Ocean Formation
16 September 2014
Theory of continental drift: all continents were unified
and drifted apart over time to current positions.
First proposed by Alfred Wegener in 1912.
Why do the continents drift in the first place?
Earth Layers
Crust(solid)
Mantle (molten)
Outer Core (liquid)
Inner Core (solid)
Lithosphere: the outer shell of the Earth
consisting of the crust and upper mantle.
Tectonic Plates: Large pieces of the Earth’s crust
Involved the movement of plates.
Mid-Ocean Ridge: An underwater mountain range
The Great Global Rift: A break in the Earth’s crust
through which magma emerges.
The magma pushes through because of convection.
This leads to Sea Floor Spreading.
Sea-Floor Spreading
Sea floor spreading is the outward spreading of
the lithosphere from ocean ridges.
Trenches encircle most of the pacific rim. They form
when 2 plates collide and one plate plunges under the
other.
This region is also known as a convergent plate
boundary
Earthquakes, tsunamis, volcanic eruptions can result
from the friction and stress near trenches.
Interaction between seawater and magma
Seawater soaks through pores and is heated by
magma.
The rising water dissolves minerals and is released
through vents near ocean ridges.
These minerals include Fe, H2S, Mg, and methane.
These minerals are necessary for hemoglobin,
chlorophyll, and sulfur-fixing bacteria.
phytoplankton take in these minerals which makes it
available for other organism