The number of earthquakes in the central United has increased dramatically over the past decade. Between the years 1973–2008, there was an average of 25 earthquakes of magnitude three and larger in the central and eastern United States. Since 2009, the average number of M3 earthquakes has jumped to 362 per year. The rate peaked in 2015 with 1010 M3+ earthquakes. Since 2015 the earthquake rate has declined, with 690 and 364 M3+ earthquakes in 2016 and 2017, respectively. Nonetheless, this rate is far higher than the average of 25 earthquakes per year. 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. Damage has been caused by some of the larger events, including the M5.8 Pawnee and M5.0 Cushing Oklahoma earthquakes that occurred in 2016.
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 Really Are Causing Earthquakes!
USGS scientist Justin Rubinstein gives an overview on how energy industry practices are causing earthquakes in America’s Heartland.
- USGS Energy Program: Geologic Carbon Sequestration