the ross ice shelf

The Ross Ice Shelf is the largest ice cube on the planet. It is a
block of ice about the size of France that moves up and down on the
ocean. No matter how many times I think about that I am still
amazed. Our plan over the next few days is to stop at approximately
25-30 stations within a few hundred meters of the ice shelf front to
do CTD casts, as well as other sampling.

We'll be repeating a track performed by at least two other cruises
(with many of the same people aboard), which is valuable because you
can track changes in the characteristics of the water which flows
into, out of, and around, the ice shelf cavity. There is a record
going back to the 60's for some locations in the Ross Sea. One of the
objectives of this particular track is to determine whether the
freshening trend which has been seen over the past decade or so is
continuing, and to try to determine the mechanisms which might be
causing it. Although it is tempting to say that the freshening is
due to an increase in melting of continental ice, it is by no means
the only potential cause. Even if melting is responsible, it may be
due to transport of fresher water from locations far away along the
coast. One of the ways we try to determine the source is by using
tracers to determine the chemical signatures of the component water
masses and their concentration in the sample.

We're working out a plan for the number of samples we plan to take,
both in the horizontal and vertical. It's a complicated process
which takes into account what we expect to see based on past
observations, time limitations, sampling limitations, and our other
objectives. As well as us screwing up a few samples. It's easy to
do and I'm hoping I do it less with the practice we'll be getting in
a few days.

We start on the transect around 10 pm tonight. I will likely be
sleeping since I am starting on a 3am-3pm shift tomorrow.

Our location is 167 30 min longitude, -76 deg 36 min latitude. since
i've neglected location updates recently, here is our northernmost
point on the weather-shortened trip to Cape Adare: -71 24, 172 49.
We've be going south much faster today than yesterday.