Dale C. S. Destin |
Two Fridays ago, on a popular midday radio program, a very prominent member of our society, uttered a myth that may have caused many persons to question their high school geography; for others, it may have reinforced a fable told to them by their well meaning elders. The prominent person made a statement indicating that droughts cause earthquakes. This is nothing but a myth or as some would say a fairy tale.
There is no connection between the dryness of the atmosphere and the movement of the earth’s crush or tectonic plates; there is no connection between below normal rainfall and plate tectonics. Droughts are a natural part of climate variability – they happen everywhere. Meanwhile, earthquake occurs when there is a sudden release of energy in the earth’s crust, which happens when stress, building up within rocks of the earth’s crust, is released in a sudden jolt. Rocks crack and slip past each other causing the ground to vibrate.
This belief, that droughts cause earthquakes, most certainly has no basis in science but rather from the elders in our society. As a child, I too was told this by the elders in my community. There are many things that these elders have correct, but this is just not one of them. Perhaps the myth was formulated after the magnitude 7.5 quake that occurred October 8, 1974 on the heels of a severe drought of 1973 – 1974. Interestingly, the drought ended the September of 1974. However, since then, there have been six other severe droughts; the last took place in 2002; otherwise, there have been many droughts of varying intensities since 1928. However, there have been no associated notable earthquakes. The probability of a drought in Antigua for a portion or all of a year is 36%; hence, it would not be uncommon for a quake to occur during a drought.
The myth seems to be suggesting that somehow dry land with superficial cracks can cause earthquakes. However, most quakes globally, conservatively over 90%, take place under the world’s oceans. Just about 100% of all earthquakes to shake Antigua have there epicentre under the Caribbean Sea or under the Atlantic Ocean. Thus, clearly, water is no ‘cooler’ of earthquakes.
So, the next time you hear some crediting earthquakes to droughts, be assured that this connection is a myth. And, if the circumstance permits, try to help that person to see that this connection is scientifically impossible.