Publication Date:
2016-04-29
Description:
The Gutenberg-Richter b -value is commonly used in volcanic eruption forecasting to infer material or mechanical properties from earthquake distributions. Such studies typically analyze discrete time windows or phases, but the choice of such windows is subjective, and can introduce significant bias. Here we minimize this sample bias by iteratively sampling catalogs with randomly-chosen windows and then stacking the resulting probability density functions for the estimated b̃ -value to determine a net probability density function. We examine data from the El Hierro seismic catalog during a period of unrest in 2011-2013, and demonstrate clear multi-modal behavior. Individual modes are relatively stable in time, but the most probable b̃ -value intermittently switches between modes, one of which is similar to that of tectonic seismicity. Multi-modality is primarily associated with intermittent activation and cessation of activity in different parts of the volcanic system rather than with respect to any systematic inferred underlying process.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
