I
igorsboss
Guest
Watching the washington state webicorders, I've noticed something that looks a little strange happening recently.<br /><br />When I compare webicorder records for Oct 4th to those from Oct 8, and I pay special attention to the times in-between quakes, the webicorder line looks a lot more wavy now than it did then.<br /><br />On Oct 4, when a webicorder was quiescent, that is, when it was recording minimal activity, the trace looked like a straight line.<br /><br />On Oct 8, when a webicorder was quiescent, the trace appeared to have a consistent low-amplitude and ultra low-frequency background wave.<br /><br />What's going on here???? Have the webicorders changed their recording resolution somehow? Is this a real rumble?<br /><br />I observed this on the following webicorders: <br />LON EHZ UW : Longmire, Mount Rainier, <br />http://www.pnsn.org/WEBICORDER/GREEN/LON_EHZ_UW.2004100400.html versus<br />http://www.pnsn.org/WEBICORDER/GREEN/LON_EHZ_UW.2004100812.html<br /><br />JCW EHZ UW : Jim Creek, West Cascades, comparing<br />http://www.pnsn.org/WEBICORDER/GREEN/JCW_EHZ_UW.2004100400.html versus<br />http://www.pnsn.org/WEBICORDER/GREEN/JCW_EHZ_UW.2004100812.html<br /><br />and also <br />STW EHZ UW : Striped Peak, Olympics <br />HTW EHZ UW : Haystack Peak, West Cascades <br />GNW EHZ UW : Green Mt, Kitsap<br /><br />See also: http://www.geophys.washington.edu/SEIS/PNSN/WEBICORDER/GREEN/welcome.html