Are Earthquakes Really on the Increase?

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We continue to hear from many people throughout the world that earthquakes are on the increase. Although it may seem that we are having more
earthquakes, earthquakes of magnitude 7.0 or greater have remained fairly constant throughout this century and, according to our records, have actually seemed to decrease in recent years.
A partial explanation may lie in the fact that in the last twenty years, we have definitely had an increase in the number of earthquakes we have
been able to locate each year. This is because of the tremendous increase in the number of seismograph stations in the world and the many improvements in global communications. In 1931, there were about 350 stations operating in the world; today, there are more that 4,000 stations
and the data now comes in rapidly from these stations by telex, computer and satellite. This increase in the number of stations and the more timely receipt of data has allowed us and other seismological centers to locate many small earthquakes which were undetected in earlier years, and we are able to locate earthquakes more rapidly.
The NEIC now locates about 12,000 to 14,000 earthquakes each year or approximately 35 per day. Also, because of the improvements in communications and the increased interest in natural disasters, the public now learns about more earthquakes.
According to long-term records (since about 1900), we expect about 18 major earthquakes (7.0 - 7.9) and one great earthquake (8.0 or above)
in any given year. However, let's take a look at what has happened in the past 28 years, from 1969 through 1996.
Our records show that 1992 is the first time that we have reached or exceeded the long-term average number of major earthquakes since 1971. In 1970 and in 1971 we had 20 and 19 major earthquakes, respectively, but in other years the total was in many cases well below the 18 per year which we may expect based on the long-term average. The following is a list of major and great earthquakes during this period: Earthquakes
Year
Major
Great
1969 15 1
1970 20 0
1971 19 1
1972 15 0
1973 13 0
1974 14 0
1975 14 1
1976 15 2
1977 11 2
1978 16 1
1979 13 0
1980 13 1
1981 13 0
1982 10 1
1983 14 0
1984 08 0
1985 13 1
1986 05 1
1987 11 0
1988 08 0
1989 06 1
1990 12 0
1991 11 0
1992 23 0
1993 15 1
1994 13 2
1995 22 3
1996 21 1

Great earthquakes during this 27 year period were also below the level indicated by the long-term average.

Source: http://neic.usgs.gov/neis/general/handouts/increase_in_earthquakes.html

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