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West Coast and Alaska Tsunami Warning Center
Earthworm/EarlyBird Processing System

## USGS Earthworm software acquires seismic data of various formats

WC&ATWC EarlyBird software processes this data

URL Last Updated: July 23, 1999
Contact: Tom Sokolowski (wcatwc@wcatwc.gov)
West Coast & Alaska Tsunami Warning Center (WC&ATWC)
910 South Felton Street
Palmer, Alaska 99645
Voice: 907-745-4212
FAX: 907-745-6071

## OVERVIEW

The Earthworm/EarlyBird system acquires, processes, and analyzes both digital and analog seismic data in real-time from seismometers located worldwide. The USGS Earthworm software acts as a data interface for the WC&ATWC. All data imported from other networks or exported to other centers is received/SENT via Earthworm modules. A module written by the USGS for the WC&ATWC passes data to the NT based EarlyBird processing system in a local format. The EarlyBird system was developed at the WC&ATWC for locating and sizing earthquakes as rapidly as possible and issuing tsunami notifications to the appropriate emergency personnel. This software automatically locates and sizes local, regional, and teleseismic earthquakes upon P-wave arrivals.

The Earthworm initiative at the WC&ATWC began as a result of NOAA's National Tsunami Hazard Mitigation Program. One aspect of this program is to enhance the tsunami warning centers with seismic data from networks operated by regional earthquake centers. The USGS is implementing this task and has chosen Earthworm as the standard for seismic data and hypocenter parameters exchange.

A system of dedicated circuits was installed to connect the WC&ATWC and the Pacific Tsunami Warning Center (PTWC) with the National Earthquake Information Center, the USGS at Meno Park, the University of Washington, the Alaska Earthquake Information Center, and the Hawaii Volcanoes Observatory. Connections can be made with other organizations also (such as the Alaska Volcano Observatory and the Pacific Geoscience Center, Canada). These other connections are made through public internet. The Earthworm/EarlyBird configuration is set up so that two processing systems are running concurrently in case of a system or network malfunction. The primary system, Worm1, acquires data from the regional centers through the dedicated circuits along with data from other sources through the internet. It also exports data as needed via the dedicated circuits. The secondary system, Worm2, acquires all data through the internet. Each of these SOLARIS systems has a direct TCP/IP connection with a Windows NT PC (EarlyBird 1 and 2). The Earthworm software also runs on these systems to acquire the data from Worm1 and 2 and to operate an analog-to-digital card for acquiring the WC&ATWC Alaska seismic network. An Earthworm module, ew_atwc, reformats the data and passes it to the EarlyBird processes. EarlyBird sees all data in a consistent format and performs all seismic analysis. EarlyBird 1 and 2 are also on a local Windows NT LAN. This LAN accomodates data transfer between the various PCs in use operationally at the WC&ATWC and enhances tsunami message dissemination.

At present, the systems process approximately 90 channels of seismic data. The data comes from the following sources: WC&ATWC Alaska network, USGS National Earthquake Information Center, USGS Menlo Park, UC Berkeley, University of Washington, IRIS/IDA Near Real Time System, IRIS/Albuquerque Seismic Lab, Alaska Earthquake Information Center, and the Southern California Seismic Network. Aproximately half the channels are analog and half are digital broadband.

In addition to exchanging seismic data with other centers, the Earthworm modules in Worm1 and Worm2 accomodate transfer of near real-time hypocenter information computed at other centers. As locations and magnitudes are computed for local earthquakes at the USGS Menlo Park and the University of Washington, these are printed out at the WC&ATWC and are displayed on a map. The WC&ATWC program EarthVu displays the locations of all earthquakes located by the other centers over the last week.

## Earthworm Modules Currently in Use

- import_generic - Receive Earthworm TRACE_BUF and H71SUM messages from other centers. Each center's connection requires a separate import_generic.
- export_scn - Transmit Earthworm TRACE_BUF messages to other centers when just certain channels are to be transmitted from a ring. Each center's connection requires a separate export_scn.
- import_ida - Receive data from the IRIS/IDA Near Real Time System and convert this to TRACE_BUF format.
- ringtocoax - Send all data from ring on Worm1(2) to connection on EarlyBird1(2).
- coaxtoring - Take all data delivered to EarlyBird1(2) by ringtocoax on Worm1(2) and place it in a new ring.
- adsend - Digitize up to 64 channels of data from the WC&ATWC's Alaska network.
- hypo_print - Print and send to EarthVu latest locations and magnitudes determined by regional centers.
- ew_atwc - Take TRACE_BUF data from the WAVE_RING on the NT PCs and pass it to the EarlyBird processing system.
- startstop, copystatus, statmgr - System monitors

Return to main Earthworm page, Sites page, or WC&ATWC home page.