Background to the 1737 "event"

The history of earthquakes in India should be one of the best in the world due to the existence of a written record that extends back at least three millenia. The Vedic writings are not informative, however, and Urdu and Persian scripts have but recently been investigated for their seismological content. The 1737 "earthquake", however, was not an earthquake.

The figure below summarises data 1800-2001 for the Indian Plate (including Pakistan, Nepal etc). Ominously the recent rate of fatal earthquakes in India (5 in the past decade) is much higher than at any time in the past 200 years. In just 5 years since 2001 the Andaman-Sumatra earthquake and Kashmir earthquakes have doubled the 100,000 people who were killed by earthquakes in the Indian region in the previous past two centuries.

(a) More than 100,000 fatalities from earthquakes have occurred on the Indian Plate in the past two centuries. Prior to 1800 the historical record is incomplete although we know of no fatal events in the 18th century. (b) The rate of occurrence of fatal earthquakes in the past two decades is more than double its mean value in the past 200 years.

1737 - The earthquake that didn't

The 1737 Calcutta cyclone is mistakenly included in many elementary texts and popular-press listings, with a deathtoll of 300,000 people. However, the population of Calcutta at the time was of the order of 3000, and not for a further century did the population grow to 30,000. The number of burials in St. Annes Church, Calcutta, was only 10% higher in 1737 than in the preceding and following decades.

The event is documented in the handwritten daily log of the East India Company as a storm surge that flooded the coastal regions of Bengal and Calcutta causing an unknown number of deaths. The erroneous attribution of the number of deaths, and the provenance of historical documents mistakenly cited by early earthquake seismologists, is discussed in Bilham, R.,The 1737 Calcutta Earthquake and Cyclone Evaluated, Bull. Seism. Soc. Amer. 84(5), 1650-1657(1994). (Download 80k PDF file)

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