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Sunday April 28, 2024

Strongest earthquakes are not necessarily the deadliest

LAHORE: Although the seismologists, scientists who monitor the earth’s crust, study earthquakes and other planetary activities by using instruments to gather data, are in a much better position to tell why the strongest earthquakes are not always the deadliest, the fearsome Monday earthquake in Pakistan may not fortunately claim as

By Sabir Shah
October 27, 2015
LAHORE: Although the seismologists, scientists who monitor the earth’s crust, study earthquakes and other planetary activities by using instruments to gather data, are in a much better position to tell why the strongest earthquakes are not always the deadliest, the fearsome Monday earthquake in Pakistan may not fortunately claim as many human lives as did the October 8, 2005 tremors that had resulted in considerable destruction, rubble and ruin.
However, more destruction is normally caused if the quake has badly struck densely populated areas where building structures are not built on modern lines to survive the tremors or jolts. Modern buildings, of course, withstand earthquakes compared to the brick built houses, which can tumble like a house of cards.
Secondly, if the epicenter of the earthquake is not far away from the unfortunate areas hit, the damage caused would be far greater. There might be a few other technical reasons too.
There are many examples where the strongest earthquakes have not always proved to be the deadliest, but to cite just one precedent due to paucity of time and space, the May 22, 1960 Valdivia earthquake of Chile was the most powerful earthquake ever recorded in human history, rating 9.5 on the Moment Magnitude scale, but the resultant death toll was placed between 2,231 and 5,700 only.
The Moment Magnitude scale, which measures the size of earthquakes in terms of the energy released, was developed in the 1970s to succeed the 1930s-era Richter Magnitude Scale, and is being used by the United States Geological Survey to estimate magnitudes for all modern large earthquakes.
More than two million people had been rendered homeless due to the 1960 Chilean tragedy though.The Chilean quake had occurred in the afternoon and had lasted approximately 10 minutes. The resulting tsunami had thus affected southern Chile, Hawaii, Japan, the Philippines, eastern New Zealand and southeast Australia.
Different sources have estimated that the monetary cost of this disaster had ranged from $3.19 billion to $6.38 billion of today.The tsunami had caused 61 deaths, $75 million damage in Hawaii; 138 deaths and $50 million damage in Japan; 32 dead and missing in the Philippines; and $500,000 damage to the west coast of the United States.
On the other hand, the January 23, 1556 Shaanxi earthquake of China happens to be the deadliest natural catastrophe of its kind, killing approximately 830,000 people.
An 840-kilometre-wide area was destroyed and in some towns, as much as 60 percent of the population was killed.
Modern estimates, based on geological data, give the earthquake a magnitude of approximately 8 on the Moment Magnitude Scale or the Mercalli Intensity Scale (used for measuring the intensity of an earthquake), though more recent discoveries have shown that it was 7 actually.