While the specific number is not mentioned, the fact that people will be aware of earthquakes "in diverse places" tells us that science will have the ability to report such events. And, in that sense, frequency and magnitude may be compared to the pains of a woman in labor ("beginning of sorrows" - Mt. 24:8; Mk. 13:8). The Greek ὠδίν (ōdin), which is translated "sorrows," is translated "travail" in 1 Thessalonians 5:3 which reads, "For when they shall say, Peace and safety; then sudden destruction cometh upon them, as travail upon a woman with child; and they shall not escape."
In light of that, I checked the United States Geological Survey for data to see if, in fact, there is evidence of an increase in frequency and magnitude. Here is what they report:
* From 1863 to 1900, there were twelve recorded earthquakes of at least 7.0.
* From 1901 to 1938, there were fifty-three.
* From 1939 to 1976, there were seventy-one.
* And from 1977 to the year of the report (2011), there were one hundred sixty-four.
In addition, comparing the number over just the past two decades, the number has increased from fifteen to ninty-nine!
Of the other signs included in the "beginning of sorrows" (wars, rumors of wars, famines, and pestilences), there is little doubt that they have also increased. At no time in our nation's history have we been involved in two wars at one time, while being threatened by two other nations (North Korea and Iran). The Center for Disease Control reports an alarming increase in Autism, Attention Deficit Hyperactive Disorder, types and severity of the Flu, the number of Food-borne illnesses, Human Immunodeficiency Virus, strokes in pregnant women, etc. Again, the fact that science is capable of diagnosing and reporting these increases worldwide, supports the closeness of the Tribulation, followed by Christ's Second Coming!
Things are going to get worse before they get awesome!