Yes. However, the little historical data we have shows that we may be in a cycle rather than a never-ending escalation.
Magnitude and the corresponding number indicate the relative intensity of an earthquake.
Magnitude 8.0 and Higher
According to the USGS short article Are Earthquakes Really on the Increase, in a given year we would expect one great earthquake of magnitude 8.0 or above.
My research shows that clusters of years have a great earthquake of 8.0 or above, with clusters of other years passing without going above 7.9. We can also expect decades where magnitude 8.5 and higher earthquakes are more frequent.
The data in the USGS list of Magnitude 8 and Greater Earthquakes shows that in the five year span from 1960 to 1965, five magnitude 8.5 or greater earthquakes hit. One was 9.2, another was a stunning 9.5. Then magnitudes dropped for almost 39 years!
Between February 1965 and December 2004, nineteen years (or almost half) registered no earthquake higher than 7.9. No year had an earthquake registering higher than 8.4.
We are back in a decade of higher intensity. Between December 2004 and February 2010, four years had earthquakes of 8.5 or higher.
If earthquakes follow the pattern between 1960 and 2010, high magnitude incidents of 8.5 or higher will drop in a year or so, and in the following decades several clusters of years will have no earthquake higher than 7.9.
Magnitude 7.0 to 7.9
This led me to challenge another statement in the USGS Article Are Earthquakes Really on the Increase. It states that they expect about 17 earthquakes of 7.0 to 7.9 each year. The average I found was lower; the range was from 5 to 25.
I reviewed data in the USGS Centennial Earthquake Catalog for 1960 to 2001 (data for 2002 and later is limited or non-existent). The average number of earthquakes a year with a magnitude between 7.0 and 7.9 is 14, three lower than the USGS estimate. Forty-three percent, or almost half, had 13 to 15 earthquakes between 7.0 and 7.9. The high was 25 in 1968, the low was 5 in 1989.
My conclusion is that trying to make earthquake predictions through averaging has little value.
I also don’t agree with the article statement that ” earthquakes of magnitude 7.0 or greater have remained fairly constant.” Discussions above show a wide range in earthquake incidences of 7.0 to 7.9, and even greater variation in 8.0 and higher.
Fact: We will have earthquakes every day, every year, almost everywhere.
Prediction: At least one will be between 7.0 and 7.9.
Theory: Several earthquakes with a magnitude of 8.5 or higher occurring within a short span of years is part of a cycle rather than a steady upward trend.
Fact: We don’t have enough data yet to make valid, long term predictions. It will take many centuries of collecting and study to validate if cycles exist. And even then, nature might throw us a curve.
Disclaimer: I have no idea how accurate the data is. Measuring stations continue to be added; data from earlier years is probably incomplete. The data files are not clear if they include aftershocks as earthquakes or not. Some pages in the USGS web site say the data may not be up to date or accurate. However, working with what was provided was informative and interesting.
Are Earthquakes Really on the Increase? http://earthquake.usgs.gov/learn/topics/increase_in_earthquakes.php
Magnitude 8 and Greater Earthquakes, http://earthquake.usgs.gov/earthquakes/eqarchives/year/mag8/magnitude8_1900_date.php, USGS
Centennial Earthquake Catalog, http://earthquake.usgs.gov/research/data/centennial.php