A Source Model for Tsunami Hazards. A Case study from the Eastern Segment of the Makran Subduction Zone, Balochistan, Pakistan.

Population growth and economic development on the Pakistani coasts necessitate tsunami hazard analyses. Numerous valuable research outputs already exist given the 1945 Makran earthquake and tsunami. To fill the gap, and present additional scenarios regarding the characteristics of tsunamis at these coasts, an innovative tsunami source model is developed for simulations. The geographical information system (GIS) techniques are used for the mapping of seismogenic sources, placing the fault planes and approximation of their extent in the source model. The segmentation of the Makran subduction zone is practiced, designating its eastern segment as a tsunami source region. The extent of rupture induced by the 1945 Makran earthquake is related to the size of the tsunami source in the formulation of the new source model. The earthquake catalogs and literature on previously developed source models are consulted to estimate various constituting parameters of this model. The bathymetry profile near coasts is analyzed to assess the susceptibility of submarine landslides that may enhance tsunami impacts. Simulations of the 1945 tsunami yielded ~5 m high wave while simulation of the worst tsunami based on an Mw 8.6 earthquake scenario yielded an amplitude of ~8 m. The late and prolonged arrival of high waves after the first tsunami is also observed in simulations. [ABSTRACT FROM AUTHOR]