A: Yes (Figure 1 - 1847-2000 and Figure 1b - 2005-2009); . In historical times no earthquake with magnitude larger than about 6 has occurred in Texas. However, seismographs near El Paso record small earthquakes with magnitude of 2 or smaller every few days. Nearly every year earthquakes large enough to be felt by ordinary citizens occur somewhere in Texas.
Q: What is the largest earthquake in Texas in
recorded history?
A: The largest earthquake in Texas history
had a magnitude of about 6.0 and occurred on 16 August 1931 near the
town of Valentine, 220 km southeast of El Paso. It caused severe damage
to adobe and brick structures in Valentine, and was felt by Texans as far
away as Dallas. Texas' second largest earthquake occurred on 14 April
1995, also in west Texas. It had a magnitude of 5.8, and was felt in Austin.
Q: What is the highest death toll from a historical
Texas earthquake?
A: Only one Texas earthquake ever took a
human life, and this wasn't in Texas. On 6 March 1923 an earthquake with
magnitude of 4.7 occurred near El Paso and Juarez. Juan Ortiz, a Mexican
tenant farmer who lived in Mexico six miles from Juarez, suffocated when
his adobe house caved in during the quake.
Q: What was the most damaging earthquake in Texas
history?
A: No Texas earthquake has caused much
damage as compared to some earthquakes in other states or throughout the world.
The most damaging was the 16 August 1931 earthquake in Valentine, Texas,
where "all but frame houses were badly damaged, and all brick chimneys toppled
over....The schoolhouse, consisting of one section built of cement blocks
and another of brick....required practically complete rebuilding."
Q: Has an earthquake occurred in Austin in
historic times?
A: On 9 October 1902 an earthquake with
magnitude about 3.9 occurred about 15 km south of Austin near the town of
Creedmoor; this event was felt in Austin.
However, there were no felt reports in Austin from an earthquake with
magnitude of 3.1 that occurred in Manor (15 km east of Austin) on 1 May 1873.
Every few years Austin residents in tall buildings may feel the effects of
large, distant earthquakes, such as the 19 September 1985 Michoacan, Mexico
earthquake, and the 14 April 1995 earthquake in west Texas.
Q: What sort of earthquakes should we expect
from the Balcones Fault?
A: Probably none. The Balcones Fault is
the boundary between the central Texas hill country to the west of Austin and
the flatter plains regions to the east. About 10 million years ago this was
an active fault, but it is not active any longer. A "fault" simply represents
a boundary between two sections of the earth's crust that move or slip
relative to one another. When slip is ongoing, the fault is active.
After the slip stops, the fault remains. Thus, in Texas and elsewhere
the land is riddled with faults which no longer present any significant
earthquake risk.
Q: Where can I get a map showing the geologic faults of Texas?
A: The University of Texas at Austin Walter Geology Library (http://www.lib.utexas.edu/Libs/GEO/geology.html) has a geologic map of Texas which has the major faults on it (but not all the faults). You might also check out the Bureau of Economic Geology: http://www.utexas.edu/research/beg/pub.html
Q: Have earthquakes occurred in Houston in
historic times?
A: No. The closest earthquake occurred on
8 May 1910 near Hempstead, Texas, about 70 km northwest of Houston. This
earthquake had a magnitude of about 3.8, and was felt by individuals within
about 30 km of Hempstead, but not in Houston. Of course, Houston residents
in tall buildings may occasionally feel large very distant earthquakes that
occur in Mexico or western Texas.
Near Houston there may be examples of faults which are active,
but which don't have any earthquakes. Land in some communities southeast of
Houston such as Clear Lake and Dickenson is sinking because water has been
pumped out from the ground for many years; this sinking may be associated
with slip along faults. However, when such slip is a slow or continuous
"creep," it isn't an earthquake. To cause an earthquake the faults need to
"stick" then slip suddenly enough to radiate seismic waves.
Q: Have earthquakes occurred in Dallas-Fort
Worth in historic times?
A: Yes. On October 30, 2008, an earthquake was felt in the Dallas-Fort Worth Area. Since May 16, 2009, several earthquakes have been felt in the Dallas-Fort Worth Area.
A: No. However, since 1973 a number of
earthquakes have occurred near the cities of Fashing and Pleasanton about
50 km southeast of San Antonio. The largest of these had a magnitude of 4.3
and occurred on 9 April 1993 in Fashing. Of course, San Antonio residents in
tall building may occasionally feel effects of very distant earthquakes in
Mexico or west Texas.
Q: Have earthquakes occurred in Corpus Christi
in historic times?
A: On 24 March an earthquake with magnitude
3.8 shook Alice, Texas, a community
situated about 60 km west of Corpus Christi.
This is the only known earthquake in this local area in historic times.
Although the Corpus Christi Caller
Times reported that this quake was felt in Corpus Christi, interviews by
a team of UT students determined that this was
erroneous; apparently reporters were confused by reports of
people "near" Corpus (but actually in Alice) feeling the quake.
A felt report study determined that the
entire felt area of the earthquake was about 900 km2;
the highest Mercalli intensities of about VI were from a sparsely
populated region about 10-15 km ESE of Alice, Texas.
This region lies along the Vicksburg fault zone that runs
nearly parallel to the Fulf coast and is within a few kilometers of
the currently producing Stratton oil field.
Although this location suggests that the earthquake may have been
triggered by hydrocarbon withdrawal, another likely possibility is
that the quake has a tectonic origin and falls within a band of
weak, natural seismic activity occurring inland from the Gulf coast
eastward to the Texas-Louisiana border.
Q: Does drilling for oil and gas cause or
trigger earthquakes?
A: Research carried out by UTIG scientists
suggests that earthquakes in some parts of Texas may be induced by the
pumping of fluids at oil and gas fields, or by the injection of fluids to
dispose of chemical wastes. The earthquakes in the Fashing-Pleasanton area
southeast of San Antonio are almost certainly caused by or triggered by
pumping; such earthquakes also seem to occur in the Texas Panhandle near
Snyder, Texas.
Q: If pumping oil and gas cause earthquakes,
is it safe to continue pumping?
A: Yes, it is almost always safe.
Earthquakes induced by the injection or pumping of fluids from wells are
generally very small; most have magnitudes of 3 or less.
Moreover, while
tens of thousands of oil and gas wells exist in Texas,
only a few fields show any evidence that oil and gas
pumping induces earthquakes.
Back to main EQ FAQ page.
Date Magnitude Nearby City Remarks 1991 July 20 3.6 Falls City 1992 January 2 4.5 Midland Slight damage 1992 August 10 2.8 Jourdanton 1993 April 9 4.3 Fashing Slight damage, some aftershocks 1994 September 27 2.5 W of San Antonio Not felt?? 1995 January 4 2.5 Hallettsville Quake or
sonic boom?1995 April 14 5.7 Alpine Some damage, some aftershocks 1995 November 12 3.6 Alpine Felt In Alpine 1997 March 24 3.8 Alice Felt In Alice 1997 May 31 3.4 Commerce Felt In Commerce 2008 October 30 3.0 Dallas-Fort Worth Felt in Bedford, Euless, Fort Worth, Irving, and Dallas. Several aftershocks occurred 2009 May 16 3.0 Dallas-Fort Worth Felt widely in the Dallas-Ft Worth Area, at Bedford, Colleyville, Dallas, Euless, Grand Prarie, Grapevine, Hurst, Irving and Roanoke. 2009 June 27 2.2 Dallas-Fort Worth Felt in Cleburne.
Figure 2, an isoseismal
map of the cities of Fashing and Pleasanton.