Quarterly Report to the Harry Reid Center

UCCSN-DOE Cooperative Agreement

Task ORD-FY04-006: Seismic Monitoring

PI: James N. Brune

UNR Seismological Laboratory

Report Period: 07/01/2004 – 09/30/2004

Progress:

During this reporting period (Jul.-Sep. 2004), we have maintained seismic operations with 29 real-time SGBDSN stations under the QA procedures that have been established with the HRC. Network uptime has been 99.9% over the three months.

As of this reporting date (10/07/2004), we have nearly completed analysis of the earthquakes in the YM vicinity through September 30. Aftershocks of an M 5.5 earthquake near Mono Lake on September 18 and unusually active seismicity in California after that have impacted the analysis of the last 13 days of September. The largest earthquake which occurred in this past quarter within the SGBDSN monitoring area was apparently only M 2.3, which is abnormally low.

The draft of the report on the FY2003 seismic activity in the vicinity of Yucca Mountain has been modified to resolve all technical and QA comments. A resurvey of some station locations was required to achieve a Q stamp, and this was completed in late September.

A draft report on the preliminary observations with accelerometers at three boreholes on the ESF pad has been modified to resolve all comments. An assessment of part of the waveform data has been undertaken to obtain a Q stamp for it.

A paper on precarious rocks and Little Skull Mt. earthquake simulations has been accepted for publication in the Bulletin of the Seismological Society of America.

The SDR for the kappa determination software has been completed. The SDR for the program SEISOPTREMI is in progress. Software qualification reports ((LLR) on four programs (REF2ORB, DBPICK, DBOC2, CALIB) have been submitted – three are approved and one is pending. Two other software qualification exercises have been started for HYPOINVERSE and MLCALC; these are high-level programs.

Installation of the ESF seismic instrumentation at three locations in the tunnel (Alcove 5, ECRB Niche 5, and at the east end of the strainmeter) is complete. Data is being collected in real-time from both weak-motion and strong-motion sensors at these sites now. Factors for converting digital counts to true ground motion have been determined.

Equipment for three seismic sites over the ESF has been ordered, as well as upgrade equipment for 2 of the older strong-motion stations which will then be enabled for telemetry.

Installation of power and telemetry equipment at UZ16, Fran Ridge, and at the TCO data shack is complete as of this date (10/07/2004).

Problems:

Multiple delays in the work orders for concrete pouring at the TCO data shack for a telemetry antenna mast and at UZ-16 for solar panels and the antenna mast delayed our installations there until October.

The kappa software QA effort is behind schedule and has impacted our delivery schedule for this report (originally 9/30/2004).

Although not final, it is important to point out that plans for a tunnel powerdown and closure would severely impact our data collection in the tunnel. Battery power would be an extremely costly endeavor, and there is no means to check instrument health and performance in this case.

Status of Funds:

As of 9/30/2004, we had expended $1,642K on Task 6. This represents 95% of the total appropriated, $1,727K for FY2004. We purposely held over some funds to address the usual start-of-FY funding delays, but will exhaust those in October.

Plans:

In the next quarter (Oct.-Dec.) we plan to request approval for the 3 sites above the 3 ESF tunnel installations. We plan to install the recording equipment at UZ-16, hook up geophones in that well, and conduct a shakedown of the recording system. We plan to occupy the small building on top of Skull Mountain which has been allocated to us and move real-time data from the TCO data trailer to Skull Mt. and from there via a microwave system to UNR campus.

We will complete and deliver both the report on the FY2003 seismicity in the vicinity of YM and the report on preliminary findings at the borehole accelerometer array on the ESF pad.

We intend to finish the software qualification for the two programs needed in the kappa project this coming quarter and produce the final kappa computations. We will complete as many ReMi surveys as possible on permitted sites before the end of the year.

Several abstracts related to our Yucca Mt. seismic studies have been submitted for the fall American Geophysical Union meeting. A paper will appear in the December issue of Bulletin of the Seismological Society of America on the detection capability of the Yucca Mountain seismic network.