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WITHDRAWN Local Magnitude (Ml) Calibration and Seismic Attenuation in the Ethiopian Rift Valley: Implications for the 2024–2025 Earthquake Swarm

Description: 

WITHDRAWN This study investigates seismic attenuation in the Ethiopian Rift Valley during the 2024–2025 earthquake swarm and concurrent diking episode, demonstrating that attenuation functions developed for Southern California (Richter, 1958; Hutton and Boore, 1987) are not directly applicable to this tectono-magmatic setting. Using zero-to-peak acceleration derived from synthetic Wood-Anderson seismograms, we calibrate a region-specific attenuation function through multiple linear regression analysis. The best-fit solution for the Ethiopian Rift valley is: log(A0)= (1.05 +or- 0.1)log(r/100)+(0.0022 + or - 0.0003)(r - 100) + 3

where r is the hypocentral distance in kilometers and = is the reference distance. Comparative analysis shows Southern California has the highest attenuation at ), reflecting strong crustal absorption. The Ethiopian Rift (2024/25 Swarm) exhibits higher attenuation at than the 2006 model likely due to magma intrusion and faulting. Tanzania and Danakil show lower attenuation and , indicating less energy loss. The Ethiopian Rift’s attenuation (α=1.05, β=0.0022) suggests enhanced wave propagation, driven by magma-tectonic interactions. These findings highlight the need for region-specific models to improve seismic hazard assessment in active rift systems and provide insights into stress accumulation and volcanic-seismic risks.

Session: Late-breaking on Recent and Future Large Earthquakes [Poster]

Type: Poster

Date: 4/15/2025

Presentation Time: 08:00 AM (local time)

Presenting Author: Abel

Student Presenter: Yes

Invited Presentation: 

Poster Number: 142

Authors