November 18, 1995
Location: Bransfield Strait near Livingston Island
Update: Ship time is split nearly evenly among the two science groups
these past few days as both of the science teams try to get as much data
collected as possible during our time here in Bransfield Strait. For the
geophysicists from the University of Texas that means Sea Beam mapping of
the sea floor. For the geochemists from Oregon State that means more vent
sniffing with the ZAPS sled. The change from Texas time to OSU time
happens about 8:00 PM each day during the middle of my watch.
Changing science time zones is often a hectic ordeal. Dick and I are
responsible for making sure that the shipís bridge has the proper
coordinates to get to the starting point for OSUís night of data
collection, after a day of mapping. We are also trying to get every last
contour line on the map of the day as we make way for the ZAPS starting
point.
The map that was made today during our survey covers an area 15 miles x
15 miles near Livingston Island. These large contour maps of the sea
floor maps are made using a technique called mowing the lawn. The ship
starts the pattern by following a direct course in one of the four
directions. As the ship travels a continuous contour map of the sea floor
below is made by the Sea Beam Sonar system. At a predetermined distance,
the ship makes a 180 degree turn and heads in the opposite direction. It
is the job of the watch standers to give the bridge subtle course changes
so that the contour tracks of the sea beam overlap one another just
slightly so that a continuous map with no empty spaces is made.
This back and forth pattern is like mowing the lawn. The blank spaces
on the map are like the grass that was missed while cutting the lawn. Like
a lawn, the sea floor isnít always level, and you donít always walk a
straight line. The same holds true for the ship. We spent 8 hours doing
this map with each back and forth swath taking about two hours.
The resulting map is beautiful. We have very few open spots except
near the turns which are very hard to make with such a large ship. We
were able to identify some very interesting ridge formations and small
volcanic features. Most of the area is gradual sloping planes with an
occasional formation jutting out from the sea floor.
The OSU team continues to accumulate data. Sometimes we forget that
for scientists the absence of change is also important information as
well. The ZAPS drift tonight helped the OSU group focus their search by
eliminating areas that obviously lack the characteristics that are typical
of vent zones.
The whole process of doing science on in in the field, as we are doing
on the Palmer, takes time. Work periods are typically 14 to 16 hours long
for the scientists on board. Science, especially science on a research
ship is not done by the time clock. Science is done for as long as the
data keeps coming in and the equipment and people can keep working.
We did take a few breaks to enjoy the scenery today. As we made our
map, we traveled along the coast of Livingston Island. Livingston is a
volcanic island with black basalt rock cliffs and outcrops jutting out of
the snowy mountain slopes. The clouds play hide and seek with the
mountain tops, as they peak in and out from among the pointed crests,
pushed by the sea breeze.
The shoreline is steep and rugged marked by sharp vertical cliffs and
pyramid shaped projections. These pyramids of rock are like rows of teeth
protecting the coast, ready to chew any incoming ship that strays to close
to its banks. The island looks like an artistís pen and ink drawing. The
black rock defining the mountains outline in the white blanket of snow
drawn on the canvas of sea and sky. As the sun began to set, the island
cast shadows across the water that changed shape as they moved on the
waves.
Antarctica is a beautiful place. Each day is like entering a new room
in a museum. Each dayís brings us a new exhibit in this Antarctic museum
that is inspiring and unexplored.
