We have made a lot of
progress with our experiments so far. The first test involved studying
sensors called icepick geobuoys, which are usually dropped onto the ice
from an Aurora aircraft, and send back information about underwater sounds.
For our controlled tests, we dropped a dozen of these dart-shaped sensors
from a helium-filled kytoon, a cross between a kite and a balloon, raised
up to 200 metres.
After the icepicks were
dropped, we set up a heated science tent nearby and wired the icepicks
to our computers inside.
This small octagon tent
is our "office" on the ice. Outside, we drop sound sources into the water
through holes drilled in the ice. Inside, our laptop computers record the
vibrations picked up by the icepicks on the ice surface.
We also started many
underwater tests. In order to place sound sources and hydrophones
(underwater microphones) under the ice, we have cut out a 5'x8' (1.5 m x 2.5 m) hole
and put up a heated tent over it so that it would not freeze
over.
To place things in exact
positions, we use a remote operated vehicle called Phantom.
This mini submarine is
controlled using 2 joysticks for diving, surfacing and steering,
along with a zoom video camera allowing the operator to see underneath
the ice.
Phantom has a manipulator
arm, like a miniature Canadarm, which is used to retrieve small objects and
cut tangled ropes.
