Liz earned a Bachelor of Science degree in Veterinary Medical Technology from Lincoln Memorial University In Harrogate, TN.
The Largest Recorded Earthquake to Have Occurred in the State of Texas
The 1931 Valentine earthquake occurred on August 16, 1931. It had a magnitude of 6.5 and a maximum Mercalli intensity of VIII, which is severe. Though no casualties were reported, the most severe damage was reported at Valentine, where all of the buildings, except for wood-frame houses, were severely damaged. All brick chimneys were toppled or cracked. In terms of magnitude and damage, the Valentine earthquake is the largest recorded earthquake to have occurred in the state of Texas.
The schoolhouse was so badly damaged that it had to be completely rebuilt, and small cracks formed in the schoolhouse yard. Some walls collapsed in adobe buildings, and ceilings and partitions that were made of wood were cracked. Some concrete and brick walls were cracked, and one low wall, reinforced with concrete, was broken and collapsed. Tombstones in a local cemetery were reported to have been rotated. Property damage was reported from widely scattered points in Brewster, Jeff Davis, Culberson, and Presidio counties. Several landslides were reported as well, occurring in the Van Horn Mountains, southwest of Lobo, in the Chisos Mountains, in the area of Big Bend, and near Pilares and Porvenir. Additionally, landslides occurred in the Guadalupe Mountains, near Carlsbad, New Mexico, and slides of rock and dirt were reported near Picacho, New Mexico. Hydrologic issues occurred in several artificial water bodies, and many wells and springs that were used as water sources were muddied throughout the area. People in parts of Oklahoma, New Mexico, and Chihauhua and Coahuila, Mexico claimed that they also felt the tremors.
Seismic Zones and Tectonic Plates
This earthquake may have been associated with seismic zone 1. The main reason that earthquakes are more frequent is the western US than the eastern US is because the eastern US lies closer to/right above the boundary of two tectonic plates; the North American plate and the Pacific plate. In contrast, the eastern US is arranged more in the middle of the North American plate, which stretches from the California coast to the middle of the Atlantic Ocean. Plate movements (which cause earthquakes) are more likely to be felt closer to plate boundaries than in the middle of plates. Although earthquakes are less frequent in the eastern US than in the western US, they are usually felt over a broader area. An earthquake east of the Rocky Mountains is typically felt over an area ten times larger than a similar earthquake on the west coast. However, just because earthquakes are less frequent in the eastern US does not mean that they are less dangerous; they actually tend to do more damage in the east than the west. This is because building codes in the east are less strict, and therefore, infrastructures are less able to withstand seismic activity.
- USGS. Historic earthquakes: largest earthquake in Texas. USGS Earthquake Hazards Program.
- Ni, J. F.; Reilinger, R. E.; Brown, L. D. (1981). Vertical crustal movements in the vicinity of the 1931 Valentine, Texas, earthquake. Bulletin of the Seismological Society of America, Seismological Society of America, 71 (3): 857–863.
- Herper, M. (2011). Why are there so few earthquakes on the east coast? Forbes magazine. Retrieved from http://www.forbes.com/sites/matthewherper/2011/08/23/why-are-there-so-few-earthquakes-on-the-east-coast/#10de5fe2347b
- Notes from Geology college course.
© 2019 Liz Hardin