Yesterday we passed through the Aleutian Islands. The Aleutian Islands are a chain of volcanic islands dividing the Bering Sea from the Pacific Ocean. We were lucky: the visibility was good, and it was still light outside, so that we could see one of the islands relatively clearly, and two others could be seen (using binoculars) on the horizon. South of the islands is the Aleutian trench, where the Pacific Ocean is nearly 8000 meters deep.
The Bering Sea is a marginal sea of the Pacific Ocean, just as the North Sea is a marginal sea of the Atlantic Ocean. But the Bering Sea covers four times as much area as the North Sea and is also much deeper. For our last two stations, we will deploy our instruments once more to depths of 3500 meters, in order to collect sediments and water.
Yesterday we passed over the deepest part of the ocean on our transect: the Aleutian trench. The deepest depth that I saw on the depth meter was 7231 meters! At such a depth, we would not have been able to send our instruments all the way to the bottom. Some of the sensors on the CTD, for example, cannot withstand the pressure at such depths.
Shortly after we passed over this deep trench, we could see the outline of an island at the edge of the horizon – exactly twenty days since we last saw land! That was a very special moment. It is also interesting how much otherwise ‘normal’ observations have become notable after so much time at sea: seeing other ships passing by, individual birds, floating seaweed, low clouds on the horizon; all captured in photos… Yesterday morning we had a very special highlight: a fur seal found a place where warm water is piped out of the Sonne’s interior, and spent a long time swimming and diving near the stern while we were at our last station. Everyone on board had a chance to watch this graceful animal swim!