Arnie, I don't know your sources, but the Channel Tunnel actually crosses two faults in the Paleozoic basement (one may control the shape of the valley leading up from Dover). There was a fairly major earthquake in 1382 which demolished several buildings in Canterbury and was felt in London, during debates about the Peasant's Revolt. Interestingly, considering our perceptions of the superstitious middle ages and interpretations of the lightning strike on York Minster after the installation of David Jenkins as bishop of Durham (God's wrath), no-one seems to have suggested that the earthquake was anything but an earthquake.

In the 1930's there was another fairly major quake at Brussels, felt as far as Brighton, at least, where buildings shook and people ran into the streets. (There was also a fairly dramatic one centred at Colchester in 18something or other, felt as far as London, where the Great Tower of Parliament shook, causing workmen to run down to ground level pdq, and a small tsunami was seen crossing the Thames, but this probably involved another fault system.)

SE England is not seismically inactive, and could be dangerous. If the Colchester quake had occurred on a Sunday, there would have been may deaths, as a number of church roofs and spires fell. As it was, one person died from a heart attack. Quakes are infrequent, but do cause damage, and because they are not at a plate margin, the effects travel further. There is a web site which lists British earthquakes - read it and see if the Channel is or is not an earthquake zone.

Useful map for planning Channel Crossings - note size of blobs

Home Page - rummaging about a bit will uncover a reference to the Channel

If all the Tunnel people could report was a line of French nuns being discomnobulated, they were either not researching properly, or attempting to spin the situation. Probably the latter, since much was made of the grouting procedure which sealed fissures in the marl surrounding the tunnel being earthquake proof.

Penny