"Is Jehovah causing these earthquakes?"
Whether or not Jesus said that earthquakes would 'increase', Jehovah's Witnesses assert that earthquakes are a sign of the 'Time of the End'. The recent cluster of awful earthquakes has only increased that sense of expectancy.
Does this mean that Jehovah is responsible for these earthquakes? If not, then in what sense are they a sign of anything? If Jehovah is not causing these earthquakes then presumably they are a natural phenomena and are insignificant insofar as 'prophecy' is concerned.
Of course, if Jehovah really is causing these earthquakes, what does that tell you about him . . . . . . . . . . ?