Earthquakes in Oklahoma

• In Cushing, Oklahoma, 11-year-old Caden Kennedy experienced an earthquake while at home
• The earthquake shook the house, knocked out the lights, and made pictures fall off the walls
• Caden and his family evacuated, and had to stay with friends for five days while waiting for their home to be inspected for damage
• Earthquakes have become common in Oklahoma

Earthquake Measurement and Frequency

• Scientists measure earthquakes by magnitude
• Earthquakes with a magnitude of 3 or higher can be felt by most people
• In 2016, Oklahoma had over 600 earthquakes with a magnitude of 3 or greater
• The November 6 earthquake in Cushing measured a magnitude of 5
• Strong earthquakes measure 9 or higher, but these are very rare
• Oklahoma historically averaged fewer than 2 earthquakes per year with a magnitude of 3 or greater

Human-Made Earthquakes

• Alaska and California, which are located near tectonic plate edges, experience the most earthquakes
• Most earthquakes occur when tectonic plates slide, push together, or pull apart from each other
• Oklahoma is not near any major tectonic plate edges
• The increase in Oklahoma earthquakes is likely linked to oil and natural gas drilling
• Oklahoma's oil and natural gas production has drastically increased in the past decade
• Oil and gas drilling involves extracting liquid which is often mixed with water and chemicals
• The extracted water cannot be reused, as it is very salty and contains bad chemicals
• To dispose of the waste water, oil and gas companies pump the water back into the earth through deep wells
• Scientists believe this process is likely causing the earthquakes

Oklahoma's Response

• The Oklahoma Corporation Commission oversees the state's oil and gas drilling and is working to address concerns about the increase in earthquakes
• The Commission placed new limits on the amount of wastewater that companies can pump into the ground
• These limits appear to be working, as the number of earthquakes dropped in 2016 from a record high of 907 in 2015
• Many Oklahomans have become accustomed to living with earthquakes