QUESTION:   
How deep is the water just off the coast of
Antarctica?  How deep do you go to study the sealife? 
                 
                 Derek S., 3rd grader in Mr. Thom Lewis' class
                 Charlottesville, Virginia


ANSWER from Robin Ross aboard the Polar Duke
Date: Sat, 1 Feb 1997 11:01:29 +0000 (GMT)

Dear Derek,

When we look at how deep the bottom is off Antarctica there is a shallow 
region (0 to 200 meters - remember a meter is about 3 feet so that would 
be around 600 feet) quite close to shore, within about 2 miles.  Then we 
have a gently sloping region called the shelf than is pretty wide in the 
Palmer LTER region, nearly 200 kilometers, that drops off to very deep 
ocean waters.

The shelf off the west coast of Antarctica is actually quite deep, 350 
to 500 meters (around 1050 to 1500 feet) over much of its breadth.  The 
inner shelf also has depressions caused when glaciers covered the area 
and the weight of the ice depressed the bottom.  So in two place within 
the Palmer LTER region we have deep water (>500m)  right next to land - one 
area very near Palmer Station and one down where we are now off Adelaide 
Island.  

Some researchers go right to the bottom to study the sea life, trawling 
for the fishes or taking pictures of the starfish, but the Palmer LTER 
focuses on the upper layer of the ocean where there is enough light for 
the microscopic plants to grow.  This upper layer is also where Antarctic 
krill, that eat the plants, lives.  Most of the abundant predators like 
the Adelie penguins and crabeater seals are feeding on Antarctic krill so 
they too are in the upper layers.  So most of our experiments are done 
with plants and animals from the top 150 meters (about 450 feet) with 
some sampling down to 500 m (about 1500 feet).

Scientist in general use metric units to describe distances and weights 
so that is what I have given you, with the approximate feet in 
parentheses.  For kilometers, however, you need to know that a kilometer 
is less than a mile, i.e. there is only 6/10 of a mile in a kilometer.

with regards, 
from on board the RV Polar Duke

Robin

Robin Ross
Marine Science Institute
University of California at Santa Barbara