Dam causes quakes

Scientists from the U.S. Geological Survey have tied Oroville Dam to nearly 20,000 micro earthquakes over 25 years, with the largest two coming the day of the spillway crisis last year.

In a report published Tuesday (Dec. 18) by the Seismological Society of America, the researchers found more than 19,000 “smaller-magnitude events similar in character” to the Feb. 14, 2017, tremors measuring 0.8 and 1.0 on the Richter scale. The micro quakes “strongly correlate with periods of spillway discharge.”

The scientists attribute the seismic activity to leaks, “long before any damage to the spillway,” and did not determine the dam is in danger of breaching.