INVESTIGATIONS
This project provides support for the installation and operation of the TERRAscope broad-band seismic network. Earthquake data from TERRAscope contribute to the goals of the master model and the seismicity and source processes groups. This year in cooperation with the USGS Pasadena Office we have connected 10 TERRAscope stations to real-time telemetry. We have also implemented the IRIS Portable Data Management Software (PDMS) to quality check the data at Caltech. Scientific analysis of the data is being undertaken by both SCEC faculty and graduate students as well as at other institutions around the country.
RESULTS
We report the following accomplishments:
Station Installation
In 1997 we maintained existing TERRAscope stations and added four new stations with equipment funding from the NSF/ARI program (Figure 1). All of the TERRAscope stations will be transmitting data real-time to Caltech by the end of 1997. These data are being used by the Southern California Seismographic Network for routine earthquake catalog processing and archived at the SCEC Data Center and at UCSB as part of the Group B Greens Function Library.
Data Quality Checking
During FY 1997 we performed the following work with the support of different sources including this subcontract from SCEC. We presented posters summarizing our work at the 1996 and 1997 Fall AGU meetings. Two oral presentations of our progress were also made at the IRIS/Quanterra users meeting that we sponsored in November 1997 at ASL in New Mexico.
TERRAscope data have been collected in two different ways in the past. First, the stations were dialed up by using the IRIS/SPYDER software. This made it possible to retrieve specific time windows for both local, regional, and teleseismic events. Second, data were recorded at the site on tape and the tapes were retrieved every few weeks. The data from the tapes formed the authoritative data stream that has been archived in the IRIS Data Center. For many different reasons the recovery of data from the tapes has been only 60%. This rate of data recovery is too low and we have changed our mode of operation to solve this problem. In May 1996 we sent a data analyst to a workshop hosted by IRIS/DMC in Seattle to receive training in the use of the new IRIS Portable Data Center Management Software. This software has been implemented at Caltech and is being used to generate SEED volumes of TERRAscope data.
Publications
Maechling, P., R. Clayton, K. Hafner, E. Hauksson, T. Heaton, K. Hutton, H. Kanamori, W. Miller, A. Acosta, G. Cone, D. Given, L. Jones, C. Koesterer, J. Mori, Caltech/USGS Element of TriNet - Current Status, (abstract), 1997 Annual Fall Meeting, San Francisco, CA, December 8-12, 1997.
Pinkston III, D., P. Maechling, E. Hauksson, H. Kanamori, AWARE: A Real-time Ground Motion Display Program, (abstract), 1997 Annual Fall Meeting, San Francisco, CA, December 8-12, 1997.
Maechling, P., R. Clayton, K. Hafner, E. Hauksson, T. Heaton, K. Hutton, H. Kanamori, W. Miller, A. Acosta, G. Cone, D. Given, L. Jones, C. Koesterer, J. Mori, Caltech/USGS Element of TriNet - Current Status, (abstract), 1997 Annual Meeting, Southern California Earthquake Center, Costa Mesa, CA, October 4-7, 1997.
