Summary

This report highlights the activities of the Saint Louis University of the Cooperative New Madrid Seismic Network for 1999. The network provides locations of regional earthquakes, data for research and serves as a focal point for local and regional interest in earthquakes.

Progress has been made in creating a modern broadband digital seismograph network in the central U.S. While the network is not complete, stations are running and providing coverage. With the exception of Kentucky, there are existing stations in the region covered by the Central United States Earthquake Consortium. A station in Kentucky is planned.

Stations

The networks run by Saint Louis University consist of short-period and broadband stations.

Short Period Network

The short-period analog systems feed into Southeast Missouri State University, Cape Girardeau, Missouri and into Saint Louis University, St. Louis, MO. In November, 1999 Mitch Withers and Greg Steiner installed USGS provided Earthworm systems at both locations which provides direct transfer of Cape Girardeau data to St. Louis, where is combined with other data streams to feed to CERI, The University of Memphis. The combined short-period and broadband data streams at SLU provides us with new opportunities for rapid location of regional earthquakes.

Broadband Network

The planned broadband network consists of 14 stations in the region. The figure below shows currently operating broadband stations (symbols surrounded by bold black outline) run by SLU and the USGS.

The BILLIKEN stations are the result of an independent effort by Dr. Brian J. Mitchell of this Department

The USNSN stations are run by the U.S. Geological and contribute to the national ability to respond to US and worldwide earthquakes. A recent development is the Advanced National Seismic System which should receive initial funding in FY01. The ANSS radically improve the nations ability to rapidly locate and assess earthquake impact on the U.S.

The broadband stations of the SLU portion of the USGS funded Cooperative New Madrid Seismic Network will consist of 14 sites. As as November, 1999, the installed stations are

• SLM - St. Louis, MO (15 Feb 1997)
• BLO - Bloomington, IN (27 Mar 1998
• MPH - Memphis, TN (15 May 1998)
• PLAL - Pickwick Lake, AL (01 July 1998)
• SIUC - Southern Illinois University, Carbondale, IL (18 February 1999)
• UALR - University of Arkansas, Little Rock, AR (30 June 1999)
• UTMT - University of Tennessee at Martin, Martin, TN (4 June 1998)

• FVM - French Village, MO (Jan 00)
• PVMO - Portageville, MO (Apr 00)

1975-1995 Central U.S. earthquake catalog is show in gray

The data transmission aspects of the network are interesting. All stations are running DACOMMO/COMSERVE between Sparc workstations and the Quanterra data acquisition system. The connection between the two is by Internet, by serial link or VSAT. David Ketchum installed vdl on many of the Sparc's, which permits a data stream to Golden, to assist the USNSN national location capability. This was useful for responding to public inquiries. The local network recordings shown below were essential for locating this event. The presence of short-period Rg waves is a direct indicator of shallow depth.

Seismic station installation has been delayed for some very important reasons:

• Sensors: We have had major stability problems with 12 of the 15 broadband sensors that we purchased for the network. During the summer of 1998, we implemented an automatic daily seismogram generation which deposits images on our web server for daily review. We later improved the presentation on the web page

  http://www.eas.slu.edu/Earthquake_Center/NM/bbsta.html

  by a special display of the seismograms of the previous day. We sent a letter to the manufacturer on March 16, 1999 and received a positive response concerning our problems with the instruments. Unfortunately, instruments have not been upgraded yet, and we have several that are unsuitable for deployment. We have made the USGS aware of this problem.

  We replaced the Q380 3-component system at SLU with a Q680 6-component recorder. This permitted us to run two instruments side-by-side to compare their performance with time and to estimate instrumental noise using a cross-correlation/coherency technique developed at ASL. We strongly recommend that anyone purchasing broadband instruments do the same as a quality control.

• Hardware Upgrades: The GPS clocks in the Q380 and Q680 data acquisition systems were examined for the GPS epoch problem of August 1999. Unsuitable GPS receivers were replaced. This successful upgrade effort began in 1998 upon appraisal of the problem by Quanterra.

• Software Upgrades: Most of the Q380/Q680 are now running MultiShear rather than UltraShear. This software upgrade provides new capabilities to the systems and also handles the Y2K problem. We are having some difficulty since the 68000 systems are underpowered for some of the systems, e.g., those with ethernet cards.

• Routine Maintenance: We replaced the Q380 disk drive at PLAL, and the Sparc at MPH. The CMG3-ESP as PLAL as replaced by a CMG-40T when the ESP stopped working.

Plans for 2000

• Eric Haug will go the Quanterra users group at Berkeley in December.

• Melanie Whittington and Roberto Ortega will attend the PDCC training class at the IRIS DMC in Seattle at the end of January, 2000. Having these individuals trained will permit us to archive our digital data to the IRIS DMC.

• Archive data at IRIS DMC.

  This will include not only incoming data but also the data from the past two years. Melanie Whittington has preserved all digital data by writing them to CDROM's

• Complete station installation.

  We will make use of two additional data transmission technologies: spread spectrum radio and frame relay. Fram relay will be used between St. Louis and Portageville, and may be used between St. Louis and French Village. It may also be advantageous to put in a frame relay link to the CERI data hub at New Madrid, Missouri, which would be at the northern end of their microwave link. Such a connection would provide CERI with a point-to-point connection to the hub through St. Louis, and would permit SLU to receive CERI broadband data streams.

• Complete system integration with Earthworm

  The Earthworm system has a module that converts Quanterra DACOMMO packets to Earthworm packets. We will replace Sparc I's at local sites with later Sparc's that can run the Solaris thread library and thus support the conversion to earthworm packets.

Education

The Earthquake Center web address

serves the public. The following figure illustrates the prominence of requests to the Earthquake Center on the Department's web server.

We live in Athens Greece. My daughter is 5 years old and two days after the 5.9 earthquake she still won't come in the house. Where we are we felt the earthquake but nothing was damaged. We are sleeping outside in a trailer because she is so panicked. We came in last night and her father went to the bathroom, she heard a motorcycle and started to cry that daddy was going to die we have to get him out. She starts panting and her heart goes crazy. I don't know what to do. Right now we are putting no pressure on her but she is showing no signs of coming in. The aftershocks of course are complicating her fear and of course she saw the coverage on Turkey. Any advice? Or could you tell me where I could get some help, please?

We were able to provide a contact with an individual having experience in these crises. We believe this one request justified our web presence.