Since New Years Day Mount St. Helens has experienced 40 earthquakes within its vicinity as tremors continue every few hours. The most powerful earthquake was a magnitude 3.9 that occurred around midnight west coast time about 5 miles from Mount St. Helens and 23 miles from the town of Morton.
The 3.9 magnitude earthquake was felt in Portland but there were no reported injuries or damage. Since that earthquake there have been 16 more earthquakes, averaging about every half hour with magnitudes from 0.6 to 2.6.
It is common to experience swarms of earthquakes at Mount St. Helens. While it is certainly not a sign of an impending eruption, the earthquakes are a result of an active volcanic system.
Mount St. Helens is most commonly known for its major eruption in 1980, the deadliest and most economically damaging volcanic event in the history of the United States. The stratovolcano is situated just 96 miles from Seattle and 50 miles from Portland, making an eruption especially dangerous.
While Mount St. Helens hasn’t had a significant eruption for the past almost 38 years it is still considered an active stratovolcano by geologists. In fact, Mount St. Helens is considered a relatively young volcano, forming in the past 40,000 years and has been the most active volcano in the Cascade Range within the past 10,000 years.
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