In article , dxAce wrote:


wrote:

I talked by phone, about an hour ago, with a gentleman on DG and he
said they experienced waves 3 to 4 feet high but suffered no damage.
If the island's elevation is only 4 to 22 feet high, that makes sense.
But why was there so much damage to the coast of Somalia, another 2000
miles further west, and no damage to DG?? Would they tell us if there
really was damage on DG??

Nah, it's all a big secret to get you conspiracy kooks going!

But actually it probably has a lot to do with the mechanics of the wave itself
and the sea floor/bed around Diego Garcia itself. The wave may have 'flowed'
around Diego Garcia, but when it reached Somalia it had nowhere else to go but
up the beach.

It's pretty simple physics.

Yes, I dug out the Nat. Geo. World Atlas and the physical map of the
Indian Ocean shows why some areas like India and Somalia got plastered.
The continental shelf and the shoreline are parallel to the wave front,
so the energy got concentrated vertically. Diego Garcia and the Chagos
have the Chagos Trench that runs east and south of DG, so the energy
could diffract around.

The surprise for me is that Broome and Northwest Australia didn't get
it hard. One description (can't remember if it was in the newspaper or
on one of the American TV news broadcasts) said that in these subduction
quakes, some of the seabed falls and some areas rise. So there's a
dipole effect where, for some directions, the waves cancel out.

They said Sumatra moved 100 ft. I'd hate to be a land surveyor there
using GPS. Until they recalibrate their local benchmarks, it'll be
hopeless.

Mark Zenier Washington State resident