Within the central and eastern United States, the number of earthquakes has increased dramatically over the past few years. Between the years 1973–2008, there was an average of 21 earthquakes of magnitude three and larger in the central and eastern United States. This rate jumped to an average of 99 M3+ earthquakes per year in 2009–2013, and the rate continues to rise. In 2014, alone, there were 659 M3 and larger earthquakes. Most of these earthquakes are in the magnitude 3–4 range, large enough to have been felt by many people, yet small enough to rarely cause damage. There were reports of damage from some of the larger events, including the M5.6 Prague, Oklahoma earthquake and the M5.3 Trinidad, Colorado earthquake.
This increase in earthquakes prompts two important questions:
- Are they natural, or man-made?
- What should be done in the future as we address the causes and consequences of these events to reduce associated risks?
Increasing Rate of Earthquakes Beginning in 2009
Yes, Humans Are Causing Earthquakes
USGS scientist Justin Rubinstein gives an overview on human-caused earthquakes.
Special Issues on Induced Seismicity
The Leading Edge
The June issue of The Leading Edge features a special section on Injection-induced seismicity. Four USGS studies were included as part of this issue.
- USGS Energy Program: Geologic Carbon Sequestration