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Welcome to GEO's Baja California (Sierra El Mayor), Mexico, Event Website

Sections
SAR, Creep, Visible, GPS, Strain , Earthquakes, Links
Data Source availability

Revisions

New on Thursday July 29:       UAVSAR interferogram
New on Monday May 17:       slip model
New on Monday May 10:       Envisat track 77 and 84 interferograms
New on Tuesday Apr 27:       GPS coseismic Google map
      New ALOS interferogram       New Envisat interferogram
New on Friday Apr 23:       Infrasonic Ground Motion
New on Monday Apr 19:       Postseismic Envisat
New on Sunday Apr 18:       Rapid GPS at PFO
      Updated Displacement movie       Two ALOS interferograms
      2.5 m SPOT displacement map
New on Friday Apr 16:       Envisat interferogram
      SPOT displacement map       5Hz GPS ground motion
      Envisat interferogram
New on Thursday Apr 15:       ScanSAR interferogram
      Creep observations       GPS waveforms
New on Friday Apr 9:       ALOS interferogram
      GPS offsets       UAVSAR flight plan
New on Thursday Apr 8:       GPS vectors       Displacement movie
      Envisat archive       Areal strain       long baseline strain
      source model
New on Wednesday Apr 7:       Seismicity map       Borehole strain
      Pore pressure       Stress on faults
New on Tuesday Apr 6:       Envisat order
      Stress transfer model       vertical velocity
New on Monday Apr 5:       shakemap       aftershocks

  

SAR
Envisat most recent
July 11 2010
ERS Feb 14 2002
ALOS No data available
UAVSAR available through JPL
TerraSAR-X No data available
Radarsat-1 No data available
Radarsat-2 No data available
Cosmo No data available
Seismic
Short-period IRIS Baja Map
Long-period No data available
Broad-band No data available
Geodetic
Continuous GPS UNAVCO's DAI
Campaign GPS UNAVCO's DAI
Strainmeter No data available
Tilt No data available
Others
Gas No data available
gravity No data available
High-res No data available
Lidar No data available

The April 2010 Sierra El Mayor earthquake has been selected because this earthquake has changed likelihood of a significant earthquake on the San Andreas Fault system in Southern California which would affect a much larger population.
Earthquake, 4 April 2010 22:40 UTC, Latitude 31.13°S,Longitude 115.30°W, 7.2, Depth 10 km (USGS).

If you have data or results that you would like to post on this webpage, please e-mail Falk Amelung, the Task Leader of GEO's Supersite initiative (famelung@rsmas.miami.edu) or Susanna Gross (supersites@unavco.org). If appropriate, a KMZ file is convenient to use in the field.

Instrumental intensity from the USGS (estimate):

SAR, Creep, Visible, GPS, Strain, Earthquakes, Links

SAR Data

Natural Laboratory ESA SAR Data for Download index of SAR data for download

ALOS PALSAR


Eric Fielding of JPL has prepared an unwrapped interferogram from ALOS path 533 using dates 2009/11/30 and 2010/04/17 (precise orbit). This is also available as a kmz file.


Yuri Fialko of UC San Diego has prepared an ALOS interferogram.


Eric Fielding of JPL has prepared a preliminary unwrapped interferogram. for the PALSAR path 211 data acquired on April 17. For more information, see posting at the SCEC response site (registration with SCEC required): http://response.scec.org/node/273/584#comment-584 A .KMZ version is available also, without registration.


ScanSAR interferogram by David Sandwell. ScanSAR to ScanSAR interferogram derived from ALOS PALSAR acquisitions on December 23, 2007 and April 5, 2010. This is combined with a partial ALOS PALSAR ascending interferogram. Increasing color is increasing range. The ascending interferogram has most of the fringes on the northwest side of the fault near highway 2. This shows decreasing range which represents motion toward the radar due to right lateral strike slip. The pattern is asymmetric with almost no LOS deformation on the west side. This indicates that the increasing range on the west side due to the right lateral strike slip is largely cancelled by upward deformation on the west side. This is consistent with the ascending interferogram which shows a decreasing LOS displacement on the northwest side of the fault. These results indicate a combination of right-lateral strike slip and a east-side-down normal faulting. Unfortunately the correlation of the interferogram is poor along much of the fault partly because of the very low SNR of these ScanSAR data. KMZ file


David Sandwell and Matt Wei have prepared the first interferogram of the 2010 Baja event, using GMTSAR to process PALSAR Track 213. Each fringe is 11.6 cm of displacement along the line of sight. KMZ file

It would be very helpful if the following PALSAR images could be acquired in FBS or FBD mode, level 1 processing:

T531 F2960-3000
T532 F2930-3000
T533 F2950-2990
T212 F0620-0650
The more frequently the above images are acquired, the more we can learn about the post-seismic strain field. It would be very valuable to get every possible orbit for the first few months.

ERS-2:

It would be very helpful if the following SAR images could be acquired with level 0 (raw) processing, in CEOS format:

Tracks 77 and 306, Frame 639
Track 84, 356 and 313, Frames 2925, 2943, 2961 and 2979

ENVISAT:

It would be very helpful if the following ASAR images could be acquired in I2 mode, with level 0 (raw) processing:

Tracks 77 and 306, Frame 639
Track 84, 356 and 313, Frames 2925, 2943, 2961 and 2979

The more frequently the above images are acquired, the more we can learn about the post-seismic strain field.

Archive order file, in eolisa shopping cart format now available from the SAR data index .


Eric Fielding of JPL has prepared an unwrapped interferogram from Envisat decending track 84, using preliminary orbits and scenes from 2010/03/28 and 2010/05/02.


Eric Fielding of JPL has prepared an unwrapped interferogram from Envisat ascending track 77, using preliminary orbits and scenes from 2010/03/28 and 2010/05/02.


Eric Fielding of JPL has prepared an unwrapped interferogram from Envisat decending track 356, using dates 2010/03/12 and 2010/04/17. This is also available as a kmz file.


Eric Fielding of JPL has prepared a preliminary Envisat interferogram from ascending track 306, using the pair from 2009/11/24 to 2010/04/13. This is also available as a kmz file.


Yuri Fialko of Scripps prepared an interferogram with Envisat, ascending track 306, Mar 9 2010 - Apr 13 2010 (preliminary orbits, perperdicular baseline of 270 m). Change in radar range is 2.8 cm per fringe. Mapped surface ruptures are shown in heavy black lines. For more information, please see Yuri's Baja page .

UAVSAR:


UAVSAR coseismic interferogram from JPL. Please click on the thumbnail above for more information and to download the original binary data files and Google Earth .kmz versions.
UAVSAR postseismic interferogram from JPL. Please click on the image above for more information and to download the original binary data files and Google Earth .kmz versions.


The NASA/JPL airborne repeat-pass InSAR system, UAVSAR will start the first San Andreas 'lawn mowing' flight of 2010 on Monday, April 12. The plan also contains one line over the Salton Sea, making it a total of 14 lines repeating flight lines flown in 2009. These lines should capture all of the deformation from the April 4th earthquake that we can measure with UAVSAR. For more information please see flightplans at JPL. UAVSAR completed the 14 flight lines on April 12, 2010, but some of the flight lines had to be reflown on April 13 due to unusually strong winds. Another similar set of lines was flown on July 1, 2010 under the request of Andrea Donnellan to study the postseismic deformation.

TERRASAR-X:

SAR, Creep, Visible, GPS, Strain , Earthquakes, Links

Creep Observations


    After a creepmeter operated by Roger Bilham recorded 2.3 cm slip on the Superstition Hills Fault, a group of researchers from UCSD and SDSU surveyed the Superstition Hills Fault on April 9th. We found crack continuously for 11 km. The northern part of the SHF was not surveyed. The maximum displacement is 3.5 cm. Surveyors: Matt Wei, Robert Mellors, James Means, Xiaowei Chen, Duanwei Huang, Greg Fisch. Financial support: NSF - Sandwell PI.

SAR, Creep,Visible, GPS, Strain , Earthquakes, Links


Visible/Infrared Images


East-west surface displacement map by the USGS and Caltech.
Surface rupture accompanying the Sierra El Mayor earthquake derived from subpixel correlation of SPOT 10m panchromatic images using COSI-Corr. The rupture involves multiple faults and exhibits an overall left-stepping character. Displacement profiles across the rupture show lateral offsets of over 4.5 meters.


Surface rupture accompanying the Sierra El Mayor earthquake derived from subpixel correlation of SPOT 2.5 m panchromatic images using COSI-Corr. The east-west and north-south components of displacement are shown. The rupture extends for 60 km across the image and projects directly toward the epicenter near Durango, Mexico. Analysis by Sebastien Leprince (Caltech) and USGS.


SAR, Creep, Visible, GPS, Strain, Earthquakes, Links

GPS Data

UNAVCO's GPS data archive interface for this earthquake.

Rapid GPS


    SOPAC's rapid coseismic displacement map based upon on-the-fly total displacement waveforms at more than 90 stations of the California Real Time Network (CRTN), in 3 dimensions, estimated from 1 Hz data collected by CRTN with a latency of less than 1 second. This represents a significant breakthrough in rapid processing of GPS data to quickly produce finite slip models, station displacement and waveforms. The complete set of on-the-fly displacements (values and plots) can be downloaded from the GPS Explorer portlet for the earthquake at http://geoapp03.ucsd.edu/gridsphere/gridsphere?cid=Earthquakes.
    SOPAC also rapidly posted real-time 1 Hz RINEX data at ftp://sopac-ftp.ucsd.edu/pub/highrate/cache/rinex/2010/094/


    Sharon Kedar (JPL) and Yehuda Bock (SCRIPPS) produced plots comparing GPS observations sampled at 1Hz to co-located seismometers. Additional plots of the PFO North displacement and all 3 components at PFO are available in pdf format. Most of the broadband seismometers in southern California clipped during this earthquake. These on-the-fly GPS 1 Hz displacements provided the only direct measurements of dynamic and static (i.e., total) displacements for this earthquake. Note that even at PFO, 180 km from the epicenter) the broadband seismometer clipped. Therefore real-time regional GPS networks are shown to be essential to medium to large earthquake response.


    SOPAC's California Real Time Network GPS observations sampled at 1Hz compared to seismic displacement at Pinion Flat. Plot by Sharon Kedar, JPL

    UCSD's Displacement movie The movie shows horizontally interpolated CRTN 1 Hz GPS horizontal displacements. The movie is an interpolation of the horizontal displacement through CRTN computed each second. The colors represent the amount of displacement at that time. Red is high displacement, with the high end of the scale being 20 centimeters and blue is no displacement.

Coseismic GPS


    Marcelo Santillan (CWU) computed the displacements for the Baja earthquake using 15 min of data from point positioning using GIPSY 5. Interactive results can be seen on this Google map.


    Tom Herring of MIT has plotted coseismic offsets from the rapid PBO and USGS solutions two days before and two days after the mainshock, complete with error ellipses. Also see an earlier version of this map


    Kristine Larson has prepared plots of surface displacement at GPS station P496 (above) and P744 sampled at 5Hz.

SAR, Creep,Visible, GPS, Strain, Earthquakes, Links


Strain

SAR, Creep, Visible, GPS, Strain, Earthquakes, Links

Earthquake Data

Ground Motion


Seismicity

IRIS

US Geological Survey

The Global Centroid-Moment-Tensor (CMT) Project

Source Model


Finite slip model from Yuri Fialko, SIO. Colors denote the magnitude of slip, in meters. Arrows show the sense of slip on the west side of the fault. The model was derived from inversion of line-of-sight displacements from 6 conventional interferograms (ALOS and ENVISAT), horizontal displacements from along-track interferograms, and continuous and campaign GPS data. Baja page at UCSD


Brendan Crowell and Yehuda Bock (Scripps) have modeled the source and plotted the slip on the eastern block with respect to the western block above. They fit 3-D coseismic vectors from continuous GPS, computed in post-processing at SOPAC using GAMIT/GLOBK. The fault geometry is 65 km long, 20 km deep, striking at 320 degrees and dipping towards the west at 80 degrees. Their computed moment magnitude is 7.15, with strike slip between 1.2 and 1.7 meters, reaching a maximum near the hypocenter. They have also prepared maps of surface displacement for this model as horizontal vectors and vertical displacement in colors and total horizontal displacement in colors.

Stress Transfer


Volkan Sevilgen and Ross Stein (USGS) and Shinji Toda (Kyoto University) have resolved stress changes on the regional fault system.

A Coulomb stress transfer model has been prepared by Ross Stein of the USGS and Shinji Toda of Kyoto University.

SAR, Creep, Visible, GPS, Strain , Earthquakes, Links

Links

               

         

     

The Supersites website is provided by UNAVCO and WInSAR on behalf of the Group on Earth Observations (GEO)
and the European Space Agency (ESA).

Users of ESA data should agree to these Terms and Conditions and acknowledge ESA's contribution with the phrase "Data provided by the European Space Agency" in publications. The GEO Geohazards Supersite website pages include preliminary results contributed by researchers.
The copyright of these results remains with the contributors.

Any reuse of the material posted here requires prior written permission from the copyright holders, unless otherwise specified.