First sight of the Petermann ice island

9 August

Ever since a large piece of the glacier tongue of Petermann Glacier broke off on the 22nd of July (now commonly referred to as ‘the ice island’), we have been anxiously monitoring the movement of this island. The event gives us both opportunities and threats: We are studying the ocean circulation (and its effect on glacial melting) in this fjord. This piece of the glacier breaking off may give us the opportunity to take measurements in a previously covered and therefore inaccessible area. The last time a ship went here to take measurements was in 2009, and incidentally two large calving events have taken place since then (the first one being in August 2010), so really a large part of the fjord that was previously covered under ice is now accessible by ship. On the other hand, the island can block the entrance to the fjord altogether and we may not be able to get in at all.

We are close to the ice island now and are very curious to see it. The news of the piece breaking off made the TV news all over the world, but we are probably the first people to see the island in real life. The captain announces this long awaited moment by: “All ship personnel, all ship personnel; there is a little piece of ice next to the ship if you’re interested”. The bow quickly crowded with people with cameras taking lots of pictures. By the time this ice island will reach the more inhabited part of the world (say Newfoundland) it will have been broken into smaller pieces and not be so gigantic anymore.

This ice island breaking off of the ice tongue of Petermann Glacier is not necessarily a dramatic and life changing event. This glacier tongue loses 80 to 90% of its ice through melting from below, because the ocean water is relatively very warm (don’t get too excited now, it is only about 0.2 degrees Celsius so not particularly hot-tub temperatures). Calving of ice from the edge is only responsible for a tiny fraction of the total ice loss. That being said, if the glacier continues to calve off ice, this may be different in the future.

After the ice-island sight-seeing moment it was time for dinner (or ‘supper’ as it is called on the ship). Supper time is quite early, from 16.30 h to 17.30 h. Chief scientist Humfrey decided on a night-time CTD section (up to about midnight) in the alongside direction of the fjord, away from the ice island and away from the fjord. Tomorrow we will see whether we can go into the fjord and do the rest of this section and another one. Things don’t look good though: the ice island is completely blocking the northeast side of the entrance, while the southwest side is stuffed with thick multi-year ice. But first to bed, and we will see what happens in the morning.

The entrance to Petermann Fjord (taken in 2009).

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