"The bird" is a torpedo-shaped probe that is suspended by a cable a few meters below a helicopter flying over the ocean. The measuring equipment itself, which measures the magnetization at the ocean floor, is located inside the helicopter. The researchers are looking for anomalies in the magnetization data in order to be able to record and make detailed reconstructions of continental drift.
The longitudinal axis at the Earth's magnetic poles function as a type of bar magnet. Every million years or so, the poles reverse, and so does the magnetization on the sea floor. If there is continental drift as volcanic magma flows from inside the Earth's crust, the magma solidifies at several hundred degrees Celsius, preserving its direction of magnetization. The extent of the continental drift can be reconstructed by looking at the different layers with opposite magnetization.
Kopsch starts the equipment inside the helicopter and positions his laptop in the middle, so as to be able to have a good view of the display from the back seat. His computer runs a program that monitors and stores the flight data. The measuring takes on average two hours and is conducted over open seas. Survival suits are mandatory, together with an emergency dingy, which is located on the left front seat.
It takes some skill to climb into the uncomfortable rubber suits and then into the helicopter, fastening the safety belt. Pilot Anton Rudolf then starts up the Bo105 and the helicopter lifts up very slowly from the deck of the Polarstern. The suit does not get any more comfortable during the flight either.
The “bird” is held by the ship's personnel before being let go, so as to avoid any chance of the probe hitting the deck. Waves are the biggest danger during the launch, as the stern of the Polarstern can move up and down a good two meters. The pilot then sets course for the planned measuring area; then, for the next two hours, he flies the helicopter as accurately as as possible along the predetermined measuring lines. Kopsch checks and notes continuously as the measurements are made — meanwhile, many bright icebergs zoom past outside; some are a fair distance from the helicopter, but others are directly next to or below us. Even though Kopsch has many flight hours under his belt, he is still fascinated by this Antarctic ice world.
Author and fotos: Michael Trapp