As soon as there is an earthquake, everybody wants to know how much it has measured on the Richter scale. Yet, how many of us know what the Richter scale really means and whether it is a technically sound and viable yardstick of earthquakes?
Contrary to popular beliefs, the Richter scale does not measure the magnitude of an earthquake's effects, but the seismic energy it releases. The scale has no upper limit, and succeeding units are 10 times greater than preceding ones. In plain English this means that each successive notch releases 32 times the energy of the previous notch.
This leads to the corollary that a seemingly slight difference in the readings of a quake on the Richter scale can, in reality, have far greater proportions. This is exactly the case with the current earthquake in Gujarat. The initial Richter scale readings released in India were around 6.9, while China recorded its intensity as 7.9, and France as 7.6. Seismologists have now settled on the 7.9 figure. This leaves a lot wanting on the technological side.
The bigger the quake, the more serious the disaster management plan must be. Post-quake rescue operations can be severely skewed by misleading technical information. Moreover correct information helps curtail the time spent on physical assessment of damage, thus speeding up the restoration process.
Unfortunately, even though giant quakes like Koyna and Latur have rocked India in the past, technology has not been employed optimally to record and analyse the intensity and impact of these events.
How big is the difference between 6.9 and 7.9 on the Richter scale?
|Magnitude Change||Ground Motion Change (Displacement)||Energy Change (Approx.)|
|1.0||10.0 times||32 times|
|0.5||3.2 times||5.5 times|
|0.3||2.0 times||3 times|
|0.1||1.3 times||1.4 times|
The above table shows, for example, that a magnitude 7.9 earthquake produces ten times more ground motion that a magnitude 6.9 earthquake, but it releases about 32 times more energy. The energy release best indicates the destructive power of an earthquake.
What does this mean? A simple analogy will bring out the difference. Assume that you are hit by a cycle when crossing the road. Let's take that as 6.9 on the Richter scale. So what would it be like when 7.9 on the Richter scale? It's being hit by a 2-tonne truck.
Another example: How much bigger is a magnitude 9.7 earthquake than a 6.8 earthquake? A magnitude 9.7 earthquake is 794 times BIGGER on a seismogram than a magnitude 6.8 earthquake.
Since it is the energy that knocks down buildings, this is the important statistic. It would take about 23,000 quakes of magnitude 6.8 to equal the energy released by one magnitude 9.7 event.
This explains why big quakes are so much more devastating than small ones. The amplitude ("size") differences are big enough, but the energy ("strength") differences are huge. The amplitude numbers are neater and a little easier to explain, which is why those are used more often in publications. But it's the energy that does the damage.
Source: USGS National Earthquake Information Centre
Prof Vinod Chandra Menon of the Pune Centre for Disaster Management defines it as the process by which the uncertainties that exist in potentially hazardous situations can be minimised and public safety maximised. This is achieved through a range of strategies from hazard management and prevention to speedy restoration of the affected community.
With IT penetrating into all disciplines, the management of information and knowledge is becoming more efficient, cost effective and almost in virtual real time. IT applications such as the design and development of databases, relational database management systems, management information systems, decision support systems, expert systems, knowledge bases and simulation models make disaster management more effective.
The phenomenal expansion of telecommunication facilities in developing countries in the recent past makes it easier for the integration of information technology with telecommunication interfaces. Thus, the facility of information technology interfacing with satellite telecommunication provide opportunities for video teleconferencing, setting up a site operations centre at the site of a disaster for video teleconferencing with the main emergency operations centre.
Another major breakthrough of information technology applications in disaster management is the design and development of Geographical Information Systems (GIS) which permit the development of base maps with district boundaries, village locations and their access to critical infrastructure like primary health centres, blood banks, pathological laboratories, police stations, fire brigades and transport depots. This helps efficient decision making, policy analysis and problem solving both during an emergency and at normal times.
Developments on the Internet have opened up the possibility of creating Web sites for specialised institutions working in disaster management. The potential of the Internet has been tapped by specialised institutions in advanced countries, and Net surfers worldwide can browse the content on their sites.
Technology is flaunted as the saviour of mankind from its primitive existence. Yet when we needed it the most it failed us. The killer earthquake caught everyone unawares. Where was the much-touted Geographical Information System? Where were the Decision Support Systems and Management Information Systems we have been hearing about since the Latur earthquake in 1993?
And what happened to the government's plans to integrate telecoms with IT to ensure uninterrupted communication with the affected area?
According to sources in Ahmedabad, the biggest problem faced by rescue operations in the area was that of a total lack of communication. Land lines were totally destroyed. Even mobile phones were not effective as signals could not be received. The only way out was to deploy satellite phones, especially to totally cut-off areas like Bhuj and Bhachau.
Yet it was only on Saturday night, almost 36 hours after the quake, that the government requested that mobile giant Motorola send 100 sets of regular 30km phones to Gujarat.
What is the use of technology if it cannot be useful to the very people who created it? What is the justification in spending millions of dollars every year on IT research, when it doesn't get used during catastrophes?
But maybe now we will wake up from a forced hibernation realise that IT is here to serve humanity, not to be served by it. Even if we might not be able to prevent nature from unleashing its wrath, we might at least be able to deal with the consequences.
To make a donation to the Indian earthquake appeal, go to the Red Cross Web site
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