Elevated seismicity continues at Mount Rainier (station STAR) and near Mount Saint Helens (station SHW) volcanoes in the Washington Cascades. Event depths at Mount Saint Helens average around 13 km and form a radial pattern in relation to the volcano, nearly opposite the northeast-trending spoke of seismicity which had affected the volcano through most of this summer. Earthquake depths at Rainier are much shallower (averaging 3 to 4 km depth) and likely reflect minor adjustments within the volcano’s hydrothermal system. Small earthquakes also continue to emanate from the hydrothermal system beneath Lassen Peak volcano (CA) (station MEM), as “slow-slip” continues along the subduction zone west of the volcano. Seismicity seems to be easing beneath the “South Moat” of Long Valley caldera (CA).
Posted on: Sat, 03 Aug 2013 23:04:09 +0000