Sometimes I feel that what i have learned through years, what i m learning and what I will to learn ....is it really making sense in any manner? Being a geophysicist, i sometimes have the dillemma in my mind, as to what contribution I am making - writing some journal papers, formulating some algorithms , modelling the earth's processes and simulating them; Does all this go the pragmatic world of mitigating a disastor or predicting an earths process. Well I must boldly say that despite having a plethora of technical maneuvers and skills, we still are way behind predicting an earthquake or estimating the danger that can be caused by a natural disastor.
Considering the very fact that prediction always follows the hiesenberg trend, I will not comment on the potential for expectation or uncertainties, but we can always collimate our attention to the other dimension of disastor management and mitigation.
theres always the saying that will hold good for ages : "Prevention is better than cure"
Striking the fact on the recent Tsunami disastor, its a pity that we were lacking state of the art warning and mitigation strategies, which would have otherwise saved a lot of lives.
Giving a comprehensive information on the occurrence of the recent Tsunami and how the recorded information could have saved a lot of lives will be clear in our eyes now:
A very interesting factual description of the plate tectonics will be enlightened and the future trend of the indian plate motion is intriguing to many of us.
A shallow, thrust-type earthquake occurred off the west coast of northern Sumatra at the interface between the India and Burma plates. In this region, the Burma plate is characterized by significant strain partitioning due to oblique convergence of the India and Australia plates to the west and the Sunda and Eurasian plates to the east. Off the west coast of northern Sumatra, the India plate is moving in a northeastward direction at about 5 cm per year relative to the Burma plate. Preliminary locations of larger aftershocks following the earthquake show that approximately 1000 km of the plate boundary slipped as a result of the earthquake. Aftershocks are distributed along much of the shallow plate boundary between northern Sumatra (approximately 3 degrees north) to near Andaman Island (at about 14 degrees north).
Scientists have known that for some 50 million years, the Indian subcontinent has been pushing northward into Eurasia, forcefully raising the Tibetan Plateau and the Himalayan Mountains. The new research suggests that starting about 8 million years ago, the accumulated mass became so great that the Indo-Australian Plate buckled and broke under the stress.
Commenting on the recent earthquake that occured, it took place in a seismically active region at the plate boundary separating the Indian-Australian and East-Asian Plates. There are 12 plates in the world and earthquakes occur when these plates collide. The active seismic zonation map is present with the Global Seismic Hazard Assessment Program (GSHAP) in the framework for the United Nations International Decade for Natural Disastor Reduction.
The Lamount Doherty Seismographs on 26th of December, 2004 showed extraordinary ocsillations in the seismic wave recording patterns.
Collecting from sources, the earth quake location and magnitude as recorded by the US Geological Services Earth Quake Network provided the sequence of Earthquakes with those in Red being above 6.0 in the Richter Scale as below:
MAG DATE UTC-TIME LAT LON DEPTH region
y/m/d h:m:s deg deg km
MAP 6.3 2004/12/26 11:05:01 13.542 92.877 10.0 ANDAMAN ISLANDS, INDIA REGION
MAP 6.2 2004/12/26 10:19:30 13.455 92.791 10.0 ANDAMAN ISLANDS, INDIA REGION
MAP 6.5 2004/12/26 09:20:01 8.867 92.382 10.0 NICOBAR ISLANDS, INDIA REGION
MAP 5.8 2004/12/26 07:38:25 13.119 93.051 10.0 ANDAMAN ISLANDS, INDIA REGION
MAP 5.7 2004/12/26 07:07:10 10.336 93.756 10.0 ANDAMAN ISLANDS, INDIA REGION
MAP 5.7 2004/12/26 06:21:58 10.623 92.323 10.0 ANDAMAN ISLANDS, INDIA REGION
MAP 7.3 2004/12/26 04:21:26 6.901 92.952 10.0 NICOBAR ISLANDS, INDIA
REGION
MAP 6.1 2004/12/26 03:08:42 13.808 92.974 10.0 ANDAMAN ISLANDS, INDIA REGION
MAP 5.9 2004/12/26 02:59:12 3.177 94.259 10.0 OFF THE WEST COAST OF NORTHERN SUMATRA
MAP 6.0 2004/12/26 02:51:59 12.511
92.592 10.0 ANDAMAN ISLANDS, INDIA REGION
MAP 5.8 2004/12/26 02:36:06 12.139 93.011 10.0
ANDAMAN ISLANDS, INDIA REGION
MAP 5.8 2004/12/26 02:34:50 4.104 94.184 10.0 OFF THE WEST COAST OF NORTHERN SUMATRA
MAP 6.0 2004/12/26 02:22:02 8.838 92.532 10.0 NICOBAR ISLANDS, INDIA REGION
MAP 5.8 2004/12/26 02:15:58 12.375
92.509 10.0 ANDAMAN ISLANDS, INDIA REGION
MAP 5.9 2004/12/26 01:48:47 5.393
94.423 10.0 NORTHERN SUMATRA, INDONESIA
MAP 8.9 2004/12/26 00:58:51 3.298 95.779 10.0 OFF THE WEST COAST OF NORTHERN SUMATRA
The Pacific Tsunami warning Center Detected the Earthquake and after 15 minutes issued a communique to Pacific Islands saying that there shall be no threats to them and also provided the information that there is a Tsunami watch going on but not an alert. After 65 minutes later, a second communique repeats the same information and says that there may be a possibility of a Tsunami at the epicenter.
(http://www.prh.noaa.gov/ptwc/olderwmsg)
The tragedy is that this information was not communicated to the Indian Ocean region. The NOAA officers says that they did not have the addresses of the appropriate officials.
There is no warning system in place for Tsunamis or tidal gauges in the Indian Ocean. If there had been such a warning system then alarm could have been raised 20 minutes to 2 hours in advance. Also the aftermath of a coastal earthquake was not known to many. The people residing near the coast should have been immediately ordered to flee inward after they felt the tremors of the earthquake. The knowledge of such an aftermath was not residing on many of the big minds by then. Since a tsunami is generated at the source of an underwater earthquake, there is usually time -- from 20 minutes to two hours -- to get people away as it builds in the ocean. So the whole episode of the devastating Tsunami was not at all by any surprise: mankind was clever enough to know the precursors to this process, but they were not clever enough to let the people know of such a thing. We boast of our big telecommunication and wireless networks , I guess they were sitting idle on this day of calamity and I wonder from the above facts , that theres still lot more to do in our communication strategies to reach more and more people. Provided we had a good network and warning facility team, we could have recieved the information from USGS in no time and could have warned everyone ahead of the disastor.
This was enough of a booster dose, that would open up all our eyes and set platform for developing state of the art and modern warning systems and networking facilities so that in future, we dont let loose one front while we are strong on the other. We predicted it, we sensed it , we measured it, but could not save millions of people, when it occured. An hour could have saved a lot. Information was residing in the minds of few; it should have reached everyone.
Learning a lot from this, we are now investing money towards setting up big warning network systems and gauges along the coasts for tsunami warnings which in future will secure us all from such ominous scale natural disastors.
Sangram Ganguly
Doctoral Student
Centre for Remote Sensing/ Department of Geography
Boston University
