Wednesday, November 9, 2011

Land Ahoy!

My sleepless wanderings on the last night of our voyage lead me to the
bridge. The clouds to the east are lit from below with a yellow hazy
glow - Perth nightlights. The city itself is still under the horizon
but the towering lighthouse on Rottnest island periodically waves its
strobe our way. Recalling a simplified calculation that Nathan and I
performed yesterday, regarding how far we could see until the Earth
curves under the horizon - the city is at least 100km away.
No shift tonight. Once we entered Australian waters some 15 hours ago,
there was no need for further data logging since the international
dataset is pretty substantial over the continental shelf. Getting our
sleep cycles in order was of high priority even though a few others
and I are still walking up and down the corridors.
We have been commuting in a straight line for the past 3 days
collecting our last magnetic track. As a parting gift from Poseidon we
were offered 8 meter high waves with rolls of over 10 degrees. When it
was time to pull the magnetometer back in for the last time, I went on
deck to assist in manoeuvring it with ropes away from the side of the
ship. The waves were rising up like blue walls over our heads, coming
so close but never too close thanks to the ships buoyancy. Definitely
one of the exciting moments of the voyage. Its funny how seasickness
is amplified inside the ship whereas on the deck I couldn't feel a
thing. Maybe it was the adrenaline too.
Soon the pilot ship will be available to escort us into Freemantle
port. Getting the magnetometers loaned to us by the Australian
Geological Society shouldn't take too long and other than that only
the buckets of rock samples from the dredges will need to be unloaded.
In the next few months we will start to put together the clues we have
collected for the past 20 days. Magnetic tracks will help us gain
insight to the ancient spreading directions and rates of the Southeast
Indian Ocean, adding to the resolution of global tectonic kinematic
reconstructions. Thin sections of the many oceanic and continental
rocks we collected will be used to further constrain timelines and
raise new questions about what kind of margin or extinct ridge lies in
the Perth Abyssal Plain. Just imagine a huge chunk of continent,
braking off painstakingly slowly, tens of millions of years ago, and
being left behind as the rest of the continent speeds north perhaps to
create the Great Mountains of Asia. This may all be entirely premature
or even totally wrong - is that not the beauty of science?

Thursday, November 3, 2011

A Mexican Party

What day is it?
Routine and a lack of change in the surroundings have blurred all
higher order of time. Only the arbitrary relativity to the shifts
start and end points has any meaning. Asking what day it is might just
be left unanswered.
Who knew ?! Coffee also comes in teabags, or should I say coffee bags.
I found these little sacks of coffee in a can in the galley."Mocha
Kenya style", each with its own multicolour string and cardboard for
dunking, KGB interrogation style, in and out of boiling water. For
easy use and disposal, no mess - no stress. Ahhh.. the little things
in life.
Most of the magnetic analysis and mapping is done using a UNIX
open-source prompt line programming language called GMT. Very
powerful, but as a wise man expressed to me before the cruise:" 
welcome to a world of pain". I can safely say that he was right - but
hey, no pain no gain! Following 3 consecutive red-eyed nights, I have
mastered the basics and even produced some pretty good plots.
After swathing Dirk Hartog ridge two days ago, it was decided that
dredging the site would be postponed by a week, for our way back to
Freemantle. Instead, we headed west to Gulden Draak seamound to carry
out the same ritual. Remember that the point of our dredging
shenanigans is to hopefully recover some specimens that will clearly
explain the origin of the seamounts. Its always a gamble, albeit a
educated one.
Hours of watching cable tension figures as the dredge net is being
reeled in can be nerve wracking (for the geochem team). Only the
highly experienced can decipher this series of numbers. Is the sack
empty? Has it spilled? As the bulging nets gaping metal mouth rises
above the waterline, sighs of relief are released all round. Best
dredge ever!
We spoke too soon. Twenty minutes later the net was still full,
hanging like a Mexican piñata above the weather deck, swaying to and
fro - nearly decapitating a few heads. Don, our CSIRO liaison officer,
and "The Winchman" were taking turns swinging 5kg sledge-hammers.
Matters were worsened by the second mate, Tom, screeching from the
dog-house to "Give it to her" and doubling over with laughter. We
would have laughed too, had the back gates been closed, but they were
open and the thought of the guys swinging the wrong way and sliding
down the ramp like dead whale blubber did cross a few minds.
Eventually the piñata broke, releasing all its goodies. Metamorphic,
sedimentary and perhaps even igneous rocks fell everywhere. Even two
large rounded pebbles rolled about. This means months of painstaking
microscope work with the slides, but possibly good things for science.