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

2021 ◽  
Vol 21 (10) ◽  
pp. 3085-3096
Author(s):  
Hira Ashfaq Lodhi ◽  
Shoaib Ahmed ◽  
Haider Hasan
Keyword(s):  
Subduction Zone ◽  
Plate Boundary ◽  
Arabian Plate ◽  
Great Earthquake ◽  
Eurasian Plate ◽  
Arrival Times ◽  
Makran Subduction Zone ◽  
Archival Documents ◽  
The Impact ◽  
The Town

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.

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

2021 ◽  
Author(s):  
Hira Ashfaq Lodhi ◽  
Shoaib Ahmed ◽  
Haider Hasan
Keyword(s):  
Subduction Zone ◽  
Plate Boundary ◽  
Arabian Plate ◽  
Great Earthquake ◽  
Eurasian Plate ◽  
Arrival Times ◽  
Makran Subduction Zone ◽  
Old Maps ◽  
Archival Documents ◽  
The Town

Abstract. The towns of Pasni and Ormara were the most severely affected by the 1945 Makran tsuami. The water inundated almost a kilometer at Pasni, engulfing 80 % huts of the town while at Ormara tsunami inundated two and a half kilometers washing away 60 % of the huts. The plate boundary between 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 of an associated tsunami. Estimated death tolls, waves arrival times, extent of inundation and runup remained vague. We summarize observations of tsunami through newspaper items, eye witness accounts and archival documents. The information gathered is reviewed and quantized where possible to get the inundation parameters in specific and impact in general along the Makran coast. The quantization of runup and inundation extents is based on a field survey or on old maps.

scholarly journals ASSESSMENT OF OPTIMUM VALUE FOR DIP ANGLE AND LOCKING RATE PARAMETERS IN MAKRAN SUBDUCTION ZONE

2017 ◽  
Vol XLII-4/W4 ◽  
pp. 523-529
Author(s):  
A. Safari ◽  
A. M. Abolghasem ◽  
N. Abedini ◽  
Z. Mousavi
Keyword(s):  
Subduction Zone ◽  
Subduction Zones ◽  
Arabian Plate ◽  
Eurasian Plate ◽  
Makran Subduction Zone ◽  
South Eastern ◽  
Best Value ◽  
Proposed Model ◽  
Sparse Measurements ◽  
Dip Angle

Makran subduction zone is one of the convergent areas that have been studied by spatial geodesy. Makran zone is located in the South Eastern of Iran and South of Pakistan forming the part of Eurasian-Arabian plate's border where oceanic crust in the Arabian plate (or in Oman Sea) subducts under the Eurasian plate ( Farhoudi and Karig, 1977). Due to lack of historical and modern tools in the area, a sampling of sparse measurements of the permanent GPS stations and temporary stations (campaign) has been conducted in the past decade. Makran subduction zone from different perspectives has unusual behaviour: For example, the Eastern and Western parts of the region have very different seismicity and also dip angle of subducted plate is in about 2 to 8 degrees that this value due to the dip angle in other subduction zone is very low. In this study, we want to find the best possible value for parameters that differs Makran subduction zone from other subduction zones. Rigid block modelling method was used to determine these parameters. From the velocity vectors calculated from GPS observations in this area, block model is formed. These observations are obtained from GPS stations that a number of them are located in South Eastern Iran and South Western Pakistan and a station located in North Eastern Oman. According to previous studies in which the locking depth of Makran subduction zone is 38km (Frohling, 2016), in the preparation of this model, parameter value of at least 38 km is considered. With this function, the amount of 2 degree value is the best value for dip angle but for the locking rate there is not any specified amount. Because the proposed model is not sensitive to this parameter. So we can not expect big earthquakes in West of Makran or a low seismicity activity in there but the proposed model definitely shows the Makran subduction layer is locked.

Modeling of Tsunami Propagation in the Vicinity of the Southern Coasts of Iran

2007 ◽  
Author(s):  
Mohammad Heidarzadeh ◽  
Moharram D. Pirooz ◽  
Nasser H. Zaker ◽  
Mohammad Mokhtari
Keyword(s):  
Indian Ocean ◽  
Subduction Zone ◽  
Initial Conditions ◽  
Indian Ocean Tsunami ◽  
Height Distribution ◽  
Tsunami Propagation ◽  
Makran Subduction Zone ◽  
Tsunami Waves ◽  
The Indian Ocean ◽  
The Impact

The extensive death toll and sever economical damages brought by the 2004 Indian Ocean tsunami has emphasized the urgent need for assessing the hazard of tsunami in this ocean, and determining the most vulnerable coastlines to the impact of possible tsunami. In this paper the hazard of tsunami for southern coasts of Iran bordering the Indian Ocean is discussed. At first, historical data of tsunami occurrences on the Iranian southern coasts are collected, described and analyzed. Then, numerical simulation of potential tsunamis in the Makran subduction zone is performed and the tsunami wave height distribution along the Iranian coast is calculated. The Makran subduction zone is among two main tsunamigenic zones in the Indian Ocean. In this zone the Oman oceanic plate subducts beneath the Iranian Micro-plate at an estimated rate of about 19 mm/yr. Historically, there is the potential for tsunami generation in this region and several tsunamis attacked the Makran coastlines in the past. The most recent tsunami in this region has occurred on 28 November 1945 which took the lives of more than 4000 people in the coasts of Iran, Pakistan, India, and Oman. Here we examine the seafloor uplift of the Makran zone and its potential for generating destructive tsunamis in the southern coastlines of Iran. Several earthquake scenarios with moment magnitudes ranging between 6.5 and 8.5 are used as initial conditions for analysis. For scenario of an earthquake with magnitude of 8.0, propagation of tsunami waves on coastlines and wave time histories in selected reference locations are calculated.

scholarly journals A review of the seismotectonics of the Makran Subduction Zone as a baseline for Tsunami Hazard Assessments

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Mohammad Mokhtari ◽  
Ahmad Ala Amjadi ◽  
Leila Mahshadnia ◽  
Mandana Rafizadeh
Keyword(s):  
Subduction Zone ◽  
Tectonic Setting ◽  
Accretionary Prism ◽  
Tsunami Hazard ◽  
Indian Plate ◽  
Arabian Plate ◽  
Accretionary Wedge ◽  
The West ◽  
Makran Subduction Zone ◽  
Velocity Models

Abstract The Makran Accretionary Wedge (900 km across) is a consequence of northward subduction of the oceanic part of the Arabian Plate beneath the Lut and Afghan blocks in the northwestern Indian Ocean. It has a complicated tectonic setting as it is located at a triple junction with the Indian Plate. Thick sedimentary layers, a shallow angle of the subducting slab and a large width of the subduction zone, ca. 500–600 km from volcanic arc to active wedge front, are some of the foremost and distinctive characteristics of the Makran Subduction Zone (MSZ). The MSZ is likely divided into at least two segments: the west and the east possibly separated by a sinistral fault known as the Sonne Fault. A division is also inferred from seismicity as it is higher in the east when compared to the west. With the exception of a notable trench, all other characteristics of an accretionary prism observed in well-studied subduction zone can be identified or inferred in the Makran. Three long seismic profiles of the western Makran (200 km long each, with shot points interval of 20 km and receivers interval of 700 m) have recently been acquired. Using these datasets, improved structural/velocity models for the western Makran were developed. This review aims to contribute to achieving a better understanding of the seismotectonic setting and dynamics of the Makran Subduction Zone as it feeds to a refined understanding of the tsunami hazard in the region.

scholarly journals Analisis Pergeseran Koseismik Gempa Sianok Tahun 2007 Berdasarkan Data Pengamatan GPS Tahun 1993-2007 dan Efek terhadap SRGI 2013

2019 ◽  
Vol 2018 (1) ◽  
Author(s):  
Joni Efendi ◽  
Kosasih Prijatna ◽  
Irwan Meilano
Keyword(s):  
Subduction Zone ◽  
Coseismic Deformation ◽  
Lake Area ◽  
Earthquake Cycle ◽  
Eurasian Plate ◽  
Earthquake Parameters ◽  
Australian Plate ◽  
Geodetic Control ◽  
Coordinate Changes ◽  
The Impact

ABSTRAKTumbukan miring Lempeng Eurasia dengan Lempeng Indo-Australia membentuk zona subduksi di bagian barat Pulau Sumatra dan sejumlah segmen sesar di darat Pulau Sumatra. Zona subduksi dan segmen sesar yang terbentuk aktif bergerak sehingga sering menimbulkan gempa bumi di wilayah tersebut. Semenjak diberlakukannya Sistem Referensi Geospasial Indonesia 2013 (SRGI 2013) sebagai referensi tunggal dalam aktivitas pemetaan di Indonesia, maka perubahan posisi kerangka referensi koordinat sebagai fungsi waktu akibat dinamika bumi perlu diperhitungkan. Dengan terjadinya dua gempabumi yang berurutan pada tanggal 6 Maret 2007 di wilayah Danau Singkarak Sumatra Barat, akan menimbulkan deformasi koseismik yang dapat mempengaruhi SRGI2013. Dalam penelitian ini dilakukan analisis untuk menentukan model koseismik gempabumi Sianok yang paling sesuai dan sejauh mana dampaknya pada SRGI 2013. Berdasarkan hasil analisis terhadap nilai residual hasil validasi dengan koseismik pada 11 titik pengamatan GPS dapat disimpulkan bahwa model koseismik dari gempabumi Sianok adalah model koseismik menggunakan data parameter gempa dari Global CMT dengan residual misfit 47.5 mm. Secara umum, pola kosesimik gempabumi Sianok mendeskripsikan mekanisme gempabumi sesar geser. Nilai kosesimik terbesar terjadi pada titik KACA dan K108, yaitu 135,43 mm dan 84,74 mm. Besarnya koseismik gempabumi Sianok tidak berpengaruh terhadap peta dengan skala 1: 1000, akan tetapi akan mempengaruhi nilai koordinat Jaring Kontrol Geodesi (JKG) yang berada di sekitar daerah gempa, sehingga perlu adanya pemutakhiran koordinat dari JKG.Kata kunci: Gempabumi Sianok, GPS, Deformasi Koseismik, SRGI2013. ABSTRACTThe oblique movement of Eurasian Plate towards Indo-Australian Plate create subduction zone in the western part of Sumatra Island and some faults on the mainland of Sumatra. These subduction zone and faults actively produce some earthquakes. Since we used the Geospatial Reference System of Indonesia 2013 (SRGI 2013) as one reference on mapping activities in Indonesia, coordinate changes as a function of time caused by earthquake cycle need to be calculated. There are two earthquakes that had been occurred on March 6, 2007 in Singkarak Lake area which affected the SRGI 2013. We analyzed the data to estimate the coseismic model of Sianok earthquake and the impact to the SRGI 2013. The residual from the coseismic model by including 11 GPS displacements shows that the coseismic model of Sianok earthquake is a model that used earthquake parameters from Global CMT with the misfit of 47.5 mm. Overall, this coseismic pattern shows the shear mechanism. The largest displacements are on KACA and K108 sites, that are 135.43 mm and 84.74 mm respectively. The coseimic of Sianok earthquake does not affect a map with scale of 1:1000, but affect the Geodetic Control Network in this area. From this analysis, we conclude that we need to update our Geodetic Control Network.Keywords: Sianok Earthquake, GPS, Coseismic Deformation, SRGI2013.

scholarly journals IS MAKRAN A SEPARATE MICROPLATE? A SHORT REVIEW

2020 ◽  
Vol 5 (1) ◽  
pp. 01-05
Author(s):  
Muhammad Imran Hafeez Abbasi
Keyword(s):  
Plate Boundary ◽  
Short Review ◽  
Point Of View ◽  
Eurasian Plate ◽  
Tectonic Plates ◽  
Makran Subduction Zone ◽  
Focal Mechanism Solutions ◽  
Lut Block ◽  
Successful Execution ◽  
Belt And Road

Makran Subduction Zone (MZS) is important as this region lies on both sides of the border of Iran and Pakistan along the coastline. Makran Subduction complex has pervasive seismicity and diverse focal mechanism solutions and being in the vicinity of Triple Junction where three major Tectonic plates; Arabian, Eurasian and Indian plates are connecting. Both of Chabahar and Gwadar ports are located in this vicinity, on which China is investing for CPEC, Belt and Road Initiative. The whole world is looking at these projects of Makran, as this may define and transform the future of trade. Hence Geoscience point of view is notable as well in consideration for the successful execution of these projects. Several Microplates/blocks have been proposed around the vicinity MSZ and Indian-Eurasian Plate boundary including the Ormara microplate, Lut Block, Helmand Block, and Pakistan-Iran Makran microplate (PIMM). The purpose of this review is to shed light on PIMM. Despite previous researches related to Makran, still many researchers are working to solve puzzles related to the complexity of MSZ. It is divided into Eastern and Western Makran due to seismicity and North to South into four parts based on stratigraphy, thrusts and folds. This review aims to give suggestions for the hypothesis on PIMM which was inferred as a separate microplate.

scholarly journals CALCULATION ANALYSIS TO DETERMINE THE LARGEST EARTHQUAKE AREA AT NORTH SUMATERA USING J48 DESICION TREE METHOD

2018 ◽  
Author(s):  
Diyan Parwatiningtyas ◽  
Erlin Windia Ambarsari
Keyword(s):  
Subduction Zone ◽  
Specific Area ◽  
Eurasian Plate ◽  
Earthquake Intensity ◽  
Moderate Earthquake ◽  
Earthquake Frequency ◽  
Value Range ◽  
The Impact ◽  
Calculation Analysis ◽  
Earthquake Area

Northern Sumatera is subduction zone region which sustain a high magnitude earthquake. It caused Sumatera region encounter two plates, viz the Eurasian plate and the Indo-Australian. They are reinforced on active Semangko fault. Because of this both plates are convergent, and formed by subduction zone, it resulting in high earthquake frequency content. Then, it area traversed three fault : Fault Renun, Fault Toru and Fault Angkola through kilometre 475, which the source and the propagation of earthquake wave from Firma terrain. The impact of the earthquake at Northern Sumatera region is quite dangerous for local people. Beside that, the main factor of damages is depend on earthquakes magnitude acceleration. And then, from this value, will gained the earthquake intensity. On this case, we trying to manage the safety environment at this area using J48 desicion tree which aims to inform the most specific area experienced an earthquake. Based on the result of data processing, the largest earthquake area at Northern Sumatera is Nias region. It showed from the earthquake acceleration value between 202,71 – 542 gal, MMI scale > 7 SR and it has 1,5 lattitude and 97,5 longitude. Then, the langkat Area, Deli Serdang and South Tapanuli include on moderate earthquake, because they have earthquake acceleration value range beetwen 100 – 150 gal, and its MMI scale is ≤ 7.

Evidence for a Large Earthquake and Tsunami 100-400 Years Ago on Western Vancouver Island, British Columbia

1994 ◽  
Vol 41 (2) ◽  
pp. 176-184 ◽  
Author(s):  
John J. Clague ◽  
Peter T. Bobrowsky
Keyword(s):  
British Columbia ◽  
Subduction Zone ◽  
Vascular Plant ◽  
Plate Boundary ◽  
Vancouver Island ◽  
Tidal Marshes ◽  
Cascadia Subduction Zone ◽  
Great Earthquake ◽  
Marsh Soil ◽  
Sand Sheet

AbstractA peaty marsh soil is sharply overlain by a sand sheet and intertidal mud at tidal marshes near Tofino and Ucluelet, Vancouver Island, British Columbia. Foraminifera and vascular plant fossils show that the buried soil was submerged suddenly and was covered quickly by sand. Radiocarbon ages place this event between 100 and 400 yr ago. The coastal subsidence suggested by the submergence occurred in an area of net late Holocene emergence, perhaps during the most recent great earthquake on the northern part of the Cascadia subduction zone. The sand sheet overlying the peaty soil records the tsunami triggered by this earthquake. Similar stratigraphic sequences of about the same age have been reported from estuaries along the outer coasts of Washington and northern Oregon, suggesting that hundreds of kilometers of the Cascadia subduction zone may have ruptured during one, or a series of plate-boundary earthquakes less than 400 yr ago.

Sign in / Sign up

Export Citation Format

Share Document