Scroll to the bottom and look at the chart of cumulative energy (moment) release over time. This is probably the easiest visualization what you're looking for without going to scientific papers. It only goes back to the 1970s though. The big steps are the Sumatran earthquakes and Tohoku (Japan). There were some equally big steps in the 1950s.
As far as I know (and I do this professionally) there is no evidence for any real variation in the global, time-averaged rate of earthquake occurrence or energy release. However the time window to average over has to be several decades to centuries depending on how comfortable one is with noise. Any individual segment of a fault will have an earthquake repeat time (for a significant earthquake) of hundreds (San Andreas fault) to tens of thousands of years, and is lots of evidence for clusters of earthquakes on individual faults or sets of faults, but this is mostly a local effect--the stress changes in the crust caused by an earthquake can basically load nearby faults and affect when they will have the next earthquake. But again, this is for the most part local (<100 km). Globally, earthquakes are essentially unrelated. That a big one may hit Chile and then Japan in short order is happenstance as far as the seismological community is concerned (though it's not dogma, and long-distance 'teleseismic' triggering is investigated--it just doesn't seem to be a big deal).
However, earthquakes in the news aren't a good reflection of global seismic statistics. Earthquakes like the Italian events (M6-6.6) over the past few months (and years) occur every day, but mostly in the ocean basins and don't affect people other than shaking some palm thatch roofs in Vanuatu. The most deadly event (minus tsunami) in my lifetime was the Haiti earthquake in 2010, killing ~200,000 people, and it was a pretty routine, moderate-magnitude event. It just hit an incredibly vulnerable population.
You're the real MVP. Thanks for your understanding of my question and the info. I get what you're saying about cumulative energy release over time and it's interesting to note the effect that earthquakes' periodicity has on how we need to sample the data. Very useful.
Scroll to the bottom and look at the chart of cumulative energy (moment) release over time. This is probably the easiest visualization what you're looking for without going to scientific papers. It only goes back to the 1970s though. The big steps are the Sumatran earthquakes and Tohoku (Japan). There were some equally big steps in the 1950s.
As far as I know (and I do this professionally) there is no evidence for any real variation in the global, time-averaged rate of earthquake occurrence or energy release. However the time window to average over has to be several decades to centuries depending on how comfortable one is with noise. Any individual segment of a fault will have an earthquake repeat time (for a significant earthquake) of hundreds (San Andreas fault) to tens of thousands of years, and is lots of evidence for clusters of earthquakes on individual faults or sets of faults, but this is mostly a local effect--the stress changes in the crust caused by an earthquake can basically load nearby faults and affect when they will have the next earthquake. But again, this is for the most part local (<100 km). Globally, earthquakes are essentially unrelated. That a big one may hit Chile and then Japan in short order is happenstance as far as the seismological community is concerned (though it's not dogma, and long-distance 'teleseismic' triggering is investigated--it just doesn't seem to be a big deal).
However, earthquakes in the news aren't a good reflection of global seismic statistics. Earthquakes like the Italian events (M6-6.6) over the past few months (and years) occur every day, but mostly in the ocean basins and don't affect people other than shaking some palm thatch roofs in Vanuatu. The most deadly event (minus tsunami) in my lifetime was the Haiti earthquake in 2010, killing ~200,000 people, and it was a pretty routine, moderate-magnitude event. It just hit an incredibly vulnerable population.