the scientist with the alarmist doomsday scenario was suggesting the entire chunk would slide off into the sea. if you have a one huge piece, I would imagine the scenario is possible. also, if you have the whole thing slide off in pieces that all fall at once it will be very similar to the entire piece coming down at once.

Personally, I'm not worried about it, even if my 16th floow NYC apartment might become oceanfront property.

yes your right, But what the geologist is saying makes sense, it is very unlikley for it all to give way at the same time to create one "large piece" and it is very unlikely for all the small pieces to fall at the same time.

Rock, with three undergraduate courses, none of which were marine or seismology, I am certainly not going to enter a urinary olympiad -- especially with folks who do this for a living.

And I certainly believe any stories about a Harbor Wave with a one-hundred-meter-high runup are bogus.

However, If you look at long-frequency terms, such a tsunami is possible if not probable within the short term (say 100 years). Look at Lisbon in 1755, and the Maritimes tsunami this century (oops, I mean last century! The 1900's, anyway.).

One other thing I read about that might be worth noting: the post-glaciation rebound phenomenon.

I'm sure you're aware that millennia of glaciation can actually compress the land under its weight, and, after the glaciers melt, the land begins to rebound (although it does so slowly; we are talking geology here).

I think there's a lot of evidence, from the Laurentian Mountains in Quebec and Ontario all the way down to Chesapeake Bay, of ongoing geological rebound after the melting of the Pleistocene glaciers.

If the current thinning of the arctic ice-pack in Greenland continues, what kind of rebound-driven earthquakes can we expect a couple of thousand years from now?