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WITHDRAWN Seismic Hazards in the Makran Accretionary Wedge, Pakistan

Description: 

WITHDRAWN The Makran Accretionary Wedge, a remarkable geological feature stretching over 900 kilometers across the northwestern Indian Ocean, has garnered significant attention due to its distinctive geological traits and the seismic threats it presents to the rapidly developing coastal region of Pakistan. This research provides an in-depth overview of the wedge's geological significance and the thorough evaluation of seismic hazards in Pakistan's coastal areas.
The seismic hazard assessment (SHA) for this region employs a dual methodology, integrating both deterministic and probabilistic approaches to fully evaluate earthquake risks. This comprehensive analysis has led to key findings with substantial implications for the region's preparedness and resilience. A detailed study of seismotectonics and geological features has revealed the presence of eleven fault zones across five seismic provinces. These fault zones are identified as potential sources of seismic activity. To assess the worst-case earthquake scenarios, the maximum credible earthquake magnitude for each fault source is calculated. A key component of the seismic hazard evaluation is determining the Peak Ground Acceleration (PGA) values for seven coastal cities. These values reflect the intensity of ground shaking and are derived from the maximum credible earthquakes associated with each fault source. The cities of Gwadar and Ormara are recognized as having high seismic risks, with PGA values of 0.25g and 0.30g, respectively, indicating their susceptibility to severe ground shaking. In contrast, Turbat and Karachi are categorized as low seismic risk areas, with PGA values below 0.15g, signifying their reduced vulnerability to earthquake-induced ground motion. The probabilistic analysis further produces PGA maps for return periods of 50 and 100 years, each representing a 90% probability of non-exceedance. These maps, which feature contour intervals of 0.07g, provide a probabilistic perspective on seismic hazards. In summary, this comprehensive seismic hazard assessment offers a detailed understanding of the earthquake risks facing Pakistan's coastal region.

Session: Advancing Time-dependent PSHA and Seismic Risk Assessment: Accounting for Short- to Medium-term Clustering [Poster]

Type: Poster

Date: 4/15/2025

Presentation Time: 08:00 AM (local time)

Presenting Author: Mona

Student Presenter: No

Invited Presentation: 

Poster Number: 75

Authors