There has been a statistical rise in the global incidence of earthquakes in the last 15 years, compared to the historic average rate. Earthquakes have occurred in places where there are no underground faults or other reason to expect a high seismic risk. This has been the era of fracking in the US. It is well-established that fracking increases the risk of earthquakes. But this is unlikely to explain the most violent quakes. It is not difficult to create an earthquake with an underground nuclear explosion. Some geologists claim to detect the signature of nuclear explosions in the seismic records.
Exhibit A in this story is the statistical record showing that there has been an increase in the most violent earthquakes. 8 on the Richter scale is a convenient dividing line because major quakes >8 are rare, highly destructive events, but the number of them is large enough to show statistical patterns.
From 1900 to 2004, there were 71 earthquakes of this size. 71 divided by 104 years is a historic rate of 6.8 major earthquakes per decade. But the decade from 2004 to 2014 had 18 major earthquakes. I've done a basic calculation and the probability of this occurring by chance is less than 1 in 10,000. When I extend the record from 2014 through 2017 and account for the fact that earthquakes cluster by year, the probability rises somewhat, but still well under 1 in 1,000. In my mind, that's good enough reason to look for some explanation.
I became more suspicious, not less, when I saw this headlined, published prominently in the high-profile journal, PNAS:
The conclusion in the headline is not at all warranted by the data they present, and it is usual scientific editorial policy to keep the headlines and abstract conservative and accurate. In fact, the article presents the evidence that big earthquakes are more frequent than they used to be, and then makes a number of esoteric arguments that are obscure and difficult to evaluate objectively, all trying to convince us that we shouldn't take the statistic at face value.
The 2010 earthquake in Haiti stuck in an area where earthquakes had been previously unknown, and had one of the largest death tolls in modern history, even though it was less than magnitude 8. The earthquake and tsunami that destroyed the Fukushima power plant was reported as Richter 9.1, though I've seen that number disputed. Its cost and death toll are still mounting.
Who could be creating earthquakes? Any country with nuclear weapons. USA, Russia, Great Britain, Israel, China, France, with much smaller arsenals in India, Pakistan and N. Korea.
Why would they do such a thing? "Natural" disasters, like wars, create incomparable opportunities for profiteering. Review Naomi Klein's book, The Shock Doctrine. Her thesis is that disasters create excuses to relax the rules of fair play, and when the dust clears, capitalist domination has advanced in some way.
In August, 2011, there was a freak earthquake in the Washington, DC area, a region not implicated in any kind of geologic instability. It might have been caused by fracking two hundred miles away. Another story of the DC quake is wild and challenging, but I don't dismiss it.
Earthquake Map, 1904 to date