It has been a few days since we have seen much activity on Mount St Helens (or been able to see it due to clouds), but last night there were several bright out bursts caused by rock falls from the growing lavadome. The image below shows the location of the bright outbursts recorded by the US Forest service Volcanocam
camera during the night. As can be seen the activity was located on the top of the growing "fin
" as well as lower down on the older part of the lavadome.
An animation of the night's activity is also available here
. It is interesting to compare the timing of the events with a seismic trace of from last night. The outbursts appear to correspond to the longer, broader signals seen on this webicorder
trace located on the old dome within the crater. The larger event that occurred at 04:30 did not correspond with any visible activity, but this is possibly due to clouds obscuring the view.