 |
| A dirty iceberg, containing
soil from the times when it, as a glacier, flowed
of the landmasses of Antarctica. It is about the
size of a house. |
Latitude: 62S 07.5
Longitude: 51W 19.7
Sky: clear
Wave height: 0.1m
Air temperature: -1C
Wind Speed: 10kn
Just a quick note
from a gorgeous day. We woke up to blue skies and no
waves at all. The entire horizon was covered in icebergs,
ranging in size from minivan to several miles long.
To see them like this is quite normal for the northern
Weddell Sea, though their location is further north
than we have seen them in the past 4 years. But then
this is the latest time in the year that we have been
here.
 |
| Pancake
ice. |
Right now we are traveling
through brash ice, which consists of ice crystals lumped
together in the early stages of the freezing process.
When waves push this brash ice around it tends to form
pieces that look like pancakes, hence the name pancake
ice. When it freezes even more, these pancakes start
to stick together and form a solid sea ice cover.
Icebergs come from
the southern Weddell Sea where huge ice shelves are
located. Different from the sea ice, which, in Antarctica,
is formed in winter and melts over the summer, icebergs
are formed over thousands of years on land and slowly
flow as glaciers towards the ocean where they then break
off and are moved around by ocean currents. A typical
iceberg has a height above water of 20m, an area of
about a city block, and reaches 150m deep into the ocean.
We are thus seeing only small fractions of the bergs.
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April
15, 2003
CORC/ARCHES
Expedition
Afternoon,
Tuesday, April 15, 2003, from Dr. Gerd Krahmann
Aboard the R/V LAURENCE M. GOULD...
 |
| Hauling in the net after
it has been trawled along the sea floor for about
one hour. |
Latitude: 62S 51.4
Longitude: 59W 6.3
Sky: overcast
Wave height: 2m
Air temperature: 0.5C
Wind Speed: 20kn
We are finally on the
way to our research area. This evening we will do a
first test of one of the main instrument packages to
be used - a CTD, which stands for conductivity-temperature-depth.
It allows us to measure the salinity and temperature
of the sea water from ocean surface to bottom. At the
test station, the water depth will be 2000m but we hope
to get to places where it is 4000m deep. The CTD package
is attached to a large steel frame which also holds
24 plastic cylinders, each with a volume of 10 liters.
The whole thing is lowered from the ship on a special
steel wire and we continuously record data during descent
and ascent. The data link through the wire allows us
to close the plastic cylinders to take water samples
at different depth that we then analyze on board or
at home for traces of chemicals and isotopes.
 |
| A skate and other bottom
dwelling fish caught during the trawl. |
Before my next report,
when I can report on work begun for our CORC/ARCHES
project, I will give you an account of our colleague's
fish-biology research over the past few days.
On April 11, we left
Palmer Station to head for an area north of Anvers Island.
Within two nights and one day, the group managed to
catch a good number of fish using two different methods:
a type of trap similar to what is used in Alaska to
fish for crabs, and a small net that was trawled over
the sea floor. The catch included several different
kinds and sizes of so-called icefish, one skate, and
a number of fist-sized octopods. As the biologists want
to keep the fish alive, they are carefully handled on
deck and in aquariums to ensure their survival.
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