Seismometers at the Pacific Northwest Seismic Network’s Mount Baker website report three small, shallow earthquakes in the vicinity of Mount Baker in the past few days. The most recent, on April 15, is very near the other two from the 14th, and have estimated magnitudes between 0.7 and 1.1. The epicenters are clustered around 17 km south of Sherman Crater, north of the Skagit River and west of Lake Shannon. None of the other 20 most recent earthquakes detected by the two Mount Baker area seismometers are reported from this area, although the decadal map shows that these are not in unusual locations.
Significance? The 3 earthquakes reported in April so far are the first since January in the Baker area; another small one occurred on January 9th jsut south and west of the latest group. See the PNSN map for locations. They likely have nothing to do with Mount Baker, rather the usual tectonic rumblings in the area. The last detected seismic activity at the mountain was September 1, 2009, and was probably related to glacial movement rather than anything at depth such as magma movement, one of many mapped beneath the volcano over the past year.
It is fun to visit the PNSN Baker webpage. When will the next little shaker occur, and where? When will activity pick up again this summer due to warming and increased glacial motion?