Quarterly Report to the Harry Reid Center

UCCSN-DOE Cooperative Agreement

Task 12: Seismic Monitoring

PI: James N. Brune

UNR Seismological Laboratory

Report Period: 01/01/2003 – 03/31/2003

Progress:

During this reporting period (Jan.-Mar. 2003), we have maintained seismic operations with 30 real-time SGBDSN stations under the QA procedures that have been established with the HRC. Network uptime has been 97.1% overall. A few winter-storm icing situations and some hardware failures at the lab have resulted in downtimes. The nine untelemetered strong-motion stations were visited in this past quarter for maintenance and data downloading.

The FY02 seismicity report has been drafted and is undergoing internal review. It contains a substantial section on the M 4.4 earthquake on 14 June 2002 at Little Skull Mountain.

At the end of this quarter, we have completed analyzing the earthquakes in the YM vicinity through November 12. Approximately 45 days of 2003 are also complete. The entire set of station triggers is reviewed within 2-3 days and all events larger than roughly M 2 are always analyzed within 2-3 days also. The backlog is still due to the occurrence of the M 4.4 earthquake near Little Skull Mountain on June 14, 2003. Over 2900 aftershocks of this event ended up in the SGBDSN catalog through the end of FY02. This number alone is greater than the average number of events per year since the SGBDSN started.

The accelerometers for the three boreholes on the pad of the proposed Waste Handling Building were installed in two separate efforts, January 21-22 and March 18-19. There are 9 3-component sensors for a total of 27 channels of data that is being collected onsite by the Antelope software system and also in onsite disks as backup. Daily QC checks of the data are being done by remote login. A problem with the onsite calibration is not yet solved and has required returning one set of the instrumentation to the lab for diagnosis.

RefTek instruments that were earmarked for the ESF had to be returned to the manufacturer to fix a firmware bug. The firmware fix is necessary to receive correct timing information from the True-Time GPS receiver that is installed outside of the ESF along the fiber connection. We have requested that small pads be constructed at the ECRB Niche 5 location and at the strainmeter location. The decision on the installation at Niche 5 is dependent on UC Berkeley activities in the alcove. Fiber connections to hardware that provide accurate time to the ESF units are being completed by the TCO.

We have submitted the dataset for all the events located with the SGBDSN from 1995-1999 (roughly 10,000 earthquakes). This was submitted on DVD media to the HRC TDA in January. QA activity to qualify old datasets consisting of 1992 and 1995 analog network hypocenter lists has been completed.

Data qualification efforts are proceeding for the project to reevaluate kappa. Borehole seismic data from 1997-1998 portable recorders and portable weak-motion data at TerraTek strong-motion sites are top priorities. Functional definition and programming are nearly done for software to measure kappa and present results. The IPR governing the field procedures for refraction microtremor surveys in support of the kappa study was submitted for review and is now being rewritten to address the reviewers’ comments. Fieldwork is on hold until the environmental standdown for YM work is cancelled.

In January we were able to complete the hiring for our system administrator slot. There was a good field of candidates and we were able to hire a very talented individual.

Problems:

The backlog of events to be analyzed following the June 14, 2002, earthquake continues at roughly three months. We have been working to reduce this backlog, making slight headway this past quarter.

The environmental standdown is a serious impediment to our fieldwork in support of the kappa investigation.

Status of Funds:

We have expended approximately $653K of our 9-month funding of $1336K through March 31. This is only 49% of the funds, while a straight-line projection would be 67%. We are thus significantly under-running. The reasons for this are largely due to two unfilled job positions (new seismic technician, and a new post-doc). The difficulty of attracting suitable candidates has hampered these searches. Also, fieldwork originally planned in support of the kappa project has been postponed repeatedly.

Plans:

Approval will be sought for construction plans at Alice Ridge and at Skull Mountain for telemetry relay stations. These relay stations will allow us to transmit the WHB borehole data and the ESF data to Reno. They are the first facilities in a planned upgrade of the entire seismic monitoring network to IP packet transmission.

Contingent on not having a shutdown of ESF operations and also on having the instruments returned from the manufacturer, the seismic equipment for three ESF sites will be installed in the current quarter and data from these sensors will be collected by the Antelope software system at the TCO data shack near the ESF north portal.

We will have the FY02 seismicity report reviewed in April and deliver it by the end of May. The kappa report will be ready for review in May and will be delivered in June.

QA of the kappa estimation code will be starting in mid-April. Microtremor surveys in support of the kappa project will begin in earnest after the mid-May end of academic UNR semester.

Work on the focal-mechanism program will begin in this quarter; our Post-Doc (to be hired) will help on this project as it matures.