At Sea, Southern Ocean
Heading northeast, bearing 45o. Yesterday, the bridge officers adjusted the navigation tools for our long transition towards one of the most isolated inhabited islands in the World, Tristan da Cunha. We are now sailing in the part of the Atlantic Ocean usually referred to as the Roaring Forties, and earlier today we were in the Furious Fifties. Well, despite these dreadful designated names in these latitudes, our day was really a very pleasant encounter.
The sea was gentle and calm and we could see almost endless numbers of ice-bergs in the distance. In fact, we crossed the Antarctic convergence around midday, but even late at night the radar screen was full small luminous points showing more tabular icebergs, drifting towards the northeast (see photo). These icebergs have resulted from the major breakup of the Larsen B Ice Shelf on the eastern side of the Antarctica Peninsula. South of the Antarctic Convergence, before noon, the water temperature was only +3 oC and now at 10pm is +7 oC. The convergence really stands out as the true border for Antarctica, a continent surrounded by an ocean. This is the very opposite to the Arctic, which is a frozen ocean surrounded by continents. We are now in the “warmer” sub-Antarctic waters.
Our oceanographer, Jim Kelly, gave a very interesting lecture in the morning about the complexity of the ocean currents and how prevailing winds created by the revolution of the planet make the weather patterns at different latitudes. Since we are covering many latitudes on this trip, including crossing the tropics of Cancer and Capricorn as well as the Equator, we will have plenty of opportunities out on deck to confirm several of these theories and models.
Today, anyone spending time on deck saw signs of Antarctica by all the ice-bergs, but as the day progressed, sightings of Antarctic fur seals turned into sightings of sub-Antarctic fur seals and newly spotted pelagic bird species (kerguelen petrel & white-bellied storm-petrel) convinced us we had entered temperate waters. A good bonus today was also a good view of an elusive strap-toothed beak whale and a distant fin whale. The waters we now sail in are extremely rich.
This morning, we sailed along several tabular bergs. These can act as traps for krill, since they create small micro up-welling. Yesterday afternoon the depth-finder on the bridge showed a major concentration of krill as we cruised along the huge ice-berg. In fact, a krill mass this size needs to move continuously in the water column since they will quickly consume all the available dissolved oxygen. Around this gigantic concentration of krill, we of course saw both whales and sea birds in considerable numbers.
The convergence also acts like a mixing zone where different waters meet and form a very rich area which is always a good region for marine mammals and sea birds. We were rewarded today with many good sightings. Now we look forward for another day at sea and more good sightings. We still have three more to go!
Heading northeast, bearing 45o. Yesterday, the bridge officers adjusted the navigation tools for our long transition towards one of the most isolated inhabited islands in the World, Tristan da Cunha. We are now sailing in the part of the Atlantic Ocean usually referred to as the Roaring Forties, and earlier today we were in the Furious Fifties. Well, despite these dreadful designated names in these latitudes, our day was really a very pleasant encounter.
The sea was gentle and calm and we could see almost endless numbers of ice-bergs in the distance. In fact, we crossed the Antarctic convergence around midday, but even late at night the radar screen was full small luminous points showing more tabular icebergs, drifting towards the northeast (see photo). These icebergs have resulted from the major breakup of the Larsen B Ice Shelf on the eastern side of the Antarctica Peninsula. South of the Antarctic Convergence, before noon, the water temperature was only +3 oC and now at 10pm is +7 oC. The convergence really stands out as the true border for Antarctica, a continent surrounded by an ocean. This is the very opposite to the Arctic, which is a frozen ocean surrounded by continents. We are now in the “warmer” sub-Antarctic waters.
Our oceanographer, Jim Kelly, gave a very interesting lecture in the morning about the complexity of the ocean currents and how prevailing winds created by the revolution of the planet make the weather patterns at different latitudes. Since we are covering many latitudes on this trip, including crossing the tropics of Cancer and Capricorn as well as the Equator, we will have plenty of opportunities out on deck to confirm several of these theories and models.
Today, anyone spending time on deck saw signs of Antarctica by all the ice-bergs, but as the day progressed, sightings of Antarctic fur seals turned into sightings of sub-Antarctic fur seals and newly spotted pelagic bird species (kerguelen petrel & white-bellied storm-petrel) convinced us we had entered temperate waters. A good bonus today was also a good view of an elusive strap-toothed beak whale and a distant fin whale. The waters we now sail in are extremely rich.
This morning, we sailed along several tabular bergs. These can act as traps for krill, since they create small micro up-welling. Yesterday afternoon the depth-finder on the bridge showed a major concentration of krill as we cruised along the huge ice-berg. In fact, a krill mass this size needs to move continuously in the water column since they will quickly consume all the available dissolved oxygen. Around this gigantic concentration of krill, we of course saw both whales and sea birds in considerable numbers.
The convergence also acts like a mixing zone where different waters meet and form a very rich area which is always a good region for marine mammals and sea birds. We were rewarded today with many good sightings. Now we look forward for another day at sea and more good sightings. We still have three more to go!
