Many Early Earthquake Records Missing

  • 11 years ago
According to the historical record, there have been more high magnitude earthquakes in the 20th century, but that might be because quakes that measured higher than 8 point 5 are reportedly missing from the records during the 19th century.

According to the historical record, there have been more high magnitude earthquakes in the 20th century, but that might be because approximately half of the quakes that measured higher than 8 point 5 are reportedly missing from the records during the 19th century.

Doctor Susan Hough from the United States Geological Survey said: “Seismometers were developed around 1900. As soon as we had them, earthquakes started to look bigger.”

Experts are examining other historical accounts to try to understand the apparent rise in earthquake activity, and they have found several examples where similar significantly size events happened in the past.

At the American Geophysical Union Fall meeting in San Francisco, California, researchers presented their database of earthquakes between the years 1000 and 1900.

The record shows how cataclysmic events have happened throughout antiquity, and not just recently in places heavily covered by the media like Chile, Japan, and Haiti.

Historical records also reportedly underestimated the size of quakes during the 19th century. For example, in 1841 an earthquake in Russia was clocked at 8 point 3, but based on recent research Hough calculates that it was closer to a 9 point 2 magnitude.