TSUNAMI: A Jolt from the blue

On 26 December 2004, when people were about to wake up and open the Christmas
presents, from Sumatra emanated one of the worst natural disasters mankind has
ever seen. An earthquake registering almost 9 on the Richter scale tore through
the tectonic plates near Sumatra, and generated giant tsunamis in the entire
Indian Ocean. Such was the force of this tsunami that it smashed the coastline
of 14 countries including Bangladesh, India, Indonesia, Malaysia, Maldives,
Myanmar, Somalia, Sri Lanka, and Thailand; and swept away lives of more than
280,000 people-destroying millions of others.

The tsunami started at around 6:30 am (IST) in the Sumatran islands and
within minutes its killer waves gathered momentum and started spreading across
the Indian Ocean region. They reached as far as Somalia, Africa leaving behind a
trail of devastation.

If the people living along the unfortunate coasts could have been warned of
this calamity, thousands of lives would have been saved. While tsunami warning
systems function in the Pacific Ocean region, it is sad to know that there is
none in this part of the world. Most people in the Indian Ocean region didn't
even know what a tsunami is, as they have not been witnessed here in the last 60
years. So people in coastal areas of Andhra Pradesh, Tamil Nadu, and Andaman
& Nicobar were neither warned, nor were they aware of the devastation this
force could cause. Such was its speed that within half an hour of the
earthquake, the tsunami hit Indonesia and Andaman & Nicobar Islands. One and
half-hour later it hit the Tamil Nadu coast, 1,600 km away from the epicenter,
and it was inundated and washed away by the waves. Even Somalia, 4,480 km away
from the epicenter, took the impact of the killer waves and reported casualties.

What is a Tsunami?

Tsunami is a Japanese term meaning wave in the harbor. It is a system of
waves formed in the sea as a result of a large-scale disturbance of the sea
level over a short duration of time. A tsunami can be generated by submarine
volcanic eruptions, displacement of submarine sediments, coastal landslides,
meteor impact, and by the movement of earth's crust on the ocean floor.

As
per the records of National Institute of Oceanography (NIO), there were four
tsunamis in the Indian Ocean region from 1881—1945. The first hit Car Nicobar
on 31 December 1881. The second hit Indonesia in August 1881. The third hit
Andaman on 26 June 1941, and the fourth hit Karachi on 27 November 1945. The
26th December 2004 tsunami was the worst natural disaster mankind has ever seen
in terms of magnitude and spread. On the other hand, about five tsunamis hit the
Pacific Ocean's coastlines every year. The increase in frequency was a
blessing in disguise for the Pacific Rim as it forced the region to install a
tsunami warning system way back in 1968, with the help of Unesco.

Tsunami is a new phenomenon for India. Though, India has evolved warning
systems for earthquake, flood, and cyclone; there is none for tsunami as they
have been so rare in India. But its ferocity this time has forced government to
look for solutions. Kabil Sibal, minister for science and technology went on
record saying, "Tsunami early warning system would be in place by 2007 at a
cost of Rs 125 crore."

Is a Warning Network Needed?

Not only in the Indian Ocean region, but tsunami warning system is missing
from the Atlantic and the Mediterranean regions too. The main reason for lacuna
is the long gap between tsunamis hitting these regions and their negligible
impact on life and property there. Second is the capital expenditure of the
warning system at around $30 million. Third is the operating expenditure of the
system in the region, at $3 million per year; as per Unesco estimates.

The recent tsunami was an eye opener for the entire world. According to
Munich-based insurer Munich Re's risk research division, economic damage from
the calamity is in excess of $13.6 billion (which includes damage to all the
affected 14 countries). The total capex and opex required for warning system is
just a small fraction of the total cost-around 0.2 percent.

Dr Tad Murthy, president, Tsunami Society, Ottawa has been stressing the need
for a warning system in the Indian Ocean region. In the past, he has taken up
the issue with many governments at the center. He says, "Science has never
failed and since 1948 we have not missed predicting a single tsunami. However,
countries must guard against issuing false tsunami alarms."

At the World Conference on Disaster Reduction held in Kobe recently, tsunami
experts were of the opinion that with the Pacific model already in place, there
would be no problem in transferring the technology to other parts of the world
as this is a well-tested system. Already, Germany, United States, and Australian
scientists have offered assistance in building up a cost-effective warning
system in the Indian Ocean region.

How Will the System Work?

Tsunami warning network has three basic components-detection, measurement,
and transmission; data analysis; and dissemination of information. It is a
complex system and needs active support of all the agencies involved to make the
warning system effective.

Care should also be taken that all the three process take the least possible
processing time so that information can be disseminated at a faster pace and
people can take preventive action at the earliest.

Buoys fitted with sensors gather data in real time and transmit it to a control base center via satellite, to be analyzed

The detection and measurement module consists of seismographs, tidal gauges,
sensors (wind, pressure, temperature, humidity), special buoys, RF antennae, RF
modems, GPS antennas, and satellite antennas. The tsunami warning system has
seismographs to detect earthquakes, and tidal gauges and special buoys for deep
ocean assessment and reporting. These buoys are installed in the high seas and
are connected to satellites through RF modems and satellite antennas.

The premise of the disaster warning network is that it should reduce the
damage caused by this force of nature; as the damage can neither be totally
prevented, nor eliminated, nor can its frequency be altered. The network relies
heavily on the available sensor technologies to gather data real time and
transmit it to a control base center via the satellite, to be analyzed.

For detecting warning signs of tsunamis, India Ocean needs around five to
eight buoys for deep ocean assessment and reporting so that one can measure
changes in the ocean bed at different locations. Once the sensor picks up data,
it passes the information to the RF modem, which in turn passes it to the
satellite. From the satellite, the information travels to the tsunami warning
center where the information is processed.

The data analysis module is a control room where network of computers are
programmed with various models to analyze the gathered data. The pattern of
analysis determines the magnitude, direction, and speed of the approaching
disaster. Then the areas to be altered and warned are identified and signals are
beamed to these areas with level of warning.

After analysis of data, one has to disseminate information at the earliest
and care should be taken that false alarms are not issued. Information
dissemination can be through a mix of public address systems, cellphones,
pagers, televisions, radios, or any type of communication device that can sound
an alarm. All this will help in people taking corrective measure. One also needs
to educate people about what to do in case of a warning, so that warnings do not
lead to panic situations.

India has the advantage of leveraging the existing systems when designing the
tsunami warning network. The country has an effective seismic monitoring system
through Indian Metrological Department (IMD) and Geological Survey of India (GSI).
The IMD further monitors the wind patterns and ocean current movements to
foretell natural calamities. In fact, IMD utilizes the Insat satellites to issue
warnings about cyclones. Indian Space Research Organization (ISRO) can
contribute to the system by having dedicated tsunami transponders in its
satellites. The experience of IMD, GSI combined with the expertise of ISRO and
other institutes dealing in oceanography will be instrumental in putting up the
tsunami warning network.

What are the challenges?

Today the technology exists to measure and record magnitude, intensity,
speed, and direction of these disasters in almost real time. The most difficult
part is in getting the collected information to the right people, at the right
places, and at the right time. In the case of this tsunami, people were
completely unaware of the phenomenon and information dissemination was a major
issue. In Indonesia, some resorts had prior warning of the coming waves but
they had no idea of the scale of the impact. Therefore, major initiatives has to
be taken in creating awareness and educating people to react to such situations.
Apart from technical preparedness, countries across the globe need to come
together and share information that will help in developing computer models to
accurately decipher the signs of a tsunami warning.

At the Kobe conference, Asian countries raised the valid point of funding
such a warning system. The Pacific countries are able to pump in huge amounts of
money to run the system in their region, but in the Indian Ocean region most of
the countries are developing economies. High investments required for such a
system might lead to loss in interest as time passes. There needs to be a
concerted effort by global agencies to lay down a solid foundation for a global
warning system.

Pravin Prashant and Anurag
Prasad