Now we are back in the Atlantic heading for Buzzards Bay and our arrival to Taylor's point on Sunday, February 24. With all our port visits behind us we’ll be collecting S2 wrist bands for storage until next year. Then we’ll have an examination day on Friday, and a day long cleaning day on Saturday that we call Field Day.
For centuries, people have been challenged by the mysteries that lie beneath the blue depths of our ocean planet. Very little was known about the ocean until late in the nineteenth century, although nearly three-quarters of the planet is covered by ocean or seawater. Myths and misconceptions abounded. We used to think that the ocean depths were devoid of life. We thought that the seafloor was flat and that it was the same age as the continents. How different a picture we now have of the ocean as the sea has begun to yield its secrets.
As we sail through the Atlantic one can't help but ponder what lies beneath the deep blue water. In the 1870s, the HMS Challenger left England and sailed the world's oceans, throwing out weighted lines and taking soundings to measure the depths of the Atlantic, Pacific, Indian, and Arctic Oceans. For the first time, scientists had an inkling of the contours of the ocean floor, took samples of the plants and animals, and measured differences in water temperature and salinity. But the cold, dark water and extreme pressure of the depths kept scientists from knowing the secrets of the deep abyss.
Scientists collect all of this data to understand how the ocean basin was formed and continues to evolve. Molten magma from Earth's interior spews out at the mid-ocean ridges, spilling over to either side and hardening to rocky basalt. As the crust pushes away from the ridges, it cools and thins, forming new seafloor and thus "widening" the ocean here. As this portion of the ocean floor widens, a section of the seafloor elsewhere is slowly sliding beneath the crust, becoming part of Earth's magma once again. Plate tectonics, the theory of Earth's crustal plates, thus helps explain ocean formation.
These activities will show you how we map the ocean floor.
Explore the ocean floor
Mid Ocean Ridge activity
Use ships logs to map the ocean floor
Try this interactive