Real-time Monitor Displays for the
SMU TXAR and NVAR Seismic and Infrasound Stations.

Requires JavaScript.

Here are some low bandwidth versions for txar and nvar.


The Geophysics Program in the Department of Geological Sciences at Southern Methodist University operates two seismographic stations. One is in Lajitas, Texas, and the other in Mina, Nevada. Both are Designated US Atomic Energy Detection System and International Monitoring System Primary Seismic Arrays.

Chris Hayward has written an in-depth discussion of the planning and construction of The TXAR Array. Below is a brief description of the array and of the real-time seismographic monitor displays.

The TXAR Seismic Station


Southern Methodist University's Department of Geological Sciences operates and maintains a remote telemetered seismic observatory near the town of Lajitas, Texas, on the southern Texas border with Mexico. Chosen for its remote location far from common cultural and seismic noise sources, the Lajitas area is an ideal location for recording very small signals from seismic events. Designed and developed at SMU under contract from the Defense Advanced Research Projects Agency this seismic station is a Certified Primary Array of the Comprehensive Nuclear Test Ban Treaty Organization Worldwide Monitoring System.

This view is of the Chisos Mountains in the background with the seismic instrument array locations in the fore- ground. Summer thunderstorms over the Chisos form impressive scenic and seismic displays, and can also knock out power for days. TXAR has its own solar and propane backup generators to avoid interruptions in power service.


Arrays of closely spaced seismometers provide for enhanced detection and processing of regional and distant signals. The initial TXAR array design consisted of eight vertical seismometers arranged in two concentric 4 km and 1 km diameter circles, plus a center three-component seismometer. Two three-component broadband elements have since been added along with four infrasound stations. The rugged topography and availability of site access also determine the seismometer locations.

Click here for larger map.


The TXAR Monitor Display shows the seismic and infrasound waveforms from the array in near real-time. Earthquakes, explosions, lightning, meteor showers, and even the air pressure wave from the final approach of the Space Shuttle can be observed here. The top window contains 60 seconds of data from the nine vertical component seismic array elements, TX01 through TX10. The next three windows show 60 seconds of data from the 3 three-component broadband stations TX11, TX31, TX32. The fifth window contains 60 seconds of infrasound data from the four infra- sound stations. The bottom three windows display one hour of data for the single component array elements, two of the three-component elements, and the four infrasound stations. This display is a mirror of one in the Array Command and Control Center at SMU which is used by researchers to monitor and control the array.



Click on the image to activate the real-time JavaScript display.


We are working on an automated system to report and map seismic activity at the Nevada Test Site


last update: 02 Feb 2012 dpa