Estuary
A habitat in which the fresh water of a river meets the salt water of the ocean.
Littoral zone
area closest to the shore
Earthquake
The shaking that results from the movement of rock beneath Earth's surface.
Crust
The thin and solid outermost layer of the Earth
Mantle
The layer of hot, solid material between Earth's crust and core.
Core
Center of the earth
Seismic
relating to or caused by an earthquake
Ocean Crust
Dense layer made up of primarily basaltic rocks filled with iron and magnesium
Continental crust
Layer of the earth's crust that primarily contains granite, is less dense than oceanic crust
Continental drift
Wegner's theory that the continents slowly moved over Earth's surface and once were joined into a single landmass known as Pangea
Plate tectonics
The process where large sections (plates) of the Earth's crust are in constant movement over the fluid mantle, causing earthquakes and volcanoes at the borders between the plates
Lithosphere
The outermost layer of the Earth's crust
Mid-ocean ridge
a mountain range with a central valley on an ocean floor at the boundary between two diverging tectonic plates, where new crust forms from upwelling magma
Paleomagnetic stripes
The pattern of magnetic stripes on the ocean floor due to reversals in the Earth's magnetic field and seafloor spreading
Polarity
having two opposite states of being on either end (such as North and South pole, or the positive and negative end of a magnet)
Divergent Boundary
where two tectonic plates are moving away from each other
Convection current
the movement of fluids or air based on density differences caused by differing temperature
Convergent boundary
when two or more tectonic plates come together
Subduction
the process where one lithospheric plate slides below another at a convergent plate boundary
Trench
a long, narrow and deep depression on the ocean floor with relatively steep sides; caused by convergent plate boundaries
Volcano
a mountain or hill with a crater or vent through which lava, rock fragments, hot vapour and gas are being forced from the Earth's crust
Tsunami
a seismic sea wave created by an underwater earthquake or volcanic event; not noticeable in the open ocean but building to great heights in shallow water
Hydrothermal Vent
an area where cold ocean water that has seeped into the Earth's crust is superheated by underlying magma and forced through vents in the ocean floor
Transform Boundary
when two plates are moving in an antiparallel direction, creating friction between them
Abyssal Plain
a flat, sandy region of the ocean floor found between trenches and continental rise