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.

Tsunami hazard evaluation for Kuwait and Arabian Gulf due to Makran Subduction Zone and Subaerial landslides

2017 ◽  
Vol 93 (S1) ◽  
pp. 127-152 ◽  
Author(s):  
Panon Latcharote ◽  
Khaled Al-Salem ◽  
Anawat Suppasri ◽  
Tanuspong Pokavanich ◽  
Shinji Toda ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Arabian Gulf ◽  
Tsunami Hazard ◽  
Hazard Evaluation ◽  
Makran Subduction Zone

The Geodynamic Evolution of Iran

2021 ◽  
Vol 49 (1) ◽  
pp. 9-36
Author(s):  
Robert J. Stern ◽  
Hadi Shafaii Moghadam ◽  
Mortaza Pirouz ◽  
Walter Mooney
Keyword(s):  
Subduction Zone ◽  
Full Range ◽  
Accretionary Prism ◽  
Arabian Plate ◽  
Earthquake Hazards ◽  
Northern Margin ◽  
Magmatic Arc ◽  
Early Stages ◽  
Plate Margin ◽  
Convergent Plate Margin

Iran is a remarkable geoscientific laboratory where the full range of processes that form and modify the continental crust can be studied. Iran's crustal nucleus formed as a magmatic arc above an S-dipping subduction zone on the northern margin of Gondwana 600–500 Ma. This nucleus rifted and drifted north to be accreted to SW Eurasia ∼250 Ma. A new, N-dipping subduction zone formed ∼100 Ma along ∼3,000 km of the SW Eurasian margin, including Iran's southern flank; this is when most of Iran's many ophiolites formed. Iran evolved as an extensional continental arc in Paleogene time (66–23 Ma) and began colliding with Arabia ∼25 Ma. Today, Iran is an example of a convergent plate margin in the early stages of continent-continent collision, with a waning magmatic arc behind (north of) a large and growing accretionary prism, the Zagros Fold-and-Thrust Belt. Iran's crustal evolution resulted in both significant economic resources and earthquake hazards. ▪  Iran is a natural laboratory for studying how convergent plate margins form, evolve, and behave during the early stages of continental collision. ▪  Iran formed in the past 600 million years, originating on the northern flank of Gondwana, rifting away, and accreting to SW Eurasia. ▪  Iran is actively deforming as a result of collision with the Arabian plate, but earthquakes do not outline the position of the subducting slab. ▪  The Cenozoic evolution of Iran preserves the main elements of a convergent plate margin, including foredeep (trench), accretionary prism, and magmatic arc.

scholarly journals Megathrust and accretionary wedge properties and behaviour in the Makran subduction zone

2017 ◽  
Vol 209 (3) ◽  
pp. 1800-1830 ◽  
Author(s):  
Camilla Penney ◽  
Farokh Tavakoli ◽  
Abdolreza Saadat ◽  
Hamid Reza Nankali ◽  
Morteza Sedighi ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Accretionary Wedge ◽  
Makran Subduction Zone

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.

scholarly journals Probabilistic tsunami hazard assessment for the Makran region with focus on maximum magnitude assumption

2015 ◽  
Vol 3 (9) ◽  
pp. 5191-5208 ◽  
Author(s):  
A. Hoechner ◽  
A. Y. Babeyko ◽  
N. Zamora
Keyword(s):  
Subduction Zone ◽  
Hazard Assessment ◽  
Historical Seismicity ◽  
Tsunami Hazard ◽  
Maximum Magnitude ◽  
Coastal Regions ◽  
Plate Interface ◽  
Makran Subduction Zone ◽  
Tsunami Hazard Assessment ◽  
Probabilistic Tsunami Hazard Assessment

Abstract. Despite having been rather seismically quiescent for the last decades, the Makran subduction zone is capable of hosting destructive earthquakes and tsunami. In particular, the well-known thrust event in 1945 (Balochistan earthquake) led to about 4000 casualties. Nowadays, the coastal regions are more densely populated and vulnerable to similar events. Furthermore, some recent publications discuss rare but significantly larger events at the Makran subduction zone as possible scenarios. We analyze the instrumental and historical seismicity at the subduction plate interface and generate various synthetic earthquake catalogs spanning 300 000 years with varying magnitude–frequency relations. For every event in the catalogs we compute estimated tsunami heights and present the resulting tsunami hazard along the coasts of Pakistan, Iran and Oman in the form of probabilistic tsunami hazard curves. We show how the hazard results depend on variation of the Gutenberg–Richter parameters and especially maximum magnitude assumption.

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 PROBING THE NATURE AND CHARACTERISTICS OF ACTIVE MUD VOLCANIC CLUSTERS IN MAKRAN COASTAL ZONE, PAKISTAN

2020 ◽  
Vol 8 (3) ◽  
pp. 214-222
Author(s):  
Waseem Khan ◽  
Mahnoor Mirwani
Keyword(s):  
Subduction Zone ◽  
Continental Margin ◽  
Late Cretaceous ◽  
Coastal Region ◽  
Strike Slip ◽  
Mud Volcanoes ◽  
The West ◽  
Makran Subduction Zone ◽  
Sedimentary Environments ◽  
Lut Block

Makran Subduction Zone is formed in Late Cretaceous. It is divided into Eastern Makran at the southern edge of Helmand Block in Pakistan and the Western Makran at the southern edge of Lut Block in Iran. The velocity of convergence in Eastern and Western Makran are 42.0 mm/yr and 35.6 mm/yr repectively. Both segments are bound by strike-slip faults e.g. Ornach-Nal left lateral fault in the east and Minab right lateral in the west. Stratigraphically, the zone comprises Formations of ages ranging from Cretaceous to Holocene. In the Eastern Makran, most of the mud volcanoes are located along strike which include Awaran and Sipai-sing, Chandragup, Gwadar, Jabel-e-Gurab, Khandawari, Kund Malir, Ormara and Offshore mud volcanoes. The continental margin of Makran is an ideal environment of Oxygen Maximum Zone which receives organic rich matters in its sediments by marine organisms. Several assisting factors play significant roles in erupting the fluid and methane gasses through the mud vents in Makran Coastal Region such as tectonic stresses, oil, saltwater, and transmitting freshwater in the sedimentary environments.

scholarly journals Probabilistic tsunami hazard assessment for the Makran region with focus on maximum magnitude assumption

2016 ◽  
Vol 16 (6) ◽  
pp. 1339-1350 ◽  
Author(s):  
Andreas Hoechner ◽  
Andrey Y. Babeyko ◽  
Natalia Zamora
Keyword(s):  
Subduction Zone ◽  
Hazard Assessment ◽  
Historical Seismicity ◽  
Tsunami Hazard ◽  
Maximum Magnitude ◽  
Coastal Regions ◽  
Plate Interface ◽  
Makran Subduction Zone ◽  
Tsunami Hazard Assessment ◽  
Probabilistic Tsunami Hazard Assessment

Abstract. Despite having been rather seismically quiescent for the last decades, the Makran subduction zone is capable of hosting destructive earthquakes and tsunami. In particular, the well-known thrust event in 1945 (Balochistan earthquake) led to about 4000 casualties. Nowadays, the coastal regions are more densely populated and vulnerable to similar events. Furthermore, some recent publications discuss rare but significantly larger events at the Makran subduction zone as possible scenarios. We analyze the instrumental and historical seismicity at the subduction plate interface and generate various synthetic earthquake catalogs spanning 300 000 years with varying magnitude-frequency relations. For every event in the catalogs we compute estimated tsunami heights and present the resulting tsunami hazard along the coasts of Pakistan, Iran and Oman in the form of probabilistic tsunami hazard curves. We show how the hazard results depend on variation of the Gutenberg–Richter parameters and especially maximum magnitude assumption.

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