For our last stop we made our way by plane to the coast of Brazil and then by boat to the middle of the ocean at 1 deg 5'12.92"N and 30 deg 45'55.65"W to see the Mid-Atlantic ridge, the longest mountain range in the world. From our boat John told us that the Mid-Atlantic ridge is a divergent boundary (plates are moving apart) similar to the Red Sea only it is under water. It works like this:
Rising convection currents lift the crust forming a mid-ocean ridge and as the plates pull apart this ridge cracks and magma pours into the fissure. The magma solidifies and the process repeats itself. This type of plate boundary creates the new ocean crust while convergent boundaries destroy ocean crust. This creates underwater mountain ranges which can be found at the Mid-Atlantic Ridge. It also creates shallow earthquakes activity and volcanic eruptions in the form of fissure eruptions.
We spent a night on our boat as we headed back to the Brazilian coast and in the morning we had some time to go deep sea diving and admire all the amazing creatures in the Atlantic Ocean. It is amazing to think that that the Mid-Atlantic Ridge spreads 2.5 cm per year and goes straight through the island of Iceland! I had to say goodbye to all of the wonderful people I met on my tectonic tour including Jen and our tour guide John. I wish these two weeks weren't over but once I make it to Brazilan coast it will be time to head home...
- Katherine
No comments:
Post a Comment