Real-time Monitor Displays for the
Seismic and Infrasound Stations.
Here are some low bandwidth versions for
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
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.
We are working on an automated system to report and map seismic activity at the
Nevada Test Site
last update: 02 Feb 2012 dpa