At Sea
AsEndeavour makes her way north to South Georgia we have, at least politically, said goodbye to Antarctica, having crossed the magic line of 60 degrees south yesterday. However, we are still below the convergence, where the water temperature hovers around 30 degrees Fahrenheit, physically still placing us in Antarctica. The convergence is a pattern of ocean currents, (in Antarctica it is dominated by the movement of the southern Atlantic, Indian, and Pacific Oceans); the two main currents being the East wind drift and the West wind drift. These currents flow in opposite direction around the continent, and it is the interaction of these two currents that creates the convergence, or down welling of surface water. The water temperature will rise dramatically when we cross the convergence northbound, increasing from 30 degrees Fahrenheit to 45 degrees Fahrenheit in a reasonably short period.
As Endeavour edges closer to the convergence and warmer temperatures, our surroundings begin to change. We will find different seabirds joining us for the rest of the journey, such as the wandering albatross. The landscape will turn considerably greener with mosses and grass, yet snow will not be in absence. We will come upon giant breeding beaches of fur seals and elephant seals. It is not just the terrestrial world that will change, the undersea world will develop new characteristics as well. New species of sponges, jellyfish, anemones, and fish will arise. Kelp forests will become abundant. But still not in the tropics, these undersea creatures will have specific characteristics related to the harsh environment in which they live.
Pictured here is a dragon fish taken in Antarctica. The fish that inhabit these frigid polar waters have special uniqueness that allow them to avoid freezing, and spend as little energy as possible. The fish are very slow growing, some only expanding 2 cm a year. Scientists are not sure how old the fish in these waters live, but some are thought to live 30 years or more. They also have special physiologic adaptations to the cold. Ice fish, for instance, do not have any hemoglobin (the carrier of oxygen in the blood), but rather rely on the oxygen rich water, and a diffusion process through the skin to receive and transport the oxygen it needs to live. Still other fish, such as naked notothenids, have an antifreeze type substance in their blood, which allows them to lower the freezing point of their blood to 27 degrees Fahrenheit, where without the antifreeze it would freeze to death at 30 degrees.
Although we have come to greener lands, our adventure in the Antarctic realm is by no means over.
AsEndeavour makes her way north to South Georgia we have, at least politically, said goodbye to Antarctica, having crossed the magic line of 60 degrees south yesterday. However, we are still below the convergence, where the water temperature hovers around 30 degrees Fahrenheit, physically still placing us in Antarctica. The convergence is a pattern of ocean currents, (in Antarctica it is dominated by the movement of the southern Atlantic, Indian, and Pacific Oceans); the two main currents being the East wind drift and the West wind drift. These currents flow in opposite direction around the continent, and it is the interaction of these two currents that creates the convergence, or down welling of surface water. The water temperature will rise dramatically when we cross the convergence northbound, increasing from 30 degrees Fahrenheit to 45 degrees Fahrenheit in a reasonably short period.
As Endeavour edges closer to the convergence and warmer temperatures, our surroundings begin to change. We will find different seabirds joining us for the rest of the journey, such as the wandering albatross. The landscape will turn considerably greener with mosses and grass, yet snow will not be in absence. We will come upon giant breeding beaches of fur seals and elephant seals. It is not just the terrestrial world that will change, the undersea world will develop new characteristics as well. New species of sponges, jellyfish, anemones, and fish will arise. Kelp forests will become abundant. But still not in the tropics, these undersea creatures will have specific characteristics related to the harsh environment in which they live.
Pictured here is a dragon fish taken in Antarctica. The fish that inhabit these frigid polar waters have special uniqueness that allow them to avoid freezing, and spend as little energy as possible. The fish are very slow growing, some only expanding 2 cm a year. Scientists are not sure how old the fish in these waters live, but some are thought to live 30 years or more. They also have special physiologic adaptations to the cold. Ice fish, for instance, do not have any hemoglobin (the carrier of oxygen in the blood), but rather rely on the oxygen rich water, and a diffusion process through the skin to receive and transport the oxygen it needs to live. Still other fish, such as naked notothenids, have an antifreeze type substance in their blood, which allows them to lower the freezing point of their blood to 27 degrees Fahrenheit, where without the antifreeze it would freeze to death at 30 degrees.
Although we have come to greener lands, our adventure in the Antarctic realm is by no means over.
