“The South Pole Station explained, “The masts are spaced 200' apart and have "Danger High Voltage" signs on each side. […] We recommend that everyone avoid touching any component of the line or masts, and do not pass under, but circle around the entire antenna line.” (click to enlarge)
The 7-km VLF Antenna line in poor visibility. David Rootes from ALE says “Expeditions should avoid this area, as they would any research site or facility.” Images ExplorersWeb files (click to enlarge)
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Antenna Alert from ALE and the South Pole Station to the expeditions
Posted: Dec 10, 2008 08:40 am EST
(ThePoles.com) When approaching the South Pole Station, expeditions have to be on the outlook for the 7-km long Antenna.
In an email to ExplorersWeb, David Rootes from ALE send out the following warning, “Word has gone round in recent years that the Very Low Frequency (VLF) antenna on the approach to the South Pole has not been operating.”
“Whether that was true, it is certainly not the case now.”
Further details
The South Pole Station has alerted ALE that this scientific experiment is very much running this year and the antenna has been energised.
“All expeditions should therefore follow instructions in the South Pole ASMA No.5 Management Plan and avoid the area.”
“The "Inan Antenna" (NSF Science Event A-108-S) is a horizontal dipole transmitting VLF (Very Low Frequency) antenna. (The terms "transmitter" and "antenna" are used interchangeably in this document.)”
“The beacon transmits at approximately 20 kHz, radiating up to 1 kW of total power for about one minute of every 15 minutes.”
“A 1.8-km coaxial Lead Line connects the transmitter to a temporary electronics building next to the Dark Sector Laboratory (DSL). This cable is laid on the snow surface and marked with colored trail flags.”
Location
“The location of the antenna will vary slightly from year to year as the polar cap slides across the continent (Grid NW @ 10 meters/year). In November 2003 the antenna was located at the following GPS coordinates:”
“North End 89° 57.3776' S, 015° 19.4333' W
South End 89° 57.7890' S, 121° 20.5500' W”
Decimal Degrees:
North End 89.95629°S, 015.32389°W
South End 89.96315°S, 121.3425°W
Degrees/Minutes/Seconds
North End 89° 57’22”S, 015° 19’25”W
South End 89° 57’47”S, 121° 20’33”
The transmitter line
“The 7-km beacon transmitter line is supported by upright aluminium masts held in place with guy wires,” explains the South Pole Station. “The masts are spaced 200' apart and have "Danger High Voltage" signs on each side.”
“The transmitter cable is strung atop clamp-top insulators mounted on each of the antenna masts. The maximum "droop" between masts is approximately 2'.”
“We recommend that everyone avoid touching any component of the line or masts, and do not pass under, but circle around the entire antenna line.”
Avoid this area
David says ALE knows from reports from ALE expeditions that parts of the antenna are at chest height at best that an individual could easily stumble into it in poor contrast.
“Expeditions should avoid this area, as they would any research site or facility.”
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