New ground has been broken in the quest to predict earthquakes more accurately. The United States Geological Survey has created a new map that highlights where natural and man-made earthquakes could cause damage around the country. The issue of man-made earthquakes has become more of a concern recently as geologic surveys have shown parts of the United States to be at risk for induced seismic activity.
Natural earthquakes are difficult to predict, but the areas in which they commonly occur can be studied in order to determine what potential damages could occur when an earthquake hits. The USGS is now adding in the possibility of man-made earthquakes and researching where damage could occur in these instances. So-called ‘induced seismicity’ could impact nearly 7 million people in the central and eastern United States.
Induced seismicity is of greater interest to seismologists and geologists in places that don’t see much natural earthquake activity in the United States. These regions include the East Coast as well as parts of the central United States. Naturally occurring earthquakes are more common in the western United States.
Man-made earthquakes can be caused by improper wastewater disposal coming from oil and gas production, among other activities. This wastewater is pumped back into the ground, oversaturating existing underground wells and destabilizing portions of the Earth’s crust.
The states with the greatest chances of having a man-made earthquake include Oklahoma, Kansas, Texas, Colorado, New Mexico and Arkansas. The areas in the USGS map have between a 1% and 12% chance of having induced seismicity. There has been an increase in earthquakes in the central part of the country in recent years, and residents of these locations should be aware of the risks they face if an earthquake hits nearby.
The USGS is still researching the greater implications of induced seismicity. Some reports state that man-made earthquakes aren’t as severe as natural ones, but other studies show that induced earthquakes can weaken existing fault lines and cause more instability in the future.
More: Induced Earthquakes Raise Chances of Damaging Shaking in 2016, USGS, March 28, 2016