Let’s look at some volcanic rumblings and eruptions from the past week:
Mount St. Helens is keeping up its unsettled 2016, this time with another small earthquake swarm. The USGS detected over 120 earthquakes over the previous couple of days, all happening 2-4 kilometers (1-2 miles) beneath the volcano and all very little (less than M1). These earthquakes, such as the ones that happened before this season, are probably caused by magma moving or faults adjusting as pressure changes within the magmatic system underneath Mount St. Helens. It does n’t alter the condition of the volcano: It’s active, taking what’ll probably be a short rest before its next eruption. That could still be years from now.
The ashes floated chiefly to the NNE but luckily no one lives in that direction (or pretty much anywhere close to Shiveluch). Due to air traffic within the area, an orange aviation alert was raised to warn airlines of the Shiveluch ash plume.
Some bits that are brief:
Because of cracking on the volcano antennas on Irazu in Costa Rica will need to be moved. Whether this cracking is related to any potential changes in the volcano or only faulting of surface blocks is cloudy.
A small explosion happened from the peak Halema’uma’u crater at Kilauea when part of the crater wall fell to the lava lake. You see some remarkable chunks of debris fly at the camera, both in the kind of old wall rock and lava in the lava lake and can view video. This can be a fairly common event but can disperse ash and debris across the summit area of the Hawaiian volcano.
A growth in seismicity was noticed at Cayambe in Ecuador. The earthquakes were all small with one as large as M3.6 that lasted a few days. Much like St. Helens, this rumbling is likely merely a hint that the volcano is recharging, but no eruption seems to be forthcoming according the the Instituto Geofísico (IG). The past known eruption from Cayambe was in 1785.