GTSM Technologies

Tensor Strain for NSF’s PBO

 

The PBO project aims to install 100+ GTSM instruments across the North Western region of the United States.  This area will provide a useful of information due to a great deal of tectonic activity.  The region has extensive GPS and  seismic coverage and many different tectonic target types.

 

The Google map to the right shows the installations in 2005 and early 2006.  For a large scale image showing all of the current sites, go to the Location Map.

 

For more details, visit UNAVCO for the Plate Boundary Observatory program of Earthscope, the major Research Equipment initiative (2004) of NSF.

 

 

New Videos to Unavco installations available: Overview of Anza Cluster and Hoko Falls Installation

 

GTSM is not directly involved in provision of the details or data for this array.   Data we do have incidentally as part of our support role is available on our home page.   The complete data archive is available through the Unavco web site.  A highlight for the Pacific North West array was the direct real time detection of one of the Dragert et al. silent slip events within two months of deployment.  

 

AUGUST SEPTEMBER 2005

A Cascadia silent slip event was expected late in August 2005. this event was observed at P403 and Hoko (B004) sites, see Location Map of sites.  The event initially propagated through P403 in late August, and a second cycle was observed to begin at the HOKO strainmeter site around September 9. The total duration recorded to September 15 being about 18 days.  Examples from the record are shown below.

JUNE 2005

An early start to a new era of PBO/GTSM borehole strain meters.  With the grout only five hours old we had our first event in Northern California, the M7.2 of 02:50:54 on June 15, 2005, located 140 km west south west of Cresent City.

 

High frequency (20Hz) data was captured during this event. Obviously the data are recorded through very incompletely set grout with very low modulus. The figures are raw single component data with a nominal calibration of 0.1 nanostrain per count. Peak amplitudes are about 30 nanostrain.  The beginning of the arrival on a 10 minute time scale is shown at figure 1  and figure 2 shows the subsequent ten minutes of the event as seen at HOKO. The three channels show are at azimuths 120 degrees apart. The record is equally interesting on the fourth channel.

GTSM Technologies is located in:

Brisbane

Queensland

Australia

Phone: +61 7 3376 4848

Fax: +61 7 3376 8854

E-mail: GTSM