2004 Indian Ocean earthquake and tsunami

The 2004 Indian Ocean earthquake was an undersea megathrust earthquake that occurred on Sunday, 26 December 2004, with an epicentre off the west coast of Sumatra, Indonesia. The quake is known by the scientific community as the Sumatra–Andaman earthquake. The resulting tsunami is given various names, including the 2004 Indian Ocean tsunami, South Asian tsunami, Indonesian tsunami, and the Boxing Day tsunami.

In May 2005, scientists reported that the earthquake itself lasted nearly ten minutes when most major earthquakes last no more than a few seconds and it caused the entire planet to vibrate at least a few centimeters. The earthquake originated in the Indian Ocean just north of Simeulue island, off the western coast of northern Sumatra, Indonesia. The resulting tsunami devastated the shores of Indonesia, Sri Lanka, South India, Thailand and other countries with waves up to 30 m (100 feet). It caused serious damage and deaths as far as the east coast of Africa, with the furthest recorded death due to the tsunami occurring at Port Elizabeth in South Africa, 8,000km (5,000 miles) away from the epicentre.

Approximately 200,000 to 310,000 people are thought to have died as a result of the tsunami, and the count is not yet complete. In Indonesia in particular, 500 bodies a day were still being found in February 2005 and the count was expected to continue past June. The true final toll may never be known due to bodies having been swept out to sea, but current estimates use conservative methodologies. Relief agencies warn of the possibility of more deaths to come as a result of epidemics caused by poor sanitation, but the threat of starvation seems now to have been largely averted. The plight of the many affected people and countries prompted a widespread humanitarian response.

Devastation to Banda Aceh on the island of Sumatra as a result of the tsunami caused by the 2004 Indian Ocean earthquake.

Areas

The major subduction zone is associated with the Pacific and Indian Oceans and is responsible for the volcanic activity associated with the Pacific Ring of Fire. Since these earthquakes deform the ocean floor, they almost always generate a significant series of tsunami waves. They are known to produce intense shaking for long periods, such as several minutes.

References:

1.     2004 Indian Ocean earthquake and tsunami. (n.d.). In Wikipedia, the free encyclopedia. Retrieved December 19, 2012, from http://en.wikipedia.org/wiki/2004_Indian_Ocean_earthquake_and_tsunami

2.     The Indian Ocean Earthquake & Tsunami of 2004: Will History Repeat Itself? | Britannica Blog. (n.d.). In Britannica Online Encyclopedia. Retrieved from http://www.britannica.com/blogs/2008/12/the-indian-ocean-earthquake-of-2004-will-history-repeat-itself/

3.     Earthquake in the Indian Ocean Causes a Massive Tsunami. (n.d.). Windows to the Universe. Retrieved from http://www.windows2universe.org/headline_universe/earth_science/stories_2004/tsunami_news.html

The Bhola Cyclone

The Bhola cyclone was a devastating tropical cyclone that struck on 12 November 1970 at East Pakistan and the State of West Bengal, India. . It was the extreme tropical cyclone ever recorded and one of the lethal natural disasters in modern times. More than 500,000 people lost their lives in the storm, mainly because of the storm surge that flooded much of the low-lying islands of the Ganges Delta. This cyclone was the sixth cyclonic storm of the 1970 North Indian Ocean cyclone season, and also the season's toughest, reaching strength equivalent to a Category 3 hurricane.

The cyclone formed over the central Bay of Bengal on 8 November and travelled north and reached its peak with winds of 185 km/h (115 mph) on 12 November and made landfall on the coast of East Pakistan that night. The storm surge destroyed many of the offshore islands, wiping out villages and destroying crops throughout the region. In the most severely affected Thana, Tazumuddin, over 45% of the population of 167,000 was killed by the storm. The exact full death toll will never be known, but it is estimated that between 300,000 and 500,000 people lost their lives.

Nearly 46,000 of the estimated 77,000 fishermen of the region frozen in the cyclone, and those that survived were severely injured. Approximately 65% of the coastal region’s fishing industry was destroyed, in a region where about 80% of the protein consumed comes from fisheries.

The Bhola cyclone on November 11, 1970

Impacts

East Pakistan

The meteorological station in Chittagong, 95 km (59 mi) to the east of where the storm made landfall, recorded winds of 144 km/h (89 mph) before its anemometer was blown off at about 2200 UTC. A ship anchored in the port in the same area recorded a peak gust of 222 km/h (138 mph) about 45 minutes later. As the storm made landfall, it caused a 10-metre (33 ft) high storm surge at the Ganges Delta. In the port at Chittagong, the storm tide peaked at about 4 m (13 ft) above the average sea level, 1.2 m (3.9 ft) of which was the storm surge.

India

The cyclone brought widespread rain to the Andaman and Nicobar Islands, with very heavy rain falling in places on November 8 and November 9. Port Blair recorded 130 mm (5.1 in) of rain on November 8, and there were a number of floods on the islands. The MV Mahajagmitra, a 5,500-ton freighter en route from Calcutta to Kuwait, was sunk by the storm on November 12, with the loss of all 50 people on board. The ship sent out a distress signal and reported experiencing hurricane-force winds before it sank. There was also widespread rain in West Bengal and southern Assam. The rain caused damage to housing and crops in both Indian states, with the worst damage occurring in the southernmost districts.

Since the Bhola Cyclone, no natural disaster has resulted in as many fatalities and the number of fatalities has trended lower after every subsequent major storm. This pattern is most likely due to the increased awareness and preparation of the population. The population of Bangladesh remains extremely impoverished and vulnerable to the effects of a cyclone.  However, due to mitigation strategies and programs, as well as disaster preparation and awareness efforts, the vulnerable communities are better prepared and more aware of storms before they make landfall.

References:

1.    Hurricanes: Science and Society: 1970- The Great Bhola Cyclone. (n.d.). Hurricanes: Science and Society: Home. Retrieved from http://www.hurricanescience.org/history/storms/1970s/greatbhola/

2.     1970 Bhola cyclone. (n.d.). In Wikipedia, the free encyclopedia. Retrieved December 17, 2012, from http://en.wikipedia.org/wiki/1970_Bhola_cyclone

3.     Hurricane Sandy: The Bhola Cyclone in Bangladesh Killed Half-Million In 1970. (n.d.).International Business Times - International Business News, Financial News, Market News, Politics, Forex, Commodities. Retrieved from http://www.ibtimes.com/hurricane-sandy-bhola-cyclone-bangladesh-killed-half-million-1970-855356

4.     Bhola Cyclone 13 November 1970 : What is the real lesson of Bhola in 1970. (n.d.).YouTube. Retrieved from http://www.youtube.com/watch?v=gkcuZoR6XSU