Andaman Region Research Articles

Integrating Sustainability and Cultural Sensitivity: Clustering Muslim Tourist Lifestyles in the Andaman Coastal Cluster, Thailand

This study explores the integration of sustainability and cultural sensitivity in clustering Muslim tourist lifestyles in the Andaman coastal region. The Muslim tourist demographic, representing a significant portion of the global population, prioritizes halal standards and Islamic attributes in their travel experiences. This research investigates the lifestyle patterns of Muslim tourists and their alignment with sustainable tourism principles, particularly in Thailand’s Andaman coastal area, known for its marine and beach tourism. A multi-method approach was employed, utilizing the AIO (Activities, Interests, and Opinions) framework for quantitative data collection through the surveys of 836 Muslim tourists, and qualitative insights from in-depth interviews and focus group discussions with local stakeholders. The study identified key lifestyle clusters: Mainstream Travelers, Experience Seekers, and Chillouts, each with specific preferences for halal services, prayer facilities, and eco-friendly accommodations. The findings underscore the importance of a tailored approach in promoting sustainable tourism that respects cultural values. Recommendations include enhancing halal-certified services, improving infrastructure for religious practices, and promoting eco-friendly tourism options. By aligning sustainability with cultural sensitivity, the Andaman coastal region can attract more Muslim tourists while preserving its environmental and cultural heritage. This research contributes to the broader discourse on sustainable tourism by emphasizing cultural sensitivity and provides practical guidelines for tourism stakeholders in the Andaman region to develop inclusive and sustainable tourism strategies.

Metagenomic exploration of Andaman region of the Indian Ocean

Ocean microbiome is crucial for global biogeochemical cycles and primary productivity. Despite numerous studies investigating the global ocean microbiomes, the microbiome composition of the Andaman region of the Indian Ocean remains largely unexplored. While this region harbors pristine biological diversity, the escalating anthropogenic activities along coastal habitats exert an influence on the microbial ecology and impact the aquatic ecosystems. We investigated the microbiome composition in the coastal waters of the Andaman Islands by 16S rRNA gene amplicon and metagenomic shotgun sequencing approaches and compared it with the Tara Oceans Consortium. In the coastal waters of the Andaman Islands, a significantly higher abundance and diversity of Synechococcus species was observed with a higher abundance of photosynthesis pigment-related genes to adapt to variable light conditions and nutrition. In contrast, Prochlorococcus species showed higher abundance in open ocean water samples of the Indian Ocean region, with a relatively limited functional diversity. A higher abundance of antibiotic-resistance genes was also noted in the coastal waters region. We also updated the ocean microbiome gene catalog with 93,172 unique genes from the Andaman coastal water microbiome. This study provides valuable insights into the Indian Ocean microbiome and supplements the global marine microbial ecosystem studies.

Crustal structure beneath the Alcock Seamount in the Andaman Sea

Alcock and Sewell seamounts are important geomorphic features in the Andaman Sea due to their association with the tectonic history of the Sunda subduction zone. Despite the availability of global geophysical data, the nature of crust beneath these seamounts remains debated due to the paucity of local geophysical data. Therefore, a passive ocean bottom seismometer (OBS) experiment was conducted by deploying broadband OBSs in the Andaman region from 25th December 2013 to 10th May 2014. Based on the local earthquakes recorded by OBS, we attempted to analyse the waveforms of the events using the state-of-the-art transfer function, and estimated the crustal velocities beneath the Alcock seamount. The inferred P wave velocity increases from 5.7 km/s to 7.3 km/s at a depth of 9 km and from 7.3 km/s to 8.1 km/s at a depth of 15 km. We validated the upper velocity model using an active OBS record obtained from a concurrent multichannel seismic survey acquired onboard RV Samudra Ratnakar. Further, we carried out traveltime streamer tomography by downward continuing the shot gathers of MCS data and obtaining high-resolution velocity-depth models over two shallow ridges on the Alcock Seamount. Tomography-derived velocity-depth model matches with that estimated from the active and passive OBS records. The presence of high subsurface velocities beneath the Alcock Seamount suggests the occurrence of extensive volcanoclastic deposits, possibly formed as a result of the magmatic intrusion. Higher velocities for deep crustal layers suggest an oceanic or island arc crust beneath the Alcock Seamount, which has probably evolved due to backarc volcanism in the Andaman Sea.

Correction: Spatial analysis techniques for tsunami vulnerability and inundation mapping of Andaman region using remote sensing, GIS, AHP, and Fuzzy logic methods

Correction: Spatial analysis techniques for tsunami vulnerability and inundation mapping of Andaman region using remote sensing, GIS, AHP, and Fuzzy logic methods

Correlating volcanic emissions from Andaman-Sumatra region to atmospheric pollution in Delhi: A possible scenario

• Causes of whales stranding and Delhi pollution investigated using integrated data • Stranding of whales coincides with time of earthquake and underwater volcanism • Toxic materials from volcanic eruptions lead to increased air and ocean pollution • Prominent cyclonic events are also intimately connected to volcanism • Volcanism-related air pollution affected the human health in Indian sub-continent In the recent past there have been several incidences when large number of whales got stranded and died along the coastal areas of various continents, including India, causes of which are relatively unknown. We have investigated the possible causes of such incidences, based on the analysis of available seismological and GPS data. The time of occurrence of earthquakes of relatively larger magnitude, is found to correspond with the changes in Zenith Total Delay (ZTD). Similarly, stranding of the whales appears to coincide with the time of the underwater volcanism, for example in the Andaman region. The change in ZTD appears to be caused by the increase in the water vapor in the troposphere, as observed in one of the events (Nilam cyclone) in the Bay-of-Bengal region during October 2016. During this volcanic activity, the temperature and toxic contaminated materials from the volcanic eruptions, increased in the surrounding ocean which apparently killed the whales. The volcanic gaseous vents, through which the toxic gases emanated, seems to have apparently affected the whale's lungs. Subsequently, toxic substances which were present in water, severely affected their body organ functions, as the food intake takes place via their skin. Whales have an oxygen rich body, therefore, when lungs are not functioning properly, they may lose the oxygen and gain mass that causes their movement towards the shore. Thus, the influence of underwater volcanic activity, appeared to be a likely cause that led to the demise of sea animals. We also find that the prominent cyclonic events like ‘Ockhi’ which too have an intimate relationship with volcanism, caused severe air pollution that affected the health of the mankind residing in different parts of the Indian sub-continent, especially Delhi and nearby regions.

Spatial analysis techniques for tsunami vulnerability and inundation mapping of Andaman region using remote sensing, GIS, AHP, and Fuzzy logic methods

Spatial analysis techniques for tsunami vulnerability and inundation mapping of Andaman region using remote sensing, GIS, AHP, and Fuzzy logic methods

Characteristics of the Earthquake Swarms in the Andaman Sea Region, India, from 1960 – 2020

The Andaman Sea region is the highly tectonically and seismically active region in India. This is the perfect site for studying earthquake swarms and how the swarms are reacting with the volcanic activities and tectonic processes. Using the International Seismological Centre (ISC) catalogue and USGS NEIC catalogue, we documented 17 earthquake swarms from 1960 to 2020. The hypocentre of the earthquake swarms was reported at 5 km. to 50 km and most of the incidents occurred below 20 km. depth. We examined the seismotectonic characteristics of these swarms. The moment tensor solutions of 6 swarms showing these events are controlled by pure normal faults with a significant strike-slip component, few are dominated by strike-slip faults but no thrust mechanisms are recorded. The b value distribution for the Andaman Sea region was calculated from the swarms’ data and the b value significantly varied between 1.4 –2.17. We conclude that the earthquake swarms in the Andaman and Nicobar Island region are probably the result of magma intrusion in the thin and hot oceanic crust. High b values, active volcanoes and cratered seamount support the volcanic background of these swarms.

Air-sea CO2 exchange rate in the northern Indian Ocean based on coral radiocarbon records

Corals growing in shallow oceanic regions record the radiocarbon variations in ocean surface waters. Tracing bomb radiocarbon in various carbon reservoirs, can help understand the pathways and rates of carbon exchange between the different reservoirs. The northern Indian Ocean comprising two adjoining basins the Arabian Sea and the Bay of Bengal demonstrates contrasting behaviour both in its hydrological condition and CO2 sequestration. In this study, coral based bomb radiocarbon records from the Lakshadweep Islands and the Andaman Islands in the northern Indian Ocean have been analysed. The estimates of air-sea CO2 exchange rate based on bomb radiocarbon for the Lakshadweep is 13.4 ± 2.1 mol m−2 yr−1 and for the northern Andaman is 8.8 ± 1.3 mol m−2 yr−1. The bomb radiocarbon based air-sea CO2 exchange over the Indian Ocean follow the trend of empirical relationship with wind speed. Using the air-sea CO2 exchange rates, the net regional CO2 fluxes over the Lakshadweep and the northern Andaman region has been determined.

Occurrence of <i>Chloeia flava pulchella</i> Baird, 1868, from Off Junglighat, South Andaman, India

Fire-worms from the family Amphinomidae Lamark, 1818, act as a predator, scavenger and sedimentivores, in nearshore waters. This family has 146 valid species among them 18 numbers reported from Indian marine environment and 11 reported from the Andaman waters. Among this family, genus Choleia Lamark. 1818, reported 4 species and 1 subspecies from the Andaman waters. Among these the species Chloeia flava pulchella Baird, 1868was reported by Tampi and Rangarajan, 1964, but no detailed species description was found for this species. During the studies on continuous monitoring of the environmental parameter of nearshore waters of off South Andaman region, a specimen of Chloeia flava pulchella Baird, 1868, was collected. Later the cursory analysis for this specimen identification was revealed that the detailed description of this species found in this region was not available in the literature. So, the detailed taxonomic description was developed and presented in this article.

Depth-wise attenuation mechanism of seismic waves in the Andaman region

This study evaluates the depth-dependent seismic wave attenuation characteristics in the Andaman region which is a part of the Andaman-Nicobar Subduction zone (ANSZ), and possible causes. We have analyzed seismic waveforms of 1402 earthquakes recorded at seven broadband seismic stations located over the Andaman Island, to estimate the direct S-wave (Qs), coda wave (Qc), intrinsic (Qi) and scattering (Qsc) attenuation parameters. The coda normalization method is used to calculate Qs. Additionally, the variation of Qc with frequency and coda window length is studied using the single back-scattering method. The separation of Qi and Qsc is achieved using the Wennerberg’s method. Results show a strong frequency dependence of Qc and Qs. At 1 Hz, the values of Qc are 136, 137, 137 and 146 for coda window length of 30, 40, 50 and 60 s respectively, with the corresponding frequency-dependent coefficient (n) of 0.82, 0.83, 0.85 and 0.82. At 1 Hz the observed Qi values show a close proximity to Qc values, which indicates a strong dominance of intrinsic attenuation. Also, it is observed that Q0i shows low value and remains almost the same between 115 and 132 km depth, with a slight increase in between 132 − 140 km. The observed results imply high intrinsic attenuation, possibly due to partial melting or fluid-filled rocks at these depths. Whereas Q0sc shows a different trend. It gradually increases up to a depth of 132 km, with a slight decrease beyond that. This indicates a decrease in heterogeneity up to 132 km and a slight increase in the same below that. Further, the estimates of pressure (P) and temperature (T) conditions of the subducting slab with depth show an increase in temperature from 996° to 1015°C and an increase in pressure from 33.8 to 41.2 kbar, as the depth increases from 115 to 140 km. The phase relationship for the basaltic rocks with 5 − 6 wt% bound H2O in eclogite facies reveals that the P − T condition observed in this study lies above the solidus temperature. This promotes the formation of interstitial liquid (5 − 10%) at these depths, probably causing high intrinsic attenuation.

Persistence of marine heat waves for coral bleaching and their spectral characteristics around Andaman coral reef.

Coral reefs are fragile and endangered ecosystems in the tropical marine and coastal environment. Thermal stress due to marine heat waves (MHW) could cause significantly negative impacts on the health conditions, i.e., bleaching of the coral ecosystem. The current study is an attempt to quantify the intensity of coral bleaching in the Andaman region in recent decades using the intensity of marine heat wave (IMHW) estimated from satellite measured sea surface temperature (SST). A linear regression model was developed between IMHW and in situ observations of percent coral bleaching (PCB) which has the slope 7.767 (of IMHW unit) and intercept (- 141.7). Further, an attempt was also made to establish the relationship between PCB and the ratio between the remote sensing reflectance (Rrs) at 443 and 531nm to upscale the percentage of coral bleaching at synoptic scales. A significant positive correlation between the PCB and band ratio index was found (R2 = 0.72). This approach can be used for the operational monitoring of coral reef beaching in this region.

Spatial and temporal changes in bomb radiocarbon in the northern Indian Ocean

For improved understanding of ocean circulation in the northern Indian Ocean region, long term continuous record of radiocarbon measurement is required. Limited radiocarbon records from the region demands investigations of natural archives. Coral core records along with some literature data were analysed to study the temporal changes in 14C values over the northern Indian Ocean. The major fraction of the bomb radiocarbon appears to have transferred in to the ocean, as recent records from the surface seawater Δ14C values show comparable or even higher than the atmospheric Δ14C values. The northern Andaman region showed higher Δ14C decline rate between 1978 and 2014 compared to the southern Bay of Bengal and the Lakshadweep region. The comparable southern Bay of Bengal and the Lakshadweep Δ14C values could be due to transfer of Arabian Sea waters to the southern Bay of Bengal. The southern Andaman region shows lower Δ14C values compared to the northern Andaman region, suggesting the influence of 14C depleted waters in the region.

Report of Lamellibrachia Worm Tube from off Northwestern Andaman Island

The Lamellibrachia worm is a gutless worm, the worm producing such a long tube about more than 1m, made up of the hard materials of proteinaceous compounds. They live as a chemoautotrophic and often found in the cold seep environments ecosystem, which acts as a gas reservoir (Hydrogen Sulfide). It has especially exhibited a rich source of Methane. Under the INDOBIS program on the benthic faunal survey (During the FORV Sagar Sampada 355 cruise), found thirty-five cm of animal less tube on the western side dredge operation of the Andaman Islands. Identifying the Lamellibrachia worm tube from off Northern Andaman Island suggested that this region may contain a cold seep ecosystem. This study reveals that the Lamellibrachia tube has found in the Andaman region and reported for the first time.

Possible Linkages between Microseisms in the Andaman-Nicobar Region and Swells in the South Indian Ocean

AbstractMicroseism source characterization and its genesis play a key role in linking microseism records to prevailing atmospheric and oceanic conditions. In the present study, we analyzed the spatial and temporal distribution of microseisms in the Andaman-Nicobar region using ocean-bottom seismometers and nearby continental stations data for the deployment period of January–April 2014. We attempted to establish a linkage between microseisms and ocean wave parameters derived from the ERA5 dataset. The short-period secondary microseisms (2–5 s) show a marked difference compared with long-period secondary microseisms (6–10 s) and are associated with local climatology and geomorphology. In contrast, long-period microseisms are related to distant sources in the South Indian Ocean. The primary microseisms (11–20 s) are weak in the Andaman region and do not correlate with any ocean wave parameters.

Seismicity analysis using space-time density peak clustering method

This paper presents two-stage clustering approach for accurate analysis of earthquake catalogs where aim is to categorize events in terms of aftershock (AF) clusters or independent backgrounds (BGs). In stage I, the Gaussian kernel-based temporal density estimation is used for grouping of events based on their occurrence time. From the graph, local peak (maxima), local minima and their timing information are utilized to group the events into significant time zones. In stage II, on events of each time zone, coordinate and magnitude information is combined together (weighted mechanism) to determine effective local weighted spatial density ( $$\rho ^{\mathrm{w}}$$ ). Based on $$\rho ^{\mathrm{w}}$$ and event distance ( $$\delta$$ ), a decision graph is drawn to find out the spatial cluster centroids for each time zone. Event’s assignment to the centroid is carried out based on its nearest neighbor of higher density. Outliers (non-clustered) are also detected in stage II which is considered as independent backgrounds. The experimental analysis is carried out on historical seismicity of California, Himalaya, Japan and Sumatra–Andaman region. The results indicate that obtained AFs and total number of events follow a similar cumulative and $$\lambda$$ rate, whereas BGs have linear cumulative and consistent $$\lambda$$ rate. It is also observed that AFs and total events have similar ergodic behavior, quantified from the inverse TM metric plot. The competitive performance of the proposed approach is obtained over state-of-the-art declustering methods.

MARINE RESERVOIR AGE CORRECTION FOR THE ANDAMAN BASIN

ABSTRACTMarine reservoir age is an important component for correction in radiocarbon (14C) dating of marine and coastal samples. 14C concentration in pre-bomb marine samples of known age are used to derive marine reservoir age of a region. Annually banded coral from Landfall island in the northern Andaman has been analyzed for its 14C concentration during the pre-bomb period 1948–1951. 14C age and reservoir effect (∆R) are reported for these pre-bomb coral samples from the northern Andaman region. The mean 14C age of 331 ± 61 yr BP was obtained for the period 1948–1951 with an average reservoir age correction of –138 ± 61 yr. This reservoir age correction is lowest reported from the northern Indian Ocean. ∆R value of the northern Andaman and the Bay of Bengal appears lower than that of southern Andaman. The ∆R values obtained using mollusk shells and coral from the Andaman region shows large variability. The lower reservoir age correction for the Landfall Island situated in the northern part of the Andaman archipelago, could result due to freshwater flux and reduced upwelling in the region.

Distribution and diversity of Macroalgae in the Andaman region, India

Distribution and diversity of Macroalgae in the Andaman region, India

Geometry of the Subducting Indian Plate and Local Seismicity in the Andaman Region from the Passive OBS Experiment

Geometry of the Subducting Indian Plate and Local Seismicity in the Andaman Region from the Passive OBS Experiment

Species diversity and distribution of seagrasses from the South Andaman, Andaman and Nicobar Islands, India

AbstractA survey was conducted with the objective to study seagrass distribution, bed size and shoot density in different substrata of the South Andaman Islands. A total of 231 seagrass sites were observed during the study, in which a total of eight species were found. The South Andaman region exhibited the highest species diversity followed by Havelock, Little Andaman and Neil Islands. Eleven continuous seagrass bed were noted during the study which were confined to three different types of substrata: sand only; sand mixed with coral sand and coral rubble; sand mixed with mud.Thalassia hemprichiiandCymodocea rotundatawere found in dense canopies and covered large areas associated with sand and coral rubble.Halophila beccariishowed moderate abundance in muddy substrata andHalodulespp. grew in fine sand. The highest shoot density was recorded at Haddo, followed by Vijaya Nagar and Chidyatapu, contributed mostly byHalodulespp. In general, seagrass diversity and distribution were mainly influenced by the percentage composition of sand. The authors recommend that the seagrass meadow of Haddo should be considered for conservation priority because of multiple anthropogenic pressures, such as sewage input, dumping of solid wastes on the shoreline and anchoring of boats.

ORCHIDS GENETIC DIVERSITY FOR BLOOMING FLORICULTURE INDUSTRY

India is bestowed with different agro-climatic conditions and soil. This makes the country particularly suitable for growing a wide variety of horticulture crops especially flowers. Among the flowers, the orchids represent a fairly young, highly diverse, and successful family of flowering plants, the Orchidaceae. It is still in an active state of speciation. Some of their botanically significant features are presence of intricately fabricated and long-lasting flowers. The numerical strength of orchids, in terms of species have been variously assessed between 17,000 and 35,000. The orchids are in cosmopolitan in distribution. Rhizanthella gardneri and R. slateri are subterranean in habit and Corallorrhiza innata a rootless parasite. The orchids are essentially out breeders, having adapted to insect pollinations. India with a vast geographic expanse and climatic ones ranging from tropical to temperate, supports a rich diversity of flora. The orchids have naturalized here in great profusion; the North Eastern, the Himalayan, and the Peninsular regions (on the main land) and the Andaman and Nicobar region (off shores) are the major orchid habitats in the country, while the occurrence of nearly 1100 species in 157 genera are representing all the major orchid tribes. Efforts have been made to evolve strategies for ensuring the survival and maintenance of genetic diversity that still exists in these plants. In this connection, one need not overstress the importance of orchid breeding. Unfortunately, orchid breeding is still in infancy in the country. Now, there is a need to improve floriculture breeding to reduce the foreign exchange for good quality planting materials. Hence, it is important to explore the orchid wealth of the country. Important floriculture traits, geographical distribution and utility of orchids will also be discussed at length. Further, there is a need to create suitable varieties to different agro-climatic horti-silvi system and socio-economic condition. Since floriculture trade and consumption are increasing rapidly worldwide, there is a blooming opportunity for India to achieve better growth in its production and export due to presence of high amount of diversity in indigenous orchids flora, thus earning valuable foreign exchange through florist trade, nursery of plant saplings, potted plants, bulb and seed production, micro-propagation and other value added products of orchids.