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369 m
SPASE II
AMANDA
882 m
Ice Runway
840 m
Geographic
South Pole
South Pole Dome
Parallel Greenwich Meridian
SPASE I
Figure 11: Relative locations of AMANDA and the two sites of SPASE
the melted ice can be recycled and heated up with boilers at the surface. The drill is constituted
by a hose the length of a hole, with a drill head eight meters long attached to it, equipped with
various instruments monitoring its direction, the water flow and the diameter of the hole. This
information is logged constantly and used later to reconstruct the profile of each hole and to
calibrate the position of the array. The drill head ends with a nozzle through which ¡ C hot
water is pumped at a rate of 150 liter/minute, melting and scraping off bits of ice with its turbulent
flow. The power requirement for drilling this way with a speed of 1 cm/s is 1.9 MW.
It takes about three and a half days to drill a hole, depending on weather conditions, mechanical
problems and sporadic re-freezing of portions of the hole which makes reaming necessary
(i.e. taking the drill up to increase the hole diameter). Preparations are time consuming in the
beginning of the season and include the unpacking of new tools flown in that year, digging up of
old equipment from previous campaigns, setting up of several boilers used to heat up the water
flow from and into the hole and many other tasks. Some time is also allocated at the end of the
season for the tearing down of temporary installations and packing down most of the equipment
to be either stored at the South Pole or flown back home.
The deployment of a new string proceeds immediately after the drilling of each hole, and
must be completed within a time limit set by the re-freezing time of the hole which is 35-40
hours. After the drill has been removed, the main cable containing the HV and service cables
is lowered into the hole. An optical module is connected to a cable breakout every 20 meters
and a nylon ball with its optical fiber is attached below it. The OMs are connected one to the
other with sections of steel cable and when all 20 modules are installed, the last module is attached
to the main cable with a cable stop. The total mass load on it is large but the total weight
it must support is reduced by the buoyancy of the OMs. The main cable and the optical fibers
are rolled up on winch operated reels and released very slowly in the beginning, with frequent
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