Disaster Management and Prevention

The earthquake and tsunami of 26 December 2004, shocked most people. UNESCAP has been working on environmental issues and the use of information, communication and space technologies (ICST) for disaster management and prevention. This web site is to provide a better understanding on natural disasters including earthquakes and tsunami and about measures that can be taken to help protect people from such disasters.

Background information on earthquake and tsunami of 26 December 2004:

The earthquake took place at 00:58:53 UTC ( 07:58:53 local time) in the Indian Ocean off the western coast of northern Sumatra, Indonesia. Earthquakes occur daily, but a magnitude 9 earthquake as occurred then is rare. The earthquake's magnitude was first reported as 8.1 by the U.S. Geological Survey, but after further analysis the USGS increased this first to 8.5, 8.9, and finally to 9.0

“The hypocentre was at 3.316°N, 95.855°E, some 160 km (100 mi) west of Sumatra, at a depth of 30 km (18.6 mi) below mean sea level (initially reported as 10 km). This is at the extreme western end of the "Ring of Fire", an earthquake belt that accounts for 81% of the world's largest earthquakes. The earthquake was unusually large in geographical extent. An estimated 1,200 km (750 mi) of faultline slipped 20 m (60 ft) along the subduction zone where the India Plate dives under the Burma Plate. The seabed of the Burma plate is estimated to have risen several metres vertically up over the India plate, creating shock waves in the Indian Ocean that traveled at up to 800 km/h (500 mi/h), forming tsunamis which, while less than a metre high in deep water, resulted in huge waves when they reached land.” (http://en.wikipedia.org/wiki/2004_Indian_Ocean_earthquake)

A tsunami (a Japanese word meaning “harbor wave” is caused by a vertical disturbance in the ocean such as an earthquake or massive landslide. The tsunami that struck the coasts of the Indian Ocean was the deadliest tsunami by far in recorded history. The Sunda Trench associated with this recent earthquake activity is relatively active, and should be considered a possible location for many future earthquakes, with resultant potential for tsunamis.

The tsunamis devastated the shores of many countries including Indonesia, Sri Lanka, India, Thailand, Myanmar, Bangladesh, Maldives and Malaysia in the region, and Somalia, Kenya and Tanzania in Africa. The total death toll is over 150,000.

Warning system

Tsunamis usually occur along the Pacific Ocean coasts of the "Ring of Fire", and an effective tsunami warning system has long been in place there. However, although the extreme western edge of the "Ring of Fire" extends into the Indian Ocean (the point where this earthquake struck), no tsunami warning system existed in the Indian Ocean due to the rarity of tsunamis in that ocean — the last major one there was caused by the Krakatoa eruption of 1883.

The Pacific Tsunami Warning System (PTWS), operated by Tsunami Warning Center (TWC) which is located at Honolulu, Hawaii, is an international warning effort formalised in 1965. Comprising 26 countries, PTWS monitors seismological and tidal stations to evaluate whether earthquakes will produce tsunamis, and disseminates tsunami warning information to national authorities. Under the PTWS system, for any underwater earthquake exceeding 6.5 on the Richter scale, an alert is issued if a single wave gauge shows that the ocean id reacting. Thailand is already a member of the PTWS, but all of its ocean buoys, which relay information from wave sensors on the ocean floor, are on the east (Pacific) coast of the country. According to a report, PTWS actually sent out warnings to Thailand and Indonesia. However, there was no system for translating the alerts into quick action.

Knowledge/awareness and the use of ICST

Many lives could have been saved if the people knew about the warning signs of tsunami. In the minutes preceding a tsunami, the sea often recedes from the coast. People in the Indian Ocean region, where tsunami is rare, this rare sight induced people to visit the coast to investigate and collect fish stranded in exposed beach.

On Maikhao beach in Thailand, a 10 year old British girl, Tilly Smith, recognised the signs when the tide rushed out and boats on the horizon began bobbing violently. She told her mother she had just been studying tsunami in geography at school and that they should leave the beach. Her parents warned others on the beach and so this was one of the few areas where no-one was reported killed or seriously injured. (http://www.nypost.com/news/worldnews/37579.htm)

To warn the general public, quick conversion of TV and radio broadcasts to disaster response programming, and automated-sending of mobile/telephone messages is highly economical and practical.

“Mr. Vijaykumar, a former volunteer at a telecenter in Nallavadu, India, run by the M.S.Swaminathan Research Foundation and now living in Singapore, received word of the tsunami well before anyone in southern India did. He called his family in Nallavadu, then called the telecenter. Another telecenter volunteer living abroad, Mr. Gopu, did the same thing. Immediately the community sprung into action. Using the telecenter's public address system, local volunteers alerted fellow villagers. Among the 500 families in Nallavadu, 150 of their houses were destroyed -- yet no one died, because the telecenter responded to the imminent crisis at a time when no other local or national warning system was in place.

The Nallavadu telecenter is fortunate because it is a part of the Open Knowledge Network (OKN), an initiative that provides communities in developing countries the tools and skills they need to become content producers. In the case of Nallavadu and other local OKN communities in southern India, they're using the initiative to collect weather data and distribute it to fisherman in order to protect them when they're out at see. Because Nallavadu's telecenter volunteers had the information and communication technology (ICT) skills to gather information and get it out by all possible means - including mobile phones and public address systems -- they saved thousands of lives. The telecenter became a lifeline for the entire community.

While in-home Internet access is still a rarity in many villages, mobile phones are much more common. SMS text messaging could have been used to send warnings to millions of mobile phone subscribers, who in turn could have used community resources to alert their neighbors. For example, after the tsunami, the Swedish government sent text messages to all Swedish citizens whose mobile phones had recently been used in Thailand. These messages have helped the Swedish government pare down the list of who's missing and who's not.

Right now, a practical application could be a relief worker sending out an SMS because he/she needs access to more antibiotics: using the names of those antibiotics as key words would then route the text message to people and organizations who might be a source for those antibiotics.” (http://www.andycarvin.com)

What can be done to reduce the damage from earthquakes and tsunamis?

Earthquakes cannot be forecast with present technology. Tsunamis can be forecast within a few minutes once an earthquake occurs under conditions that could produce a tsunami. Unlike certain types of land degradation, pollution, and disease, earthquakes/tsunamis cannot be avoided by appropriate actions. However, like some other types of disasters, their risk can be mitigated by effective planning. Their effect on lives and property can be greatly reduced.

Planning: Techniques, even data, for assisting the planning process are available – even free in some cases. However, the development of such plans would be strengthened by an international advisory centre helping national authorities to develop, maintain/update, and implement such planning. The result of such a process would be an essential disaster component to national master development plans.

Public Warnings: These can be implemented in the region, as sketched above. Such systems have been operating for decades in some countries. Appropriate technology is available in most countries of the region – even to a degree in least-developed countries – to integrate existing (and perhaps strengthened) global warning systems with national and local systems to deliver such warnings to affected populations.

Followup: With better planning and public warnings, followup such as mobilizing resources for hospitals, public safety officials, and injured/displaced persons could be facilitated. If planning (including building codes and restrictions) is enforced, recovery should be facilitated, as well.