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  • walls
    2012.08.26 - Swarm near Brawley, California   4 years 29 weeks ago

    If anyone is interested in a custom dataset (1Hz or 5Hz) from PBO stations in the area please submit a request to: http://pbosoftware.unavco.org/shared/scripts/datarequests/
    Regards,
    Chris - 303-775-2159

  • angelyn
    2012.08.26 - Swarm near Brawley, California   4 years 29 weeks ago

    We've revised our solutions in ftp://sideshow.jpl.nasa.gov/pub/JPL_GPS_Timeseries/BrawleySwarm after improving the analysis strategy (specifically, fixing troposphere to that estimated in static positioning run, rather than estimating both trop and position together in the kinematic run).

    Importantly, station P498 is not moving in the East direction.  There is discernable motion in (at least) stations P502, P499, and P495.

    Angelyn Moore and Susan Owen, ARIA team

  • fielding
    2012.08.26 - Swarm near Brawley, California   4 years 29 weeks ago

    WInSAR has requested tasking of acquisitions on the next two passes of TerraSAR-X (TSX) over the Brawley area, on August 31st (ascending orbit 15) and September 3rd (descending orbit 68). TSX data was last acquired on these two tracks over the Brawley area on August 20th (orbit 15) and August 12th (orbit 68).

  • hudnut
    2012.08.26 - Swarm near Brawley, California   4 years 29 weeks ago

    Here is a bit more of an update than posted before:

    I checked throughout the epicentral area without finding any evidence of surface rupture. I did visit and speak with people at the geothermal plant near the intersection of Andre and Hovley, called Ormat, and later spoke with people from their main Reno office. I also met the Mayor and City Manager of Brawley and spoke with their engineers, and also talked with several people from Imperial Irrigation District. All of these people had been getting reports from their field personnel and all tried help lead me to anything that might be of interest, but after following all of their helpful leads I still struck out.

    I also checked but did not find any fresh evidence of creep on the Imperial, Brawley, Superstition Hills and San Andreas faults. I did not find anything today that looked like fresh cracking, certainly nothing tectonic. I did not find any evidence of liquefaction, and only minor cracking associated with slumping along irrigation water systems.

    I haven't yet downloaded photos and type in my notes. Please let me know if you would like more details, e.g., the GPS track file or photos, etc.

    Regards,

        Ken

      hudnut@usgs.gov

      cell:  626-672-6295 (text or call)

    P.S. - Attached are maps at two resolutions showing my GPS track from today.

  • hudnut
    2012.08.26 - Swarm near Brawley, California   4 years 29 weeks ago

     Today I field-checked the epicentral area and interviewed many people in the field. None of the cracking I saw appeared to be tectonic.

    I found no new evidence of creep on any of these faults; Imperial, Brawley, Superstition Hills, San Andreas.

    More details to follow later.

  • mwei
    2012.08.26 - Swarm near Brawley, California   4 years 29 weeks ago

    here is the P498 solution for August 26.

  • angelyn
    2012.08.26 - Swarm near Brawley, California   4 years 29 weeks ago

    The ARIA team at JPL has placed 30-second GPS solutions in
    ftp://sideshow.jpl.nasa.gov/pub/JPL_GPS_Timeseries/BrawleySwarm

    A README.txt file is available with details on the provided solutions. We note velocity changes beginning at the time of the swarm, particularly in the east component of station P498.

    Angelyn Moore and Susan Owen, ARIA team

  • hudnut
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

    Update:  Brian Berard of CalEnergy has replied that he and all others will perform evaluations of all their facilities and report back to us if anybody gets any info on surface faulting, liquefaction, ground deformation, etc. so hopefully we'll have more info from them by tomorrow afternoon or so.

  • hudnut
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

    Hi Joann, thank you for these contacts. I was planning to give Brian Berard a call tomorrow morning before determining further plans for field recon to see if there may be surface faulting. He is the person who alerted us about the surface faulting back in the 2005 activity, so I feel that he will almost surely be the right person for me to speak with. Earlier messages here mentioned potential for a lawsuit, and the 2005 situation did involve one, but I have not heard the outcome of it. Whomever is involved with surface faulting recon will likely call down this list of contacts and also check in with local government agencies and others in the vicinity to see whether any reports have come in from road crews, etc. I'd be glad to try to relay info, and please anyone who gets new info on faulting or liquefaction, etc., please do feel free to reply here or by e-mail. Also, I hope that if others have potentially useful contact info they may provide it as replies here, too. Thank you. - Ken (cell: 626-672-6295)

  • hudnut
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

    Attached is a KML file with the mud pots and also the volcanic and geothermal features, etc. from Lynch et al., BSSA 2008.

     

    Lynch, D.K. and K.W. Hudnut, The Wister Mud Pot Lineament: Southeastward Extension or Abandoned Strand of the San Andreas Fault?, BSSA, Vol. 98, No. 4, pp. 1720–1729, August 2008, doi: 10.1785/0120070252

  • hudnut
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

    Recon for surface rupture probably will be checked tomorrow (Monday) by USGS'ers, but e-mail is circulating tonight and I expect plans will be discussed in the morning. Thanks, Jeff.

  • djackson
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

    The document "BSZ_sequence..." is a very useful summary of the history. But the last paragraph contains the most intriguing words:

    "but bigger events are possible on the major northwest striking late Quaternary faults in this vicinity. "

    Anyone care to be more explicit?

    Dave Jackson

  • gareth
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

    I plotted this seismicity map using SCSN locations color-coded by year. It picks out the different swarms pretty well. It is approximately centered on the current swarm.

  • hauksson
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

    Updated talking points

  • baagaard
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

     

  • baagaard
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

     

  • huynht
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

     Circulated by Egill Hauksson (Caltech).

  • jmcguire
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

    Thanks Joanne,  It would be the Ormat Brawley North plant that

    is relevant.   I don't know anything about that plant, but most in

    the salton trough have to report the seismicity in their region to DOGGR.

    Hence they run local networks, such as the Cal Energy data from further north

    that is now archived at CalTech.

     

    The attached google earth capture shows where the plant is as "A". It's

    about 1km from the epicenter of the M5.5.   I don't know anything about

    their well locations, but presumably they are within a few hundred meters

    of the plant.  I think it would be great if SCEC as an organization was pro-active about

    making sure the local data gets archived somewhere if it exists.  This did not happen for

    the 2005 swarm under the Cal Energy plants and that was a major missed opportunity.

  • ybock
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

    We've posted real-time GPS displacement waveforms data at anonymous ftp://dozer.ucsd.edu/pub/public/IVSwarms2012-08-26. A page will be set up on the NASA MEaSUREs GPS Explorer portal later today with this an other information.

    A glitch in our system, precluded transfer of waveforms to SCEDC waveform pool and conversion to seismic formats (MSeed and SAC) right after the events. They will be uploaded later.

    -- Yehuda Bock

  • rolohman
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

    Screenshot with TerraSARX coverage and dates

  • stock
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

    This contact info for Cal Energy and for Ormat is from 2009. USGS Menlo Park folks (Fuis?) may have more updated info. What, exactly, would be the plan if somebody contacts them? (Is there going to be some coordinated effort to contact them?) 

    Cal Energy Operating Co.
    551 W Main St # 1
    Brawley, CA 92227
    760-351-3050
    760-351-3058 Fax

    Cal Energy Operating Co.
    7030 Gentry Road
    Calipatria, CA 92233
    Brian Berard, Geoscience Manager
    (760)348-4084
    (760)348-4024 fax
    brian.berard@calenergy.com

    Cal Energy Operating Co.
    7030 Gentry Road
    Calipatria, CA 92233
    Mark Chastain, Well Field Maintenance Coordinator
    (760)348-4053
    (760)348-4024 fax
    Mark.chastain@calenergy.com

    Bob Sullivan
    Project Manager
    Ormat Nevada Inc.
    North Brawley Geothermal Project
    P.O. Box 1807
    4780 Highway 111
    Brawley, CA 92227
    760-351-8555
    bsullivan@ormat.com

     

  • fielding
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

    TerraSAR-X (TSX) has an 11-day repeat cycle, which helps enable acquisitions sooner, but unfortunately the German data security laws mandate 5-day delay after acquisition for full-resolution data. 

    We will see if the TSX data acquired over this area previously can be included in the Los Angeles Supersite to make data access easier.

  • baagaard
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

     Attached please find v.1 talking points for today's activity, for open distribution

     Please post to NEIC and SCEC pages, etc. The figure includes event mechanisms for the largest 2 events. More later. Please feel free to send questions, corrections, etc. so that we can incorporate those into v.2 later. Thank you,  Ken

     

    office phone:  626-583-7232

    cell phone:  626-672-6295

    email:  hudnut@usgs.gov

  • baagaard
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

     Attached are Google Earth files with seismicity (ANSS catalog is updated daily and real-time is every 5min I think, Hauksson-Shearer) and USGS fault surface traces.

  • ybock
    2012.08.26 - Swarm near Brawley, California   4 years 30 weeks ago

    Its's not that exciting nor worth a map. One site, P499 (nearest the epicenter) has significant coseismic motion for the second event (M=5.4 @ 20:57:18 UTC) with a precision of about 5 mm - the north displacement is +20 mm in the east and -10 mm in the north. Peak displacement is about 100 mm at that one site in the east, and 30 mm in the north. Dynamic motions can also be seen at about 6 other stations. We will post the waveforms.

    --Yehuda