The Kenai Peninsula was rocked to sleep last night by a pair of minor earthquakes.
The first, a 4.3-magnitude quake, hit just before 7 p.m. in the Primrose area, near Moose Pass. The second, a 4.7, was just before 11:30 p.m. near Tyonek, on the other side of Cook Inlet.
Both triggered a flurry of activity on social media. Alaskans from Homer to the Mat-Su reported light shaking on the U.S. Geological Survey’s “Did You Feel It?” site.
But Michael West with the Alaska Earthquake Center said earthquakes like these happen every week in Alaska — they just occur in more isolated areas.
"These are garden variety earthquakes," he said. "Neither of these would’ve shocked geologists last night."
He said they both came from the subduction zone in southern Alaska, where the Pacific tectonic plate is sliding beneath its neighbor.
That zone drives much of the earthquake activity in the region. But usually those quakes are happening on the other side of the inlet, where fewer people will feel them.
And West said even though the quakes were close in time, they’re probably not connected in any other way.
"The answer may not be super satisfactory, but we really chalk this up to coincidence," he said.
He said large earthquakes can sometimes trigger others nearby, but that these were too small to do that.
Alaskans may remember the 7.1-magnitude earthquake that jolted Southcentral in 2018.
West said many of the quakes in the region since then are connected to that earthquake.
"I would say a disproportionate number of the earthquakes that are being felt, say, this year, can still be traced back to aftershocks of that event," West said. "And these two last night were not."
He said they were, for lack of a better term, good old-fashioned earthquakes.
