DALLAS (AP) - Seismologists say dozens of small earthquakes that have rattled North Texas in recent months have been concentrated along a narrow two-mile subsurface fault.
Southern Methodist University and the U.S. Geological Survey on Friday released a preliminary report explaining so many people felt the quakes because their trigger points were only about three or four miles below ground.
Most of the temblors had a magnitude of 2 but one Jan. 6 was 3.6. SMU says in the report that the fault extends from Irving into west Dallas.
Seismologists used more than 20 monitors placed around the quake sites to determine the fault existed. They say the task now becomes learning the cause of the quakes.
The report says the seismic activity associated with the fault appears to be diminishing over time.
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