Earthquakes

I've blogged about the Cape Ann Earthquake of 1755, the strongest to hit this area with an estimated force of over 6.0 on the Richter scale. The last "big" earthquake here was in the 1940s with force enough to knock plates off a shelf according to my mother. The tagline "biggest quake in more than a century" for Tuesday's event compares that to the August 31, 1886 quake that struck Charleston, South Carolina. It's estimated that this quake was between 6.6 and 7.3 on the Richter scale. About a hundred people died. All these quakes were what are called intraplate quakes meaning that they occurred within the giant plates that make up the continents rather than where plates rub together as in California. Intraplate quakes are often surprising because old fault line may be buried and missed by geologists.


Just two weeks before the 1755 earthquake here, Lisbon, Portugal was almost completely destroyed by a megathrust earthquake like the one that created the tsunami that devastated Southeast Asia in 2004. The Portuguese quake also struck offshore and created a tsunami that caused damage as far away as Barbados. The strength of this quake is estimated as between 8.5 to 9.0. Up to a 100,000 people were killed by the quake and fires in Lisbon.

The year 1755 was in Enlightenment Age in Europe when philosophers and scientists began searching for rational explanations of natural events. Interestingly, a young Immanuel Kant, who would go on to become one of the greatest philosophers of all time, gets credit as a father of seismology with his attempt to provide a rational explanation for the cause of this quake. Voltaire used the quake to attack religious arguments for the omnibenevolence of God in his book Candide. For Voltaire the quake proved that "all was for the best, in this best of all possible worlds" was a bogus philosophical position. Another French philosopher Jean-Jacques Rousseau took the more pragmatic view that mankind might have made a mistake when it decided to live in cities. The intellectual grandchild of that idea is a generation of elementary school teachers promoting the myth of the Environmental Indian.  I still agree with Rousseau despite his noble savage myth making. If you want to read a paean to the greatness of cities, however, check out the newly released special edition of Scientific American. It's sad to see a great magazine turn to the soft social sciences to argue an essentially political position. There are more holes in their arguments than Swiss cheese.


Here in Puritan Massachusetts where no innocents were killed in our 1755 earthquake, traditionalism gave ministers free play to search out sin and sinners as a cause of the quake. Even here, however, a Harvard professor, John Winthrop, suggested a scientific cause for the quake. Cambridge had its pointy-headed intellectuals even then. By the way if a similar quake struck today, estimates indicate $5 billion in damages and hundreds of deaths. Just thought you needed something to worry about besides hurricanes.