• New Temporary Broadband Array with Open Public Data Set Will Facilitate New Research: IRIS PASSCAL, Sweetwater, TX

    | Case study

    Purpose of the study: To establish a temporary mixed phase broadband seismic array with publicly open and available data that will facilitate new research. This was a 6 week study that began on March 11, 2014.

    Opportunity

    To establish a temporary mixed phase broadband seismic array with publicly open and available data that will facilitate new research. This was a 6 week study that began on March 11, 2014.

    Challenge

    Several noise sources were present in the area, consisting of hundreds of wind turbines, hydraulic fracturing activity and active vibroseis trucks. Additionally, there was a consistent 3Hz signal observed in the area. There was also a limited amount of time available, as the project had not originally been budgeted for by PASSCAL.

    Solution

    Deployed in under 3 days using a direct burial technique, with a posthole auger, Nanometrics worked closely with the IRIS PASSCAL team to deploy a 25-station array. Nanometrics donated two field engineers, along with field equipment for 25 stations, to facilitate the speedy installation and provide training on the new direct burial technique. The direct burial technique was chosen for ease and speed of deployment.
     

    Mixed Phase Array – 25 Stations
     

    PASSCAL provided:
    5 x Trillium 120 Postholes
    25 x Field enclosures
    25 x Solar panels
    4 x Personnel
    Nanometrics provided:

    20 x Trillium Compact Posthole
    20 s BroadbandSeismometers
    25 x Centaur Digital Recorders
    2 x Personnel
     

    Results

    Staff Scientists digging a posthole for installationDeploying the Trillium Compact Posthole seismometers using this direct burial technique saved significant time and resources, without loss of performance, over older, vault style techniques that are susceptible to thermal instability and water ingress.

    Link to IRIS open data set: http://ds.iris.edu/gmap/XB?timewindow=2014-2014

    Photo: Katherine Aur, Staff Scientist, IRIS PASSCAL (left) and Zhingang Peng, Assoc. Prof., School of Earth and Atmospheric Sciences, Georgia Institute of Technology (right).