensor solution for the September 9, 2017 Chiapas earthquake using rapidly computed coseismic offsets from the Nevada Geodetic Laboratory (NGL). [See Related Links for data sources.] Green's functions are from Hashima et al. [2008] using a homogeneous half-space formulation. The deviatoric moment tensor is solved for at all depths between 0 and 100 km at the location of the GlobalCMT solution, and the L1-norm minimizing solution is chosen for the depth. The nodal planes of the double couple solution, the depth, and the moment magnitude are shown on the plot as well as the focal mechanisms for the GlobalCMT (black) and the GNSS (red) solution. The vectors show the coseismic offsets computed by NGL (red) and the modeled values from the CMT (grey). The formalism of the inversion is laid out in Crowell et al. [2016 - SRL]. (Analyses and figure by Brendan Crowell, University of Washington)](http://facility.unavco.org/highlights/2017/chiapas-15-small.jpg)
Figure 15. A GNSS point source centroid moment tensor solution for the September 9, 2017 Chiapas earthquake using rapidly computed coseismic offsets from the Nevada Geodetic Laboratory (NGL). [See Related Links for data...Read more »
UNAVCO Data and Support
- Please contact archive-gps
unavco.org for information on data availability. - To request access to these and other RT-GPS stations operated by UNAVCO please send an email request to rtgpsunavco.org.
- For information on past event responses, see the UNAVCO Geophysical Event Response page.
Related Links
- UNAVCO Geophysical Event Response page
- USGS event page
- Servicio Seismológico Nacional Special Report
- IRIS Special Event Page
- NASA JPL-Caltech ARIA products
- Trans-boundary, Land and Atmosphere Long-term Observational and Collaborative Network (TLALOCNET)
- UNAM-Geofísica
- Nevada Geodetic Laboratory
- Attribution list for data included in Nevada Geodetic Laboratory solutions
- The unusual case of the Mexican subduction zone
- EarthScope Plate Boundary Observatory
- Lake Yellowstone Lake Level Gauge
Map Center:
Pijijiapan, Mexico
Last modified: 2020-01-28 22:54:36 America/Denver
2021