OFF: Watery Graves and stuff

[M Holmes]

Mark Lee writes:

> Answer:
>
> You get bubbles in yer Jack Daniels :)
>
> But:
>
> Apparently we have more chance of tsunamis from landslip than
> we do of the same from ice-slip.  It's already happend somewhere
> in Scandinavia (ish) a couple of times, estimated wave heights
> of over 300 meters IIRC.

There was a documentary on tsunamis on the box recently. They had an
interview with a guy who'd been in a fjord off Alaska when a landslip
around the bay head had caused a tsunami. He'd heard the rumble from his
boat, but first he knew he was in trouble was when a 500 foot wave came
*over* the headland from the next bay. He threw a lifejacket at his son
and said "put this on and pray". The boat went up and over the wave and
came down intact. A boat half a mile from him had been lifted ten miles
out to sea and smashed to smithereens.

The big part of the programme was about some eastern atlantic volcanic
island. Apparently the typre of rock it's made of is in almost vertical
layers where some layers are permeable to water and some are not. The
volcanic vents mean that lave heats the water layers into steam, which
then means that the impermeable layers are forced apart. The result is
very large cracks along the island, some near the cliffs. The final
result, sooner or later, is that volcanic heating will one day drop a
three mile length of cliff, almost half a mile high, down into the
atlantic. This will produce a spreading tsunami about 20 feet high. When
this hits the atlantic shelf at the US end six hours later, the wave
will shorten wavelength and produce a tsunami somewhere between 200-300
feet high. This will destroy pretty much every city and town on the east
coast of the United States. On the plus side, they will get six hours
warning.

Quite what could be done about it isn't clear, but I'd certainly be
thinking of drilling steam vents through the impermiable layers, and
lots of steel bolts and concrete.

FoFP