Quarterly Report to the Harry Reid Center

UCCSN-DOE Cooperative Agreement

Task 12: Seismic Monitoring

PI: James N. Brune

UNR Seismological Laboratory

Report Period: 07/01/2002 – 09/30/2002

Progress:

During this reporting period (Jul.-Sep. 2002), we have maintained seismic operations with 32 real-time stations under the QA procedures which have been established with the HRC. Data collection has been above 99.7% overall. Several changes have been made in hardware at the recording lab to improve recording reliability and data archiving.

The independent, non-telemetered strong-motion stations (9 TerraTech recorders) were visited, data downloaded, and system checks performed in this quarter. All current data has been submitted.

The FY01 seismicity report, finished in June, is waiting only for completion of a Technical Assessment of two datasets (Oct.-Dec. 1992 and Jan.-Sep. 1995 earthquake catalogs) used in preparation of that report. This assessment has been drafted and is under internal review as of 10/01/2002. We anticipate submittal of this report within two weeks.

The summary report on the seismic parameter “kappa” is still in progress.

At the end of this quarter, we have completed analyzing the earthquakes in the YM vicinity through July 26. Completion of analysis on a delayed basis is acceptable because the entire set of station triggers is reviewed within 2-3 days and because all events larger than roughly M 2 are always analyzed within these 2-3 days. The reason for the backlog now is the occurrence of the M 4.4 earthquake near Little Skull Mountain on June 14. Over 1600 aftershocks of this event have already been located, and we anticipate nearly 2000 when done through September 30. Some additional material has been added to our web site for this earthquake; this site is located at

http://www.seismo.unr.edu/htdocs/monitoring/06142002/06142002_eq.html

Instrumentation (seismometers and recorders) ordered for the three seismic station installations in the ESF tunnel have been delivered by the vendor in early October. Also, the instrumentation order for the three boreholes on the pad of the proposed Waste Handling Building has also just been delivered. We completed an Implementing Procedure in this quarter to cover installation and operation of these borehole instruments.

All Southern Great Basin Seismic Network (called “analog” network) in NSL possession have been remastered to 4-mm tape and read into files on NSL computers. Data recovery from the old archive tapes has been good overall, even though roughly 20% of the originals had some sort of reading problems on the first pass. The transfer of USGS tapes to NSL in the early 1990’s was incomplete, and discussions are underway with the RPC to fill in the archive from RPC tapes so that we can complete the recovery task.

Problems:

The backlog of events to be analyzed following the June 14, 2002, earthquake has grown to roughly two months. This will be gradually reduced, provided no more significant earthquakes occur in the network, but will delay our processing of the final catalog of earthquakes for FY2002.

The delay in the delivery of instrument orders for the tunnel and for the boreholes has pushed the finish dates for these subtasks out a couple months.

Status of Funds:

We are working now to incorporate all charges up to September 30 into our accounting of funds. We anticipate having approximately $53K to carry forward into FY03, earmarked for the purchase of two trucks for this task.

Plans:

We will devote considerable effort in the coming quarter to the hiring of three more personnel: computer system administrator, field technician, and a post-doc. These positions are key factors in completing our workscope in FY03.

We will take set up equipment received for the ESF tunnel and the WHB pad boreholes, perform bench testing of it, and install it in the coming quarter.

We will deliver the long-delayed FY01 seismicity report in October and begin work on the FY02 report late in the coming quarter.

We will begin work on the numerous subtasks for which we have been funded in FY03, notably attenuation, stress-drop, and focal-mechanism efforts.