Disasterous Earthquakes in Texas
POSTED: Sunday, February 9, 2014 - 6:20pm
UPDATED: Sunday, February 9, 2014 - 6:21pm
BROWNSVILLE (NEWS CENTER 23) — Given the Valley’s distance from fault lines, a large earthquake would barely be noticeable.
Fact number one is Earthquakes do happen in Texas.
In fact, there are four regions within Texas that have experienced historical earthquakes. El Paso is one of them. Data shows that the two out of four regions in Texas, near El Paso and in the Panhandle, should expect earthquakes with magnitudes of about 5.5-6.0 to occur every 50-100 years.
On the Richter scale, an earthquake is usually considered much more serious, and is felt by most people, once it hits about 5.0.
Each number of the Richter scale is equal to an increase in the magnitude of an earthquake, by ten.
For example, an earthquake measuring 6.0 on this scale has a magnitude ten times greater than a 5.0 quake.
One whole number increase also means that about 31 times more energy was released during a quake.
In south-central Texas the hazard is generally low, but residents should be aware that small earthquakes can occur there, including some which are triggered by oil or gas production.
On 24 March 1997 and on 25 April 2010 two very similar earthquakes with magnitude 3.9 shook Alice, Texas, a community situated about 60 km west of Corpus Christi.
These are the only known earthquakes in this local area in historic times.
Although the Corpus Christi Caller Times reported that the 1997 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.
Felt report studies for both quakes determined that the entire felt areas were 559 miles, the highest Mercalli intensities were from a sparsely populated region about 5-10 miles of Alice, Texas.
This region lies along the Vicksburg fault zone that runs nearly parallel to the Gulf coast and is within a few kilometers of the currently producing Stratton oil field.
Although this location suggests that these earthquakes may have been triggered by hydrocarbon withdrawal, another likely possibility is that they have a tectonic origin and fall within a band of weak, natural seismic activity occurring inland from the Gulf coast eastward to the Texas-Louisiana border.
A 3.9 earthquake isn't too intense. It basically means these temblors are not felt, although those at the higher end may be, and it may cause very minor damage.
Between 1847 and 1994 there were more than 110 recorded earthquakes of magnitude three or greater in Texas.
Note: No Texas earthquake has exceeded a magnitude of 6.0, and most have been fairly small and caused little or no damage.
On a Richter scale, a 6 magnitude is classified as strong and can cause significant damage, especially in populated areas.
Only one earthquake in Western Texas has caused a death. And the earthquake took place in Juarez, Mexico.
On March 7, 1923, in Ciudad Juárez, Chihuahua, a few kilometers from the quake's epicenter, an adobe house collapsed and suffocated the man inside.
The largest earthquake in Texas history had a magnitude of about 6.0 and occurred on 16 August 1931 near the town of Valentine, about 130 miles 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.
Verdict: Although earthquakes are not uncommon in the Valley, the chances of experiencing a strong earth quake in Texas is not very likely.