Tsunami heights and limits in 1945 along the Makran coast estimated from testimony gathered 7 decades later in Gwadar, Pasni and Ormara

Hira Ashfaq Lodhi,Shoaib Ahmed,Haider Hasan

doi:10.5194/nhess-21-3085-2021

Hira Ashfaq Lodhi, Shoaib Ahmed + Show 1 more

Open Access

https://doi.org/10.5194/nhess-21-3085-2021

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Abstract

Abstract. The towns of Pasni and Ormara were the most severely affected by the 1945 Makran tsunami. The water inundated land for almost 1 km at Pasni, engulfing 80 % of the huts of the town, while at Ormara the tsunami inundated land for 2.5 km, washing away 60 % of the huts. The plate boundary between the Arabian Plate and Eurasian Plate is marked by Makran subduction zone (MSZ). This Makran subduction zone in November 1945 was the source of a great earthquake (8.1 Mw) and an associated tsunami. Estimated death tolls, waves arrival times, and the extent of inundation and runup have remained vague. We summarize observations of the tsunami through newspaper items, eyewitness accounts and archival documents. The information gathered is reviewed and quantified where possible to obtain the inundation parameters specifically and understand the impact in general along the Makran coast. The quantification of runup and inundation extents is based on a field survey or old maps.

Highlights

The recent events of the 2004 Indian Ocean (Sumatra– Andaman) tsunami and 2010 Chile and 2011 Tohoku Pacific Ocean tsunamis have highlighted the vulnerability of coastal areas and coastal communities to such events
The data from past events are crucial as they form the basis for numerical models that simulate tsunami and tsunami hazard assessment (Hoffmann et al, 2013) which in turn can be used for planning and mitigation, and most importantly they can serve as an input for the development of tsunami early warning systems (TEWSs)
We first summarize the description of the 1945 event in newspaper items, historical reports and eyewitness accounts and use eyewitness accounts and newspaper items combined with a field survey to extract the runups and inundation extents for coastal cities of Pakistan through the reported tsunami observations therein

Summary

Introduction

The recent events of the 2004 Indian Ocean (Sumatra– Andaman) tsunami and 2010 Chile and 2011 Tohoku Pacific Ocean tsunamis have highlighted the vulnerability of coastal areas and coastal communities to such events. A similar study that assesses the inundation parameters several years after the event has been conducted in Chile for the 1960 tsunami by Atwater et al (2013). This technique was pioneered by Okal et al (2002) and was applied first to the Aleutian tsunami. The findings are based on the information provided in the eyewitness accounts and newspaper items; a ground survey is conducted to locate the landmarks and come up with the runups and inundation extents along the coast of Gwadar, Pasni and Ormara

Makran earthquake of 1945 and tsunami

Impact of the 1945 Makran tsunami

Gwadar

Ormara

Results and discussion

Conclusions