We are currently at one of our most exciting stations across the basin, the Mid-Atlantic Ridge. If you look closely at our position on the map posted below you’ll notice a light blue line (indicating higher elevation) running down the middle of the Atlantic between North/South America and Europe/Africa. This is the Mid-Atlantic ridge, a divergent boundary where two plates are spreading in opposite directions, one to the east and one to the west. As the two plates spread apart, molten magma from Earth’s crust rises, cools and spreads to create new ocean floor. This process is very slow and the ridge is estimated to widen only a few centimeters per year.
Hydrothermal vents (pictured below), which are like underwater volcanoes, also form at the ridge. When cold bottom water comes in contact with hot magma it dissolves minerals and metals in Earth’s crust and shoots up through vent fields at the ridge. Some of the minerals precipitate creating black or white chimneys where the water spills out. Plumes of hot mineral/metal rich water travel from the vents around the ridge which is what we are trying to sample. Chief Scientists have been searching all night, taking their time to make sure we catch the plume. Most of the metals analyzed throughout the cruise have been in the ocean for decades, but seawater from these hydrothermal vents contain a new source of metals that have only been in the water for a matter of days.