|
Monday August 2, 2004 21:21:56
GMT, 2:21pm ship time
Denson Seamount, Gulf of Alaska 54N 137W
Gentle Readers,
DSV Alvin, at this very minute, is probing
the depths of
Denson Seamount. We arrived 6ish this
morning, and while we breakfasted on scrumptious
muffins and bacon the ship was passing
and re-passing over the seamount. An array
of 150 transmitters was sending out sound
waves that bounced back from the seafloor
and were picked up by receivers. The length
of time required for the signal to return
depends on the depth of the water, and
all this information is processed into
a highly colored map of the seamount topography.
This process, for the oceanographically
challenged such as myself, is known as
"sea-beaming".
So at 9am, the computer lab was packed
with a motley crew of scientists hunched
over the computer, oohing and aahing at
the emerging picture. Such moments are
often the opportunity for some non-scientific
discourse, and our conversation ranged
from the deficiencies of Mr Bush, to Kennewick
Man, to the stem cell debate. The Atlantis
crew and Alvin group (a.k.a. Alvinoids)
are an impressively well-read and well-informed
bunch, sometimes I think more so than
those of us who have regular access to
the news media. There are always some
pretty spirited discussions. Fortunately
we all have to live together so no-one
stays mad for too long.
Anyway, I digress...the completed sea-beam
picture allowed the Chief Scientists to
decide on the first dive site, and the
Alvin launch machinery was set in action.
Unfortunately the weather decided to be
uncooperative - Alvin does not launch
in winds greater than about 30mph, and
launch was postponed by a couple of hours
due to high winds.
When word finally passed around that
conditions had improved, the scientist
herd trotted out to the stern. The first
few launches of any cruise are always
very well attended, with scientists hanging
from every possible vantage point with
cameras. As the cruise progresses, attendance
dwindles especially on nasty-weather days,
but I always try to watch the launch and
recovery each day. I kind of feel that
with all the effort that goes into preparing
and launching the sub, the least we can
do is watch it go down.
Alvin rolls out of its hanger on a kind
of railway track, emerging from its burrow
like some kind of giant mechanized insect
(hope the Alvinoids don't take offence
at that description). This is the first
dive since June, and Alvin has acquired
a bit of a grubby coating. So Bruce is
up on top, scrubbing it down with a broom
and soapy water. There is a brief pause
outside the hanger, for the weights to
be loaded on each side of the sub, then
it trundles on to the end of the track,
underneath the A-frame, which is a gigantic
blue hydraulic lifting structure clearly
visible in any pictures you might see
of the Atlantis. An enormous line (as
thick around as my leg) is attached to
the top of the sub, and various other
cables attached.
At this point, our first two divers,
Randy and Tom, climb the A-frame steps,
slip their shoes off, and clamber into
the sail of the sub. Our photographers
are hoping for smiles and waves, but the
divers are a bit preoccupied and don't
produce a Kodak moment. Several minutes,
and much radio communication later, the
hatch seals, the walkway swings away from
the sub, and the A-frame goes to work.
There is a kind of squealy groaning as
18 tons of submarine, and its three encapsulated
humans, is lifted up and over the stern
of the ship. There are two wet-suited
Alvin swimmers along for the ride, perched
on each side at the top. When the sub
hits the water, they unhook the sundry
lines and cables and hang on until the
sub is clear of the ship. On today's launch,
we hear from the sub pilot that something
has broken loose from the basket of tools
at the front of the sub, so one of the
divers has to go down and fix it up. After
that, with permission from the bridge,
Alvin sinks slowly out of sight, the orange
sail being the last part to submerge,
and a ghostly white shape drifts down
for a few seconds before there is nothing
there but blue water.
That is the last we will see of Alvin
until about 5pm this afternoon, when it
will return to the surface and the whole
ballet will be repeated, this time in
reverse. In the meantime, I took a trip
up to Top Lab (next to the bridge), where
one of the Alvin crew always stands by
for intermittent communications with the
sub. Today it is Gavin, an old friend
from my first Atlantis cruise to the Galapagos
Rift. Up in Top Lab, there are machines
that go "ping", machines that
plot things on paper, and occasional crackly
communications with the sub. At 4:30,
we will receive the Science Report from
the sub via radio, and this dispatch will
send scientists and their students/assistants
scuttling all over preparing for Alvin's
booty of corals, rocks, or whatever is
today's catch.
Next episode: Alvin's treasure
Best wishes to all,
Naomi
|
