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Ranking and developing ground-motion models for Southeastern Africa

delete2024-04-03
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OA
AI
J
Joanna M. Holmgren *
M
Maximilian J. Werner
K
Katsuichiro Goda
M
Manuela Villani
V
Vítor Silva
P
P. R. N. Chindandali
DOI:10.1177/87552930241236765delete
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Abstract

Abstract

En 中文
The southern East African Rift System (EARS) is an early-stage continental rift with a deep seismogenic zone. It is associated with a low-to-moderate seismic hazard, but due to its short and sparse instrumental record, there is a lack of ground-motion studies in the region. Instead, seismic hazard assessments have commonly relied on a combination of active crustal and stable continental ground-motion models (GMMs) from other regions without accounting for the unusual geological setting of this region and evaluating their suitability. Here, we use a newly compiled southern EARS ground-motion database to compare six active crustal GMMs and four stable continental GMMs. We find that the active crustal GMMs tend to underestimate the ground-motion intensities observed, while the stable continental GMMs overestimate them. This is particularly pronounced in the high-frequency intensity measures (>5 Hz). We also use the referenced empirical approach and develop a new region-specific GMM for southern EARS. Both the ranked GMMs and our new GMM result in large residual variabilities, highlighting the need for local geotechnical information to better constrain site conditions.
Keywords:
East African Rift System
seismic hazard
ground-motion model
ranking ground-motion models
referenced empirical approach

Journal

Earthquake Spectra cover
Earthquake Spectra
IF:
3.7
Papers:
2.3K
Citations:
9.7K

Organization

U
University of Bristol
Scholars:
3.1W
Papers: 3.0W
Citations: 5.3W