Unmixing the Gutenberg-Richter Law

Session: Earthquake Source Parameters: Theory, Observations and Interpretations [Poster]
Type: Poster
Date: 4/30/2020
Time: 08:00 AM
Room: Ballroom
Description: 

Magnitudes of earthquakes are typically observed to be exponentially distributed, following the Gutenberg-Richter (G-R) Law. Much attention has been paid to the G-R b-value, and there are well-established trends seen in the estimated b-value with respect to earthquake faulting mechanism and depth, and more recently, distance from a recent mainshock (van der Elst and Shaw, 2015; Gulia et al., 2018).

However, G-R distributions with different b-values do not sum to yield a G-R curve. Given the observation that earthquakes within large volumes follow the G-R Law so robustly, observed variations in mean magnitude must be different than simple variations in b-value. Similarly, while aftershock rates on the whole are consistent with Bath’s Law and the rates of the largest aftershocks, near-field aftershocks are deficient at the largest magnitudes. To reconcile these seemingly disparate observations, we investigate the parametric form of spatio-temporal variations in the magnitude distribution and how these could be incorporated coherently into earthquake forecasting approaches.

Presenting Author: Morgan Page

Authors