Mitigating the hazards of the tsunami
By Dulip Jayawardena Retired Director, Geological Survey Department (present GSMB)
There has been harsh criticism of the Geological Survey and Mines Bureau and the Meteorology Department over the tsunami issue. Both these institutions were established during the colonial regime and are over 100 years old. I strongly feel that instead of leveling criticisms which are sometimes unreasonable, the government should take immediate action to upgrade the facilities of these units.

Both the GSMB and the Meteorology Dept are hamstrung with the lack of proper buildings, trained scientific personnel and state of the art equipment. The decision makers should take immediate action to see that these deficiencies are immediately rectified with foreign assistance. If this drawback is not corrected Sri Lankans will have to face similar calamities in the future. Accordingly I would like to flag this issue as mandatory for any long-term plan for disaster mitigation.

Distinction between earthquake and tsunami
I have noticed the general public is not educated in layman's language about the above distinction. For the generation of a Tsunami there should invariably be an undersea earthquake in an area not far from the coastline. The quake should generally be at two converging plate margins.The magnitude in general should be above 6.3 on the Richter scale. Accordingly it could be stated that the Tsunami is an after effect of a under sea earthquake.

Undersea earthquake characteristics
The earthquake magnitude was first reported by the US Geological Survey (USGS) as 8.1 but after further analysis it was increased to 8.5 and 8.9 and finally to 9.0. There had been only five earthquakes larger than this one since 1900 and the largest recorded was of magnitude 9.5 in Chile in 1960. Each of the above earthquakes also gave rise to tsunamis (in the Pacific Ocean) but the death toll from these was significantly lower ranging from zero to a few thousands.

The recent earthquake was at about 100 miles off the west coast of Sumatra at a depth of 18.6 miles This is in the extreme western end of the "Ring of Fire" an earthquake belt that accounts for over 80 percent of the world's largest earthquakes.

The quake itself (apart from the tsunami) was felt as far away as Bangladesh, India, Malaysia, Myanmar, Singapore, Thailand and the Maldives. Unconfirmed reports state that it was also felt in Sri Lanka. The earthquake was enormous in magnitude and also in geographical extent. An estimated 1200 km or 750 miles of fault line to the north of the epicenter along the Andaman Islands slipped 15 meters or 50 feet where the India Plate dives under the Burma Plate (Theory of Plate Tectonics).

Consequently the sea bed of the Burma Plate is estimated to have risen 10 meters vertically up over the Indian Plate, creating shock waves in the Indian Ocean that travelled at up to 800 km per hour or 500 miles per hour the speed of a modern jet plane at full throttle. This phenomena formed tsunamis when the waves reached land.

The Indian Plate is a part of a great Indo -Australian Plate. Recent research has shown that the Indio Australian Plate has separated in an area very close to the epicenter of the recent earthquake and the Australian sub Plate is now moving anti clockwise applying more stress on the Burmese Plate.

It is said that the Australian sub continent over millions of years will move in an counter clockwise direction and will take with it all the islands in South east Asia including the Indonesian Archipelago and will press against the Chinese mainland to give rise to high mountains like the Himalayas. Modeling of the combined effects of Plate tectonics and continental drift has given rise to such scientific reasoning.

Earthquake power
The total energy released by a magnitude of 9 earthquake is equivalent to 32,000 megatons of TNT. This exceeds the total amount of energy consumed in the US in one month or the energy released by the wind of a hurricane over a period of 70 years. Equivalently the amount of energy is enough to boil 10000 litres for every person on earth. It must be noted that each unit on the magnitude of scale represents 31.6 fold increase in energy: every two units signify 1000 times more energy

It has been reported that the massive release of energy and shift in mass insignificantly altered the earth's rotation. The exact amount is still not known but theoretical models have suggested that the earthquake may have shortened the length of a day by as much as three microseconds.

Because the 1200-km of fault line was in a north-south orientation, the great strength of the tsunami was in an east- west direction. Bangladesh, which lies on the northern end of the Bay of Bengal, had very few casualties despite being a low-lying country regularly devastated by cyclones.

Coasts that have a landmass between them and the tsunami's location of origin are usually safe. However tsunamis can sometimes deflect from such landmasses for example the Indian state of Kerala was hit by the recent tsunami. Also Somalia was hit harder than Bangladesh despite being far away.

In the case of Sri Lanka there was no land mass between the location of the origin of the tsunami and had to face the full brunt of it destroying much of the coast line in the north east and the south. Ocean currents during the month of December around Sri Lanka, which travel along the equator is aggravated by the East Indian Coastal current giving rise to the northeast monsoon. This clash of ocean currents set off high intensity waves. Accordingly the force of the tsunami was further strengthened due the physical oceanography of the Indian Ocean during the month of December.

Historical records show that a similar tsunami of much less magnitude struck Sri Lanka in 1883. This was a result of a volcano exploding in Krakatoa, an island which was located between Java and Sumatra that disappeared under the sea. The waves that struck Galle, Panama, Hambantota and Negombo were on the average about 4 feet. There was hardly any damage as this particular episode happened in the month of August. In the month of December under the North East monsoon the Equatorial Indian Ocean jet propagates along the equator from Sumatra (near the epicenter of the quake) slightly to the south of Sri Lanka and to Somalia. This is the reason why the impact of the quake was so severe in Sri Lanka.

There is a lot of interest in establishing early warning systems for tsunamis in the Indian Ocean. UNESCO is involved in tsunami warning through its Intergovernmental oceanographic Commission (IOC). The IOC established in 1960 was responsible in establishing the International Coordination Group for the Tsunami Warning System (ICG/ITSU) in 1968. The International Tsunami Information Center (ITIC) together with the ICG/ITSU and the Pacific Tsunami Warning Center (PTWS) coordinate all their efforts jointly in dissemination of real time tsunami information and training of disaster mitigation due to tsunamis.

UIOC based on its mandate and experience with ICG/ITSU will forge ahead to expand the existing system in the Pacific to the World Ocean to ensure that appropriate warning systems are available to all regions of the World that are prone to tsunamis. This decision is fully consistent with the current initiative to build a Global Earth Observation System of Systems (GEOSS). The GSMB Meteorology Department and NARA should actively pursue these efforts and Sri Lanka should be an active member of the IOC Indian Ocean.

It is also pertinent to give some idea of the costs involved in setting up an early warning system for tsunami mitigation in the Indian Ocean. Geo Science experts believe that sounding an alarm on a tsunami is complex and expensive. According to the NASA web site devoted to tsunamis, three or four tsunami warnings issued since 1948 have been false, and the costs of the false alarms can be high.

The predictions of tsunamis were, in fact, accurate; the waves do arrive whether they are 40 feet high or a mere two inches. It is the destructive power of the wave that is hard to predict. That depends on many factors, including the configuration of the ocean floor and the shape of a bay. However the Indian Ocean Tsunami was, to a certain extent predictable and the scientists from Geo Science Australia, the nation's agency for earth science research issued a paper last August describing the tsunami generated by sea floor disturbances after the explosion of the volcano Krakatoa in 1883 with charts that showed a resemblance to wave destruction that accompanied the present disaster. Australia has established a tsunami-warning centre of its own which issued an alert 33 minutes after the quake occurred.

Indian Ocean nations together with the UN are hoping to create a warning system in the East Indian Ocean. The system will compose of seismographs and water level gauges which could cost US$ 5,000 to 10, 000 a piece but will cost US$ 20,000 or more if they are equipped with better instruments and quick communication abilities. It is believed that a system could be put together quickly for $50 -70 million. However the latest equipment consisting of a new generation sensors when a tsunami passes over and transmits data to a satellite and then passes the signals to the warning centres will cost over US$ 250,000 a unit. There are only seven of such "tsunameters" in use so far in the Pacific and the annual maintenance costs per unit is US$50,000.

Education campaigns are an essential part of any warning system. It is essential to educate the people how they are going to get information in an emergency and how to react to such incidents. It will be too late to do this after the calamity occurs.

The general public as well as school children should be educated about the basic facts of tsunamis. These are:

* Tsunamis that strike coastal locations are invariably caused by earthquakes, which could occur far away or near where you live.

* Some tsunamis can be very large. In coastal areas their height can be as great as 30 feet or more (100 feet in extreme cases) and they may move further inland.

* All low-lying areas can be struck by tsunamis. A tsunami consists of a series of waves. Often the first wave may not be the largest. The danger from a tsunami can last for several hours after the arrival of the first wave.

* Tsunamis can move faster than a person can run.

* Sometimes a tsunami can cause the water near the shore to recede exposing the ocean floor. The force of some tsunamis is enormous. Homes and other buildings are destroyed. All this material and water move with great force and can kill or injure people.

General precautions
* Knowledge of tsunamis can save your lives. Share this knowledge with you friends and relatives it could save their lives.

* If you are in school and hear of a tsunami warning you should follow the advice of teachers and other school personnel.

* If you are at home your family should evacuate your house if you live in a tsunami evacuation zone. Move in a orderly calm and safe manner to the evacuation site and follow the advice of the local emergency and law enforcement authorities If you are on the beach move immediately to high ground. Stay away from rivers and streams that lead to the ocean.

* Tsunamis generated in distant locations will generally give people enough time to move to higher ground. High multi story reinforced concrete hotels are located in many low lying coastal areas. The upper floors of such buildings could be good refuge sites if you cannot move quickly to high ground.

Tsunamis that hit Sri Lanka have caused an unprecedented natural disaster with the loss of lives and severe devastation to infrastructure such as roads railways and bridges. The reconstruction programme will take at least five years and both bi lateral and multi lateral aid agencies with the UN have pledged assistance. But the question remains whether the state machinery is efficient enough and extensive to effectively absorb all that assistance. It is best that the government consider strengthening public-private partnerships to achieve such objectives.

From the unexpected calamity that emerged by the worst natural disaster Sri Lanka experienced in past recorded history the government should examine why there was no effective disaster management and mitigation plan for the country. This issue is brought into focus every year when there are floods cyclones and droughts however it must be stated that the present calamity was unprecedented and all institutions of the government were taken completely by surprise. There was no emergency communication system and no one designated to take important decisions. Two state Agencies namely the GSMB and the Meteorology Department were supposed to be responsible to monitor earthquakes and give weather forecasting. The fact remains that both these organizations are not properly geared to predict natural disasters due to the lack of trained personnel equipment. The government should take immediate action to appoint a task force to see to the facilities available and the training requirements of the present staff and if required to increase the present cadre of the technical staff. I am surprised that these organizations still are functioning without a complete breakdown.

Another reason for this situation is that the government has given very low priority to building these institutions so that they perform their duties efficiently. Recently the GSMB released about four or five of its trained geologists and geophysicists to another Project called DECOM whose Head is the former Director of the GSMB. It was considered that submitting off shore scientific data to the Commission of the Delimitation of the Continental Shelf is urgent as the deadline is 2009. Sri Lanka has informed the UN that the technical data will be submitted in 2007 even two years before the deadline.

There is also a misconception among the authorities in Sri Lanka that if we do not submit the data we will lose our claim to the extended sea bed. There is no such stipulation and even India has not indicated a date or year for submission of its technical data. It is quite clear that our priorities are lop-sided and why were the trained officials released from the GSMB when it has more urgent duties of a national interest to perform. It is believed that the two geophysicists who were trained to man the Pellicle Earthquake monitoring Station which was set up with funds from the University of California are no longer with the GSMB and working for DECOM. Why were these officers who were on bond released to DECOM Project and was the Minister's concurrence obtained for this purpose? There was no necessity to form a separate entity such as DECOM when such expertise could have been obtained from the Ceylon Petroleum Corporation NARA and GSMB and the Universities.

A high level Task Force I required to look into the effective coordination of the sustainable use of natural resources and draw up an effective National Action Plan for disaster mitigation and early warning systems with the active participation of all concerned agencies.

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