Tsunami is a seismic wave, travelling at high speeds across the ocean, formed by sudden and sharp motions of oceanic plates. Tsunami is caused by displacement of the Earth along a fault. The Pacific Ocean, Indian Ocean, and the Atlantic Ocean recorded several tsunamis during the historic period. Their frequency has however, increased in the 20th century, especially in the Pacific and the Indian Oceans. The Indian Ocean tsunami of 26th December, 2004 is one of the most catastrophic events in the living memory of mankind. It was caused by a severe earthquake, measured 8.9 on the Richter Scale. The earthquake had its epic center near Banda-Ache (Sumatra-Indonesia) 3.5o N latitude and 95o East longitude. The earthquake was triggered by the collision of Indian Plate with the Burmese Plate (Fig.6.2).
This tsunami had been the most damaging in the human history. It had wrecked havoc in 14 countries, in South-East Asia, South Asia and East Africa including Somalia. The total number of deaths were more than 2.5 lakhs and the loss to property and animals was enormous.
The Bhopal tragedy (capital of Madhya Pradesh) occur red on December 3, 1984. Shortly after midnight, a poisonous gas cloud escaped from the Union Carbide India Limited (UCIL) Pesticide Factory. The cloud contained 15 metric tons of methyl isocyanate (MIC), covering an area of more than 30 square miles. The gas leak killed at least 4000 local residents instantly, caused health problems such as at least 50,000 to 500,000 people. The health problem killed around 15,000 more victims in the years that followed. Approximately 100,000 people still suffer from chronic disease consequential to gas exposure, today.
This event is now known as the worst industrial environmental disaster to ever have occurred. The cause of the incidence was water ending up in MIC storage tanks, causing an exothermal reaction that released an amount of poisonous gas large enough to open the safety valves. Normally, scrubbers would intercept escaping gas, but these were temporarily out of order for repair.
A devastating cyclone occurred along the coast of Odisha on 29th October, 1999. The velocity of wind in this cyclone was more than 260 kilometers per hour. Hundreds of people were killed, and more than 200,000 houses were destroyed mangroves damaged and vast tracts of agricultural land in the coastal areas were submerged under the saline water of the sea. The worst affected area was the Paradwip Port and its surrounding areas. The people of coastal villages like Gundlaba are working together to regenerate mangroves and other forests.
The Bhuj earthquake occurred at 8.46 A.M. on 26th January, 2001. The magnitude of the earthquake was 8.1 on the Richter Scale. Its epic center was at 23o 3′ North and 69o 8′ East (about 20 km north-east of Bhuj. More than 30 thousand people were killed, several thousand got injured and millions became homeless. The poor people of Bhuj, Bhachau and Anjar were the worst affected (Fig. 6.3).
The massive earthquake that struck Kashmir on 8 th October, 2005 killed at least 73,000 people and left more than 3.3 million people homeless. The epic center of the earthquake was near Muzarabad. Most of the people died because of falling buildings. It was difficult for the poor people of the region to recover. The physical injuries, destruction and loss of livelihood had serious long-term consequences.