Apparent break in earthquake scaling due to path and site effects on deep borehole recordings

By Satoshi Ide, Gregory C. Beroza, Stephanie G. Prejean, William Ellsworth. 2003

277 citations recorded by the source corpus.

[1] We reexamine the scaling of stress drop and apparent stress, rigidity times the ratio between seismically radiated energy to seismic moment, with earthquake size for a set of microearthquakes recorded in a deep borehole in Long Valley, California. In the first set of calculations, we assume a constant Q and solve for the corner frequency and seismic moment. In the second set of calculations, we model the spectral ratio of nearby events to determine the same quantities. We find that the spectral ratio technique, which can account for path and site effects or nonconstant Q, yields higher stress drops, particularly for the smaller events in the data set. The measurements determined from spectral ratios indicate no departure from constant stress drop scaling down to the smallest events in our data set (Mw 0.8). Our results indicate that propagation effects can contaminate measurements of source parameters even in the relatively clean recording environment of a deep borehole, just as they do at the Earth's surface. The scaling of source properties of microearthquakes made from deep borehole recordings may need to be reevaluated.

Subfields: Artificial Intelligence, Geophysics

View Paper: https://www.semanticscholar.org/paper/a0e987baaeb7c5481b760703f716668dba61b5b4

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Artificial Intelligence

1. P. Shearer
2. Y. Kaneko
3. Satoshi Ide
4. G. Prieto
5. Gregory C. Beroza
6. S. M. Mousavi
7. Weiqiang Zhu

In Geophysics

1. P. Shearer
2. G. Prieto
3. Y. Kaneko
4. Gregory C. Beroza
5. Satoshi Ide
6. A. Baltay
7. Hideo Aochi
8. G. Mclaskey

Citations in the corpus

• Variability of seismic source spectra, estimated stress drop, and radiated energy, derived from cohesive‐zone models of symmetrical and asymmetrical circular and elliptical ruptures (2015, methodology): “Similarly, estimates of scaled energy have large scatter, and as a result, the relationship between scaled energy and seismic moment remains a subject of active debate [e.g., Abercrombie, 1995; Mayeda and Walter, 1996; Ide et al., 2003; Prieto et al., 2004; Walter et al., 2006; Baltay et al., 2011].”
• Variability in earthquake stress drop and apparent stress (2011, background): “Studies of stress drop and apparent stress indicate that the two vary together [e.g., Abercrombie, 1995; Ide et al., 2003].”
• Earthquakes as multiscale dynamic ruptures with heterogeneous fracture surface energy (2005, background): “example, the ratio between seismically radiated energy Es and seismic moment Mo is constant or depends only weakly on size [e.g., Ide and Beroza, 2001; Ide et al., 2003; Kanamori and Rivera, 2004].”