Hello Doug - Yes, we can adjust the scale for the webicorders - and we do adjust them for long-term trends. The seismology at Fourpeaked is very quiet right now. Several strong wind storms have gusted through the Katmai area recently. Thank you, Cheryl -------- Doug Burney wrote: Hello, I follow your web page daily. 'Have been for years. Your webicorders seem to have an inconsistency in their measurement. Is there a procedure for setting the noise floor for baseline measurements? Does this entail adjusting analog to digital converters. (Burr Brown maybe?) Just curious. Katmai shows readings off the wall. Augustine and Redoubt have a nice noise floor bias whereas Fourpeaked has a flat line. ...Hmm? -- Cheryl Cameron Geologist, Alaska Volcano Observatory Alaska Division of Geological & Geophysical Surveys voice: 907-451-5012 fax: 907-451-5050