Quarterly Report to the Harry Reid Center

UCCSN-DOE Cooperative Agreement

Task 12: Seismic Monitoring

PI: James N. Brune

UNR Seismological Laboratory

March 2000

 

Progress:

 

During the second reporting period (Jan-Mar 2000), we have maintained seismic operations under the procedures which have been been transitioned from the M&O to HRC.  This involved four implementing procedures.  The Scientific Investigation Plan (SIP) was drafted and approved during this current period.

 

For January-March 2000, we have initiated processing of earthquakes entirely with the Antelope seismic system.  This greatly improves upon the adhoc system which we had used for seismic processing for the previous four years.  A careful review of results from the Antelope system was made for the month of January in order to establish that it was performing properly. 

 

We have completed the backlog of events in the Frenchman Lake earthquake sequence of 1999.  The number of located aftershocks in this sequence is approximately 1100 for the 1999 calendar year.  For all of FY99, we located 3098 events within our seismic monitoring network.

 

The planned small portable array on Little Skull Mountain was installed late in this quarter.  This will enable us to separate earthquake source mechanism and path attenuation effects from the seismic design parameter kappa.

 

In regard to equipment updates, we have received or ordered all equipment designated in our budget, except a DVD writer.  Seven sites chosen for strong-motion sensor upgrades have been prepared for the addition of this equipment.  A survey has been made of possible sites for the two new planned seismic stations.

 

Problems:

 

Due to many operational problems with the startup of Antelope, we have fallen approximately 40 days behind in checking locations and magnitudes of earthquakes.  Effort has begun on the FY98-99 seismicity report, but it is only about 20% complete.  The time schedule for delivery of a draft has been heavily impacted by the large number of earthquakes in 1999 (roughly 50% greater than normal) and the initiation of Antelope operations in this quarter.

 

Plans:

 

We will install the strong-motion sensors at the seven selected sites in the next quarter.  We will make permit applications for the two new seismic station sites.

 

We will continue to fine-tune the Antelope system in regard to several needs in the second quarter: 1) reliable archiving of data (DVD possibly), 2) better near-real-time reporting of locations and magnitudes, 3) more complete event identification, and 4) more efficient daily event analysis.

 

We plan to work off the backlog of seismic event processing during the next quarter.