what caused the earthquake in Kent to happen?

Answer 1

movement of the plates under the earth's surface, like anywhere else, i would assume.

Answer 2

Folkestone and this part of mid Kent are underlain by a series of East-West trending major faults that were active prior to the deposition of the chalk that covers this area at surface. The fault line runs roughly under the edge of the North Downs escarpment, then out across the English Channel and onwards to to France. These faults are by and large in-active today, but clealy still prone to minor readjustments!

North of the fault, uplift took some pretty ancient rocks up close to surface; hence the Palaeozoic (Carboniferous) coal measures of the Kent coalfield that sub-crop the Chalk just north of Folkestone. South of the fault, significant subsidence resulted in the preservation of several kilometres of Mesozoic (Jurassic/Triassic and early Cretaceous) strata under the chalk.

This is a pretty major fault system by any standards, and almost certainly the culprit for the earth tremor.

The alternative hypothesis, as proposed by Mike W above is unlikely. However, if this sort of thing were possible, it would much more probably have been caused by Mike W's girlfriend rather than Michelle McManus.

Answer 3

Movements in plates below earth.Depletion of groundwater resources and consequent "caveing in" may be reason for earthquake in Kent.

Answer 4

Michelle Mcmanus was visiting for the day.