teeks

December 12, 2008

A slog in the snow.

We have many scientific devices and instruments all around the Antarctic. Ozone detectors, air samplers, weather stations, GPS loggers etc, all of which need regular servicing and raising due to the accumulation of snow each year. Sometimes we have to install new instruments in areas that have sparked the curiosity of Mr Science, and last week the Mcdonald Ice Rumples had Mr Science all excited…

The Rumples is a fascinating feature of the Brunt Ice Shelf. The closest thing we have to a mountain lives at the Rumples, unfortunately it’s under the sea. Being under the sea isn’t a problem for this mountain though as it’s tall enough to dictate the shape and behaviour of the Brunt for hundreds of miles. As Mr Ice Shelf approaches Mr Undersea-Mountain, it gets pushed up and broken up and clogged up and all kinds of other ups, resulting in a massive bottleneck slowing the pace of the shelf towards open sea. Normally, ice shelves would happily float on the sea and break away every now and again, but stick a great big lump of rock in the way and you get all kinds of ice features forming such as massive crevasses, icebergs, cracks, holes, caves, tunnels, hills and small mountain-looking-bumps.

Halley is very fortunate that we have Mr Undersea-Mountain where it is, as it slows the eventual slip of the shelf into the sea. I don’t know how much quicker the shelf would move, but it would be much higher than the current 2 metres a day. The constant break up of shelf and iceberg creates a system of creeks which gradually move downstream as it were – these provide us with perfect areas for a large ship to park and resupply the base every summer.

Why the interest for science though? The Rumples is an incredible crevassed range of mini-mountains and valleys. It’s utter chaos and very difficult to navigate, which incidentally is impossible by vehicle due to the dangers of falling into one of these crevasses. As such, any instruments at the Rumples have to be delivered by person, typically with teams of two or three ‘manhauling’ the instruments on small sledges. Last week was such a delivery …

We drove to edge of the Rumples, clinked our crampons, tied our ropes and dragged a GPS logger plus VHF radio modem + mast 3km to a flat basin right in the middle of the Rumples. It was the flatness that sparked the initial curiosity – why would a relatively large area stay flat and stable when so much around is in utter shambles?

We manage two trips back and forth that day through heavy undulating snow. Who knows how many bridged crevasses we walked over, but I loved every second of it. It was hard work (especially with me being at the back as the last anchor if the other two fell into a crevasse … cough) but we managed it. It’s difficult to capture the state of the place with a camera, but here’s my attempt at least.

A typical apline-3 arrangement. You can see the solar panels of the main logger on the sledge. The footprints in front are from the days before.