The earthquake that caused the tsunami of December 2004 has altered the topography and ecology of the Andaman and Nicobar Islands forever, writes Pankaj Sekhsaria. So far the impact of such marked changes in topography do not seem to have been taken into account by policymakers and government
If there is one thing that immediately springs to mind when the Andaman and Nicobar Islands are mentioned today, it is the devastating tsunami of December 26, 2004. Official figures give a sense of the massive damage that was caused to life and property: over 3,500 people dead or missing; nearly 8,000 hectares of paddy and plantation rendered useless; 938 boats completely damaged; more than 150,000 head of cattle lost.
These aggregated figures for the entire island chain hide an important detail that has not received the attention and analysis it deserves.
Of the 3,513 people reported dead or missing only 64 were from the Andaman group of islands; the remaining 3,449 were from the islands in the Nicobar group. Seventy-six per cent of the agricultural and paddy land destroyed, and 80% of livestock loss were also reported from the Nicobars. Likewise, nearly 70% of the construction of new housing for the tsunami-affected is in the Nicobar Islands.
It is evident that the impact of the tsunami was much greater in the Nicobar Islands than in the Andamans. So, while the Nicobars account for only 22% and 12% of the area and population, respectively, of the entire chain of islands, 98% of the deaths and 76% of loss of agricultural land occurred here. The damage caused was inversely proportional to the area and population of the two groups of islands, and strikingly so (see Table 1 and Table 2).
Although the tsunami was seen as the main cause of the damage, it was actually the earthquake that caused the tsunami in the first place that was responsible for most of the damage here. While the tectonic movements triggered by the earthquake catalysed the tsunami, they also caused a huge and permanent shift in the lay of the Andaman and Nicobar Islands.
Assessments by a number of scientists from various institutes, including the University of Colorado in the USA and the Geological Survey of India, indicate that the Andaman group of islands were thrust upwards by four to six feet while parts of the Nicobar Islands went significantly under -- four feet of submergence in Car Nicobar; nearly 15 feet at the southernmost tip -- Indira Point -- on Great Nicobar Island. This important change in the lay of the islands was reported to have occurred almost immediately after the earthquake, a few minutes before the huge waves struck the coastline. Pre- and post-earthquake satellite maps released by the National Remote Sensing Agency (NRSA) show striking visual evidence of this. It also explains the huge submergence and damage experienced in the Nicobars, though this group covers a relatively small area and is more thinly populated.
Tectonic activity and the submergence and emergence it caused also resulted in significant ecological changes in the islands. A survey by the Andaman and Nicobar Environment Team revealed, for instance, that huge areas (nearly 60 sq km) of coral reefs along the western and northern coasts of Middle and North Andaman Islands were lifted up, permanently exposed, and destroyed. Studies in the Nicobar group of islands by the Salim Ali Centre for Ornithology and Nature (SACON) showed that immense damage was caused to coastal ecosystems by the joint impact of the tsunami waves and the permanent subsidence and resultant permanent ingress of seawater. Coastal features like beaches, mangroves and littoral forests were the most badly impacted. Coastal wildlife like the endemic Nicobari megapode, the giant robber crab and the Malayan box turtle were among the species worst affected.
Coral reefs off the coasts of the Nicobars were also hit by a combination of submergence, a resultant increase in turbidity, and physical damage caused by tonnes of debris thrown back and forth by the furious water. A survey conducted by the Zoological Survey of India reported large-scale sedimentation on coral reefs around Great Nicobar Island, following the tsunami. A drop in the number of associated coral reef fauna, including nudibranchs, flat worms, alpheid and mantis shrimps, and hermit and brachyuran crabs was also reported.
Significantly, the region is reported to have become much more seismically active now. Data gathered by the United States Geological Service (USGS) show that over 20 earthquakes of a magnitude above M6, in addition to several hundred of lesser intensity, have struck the region in the last five years. The most powerful was the September 2007 quake that had a magnitude greater than M8. It was followed by a tsunami warning; there have been at least half-a-dozen such warnings since 2004.
It would appear that the Andaman and Nicobar Islands, which have always been seismically active and therefore unstable, are even more vulnerable now. It is crucial that this increased threat becomes an important aspect of policy and development planning on the islands. Likewise, changes in the islands’ topography on account of tectonic movements must be factored into future planning. An important dimension, for instance, is the alteration along the coasts of all the islands of the high tide line (HTL). Unless this is recalibrated, any management or implementation of laws and regulations related to the coastal zone cannot be carried out effectively. They would in fact be meaningless.
|Table 1: Island-wise losses|
|Island||People (dead or missing)||Livestock loss||Agricultural land lost||Permanent housing||Area||Population (2001)|
|Total number||Per cent||Total number||Per cent||Area in hectares||Per cent||Number||Per cent||Sq km||Per cent||Number||Per cent|
|Table 2: Losses in percentage (island-wise)|
|Andamans (%)||Nicobars (%)||Total|
|Area (sq km)||6,408 (77.68)||1,841(22.32)||8,249|
|Population (2001)||314,048 (88)||42,068 (12)||356,252|
|People (dead or missing)||64 (2)||3,449 (98)||3,513|
|Livestock loss||31,521 (20)||126,056 (80)||157,577|
|Agricultural land lost (hectares)||1,877 (23.5)||6,115 (76.5)||7,992|
|Permanent housing||2,796(28.6)||7,001 (71.4)||9,797|
The changed scenario also has direct implications on issues like land that can and cannot be allotted for reconstruction or for agriculture and plantation, as also on the materials and design of new buildings being built on the islands.
All these aspects need careful consideration because they are the foundations on which any scenario for the future of the islands must be built. Many worry that they are not being given the importance and consideration they deserve. This was starkly evident in September 2009, when former President Dr A P J Abdul Kalam was in Port Blair to unveil Andaman Vision 2020 “for the strategic development of the Andaman and Nicobar Islands by the year 2020”. Speaking at a national seminar on ‘Security and Development of the Andaman and Nicobar Islands’, Kalam advocated, amongst other things, the construction of a 250 MW dedicated nuclear power station on the islands, and use of the islands as bases for static aircraft carrier and a nuclear submarine-based fleet.
It’s as though the earthquake and tsunami of December 2004, and the hundreds of subsequent earthquakes, did not happen at all! Whatever visions of power we might have for ourselves, ‘security and development’ cannot be ensured by industrial and military might alone. If we ignore the foundational contours of the region’s topography, its seismic instability, and its environment, we only increase the risks and our subsequent vulnerability. And we do so at our own peril.
(Pankaj Sekhsaria is the author of Troubled Islands -- Writings on the Indigenous Peoples and Environment of the Andaman and Nicobar Islands)
Infochange News & Features, April 2010