to spend a Saturday night. It has snowed off and on throughout most of
the evening, and there is still plenty of light in the "night" sky
so it doesn't really feel like it is the middle of the night. The
weather is cold, but it is not very windy and the seas are fairly calm.
Overall it is a very beautiful night.
To collect our water samples we use a CDT Rosette, which can collect
samples from any desired depth. The CDT is deployed using a crane and
wench; the sample bottles are tripped at the desired depth, and then the
CDT is craned back inside the ship. Once inside the ship most of the
water needs to be moved from the CDT Rosette to the aquarium room. The
aquarium room is where the sample will be pumped through fibers that
will later be analyzed for radium levels.
To move the water we use a highly technical scientific tool – the
average 5-gallon bucket. There are twelve niskin bottles in each CDT
cast, each one holds 30L of water. Ten of the twelve are used to sample
radium; the other two bottles are used to test radon, trace metals,
nutrients, carbon and oxygen.(Lab where testing occurs is pictured
above) It takes two 5-gallon buckets to move 30L of water. How many
times does Dave have to walk across the deck of a rocking ship in the
Southern Ocean, in the snow, to the aquarium room where Radium is tested
if he can carry two buckets at a time? How much weight is each load if
we know 1 gallon weighs around 8 pounds and 30L of water equals 7.9
gallons?
Tonight in the Smith-Mac grab sampler we found mud, rocky sediments
with a few small invertebrates and what appear to be pieces of coral.
The sediments from each Smith-Mac grab sample are bagged and will be
shipped back to the United States for further analysis. Above is a
picture of the very small piece of coral that was in the sediment.
We have finished 7 sampling sites so far and things are running very
smoothly. I didn't get a chance to be on deck much today, but Orcas
and Humpback whales were both spotted this morning. I was able to watch
a few Humpbacks from the bridge yesterday and I hope that tomorrow I may
have some time for whale watching.
No comments:
Post a Comment