Andaman Region Research Articles

Potentiality of Ocean Thermal Energy Conversion Systems and Enriched Evaluation of Selected Locations in Andaman and Nicobar Islands, India

The present study investigates Andaman and Nicobar Islands area to identify the best location for OTEC plant. And the investigation based on the analysis of temperature gradient and bathymetry, environmental and socio-economic characteristics. Some vital factors like sea surface temperature, deep sea water temperature, water column depth, distance from the shore, wave height, wind speed, and surface current also taken into account to investigate the area and identify the coordinates of the location in Andaman and Nicobar Islands region. After identification of the location coordinates the five locations have been selected among all locations and the TOPSIS method is applied to find out best location among all five selected location. The energy demand is continuously increasing due to the immense development in technologies so the conventional energy resources are unable to fulfill the energy demand. In this situation propagation of the renewable energy sources can play a momentous role to meet the demand. In the field of renewable energy, OTEC could be a magnificent option for electricity generation and potential of the OTEC is very high across the world. But the efficiency of the OTEC plant much more dependent on the location so the location of the plant must be suitable.

Atmospheric Storm Triggered and Intensified by Geodynamics: Case Studies from Andaman Sea and Bay of Bengal Region in the Indian Ocean

The study analyses the possible connection between the onset of cyclone and volcano-tectonic seismicity in the Andaman region. The historical data of the major volcanic, seismic, and atmospheric events from the region show that several of the geodynamic activities were followed by severe atmospheric disturbances over the region. In this study, we consider the case of three recent cyclones (Phailin, Hudhud, and Nilam) that either originated or were intensified over the Andaman Sea and Bay of Bengal, and examine their correlation with the volcano-tectonic seismic events during the cyclone occurrence. The zenith total delay (ZTD) time series, derived from Global Positioning System data from the PBR2 station on Andaman Island, overlapping with the period of the cyclone occurrence were examined to distinguish the onset and intensification of the atmospheric events. The comparison of the sharp changes in ZTD associated with the cyclone and the seismic events during the period indicates that the atmospheric changes almost coincide or follow the geodynamic activity. Our study illustrates that volcano-tectonics of the region plays a role in the triggering of atmospheric disturbances.

Spatial distribution of dinoflagellates from the tropical coastal waters of the South Andaman, India: Implications for coastal pollution monitoring

Dinoflagellate community structure from two semi-enclosed areas along the South Andaman region, India, was investigated to assess the anthropogenic impact on coastal water quality. At the densely inhabited Port Blair Bay, the dominance of mixotrophs in water and Protoperidinoids in sediments was attributed to anthropogenic nutrient enrichment and prey availability. A significant decrease in dinoflagellate abundance from inner to outer bay emphasize the variation in nutrient availability. The dominance of autotrophs and Gonyaulacoid cysts at the North Bay highlight low nutrient conditions with less anthropogenic pressure. The occurrence of oceanic Ornithocercus steinii and Diplopsalis sp. could evince the oceanic water intrusion into the North Bay. Nine potentially harmful and red-tide-forming species including Alexandrium tamarense complex, A. minutum were identified in this study. Although there are no harmful algal bloom (HABs) incidences in this region so far, increasing coastal pollution could support their candidature towards the future HABs initiation and development.

A Study on the Delineation of Coral Reefs in Andaman and Lakshadweep Islands Using RISAT-1 Data

Coral reefs are one of the most diverse of all marine ecosystems and are often referred to as the “rainforests of the sea”. Though they cover less than one per cent of Earth’s surface, they are home to one quarter of all ocean species by providing food and shelter to them. Optical remote sensing has been widely employed for mapping and monitoring coral reefs. But the application of microwave remote sensing has been an alternate domain in this area. This study explores the possibility of utilizing synthetic aperture radar (SAR) data of Radar Imaging Satellite-I, India’s first indigenous microwave satellite to delineate the coral reefs in Andaman and Lakshadweep Islands in the Indian Ocean. The dual polarized data, after reducing the speckle has been classified to delineate the coral reefs in the vicinity of both islands. SAR has a performance comparable with passive optical sensors under favourable conditions of imaging, viz. optimum tidal current and surface winds. The study results are compared with the international coral reef reference map and are found to be highly promising, with an overall accuracy of 98.3% and a Kappa coefficient of 0.944 for fringing reefs in Andaman region. For the atolls in Lakshadweep region, the overall accuracy is found to be 92.99% and the Kappa coefficient is estimated at 0.7377. This study tries to explore a different horizon for microwave remote sensing in coral reef studies. It is seen that, optical and microwave remote sensing can provide a mutually supporting platform in coral reef delineation, in terms of imaging depth as well as climatic conditions.

Morphology of submarine channel-levee systems in the eastern Bay of Bengal near Andaman region

Multibeam echo-sounder (MBES), sub-bottom profiler, singlebeam tracks and public-domain bathymetry geophysical datasets were analyzed in a Geographic Information System (GIS) for accuracy assessment and further used to update the previous map (Curray et al. Mar Pet Geol 19: 1191–1223, 2003) of submarine channel-levee systems in the eastern Bengal Fan near the Andaman region. Comparative analysis of singlebeam with MBES indicated 2.8 % of root-mean-square difference in bathymetry, and could clearly bring out distinct submarine channel profiles. The channel map revealed that the previously named E6 [updated as E7(1a)] and E7 [updated as E7(1b)] channels emanate from the middle and lower Bengal Fan, respectively and merge together at 91.28°E, 10.64°N where they form a second order channel [E7(2)] that flows southward along the east of Ninety-east Ridge. Similarly, two first order channels [E6(1a) and E6(1b)] emanate from the lower Bengal Fan which merge together at 88.78°E, 06.92°N to form a second order channel [E6(2)] that flows along the west of Ninety-east Ridge towards the equator. This channel was previously thought to be linked to the middle Bengal Fan. High-resolution MBES tracks over the channel shows extensive meandering patterns with the channel gently deepening and widening towards south. Variations in the morphology and stratigraphy indicate that the E7 channel is characterized by a curvilinear course, with higher observed sinuosity wherever gradient decreases.

Differential bleaching of corals based on El Niño type and intensity in the Andaman Sea, southeast Bay of Bengal.

The Andaman coral reef region experienced mass bleaching events during 1998 and 2010. The purpose of this study is to investigate the role of the El Niño in the coral reef bleaching events of the Andaman region. Both Niño 3.4 and 3 indices were examined to find out the relationship between the mass bleaching events and El Niño, and correlated with sea surface temperature (SST) anomalies in the Andaman Sea. The result shows that abnormal warming and mass bleaching events in the Andaman Sea were seen only during strong El Niño years of 1997-1998 and 2009-2010. The Andaman Sea SST was more elevated and associated with El Niño Modoki (central Pacific El Niño) than conventional El Niño (eastern Pacific El Niño) occurrences. It is suggested that the development of hot spot patterns around the Andaman Islands during May 1998 and April-May 2010 may be attributed to zonal shifts in the Walker circulation driven by El Niño during the corresponding period.

Indigenous Islamic Food: An Ideal Product Innovation for Creativity in Cultural Tourism: A Case Study Khao Tung Pla (Thai Crispy Rice Crackers with Anchovies)

This article offers a critique of indigenous food which has the potential to add many benefits and much creativity to cultural tourism. Food is one of the four requirements for human survival. The tourism industry is that in which tourists partake in the local food produce. The World Tourism Organization (UNWTO) forecasts the growth of the tourism industry by the year 2030 to reach 1.8 billion international tourists globally. The UNWTO further points out that most popular tourist places will specifically be those of the Asia and Pacific regions. Thailand is considered one of the most popular countries within a popular continent; however, the significant task of tourism in Thailand remains as to how to attract greater numbers of international tourists to the country. This leads us to one of the activities in which all tourists partake during their trips to Thailand, namely eating. Hence, food is an alternative tourist activity with which to specifically attract tourists. This is especially the case for indigenous food which can be presented from its cultural aspect, in addition to it being an exotic and authentic experience for visitors. This article emphasizes the indigenous food in the Andaman region of Thailand where the cuisine is mostly local Islamic food. This food is that produced by the native people in an area well-known for its Muslim community. Therefore, the local cuisine is not only presented as a food product, but also as an integral part of the culture of the native people. In other words, this local Islamic food could present the international tourist with the culture of the locals, their way of life, and the uniqueness of Thai identity through the consumption by tourist themselves. DOI: 10.5901/mjss.2015.v6n5s2p445

Evolution of b-values before large earthquakes of mb ≥6.0 in Andaman region

We have considered six earthquakes of mb ≥6.0, with focal depths within 45 km, in Andaman region during 2000 to 2012 to examine the spatial variations of b-value at epicentre within a one-year period prior to the occurrence of the earthquakes. We have found a correlation between the low b for the one year time interval and the occurrence of large events. The epicentral b-values of six earthquakes are lower than 1.0 and five out of six earthquakes show very low b-value at the epicentre. Our study may indicate that b-value can be employed as a possible precursor for the forecasting of a major earthquake.

Recent sightings of marine mammals in Andaman Islands, India

This study reports opportunistic sightings of marine mammals between August 2013 and January 2014 in the Andaman region. Seven sightings were recorded during this period out of which one was of a Dugong, which is significant considering its small population size in India and limited data on its distribution and abundance. The rest were 24 dolphins ( Tursiops sp.). Four sightings were of the same pod of dolphins on different days at the same location. Two sightings occurred during regular coral reef monitoring survey and the other five during fishery resource survey by trawling operations. These sightings are of great significance as there is a lack of studies on marine mammals from the region. Sighting records are useful for understanding aggregation site, behaviour, habits and habitat and residency patterns and provide important information for conservation of marine mammals.

Teleseismic inversion of the 2004 Sumatra-Andaman earthquake rupture process using complete Green’s functions

Spatial and temporal variations in coseismic slip distribution are often obtained by rupture process analyses using teleseismic body waves. Many analyses using teleseismic body waves were based on the ray theory because of the very efficiently computable direct P-, S-, and major reflected waves near the source. The 2004 Sumatra-Andaman earthquake was one of the largest earthquakes recorded in history, and the data that are required for the entire rupture process analysis include later phases such as PP waves and a very long period phase called a W phase. However, calculating these later phases using the conventional ray theoretical method is difficult. Here we investigate the rupture process of the 2004 Sumatra-Andaman earthquake using complete Green’s functions, including all later phases such as PP waves and W phase. We use the direct solution method, which computes complete synthetic seismograms up to 2 Hz for transversely isotropic spherically symmetric media, to calculate the Green’s functions. The obtained synthetic seismograms generated fit the observed seismograms quite well from a short period to a long period. The estimated slip distribution consists of four large slip areas: the largest slip occurred in the shallow part off the Sumatra west coast with a maximum slip of approximately 29 m, the second and third largest slips occurred in the shallow and deep parts of the Nicobar region with maximum slips of approximately 8 m and 7 m, respectively, and the fourth slip occurred in the middle Andaman region with a maximum slip of approximately 6 m. The estimated average rupture velocity is 2.8 km/s, but the rupture may have slowed between the Sumatra and the shallow Nicobar slip areas, and between the Nicobar and the middle Andaman slip areas. The delayed initiation of the shallow slips in the Nicobar region may possibly have been triggered by the deeper slip in the Nicobar region. There were no distinct depth-varying properties for the shallow and deep slips in the Nicobar region, as were reported for the 2011 Tohoku-Oki and 2010 Chile earthquake.

Wave attenuation in mangroves: A quantitative approach to field observations

Coastal mangroves, dwelling at the interface between land and sea, provide an important contribution to reducing risk from coastal hazards by attenuating incident waves and by trapping and stabilizing sediments. This paper focusses on relations between vegetation densities, wave attenuation rates, sediment characteristics and sedimentation rates in mangroves. These processes were studied along two cross-shore transects through mangroves fringing estuaries in the southern Andaman region of Thailand. Volumetric vegetation densities in these mangroves were ranging up to 32‰, depending on the water depth. Generalized total wave attenuation rates increased from 0.002m−1 in the sparsely vegetated forest fringes with Avicennia and Sonneratia species, up to 0.012m−1 in the dense Rhizophora vegetation in the back of the forests. The total wave attenuation rates integrate effects of shoaling and energy losses due to various bio-physical interactions within the mangrove ecosystem. Wave attenuation in the mangroves is presumably dominated by energy losses due to vegetation drag, since wave attenuation due to bottom friction and viscous dissipation on the bare mudflats is significantly lower than those inside the mangrove vegetation.Additionally, wave attenuation in the mangroves was found to facilitate enhanced net sediment deposition and a gradual fining of the bed material. These findings corroborate the coastal defence function of mangroves by quantifying their contribution to wave attenuation and sediment trapping. The explicit linking of these properties to vegetation composition and structure facilitates modelling studies investigating the mechanisms determining the coastal defence capacities of mangroves.

Geographical analysis of tourism sites in Andaman Archipelago (India) and ecotourism development for Smith Island of North Andaman

This paper applies the nearest-neighbour analysis to analyse the clustering of tourist attractions in Andaman region and suggests ecotourism development for Smith Island of North Andaman using remote sensing techniques. The results indicated that present tourism sites are distributed in clusters in three regions (Port Blair, Mayabunder and Diglipur). To avoid concentration of tourism sites and population pressure in one particular area, there is a need to promote tourism to other locations as well. The study provided suggestions for ecotourism development in Smith Island after analysing its various ecological features to support the Andaman Administration’s vision to promote ecotourism.

Post-2004 mega-earthquake temporal velocity variation at Andaman Islands from GPS measurements

Post-mega-earthquake velocity adjustment at Andaman region was found to vary with time. Coordinate repeatability for 5-year span shows changeover from post-seismic to inter-seismic period in between 900 and 1,000 days from the mega-earthquake. Excluding Havlock Island, all sites move from south to north and from east to west. Velocity vectors gradually rotated from the nearly perpendicular orientation after the mega-earthquake to parallel orientation with the subduction interface in later phase. Velocities in India 2005 reference frame indicate the presence of a structural discontinuity between Bedonabad and Chidiatapu at south Andaman, between Padmanavapuram and Kaushalyanagar at middle Andaman and between Aerial Bay and Radhanagar at north Andaman.

Seroprevalence and Carrier Status for Leptospirosis in Cattle and Goats in Andaman Island, India

Leptospirosis is endemic to the Andaman Islands and is emerging as an important public health problem in many other parts of India. The ecology of the Andaman Islands is ideal for the disease to remain as an endemic in the warm and humid environment within the rodent population as reservoirs, wild and domestic animals as carriers and affecting humans as incidental hosts. Furthermore, there is a lack of studies regarding the serological and genetic affinities of leptospires infecting humans and animals in Andaman region. A modest study was undertaken to understand the leptospiral carrier state and seroprevalence among animals slaughtered in an abattoir in the Andaman. Serum samples were collected from 184 cattle and 202 goats slaughtered in the abattoir during a two-year period and tested for the presence of leptospiral antibodies. Isolation was also attempted from kidney samples of each of these animals. High seroprevalence of 37% was observed in cattle and 29% in goats slaughtered. Since animals brought from different parts of the Andaman Islands showed Icterohaemorrhagiae, Grippotyphosa and Hebdomadis as the commonest reacting serogroups that are also the commonest among human cases and these animals might have been playing an important role in spreading the disease. Four leptospires were isolated from cattle, belonging to the serogroup Icterohaemorrhagiae. The study highlights the importance of a wide project involving animals and the environment for understanding the transmission dynamics of leptospirosis in the Islands which will help in devising of control and intervention strategies.

Evidence of Strain Accumulation in the Andaman Region for the Giant 2004 Sumatra Andaman Earthquake

Brief Report| December 03, 2013 Evidence of Strain Accumulation in the Andaman Region for the Giant 2004 Sumatra Andaman Earthquake Joshi K. Catherine; Joshi K. Catherine aCSIR‐National Geophysical Research Institute, Uppal Road, Hyderabad 500 007, Indiajoshicatherine@yahoo.co.in Search for other works by this author on: GSW Google Scholar Vineet K. Gahalaut; Vineet K. Gahalaut aCSIR‐National Geophysical Research Institute, Uppal Road, Hyderabad 500 007, Indiajoshicatherine@yahoo.co.in Search for other works by this author on: GSW Google Scholar N. Srinivas; N. Srinivas aCSIR‐National Geophysical Research Institute, Uppal Road, Hyderabad 500 007, Indiajoshicatherine@yahoo.co.in Search for other works by this author on: GSW Google Scholar Subhash Kumar; Subhash Kumar bTrimble Navigation India Pvt. Ltd., K511, Indu Aranya, Nagole, Hyderabad 500068, India Search for other works by this author on: GSW Google Scholar B. Nagarajan B. Nagarajan cSurvey of India, retired, Sainikpuri, Hyderabad 500094, India Search for other works by this author on: GSW Google Scholar Author and Article Information Joshi K. Catherine aCSIR‐National Geophysical Research Institute, Uppal Road, Hyderabad 500 007, Indiajoshicatherine@yahoo.co.in Vineet K. Gahalaut aCSIR‐National Geophysical Research Institute, Uppal Road, Hyderabad 500 007, Indiajoshicatherine@yahoo.co.in N. Srinivas aCSIR‐National Geophysical Research Institute, Uppal Road, Hyderabad 500 007, Indiajoshicatherine@yahoo.co.in Subhash Kumar bTrimble Navigation India Pvt. Ltd., K511, Indu Aranya, Nagole, Hyderabad 500068, India B. Nagarajan cSurvey of India, retired, Sainikpuri, Hyderabad 500094, India Publisher: Seismological Society of America First Online: 14 Jul 2017 Online ISSN: 1943-3573 Print ISSN: 0037-1106 Bulletin of the Seismological Society of America (2014) 104 (1): 587–591. https://doi.org/10.1785/0120130141 Article history First Online: 14 Jul 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Joshi K. Catherine, Vineet K. Gahalaut, N. Srinivas, Subhash Kumar, B. Nagarajan; Evidence of Strain Accumulation in the Andaman Region for the Giant 2004 Sumatra Andaman Earthquake. Bulletin of the Seismological Society of America 2013;; 104 (1): 587–591. doi: https://doi.org/10.1785/0120130141 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Abstract We report results of Global Positioning System (GPS) and tide gauge data from the Andaman region that pertain to the period before the 26 December 2004 Sumatra–Andaman earthquake (Mw 9.2). In the preceding 40 years, seismicity in the frontal arc region was generally very low, implying locking of the main thrust zone. The campaign mode GPS data support strain accumulation in the region, corresponding to a slip deficit rate of about 3 cm/year. However, the tide‐gauge data of the preceding three years from the earthquake indicate land subsidence at a rate of about 3.3 cm/year, whereas uplift was expected in the period prior to the earthquake, as the region experienced coseismic subsidence during the earthquake. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Assessment of gas hydrate stability zone and geothermal modeling of BSR in the Andaman Sea

Wide-spread bottom simulating reflectors (BSRs) are observed along available multichannel seismic profiles covering an area of about 290km2 in the Andaman Sea. The seismic data shows that the BSR occurs at places where water depth exceeds 1000m, and is identified by cross-cutting relationships with the dipping reflectors. The BSR that represents the base of gas hydrate stability field can be used to infer the gas hydrate stability thickness, which ranges between ∼518m to ∼861m depending on water depths. In situ measurement at site 17 during the Indian National Gas Hydrate Program (NGHP) Expedition-01 shows very low geothermal gradient 19±2°C/km. A conductive model was used to determine geothermal gradients from BSRs, which is calculated and varying between 10°C/km to 40°C/km. The low geothermal gradient is responsible for the deepest BSR or gas hydrate stability zone (GHSZ) in the Andaman region and in the world. The geothermal modeling shows a close match of the predicted base of the gas hydrate stability zone with the observed BSR depths.

Elastic thickness structure of the Andaman subduction zone: Implications for convergence of the Ninetyeast Ridge

We use the Bouguer coherence (Morlet isostatic response function) technique to compute the spatial variation of effective elastic thickness (Te) of the Andaman subduction zone. The recovered Te map resolves regional-scale features that correlate well with known surface structures of the subducting Indian plate and the overriding Burma plate. The major structure on the India plate, the Ninetyeast Ridge (NER), exhibits a weak mechanical strength, which is consistent with the expected signature of an oceanic ridge of hotspot origin. However, a markedly low strength (0<Te<3km) in that region, where the NER is close to the Andaman trench (north of 10°N), receives our main attention in this study. The subduction geometry derived from the Bouguer gravity forward modeling suggests that the NER has indented beneath the Andaman arc. We infer that the bending stresses of the viscous plate, which were reinforced within the subducting oceanic plate as a result of the partial subduction of the NER buoyant load, have reduced the lithospheric strength. The correlation, Te<Ts (seismogenic thickness) reveals that the upper crust is actively deforming beneath the frontal arc Andaman region. The occurrence of normal-fault earthquakes in the frontal arc, low Te zone, is indicative of structural heterogeneities within the subducting plate. The fact that the NER along with its buoyant root is subducting under the Andaman region is inhibiting the subduction processes, as suggested by the changes in trench line, interrupted back-arc volcanism, variation in seismicity mechanism, slow subduction, etc. The low Te and thinned crustal structure of the Andaman back-arc basin are attributed to a thermomechanically weakened lithosphere. The present study reveals that the ongoing back-arc spreading and strike-slip motion along the West Andaman Fault coupled with the ridge subduction exerts an important control on the frequency and magnitude of seismicity in the Andaman region.

Assessment of the coral bleaching during 2005 to decipher the thermal stress in the coral environs of the Andaman Islands using Remote Sensing

Sea Surface Temperature (SST) derived from the NOAA AVHRR satellite data were used to generate the Degree of Heating Weeks (DHW) and Hot Spot (HS) products. Combination of the cumulative temperature anomalies and the thermal stress studies were yielded to synoptically identify the probable areas of bleaching. The bleaching status of the Andaman region was assessed based on the DHW and HS for the bleaching event occurred in the Andaman region in April/May 2005. The bleaching status up to Alert Level-1 was recorded with the maximum HS of 3°C and DHW 6°C-week. Simultaneous in-situ reef observations conducted in the Andaman Sea confirmed the coral bleaching event. The maximum mortality in the region due to coral bleaching was shown by the Acropora species (43%) followed by Montipora species (22%) and Porites species (14%). This study focused on detection of coral bleaching warning based on the SST in compliment with the in-situ observations.

Response to comment on inundation studies for Nagapattinam region on the east coast of India due to tsunamigenic earthquakes from the Andaman region

The present case study deals with inundation mapping at Nagapattinam due to the tsunamigenic earthquakes from the Andaman region. Our study is definitely not to model a non-validated event but to study the run-ups at different locations along the east coast of India for large tsunamigenic events if it does happen in the Andaman source region. Several researchers have pointed out the occurrence of tsunamigenic earthquake on June 26, 1941 in the Andaman region (Jhingran 1953; Murty and Rafiq 1991; Pararas Carayannis 2005; Bilham et al. 2005; Jaiswal et al. 2008). Based on Murty and Rafiq (1991), we mention that ‘‘While some scientists have estimated deaths of over 3,000 people along the east coast of India in the 1941 tsunami, there are no reliable data on the number of deaths’’. Ortiz and Bilham (2003) have not totally ruled out the damage and the number of deaths due to the 1941 tsunami but state that no official or unofficial account of the remote tsunami exists. The source parameters for this tsunamigenic earthquake have been used by different authors for the 1941 Andaman tsunami which have been tabulated in Table 1. In our study, the source parameters given by these researchers for the 1941 earthquake have been used as an example. The strike angle and Dip angle have been taken from Ioualalen et al. (2007) where they have modeled the 2004 Sumatra earthquake by dividing the entire source region into 5 segments. In their model, the two segments S4 and S5 form the Andaman region. In our research paper, we were looking for the worst–case scenarios of large thrust type tsunamigenic earthquakes and its impact along the east coast of India from the Andaman Source region as stated in the title. This study has been carried out keeping in mind the historical tsunamis from the Andaman-Sumatra region which are known to have washed away temples along the east coast of India. We are aware of distinguishing between tsunamigenic and non-tsunamigenic earthquakes. The theoretical investigations using the seismograms of several sea earthquakes including 2004 Sumatra and 2005 Nias have been carried out to distinguish between the

Was the 1941 Andaman earthquake tsunamigenic? Comments on “Inundation studies for Nagapattinam region on the east coast of India due to tsunamigenic earthquakes from the Andaman region” by Srivastava et al. 2012

The question whether the 1941 Andaman earthquake did generate a damaging tsunami that impacted the islands and the eastern coast of India is not easily resolvable owing primarily to the non-availability of both instrumental and historical data. The available information on the 1941 Andaman earthquake is somewhat limited because of the difficulties emanating from a war in which Andaman Island was part of eastern war theater. The recent paper by Srivastava et al. (2012) deals with modeling of inundation of the 1941 earthquake along the Nagapattinam Coast on the southeastern India, which implicitly assumed that the 1941 earthquake was indeed tsunamigenic. Our findings, however, do not support such a supposition. Here, we present our arguments on the non-tsunamigenic status of the 1941 Andaman earthquake. The Andaman–Nicobar region is known to have experienced a few large earthquakes in the past (Fig. 1; inset), the biggest being the Mw 9.1 2004 earthquake. Among the historically earlier earthquakes, only those in 1881 (Mw 7.9) and 1941 (Mw *7.7) seemed to be significant (Rogers 1883; Jhingran 1952). The 1881 and the June 26, 1941, earthquakes are known to have sourced off the western margin of the Car Nicobar and Middle Andaman Islands, respectively (Rajendran et al. 2003; Bilham et al. 2005). The 1881 earthquake off the Car Nicobar Island had generated tsunami that impacted the Nicobar coast and the south eastern coast of India (Ortiz and Bilham 2003), an observation validated by direct measurements of tidal gages (Rogers 1883). The 1881 event, significant among the past earthquakes, caused a tsunami surge not exceeding 0.75 cm at Car Nicobar (Rogers 1883); wave height of 0.25 m was measured from the tide gauge stations at Madras (Chennai) on the east coast of India (Ortiz and Bilham 2003). However, there are no reliable reports of any tsunami impact due to the 1941 Andaman earthquake either from the Andaman and Nicobar Islands or from the east coast of India (Rajendran et al. 2007). To verify the reported non-occurrence of tsunami, which by itself was intriguing, this author had conducted detailed interviews with some of the senior residents in Port Blair, South Andaman, who had experienced the 1941 earthquake. They all said that they had experienced the earthquake in Port Blair, but not a tsunami. This was further verified