We made it back to Hobart! We still have busy days of packing and
unloading before we depart the vessel. We also still have to finish the
official cruise report since we got in early and had less time to work
on it than expected. The cooks did bring on some fresh fruits and
vegetables today. I cannot express how happy I am to see raspberries and
strawberries and lettuce.
Cruise Report Overview
This has been a very productive trip and we collected a lot of data.
Although we weren’t able to do everything in the original research
plan—we weren’t able to take any cores—but that is the nature of field
research. You have a detailed plan so you can be flexible. However, the
science isn’t over just because the expedition is done! Everyone has
been working hard on the ship writing up a cruise report and beginning
to analyze the data we’ve collected. The scientists will take the data
they’ve collected back to their institutions to further analyze and
process it. They can compare the data they’ve collected on this
expedition with data from previous expeditions, run statistics, and
create models with the data to draw conclusions and explanations about
what they’ve observed out here. This can take quite a bit of time, but
afterwards they will publish their results to let everyone know what
they’ve found and learned.
Here’s a quick run-through of all the work we’ve done on this research
We covered a lot of territory on our expedition. Due to a storm, our
course to Antarctica was not very direct (we then ended up running into
about a storm a week!). Once we got into the area where we originally
planned to do research, we found we had to change our plan due to thick sea
ice in some areas. However, we were able to access other areas—four
in the region—and were still able to collect a lot of compelling data.
Course track for the NBP1503 research cruise detailing CTD locations. Courtesy of Frank Nitsche.
Over the course of this expedition, we did 42
along the slope and shelf of the Antarctic continent. Compiling the
data from the CTD tells scientists a lot about the water structure here.
Below you can see a graph of data from one transect, or line, of CTDs
that shows several water masses making up the structure of the ocean in
Compiled data from multiple CTDs along a transect showing a profile of the oxygen, temperature, and salinity of water masses along the continental shelf of East Antarctica. Courtesy of NBP1503 Team.
This plot shows cold, fresher, oxygenated surface water, warmer middle
water, and colder saltier deeper water. However, we found some very
interesting water features on the Antarctic shelf. We found that in some
areas along the Antarctic coast, there is warm water deep on the shelf
close to the glaciers, and in other areas there wasn’t. When we say warm
water, we mean relatively warm—like 34 or 35F. This is still warm
compared to the usual 30F or colder water, and is warm enough to melt
glacial ice on the continent. When the scientists get back to their
institutions, they’ll further analyze and process the information
they’ve collected to understand why this may be, and what impacts it will
have on Antarctic glaciers.
Bathymetry and Subbottom
With the multi-beam bathymeter
we mapped over 3177 miles of never before mapped area along the
Antarctic coastline. We were able to get a lot of fine detail along the
continental shelf and slope.
Coverage of multi-beam bathymetry data acquired during NBP1503. Courtesy of Frank Nitsche.
Although some rough data and interpolated maps exist in the area we
were researching, you can see the difference in the existing data and
the data we obtained on this expedition.
An overlay of ocean bottom multi-beam data collected on this trip on an existing, interpolated map of the area. Courtesy of Frank Nitsche.
We also found some interesting geological features that show past
glacial movement, along the ocean floor.
Gullies north of the shelf break and a series of sediment mounds on the continental slope and rise. Courtesy of Frank Nitsche.
The scientists will use this data to help fill in and create more
accurate maps of the area. This data can be analyzed to learn more about
ice stream dynamics and past ice stream movement and it will also be
used in conjunction with the CTD data to learn more about the impact of
the warmer ocean water on the glaciers of the area.
Along the same course as the multi-beam, we also used sound (at a
different frequency) to map the subbottom. The subbottom system, which
works similarly to the multi-beam, is another way to measure depth but it
is also capable of characterizing the layers of sediment and rock just
below the ocean floor. As we had originally intended to take cores, the
subbottom profile was used to help us identify good locations with lots
of sediments. Although we ended up not doing any cores, the data
collected will help scientists identify features on the ocean floor that
we mapped with the multi-beam.
Subbottom data example of a sediment mount along the continental slope. Courtesy of the NBP1503 team.
We also did 1 XBT
to gather data that we used with the multi-beam to help us get a more
accurate calculation of how fast the sound from the multi-beam sound is
traveling through the water.
The UAV team had several successful flights. They were able to ensure
their equipment can work well in Antarctic conditions (both weather, and
being so close to the magnetic south pole). They also got some great
test images of sea ice and are designing a new computer program to
analyze floe size.
The R/V Nathaniel B Palmer in Antarctica from a UAV. Credit Dr. Guy Williams, Dr. Alex Fraser, and Ms. Eva Cougnon. Courtesy of USAP and NSF.
We deployed 10 argo floats
that will be collecting data as part of an international network of
floats that make real-time oceanographic information available to any
country in the world.
…And the Ping Pong Tournament
For those of you that were following along, Team Guyian (Dr. Guy
Williams and 3rd Mate Brian) were the winners of the on ship doubles
ping pong tournament!
Dr. Guy Williams and Brian Tweedy, NBP1503 ping pong tournament champions.
We celebrated the end of data collection and the ping pong tournament
in NBP style with liquid nitrogen ice cream!
Celebrating NBP style with liquid nitrogen icecream.