Jul 21, 2014 9:47 AM by Stephen Bowers
The U.S. Geological Survey updated its National Seismic Hazard Maps last week.
The USGS said in a press release the maps reflect the best and most current understanding of where and how often future earthquakes will occur as well as their intensity.
The map, shown below, shows 42 of our 50 states to be at risk for a damaging earthquake within the next 50 years. Colorado is included within the "moderate" risk area. Areas most would expect - the West Coast, Alaska, and Hawaii - lie within the highest risk zone, which includes parts of 16 states.
Also shown as a high risk zone is the New Madrid seismic zone along the Mid-Mississippi River Valley, which includes southern Illinois, western Kentucky, western Tennessee, eastern Missouri, northeastern Arkansas and northwestern Mississippi. Coastal South Carolina was also included in a high risk zone, while the rest of the U.S. east of the Mississippi River was in a low-to-moderate risk area. The lowest risk in the country was shown across the Upper Midwest.
The USGS also said, "Some states have experienced increased seismicity in the past few years that may be associated with human activities such as the disposal of wastewater in deep wells.
One specific focus for the future is including an additional layer to these earthquake hazard maps to account for recent potentially triggered earthquakes that occur near some wastewater disposal wells. Injection-induced earthquakes are challenging to incorporate into hazard models because they may not behave like natural earthquakes and their rates change based on man-made activities."
Recent earthquake trends, such as the 5.8-magnitude tremor that hit Virgina recently, helped in many adjustments as those recent earthquakes have sparked research that indicates a higher risk for earthquakes in parts of the East.