Hello Allen - It's difficult to know I'm answering your question as I'm not sure which webicorders you're looking at, but it looks like there was a regional earthquake in the Aleutians (not volcanic) that showed up on some of our seismic records. Thanks, Cheryl -------- allen joseph wrote: I notice that on Thurs, April 28, quite a few webicorders all have a wiggly line at the same time around 12:11-12:15 pm. What does that mean? -- Cheryl Cameron Geologist, Alaska Volcano Observatory Alaska Division of Geological & Geophysical Surveys voice: 907-451-5012 fax: 907-451-5050