larger regions than those of the western United States. In particular, it indicates that the Mid-Continent is not free of earthquakes and that the absence of recent seismicity does not rule out the presence of active faults. Other regional faults such as the Washita Valley fault which runs parallel to the Meers fault may also be capable of causing earthquakes. The USGS national hazard map states that the Meers fault has a recurrence interval of 4,500 years but estimates range from 100,000 years to 1,300 years. The fault may generate strong earthquakes in the future; earthquakes with magnitudes might be possible on the Meers fault and an earthquake similar to the Holocene ones would be felt over large parts of the continent, including Oklahoma and Texas, with intensities comparable to these of the 1886 Charleston earthquake and 1811–12 New Madrid earthquakes. Naming and research history The fault was discovered during field work in the 1930s–1940s and is named after the town of Meers; previously it was known as the "Thomas fault" after a ranch named George Thomas Ranch and then as the "Meers Valley fault". The scarp was described as a Permian fault scarp before Holocene activity was discovered and made known by Gilbert 1983 and Donovan et al. 1983. The discovery of Holocene activity at the Meers fault was a surprise to scientists and attracted the attention of geologists after two publications in 1983 highlighted the young movements on this fault. The Meers fault is the best researched fault east of Colorado and one of six faults east of the Rocky Mountains that appear in the USA national seismic hazard models. Research published in 2019 has found that it is longer than believed until then. References Sources Geology of Oklahoma Earthquakes in Oklahoma Natural history of Oklahoma Seismic faults of the United States Strike-slip faults