Observations from the East Texas Seismic Network (June 1981 - August 1982)

GC8403. Observations from the East Texas Seismic Network (June 1981 - August 1982), by W. D. Pennington and S. M. Carlson. 48 p., 33 figs., 3 tables, 1984. ISSN: 0082-3309. Print.


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ABSTRACT
Several microearthquake recording stations were operated as a network in the East Texas Basin beginning in June 1981. At least six certain and two probable earthquakes as well as hundreds of events of undetermined origin were recorded through August 1982. Three of the earthquakes were felt by people in East Texas, including one earthquake and an aftershock at Jacksonville and one earthquake near Center. The Jacksonville earthquake and the Center earthquake were recorded at enough stations to be located instrumentally. Another aftershock near Jacksonville and an earthquake near the town of Mount Enterprise were apparently not felt but were located from instrumental recordings. Yet another Jacksonville aftershock was neither felt nor recorded at enough stations to be located but can be identified from the character of the waveform and relative arrival times at two stations. In addition, two other events were recorded at one station but were not felt and cannot be located; from the character of their waveforms, they appear to be earthquakes near the network.

These earthquakes cannot be assigned to any one fault in East Texas, and their depths are not well constrained. They occurred near the Mount Enterprise fault system along a 90-km segment and may represent activity along that fault system, along nearby secondary faults, or both.

Keywords: East Texas Basin, Mount Enterprise fault zone, earthquakes, microearthquakes, isoseismic maps, seismicity, seismotectonics, seismograph network


Citation
Pennington, W. D., and Carlson, S. M., 1984,  Observations from the East Texas Seismic Network (June 1981 - August 1982): The University of Texas at Austin, Bureau of Economic Geology, Geological Circular 84-3, 48 p.