Active-source seismology

    Recent research highlights

    Gaunt Creek active source survey

    In April 2012, a multi-purpose explosive seismic survey was shot by the team from the University of Aucklandat Gaunt Creek to bridge the gap between the detailed observations of fault zone properties made in the DFDP-1 boreholes and the larger-scale seismic response.

    SAM_0075.JPG

    Drilling contractors preparing shot-holls near Gaunt Creek.

    A string of eight borehole geophones was installed in the DFDP-1A borehole and 126 channels deployed on the surface, the first field-trial of the REF TEK 160 'GOES' systems. Forty-one explosive shots, 0.15-1.2 kg in size, were set off along a 2D profile perpendicular to the fault strike for seismic reflection imaging, vertical seismic profiling and tomography. Additional offline shots around the borehole string may help to elucidate processes of seismic wave propagation through the highly anisotropic fault rocks. Larger shots of up to 12 kg in size along the strike of the Alpine Fault are hoped to induce Fault Zone Guided Waves ("Trapped Waves") that have been observed for the first time on the Alpine Fault in the DFDP-1 observatory from local microearthquake activity. 

     

    IMG_0288.JPG

    The field team looking relaxed after a successful experiment.

     

    For further details about this work, please contact Jennifer Eccles, IESE/University of Auckland, +64 (4) 373 7599 x88092.

    Tag page (Edit tags)
    • No tags
    You must login to post a comment.
    Powered by MindTouch Core