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

Author(s):  
Mohammad Heidarzadeh ◽  
Moharram D. Pirooz ◽  
Nasser H. Zaker ◽  
Mohammad Mokhtari

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.

2020 ◽  
Vol 222 (3) ◽  
pp. 1952-1964 ◽  
Author(s):  
Mohammad Heidarzadeh ◽  
Alexander Rabinovich ◽  
Satoshi Kusumoto ◽  
C P Rajendran

ABSTRACT In the aftermath of the 2004 Indian Ocean (Sumatra-Andaman) tsunami, numerous survey teams investigated its effects on various locations across the Indian Ocean. However, these efforts were focused only on sites that experienced major destruction and a high death toll. As a consequence, some Indian Ocean coastal megacities were not examined. Among the cities not surveyed was Mumbai, the principal west coast port and economical capital of India with a population of more than 12 million. Mumbai is at risk of tsunamis from two major subduction zones in the Indian Ocean: the Sumatra–Andaman subduction zone (SASZ) and the Makran subduction zone (MSZ). As a part of the present study, we conducted a field survey of the 2004 Indian Ocean tsunami effects in Mumbai, analysed the available tide gauge records and performed tsunami simulations. Our field survey in 2018 January found run-up heights of 1.6−3.3 m in the Mumbai area. According to our analysis of tide gauge data, tsunami trough-to-crest heights in Okha (550 km to the north of Mumbai) and in Mormugao (410 km to the south of Mumbai) were 46 cm and 108 cm, respectively. Simulations of a hypothetical MSZ Mw 9.0 earthquake and tsunami, together with the Mw 9.1 Sumatra–Andaman earthquake and tsunami, show that the tsunami heights generated in Mumbai by an MSZ tsunami would be significantly larger than those generated by the 2004 Sumatra–Andaman tsunami. This result indicates that future tsunami hazard mitigation for Mumbai needs to be based on a potential large MSZ earthquake rather than an SASZ earthquake.


Author(s):  
Mohammad Heidarzadeh

The 2004 Indian Ocean tsunami which exported death and destruction to far distant shores, once more emphasized the tsunami hazards associated with transoceanic tsunamis. Historical records of tsunamis in the Makran subduction zone (MSZ) reveal that Makran tsunamis are capable of producing large waves in the far-field. The Makran tsunami of 1945 produced by an Mw8.1 earthquake was reported to cause far-field effects in the Indian Ocean and reached a height of about 30 cm in the Seychelles, at the distance of about 3500 km from the MSZ. Here, we assess historical observations of this event and perform numerical modeling of this tsunami with emphasis on its far-field effects. Our numerical modeling successfully reproduces most feathers of the historical observations including its far-field effects. Southward propagation of Makran large tsunamis is investigated and their possible effects on Maldives and Seychelles islands are discussed. This study will help to better understand tsunami hazard associated with the MSZ, especially its far-field hazard.


2013 ◽  
Author(s):  
Ava Cas ◽  
Elizabeth Frankenberg ◽  
Wayan Suriastini ◽  
Duncan Thomas

2016 ◽  
Vol 25 (5) ◽  
pp. 595-610 ◽  
Author(s):  
Siri Hettige ◽  
Richard Haigh

Purpose The impact of disasters caused by natural hazards on people in affected communities is mediated by a whole range of circumstances such as the intensity of the disaster, type and nature of the community affected and the nature of loss and displacement. The purpose of this paper is to demonstrate the need to adopt a holistic or integrated approach to assessment of the process of disaster recovery, and to develop a multidimensional assessment framework. Design/methodology/approach The study is designed as a novel qualitative assessment of the recovery process using qualitative data collection techniques from a sample of communities affected by the Indian Ocean tsunami in Eastern and Southern Sri Lanka. Findings The outcomes of the interventions have varied widely depending on such factors as the nature of the community, the nature of the intervention and the mode of delivery for donor support. The surveyed communities are ranked in terms of the nature and extent of recovery. Practical implications The indices of recovery developed constitute a convenient tool of measurement of effectiveness and limitations of external interventions. The assessment used is multidimensional and socially inclusive. Originality/value The approach adopted is new to post-disaster recovery assessments and is useful for monitoring and evaluation of recovery processes. It also fits into the social accountability model as the assessment is based on community experience with the recovery process.


2020 ◽  
Author(s):  
Michael Mayer ◽  
Magdalena Alonso Balmaseda

<p>In 2014 the scientific community and forecasters were expecting a major El Nino event, which was suggested by physical indicators and predicted by several seasonal forecasting systems. However, only moderately warm El Nino – Southern-Oscillation (ENSO) conditions materialized in 2014, but one year later in boreal winter 2015/16, one of the strongest El Ninos on record occurred. Moreover, the 2015/16 El Nino exhibited very unusual energetics: Despite warm conditions in the tropical Pacific in 2014 and especially 2015, its ocean heat content (OHC) did not decrease during that period, which usually is the case during El Nino events. Overall, the 2014-16 evolution of the tropical Pacific was quite different from the evolution during the 1997/98 El Nino, which exhibited exceptionally strong Pacific OHC discharge. This discrepancy was attributed at least partly to the anomalously warm Indian Ocean and the exceptionally weak Indonesian Throughflow transports during 2015-16 that kept Pacific OHC at high levels.</p><p>This contribution aims to elucidate the role of the Indian Ocean in the tropical Pacific Ocean evolution during ENSO for the two periods February 1997-1999 and February 2014-2016. For this purpose, we perform initialized two-year predictions using the ECMWF seasonal forecasting system. To isolate the role of the Indian Ocean, we carry out hindcasts with unperturbed ocean initial conditions and hindcasts with swapped Indian Ocean initial conditions, where the 2014 (1997) hindcasts use Indian Ocean initial conditions from 1997 (2014). We first investigate the impact of the Indian Ocean on the strength of the Indonesian Throughflow and the evolution of the tropical Pacific heat budget. Second, we seize these experiments to explore the impact of the Indian Ocean state on two-yearly ENSO evolution, especially on the probability of extreme events, and which role the atmospheric bridge plays versus the oceanic bridge.</p>


Demography ◽  
2014 ◽  
Vol 51 (2) ◽  
pp. 437-457 ◽  
Author(s):  
Ava Gail Cas ◽  
Elizabeth Frankenberg ◽  
Wayan Suriastini ◽  
Duncan Thomas

2007 ◽  
Vol 7 (1) ◽  
pp. 141-147 ◽  
Author(s):  
M. Ioualalen ◽  
E. Pelinovsky ◽  
J. Asavanant ◽  
R. Lipikorn ◽  
A. Deschamps

Abstract. The 26 December 2004 Indian Ocean tsunami damaged severely most of the Gulf of Bengal's coastal areas, but the coast of Bangladesh which stands at the edge of an extraordinarily extended continental shelf. This latter feature has been built through huge discharges of river sediments along the Brahmaputra and Ganges rivers. As a result of this enormous discharge, another interesting feature of the area is the deep underwater Canyon, connected with the estuaries, running NE-SW from 25 km off the coast towards the continental slope. We investigate here how these two geological features may have modified/perturbed the Indian ocean tsunami propagation and impact on the Coast of Bangladesh. For that purpose we have realized an ensemble of numerical simulations based on Funwave Boussinesq numerical model and a validated coseismic source. It is found, at first order, that the extended shallow bathymetric profile of the continental shelf plays a key role in flattening the waveform through a defocussing process while the Canyon delays the process. The wave evolution seems to be related at first order to the bathymetric profile rather than to dynamical processes like nonlinearity, dispersion or bottom friction.


2017 ◽  
Vol 11 (01) ◽  
pp. 1740005 ◽  
Author(s):  
Syamsidik ◽  
Tursina ◽  
Asrita Meutia ◽  
Musa Al’ala ◽  
Mirza Fahmi ◽  
...  

Wave forces during the 2004 Indian Ocean tsunami have caused morphological deformations of some coastal areas in Aceh, Indonesia. The sediment transport process during the tsunami wave propagation around near shore areas is a challenging numerical problem. To observe the coastal morphological changes after the Indian Ocean tsunami, this study numerically simulates the coastline changes, sedimentation and erosion areas, and seabed profiles changes around the Ulee Lheue Bay of Aceh, which was severely damaged by the tsunami. Two-dimensional horizontal areas were simulated by Cornell Multi-grid Coupled Tsunami (COMCOT) and Delft3D. Data of the nearshore area were collected from previous measurements acquired by the Indonesian Navy. According to the results, sediment in the sea area was deposited approximately 2.5[Formula: see text]km from the initial coastline, at the northern part of one small island occupying the Ulee Lheue Bay. This island reduced the energy of the tsunami waves during the backwash process, dumping a significant amount of eroded sediment near the coastline area.


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