A Seismologically Consistent Model for Surface Rupture Length Capturing Unbounded and Width-Limited Events

Christine A. Goulet, Grigorios Lavrentiadis, Yongfei Wang, Norman A. Abrahamson, & Yousef Bozorgnia

Published September 11, 2022, SCEC Contribution #12515, 2022 SCEC Annual Meeting Poster #275

A surface-rupture-length (SRL) relationship as a function of magnitude (M), fault thickness, and fault dip angle is presented. The objective of this study is to model the change in scaling between unbounded and width-limited ruptures. This is achieved using seismological-theory based constraints in the magnitude and average displacement scaling, as well as with the aid of dynamic fault rupture simulations to capture the width rupture scaling. The empirical dataset is composed of 128 events ranging from M 5 to 8.1 and SRL 1.1 to 432 km. The dynamic rupture simulations dataset is composed of 554 events ranging from M 4.9 to 8.2 and SRL 1 to 655 km. For the average displacement (D) scaling, both an sqrt(A)-type model, which results in a L-type model for width limited events, and a W-type model were evaluated. The empirical data support a D∼sqrt(A) scaling. The proposed model exhibits better predictive performance compared to linear logSLR∼M type models, especially at the large magnitudes range dominated by width-limited events. A comparison with existing SRL models shows consistent scaling at different magnitude ranges which is believed to be the result of the different magnitude ranges in the empirical dataset of the published relationships.

Key Words
Fault displacement, rupture length, M-L-W relations

Citation
Goulet, C. A., Lavrentiadis, G., Wang, Y., Abrahamson, N. A., & Bozorgnia, Y. (2022, 09). A Seismologically Consistent Model for Surface Rupture Length Capturing Unbounded and Width-Limited Events. Poster Presentation at 2022 SCEC Annual Meeting.

Related Projects & Working Groups
Earthquake Engineering Implementation Interface (EEII)