Hello Bill - Electronic noise, for the most part. Thanks for your interest, Cheryl -------- bill skains wrote: I notice a lot of activity on the webicorder...Seems to be much more activity than almost all the other Volcanoes. What causes the elevated amount of activity? Thanks from Branson, Missouri. -- Cheryl Cameron Geologist, Alaska Volcano Observatory Alaska Division of Geological & Geophysical Surveys voice: 907-451-5012 fax: 907-451-5050