31 January, 2004
The single channel streamer has been deployed and we are collecting
seismic data in McMurdo Sound. Shot lines from one side of the sound to
the other are have been established for the next couple of days. This
will create a grid of parallel lines across the seafloor that should
allow the scientists to identify large features in the structure of the
Earth's crust in the Sound.
Even though the Sound receives regular traffic from research vessels
like the Palmer, Coast Guard Icebreakers and cruise ships, the ships
generally follow a common course through the sound to the port at
McMurdo base. Large areas of the Sound have not been mapped because of
the changing ice conditions. A number of research cruises have done
seismic surveys in the Sound and their data reveals some interesting
features in the crust. By using the single channel streamer to connect
the existing seismic lines, and by taking data in areas of the Sound
that had been missed in earlier seismic surveys, the scientists hope to
create a more thorough record that will illuminate the size and
direction of volcanic and tectonic features in the Sound.
When we are towing the streamer and guns, we have to be on constant
watch for Marine Mammals. The Sound in parcticular is an area where
marine life is abundant. While at McMurdo Base, Killer whales would
come into the open water made by the Coast Guard Icebreaker. Along the
ice edge in parcticular, it is very common to see whales and seals.
During the course of our survey work today, it was not unusual to see
whales in the distance, well outside of the safety radius, but close
enough to count the number of whales in the pod and to identify species.
The scenery is spectacular. The views of Mount Erebus and Mount
Discovery are breathtaking. The icebergs and flows change like a
kaleidoscope of white and blue against the grays of the rocks and
mountains. Nearly everything here has adopted the pallet of blue, white
and gray, even the animals. The occasional brown of one of the birds,
or the yellow on the neck of a penguin is the only variety that nature
provides. Occasionally, a small flow will have flipped over and the
reddish browns of algae clinging to the sea ice will break the elegant
monotony of the blues of the water and ice.
There are cruise ships in McMurdo Sound, taking tourists on sight
seeing junkets to the glaciers and valleys along the eastern coast of
the Sound. As we continue our survey along the eastern coast, we get
our own personal views of Terror Glacier and the many glaciers that are
slowly changing the face of the mountains along this spectacular coast.
We feel fortunate to have days with this amazing beauty. A helicopter
flew by the ship making the Palmer one of its Kodak moments.