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Earthquakes, Tsunamis and 2012

We were in the middle of preparations for Friday’s event when word broke through about the magnitude 8.9 earthquake and ensuing tsunami that hit Tokyo earlier in the afternoon. At the café, somebody put on CNN and although everyone was engrossed trying to get the café in shape for the evening event, the scenes being beamed live to the television set were horrifying enough to send everyone rushing to watch.

“2012!” somebody said, referring to the doomsday box-office hit released the other year. Although the movie was premised on radiation from a solar storm, the reference to it was induced by the sheer horror being felt by everyone watching about what the earthquake and ensuing tsunami in Tokyo might have been portending.

There was a 7.2 quake in the same area just two or three days earlier; and of course the Kiwis are still digging up bodies from the 6.3 quake that hit Christchurch. At the back of everyone’s mind, therefore, were the questions what is going on and is the Biblically foretold coming of the end near.

Earthquakes, it has to be said, are a natural occurrence. Unbeknownst to many, they occur practically everyday. While some earthquakes occur as a consequence of the movement of magma beneath the earth close to volcanoes, most quakes are of the tectonic type or those that result from the movement of the plates of the earth underneath the ground upon which the land we see above sits.

To illustrate, please look at the table below, with data courtesy of the United States Geological Survey or USGS. The table illustrates the annual occurrence of earthquakes around the world:

MagnitudeAverage Annually
8 and higher1
7 – 7.917
6 – 6.9134
5 – 5.91319
4 – 4.913,000 (estimated)
3 – 3.9130,000 (estimated)
2 – 2.91,300,000 (estimated)

Allow me to digress for a moment just to clarify a couple of terms. Magnitude refers to a amount of energy that is released at the very place where the plate has shifted, otherwise known as the quake’s epicenter. Intensity refers to the impact of the quake on particular localities as its effects travel over land. For instance, an earthquake with an intensity of 5 over Mindoro will be felt as an Intensity 2 quake over Lipa. Just to ensure that we are all on the same wavelength.

Although I initially thought that recent quake in Japan was the most horrific I had ever heard of, after introspection – not to mention sessions on the Internet – I realized that I had the same cringing feeling while watching the 2004 quake just off Sumatra in Indonesia. This one killed more than 300,000 people and was pegged at Magnitude 9.1.

A list of the world’s strongest recorded earthquakes since 1900 prior to the one in Tokyo released by CNN shows that there were, in fact, four more quakes which were stronger. That said, this recent Tokyo quake is now recognized as the strongest to have hit the country since the turn of the twentieth century. Here is the complete CNN list:

  1. Southern Chile, Magnitude 9.5, May 1960
  2. Prince William Sound (Alaska), Magnitude 9.2, March 1964
  3. Island of Sumatra (Indonesia), Magnitude 9.1, December 2004
  4. Kamchatka (Russian Far East), Magnitude 9.0, November 1952
  5. Chile, Magnitude 8.8, February 2010
  6. Coast of Ecuador, Magnitude 8.8, January 1906
  7. Rat Island (Alaska), Magnitude 8.7, February 1965
  8. Northern Sumatra (Indonesia), Magnitude 8.6, March 2006
  9. Assam/Tibet, Magnitude 8.6, August 1960
  10. Andreanof Islands (Alaska), Magnitude 8.6, March 1957

Earthquakes, per se, do not necessarily kill people. It is the consequences of these quakes that do: the collapse of structures, falling debris, fire and most dreaded of all, the tsunami. The 2004 tsunami that resulted from the Sumatra quake, for instance, killed thousands as far away as Thailand and Sri Lanka.

Geologists are quick to say that strong earthquakes are not occurring any more frequently than they used to. The main consideration, they say, is more the statistical probability of a big one occurring near a densely populated area. In other words, if a strong quake was to occur close to a sparsely populated area, it is doubtful that anyone will sit up and take notice.

Population growth, particularly in the last century, has simply meant that the chances of a strong quake passing harmlessly over a secluded area have been reduced. State that the opposite way and it means that the chances of a strong quake occurring over a densely populated area have also been increased. While not too long ago, live coverage could be beamed only to television sets by live cameras, these days footage to make people cringe can be beamed to people anywhere; yes, even cell phones.

Any chance, therefore, that this series of earthquakes since the New Year are an indication of an unthinkable cataclysm that will wipe us all off the face of the earth? Probably not; but then you cannot see the fingers I will cross after I conclude this story.

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