|
|
31 August, 1997
We've finally left Resolute Bay. The bulldozer was loaded at midnight and
by morning we were at our first sampling site. Fiona had planned to complete
five sites without working late into the evening. Her intent was to have
each group work out problems with their sampling protocols and equipment.
Our video/acoustics team is off to a slow start. It took all day for Nick to
connect cables from the ship to the underwater camera and hydrophone.
Hopefully, we'll be ready for our first trial by tomorrow morning.
As we approached our first station, I noticed curious long dark blotches in
the water. As we got closer, I could see that they were actually small
plates of ice that had clustered into groups, some aggregates were several
acres. I asked Humfrey Melling, one of the scientists who specializes in sea
ice, to explain what I was seeing. He was quick to explain that all ice was
not the same. First year ice goes through a number of stages during its
formation, it starts as small individual crystals called frazil ice. As the
frazil ice forms, it sequesters phytoplankton and floats to the top of the
water column. Since the ice is very thin during this stage, the trapped
plankton are exposed to high levels of light and they bloom. As the crystals
begin to attach to each other they form disks, up to four inches thick and
three feet in diameter, which look like large pancakes. In fact, this stage
of ice development is called pancake ice. This explained the discoloring of
the water, the chlorophyll in the ice bound plankton was absorbing light
differently than the surrounding water.
This was just the beginning of my lesson on ice. It didn't take long before
the ship was in multi-year ice and it started to feel like I was on an
icebreaker.
Contact the TEA in the field at
.
If you cannot connect through your browser, copy the
TEA's e-mail address in the "To:" line of
your favorite e-mail package.
|