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The Pattern of Earthquake Magnitude Clustering Based on Interevent Distance and Time

Description: 

The clustering of earthquake magnitudes is poorly understood compared to spatial and temporal clustering. Better understanding of correlations between earthquake magnitudes could provide insight into the mechanisms of earthquake rupture and fault interactions, and improve earthquake forecasting models. In this study we present a novel method of examining how seismic magnitude clustering occurs beyond the next event in the catalog and evolves with time and space between earthquake events. We first evaluate the clustering signature over time and space using double-difference located catalogs from Southern and Northern California. The strength of magnitude clustering appears to decay linearly with distance between events and logarithmically with time. The signature persists for longer distances (more than 50km) and times (several days) than previously thought, indicating that magnitude clustering is not driven solely by repeated rupture of an identical fault patch. The decay patterns occur across different magnitude ranges of the catalog and can be demonstrated across multiple methodologies of study. These patterns are also shown to be present in laboratory rock fracture catalogs but are absent in ETAS synthetic catalogs. Incorporating spatial and temporal decay of magnitude clustering into earthquake forecasting approaches that currently use ETAS models would likely improve their accuracy.

Session: New Insights into the Development, Testing and Communication of Seismicity Forecasts [Poster Session]

Type: Poster

Date: 5/2/2024

Presentation Time: 08:00 AM (local time)

Presenting Author: Michael

Student Presenter: No

Invited Presentation: 

Authors