Infrasound Signal Characteristics from Small Earthquakes
Abstract
Physical insight into source properties that contribute to the generation of infrasound signals is critical to understanding the differences in atmospheric signals from near-surface explosions and earthquakes. This understanding provides the background for assessing the possibility of signal discrimination from these different source types. This research attempts to develop a dataset necessary to address these issues and to provide constraints to the development of a physical basis for signal generation. The data component of this study is supported by the operation and maintenance of nine infrasonic arrays by the University of Utah Seismograph Stations (UUSS). Each array consists of four elements with an aperture of ~150 m, with one element being co-located with a seismic station. One of the goals of this project is the recording of infrasound from earthquakes of moderate size on multiple infrasound arrays in order to assess the location of the infrasound source and its sensitivity to source mechanism and depth, as well as the characteristics of the signal. We report on processing results using infrasound data for all ML > 3 earthquakes in the UUSS catalog from January 1, 2007, through March 31, 2011. We then focus on multiarray recordings of infrasound data from a moderate-sized event (Mw 4.6) in Utah. This event occurred on January 3 2011, at 12:06:37 UTC, within a known seismically active belt along the western side of the Sevier Valley in the Tushar Mountains (in the proximity of the city of Circleville). The event was widely felt in the surrounding communities, had a normal faulting mechanism and a depth constrained, by full moment tensor estimation, between 5 and 9 km. The main shock and 85 aftershocks were recorded by Utah's regional seismic network. Epicentral infrasound from the main event was detected by six of the nine infrasonic arrays distributed throughout Utah.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2011
- Accession Number
- ADA569389
Entities
People
- Brian W. Stump
- Chris Hayward
- George E. Randall
- J. M. Hale
- Kristine L. Pankow
- Relu Burlacu
- Stephen J. Arrowsmith
- Steven R. Taylor
Organizations
- Los Alamos National Laboratory