Near real-time monitoring of volcanic surface deformation from GPS measurements at Long Valley Caldera, California
Article first published online: 26 MAR 2013
©2013. American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 40, Issue 6, pages 1054–1058, 28 March 2013
How to Cite
2013), Near real-time monitoring of volcanic surface deformation from GPS measurements at Long Valley Caldera, California, Geophys. Res. Lett., 40, 1054–1058, doi:10.1002/grl.50258., , and (
- Issue published online: 27 APR 2013
- Article first published online: 26 MAR 2013
- Accepted manuscript online: 22 FEB 2013 01:17PM EST
- Manuscript Accepted: 12 FEB 2013
- Manuscript Revised: 11 FEB 2013
- Manuscript Received: 21 DEC 2012
- volcano monitoring;
- Long Valley Caldera
 Long Valley Caldera in eastern California is an active volcanic area and has shown continued unrest in the last three decades. We have monitored surface deformation from Global Positioning System (GPS) data by using a projection method that we call Targeted Projection Operator (TPO). TPO projects residual time series with secular rates and periodic terms removed onto a predefined spatial pattern. We used the 2009–2010 slow deflation as a target spatial pattern. The resulting TPO time series shows a detailed deformation history including the 2007–2009 inflation, the 2009–2010 deflation, and a recent inflation that started in late-2011 and is continuing at the present time (November 2012). The recent inflation event is about four times faster than the previous 2007–2009 event. A Mogi source of the recent event is located beneath the resurgent dome at about 6.6 km depth at a rate of 0.009 km3/yr volume change. TPO is simple and fast and can provide a near real-time continuous monitoring tool without directly looking at all the data from many GPS sites in this potentially eruptive volcanic system.