Oceanography Final

Water/ Ocean

70.8%

Pacific - more depth one
Atlantic - 2nd depth one
Indian - 3rd depth one
Arctic - less depth one

Observation
Hypothesis
Testing
Theory

A hypothesis is a tentative, testable statement. In contras a Theory is well-substantiated explanation. Also a Theory is a tested hypotheses.

The oceanic crust is composed by basalt and is denser but less thicker that the continental crust that is made of granite that is less dense but more thicker.

Outgassing–occurred during density stratification
–Water vapor, Carbon dioxide, Hydrogen, other gases
Outgassedwater vapor fell as rain

According to the theory of continental drift the outermost portion of earth is composed of a patchwork of thin, rigid lithospheric plates that move horizontally with respect to one another. the idea began with a hypothesis of continental drift.

Divergent: move apart Ocean-ocean: new sea floor is created (sea floor speeding) Mid- ocean ridge
Continent-continent: as a continent splits apart, new sea floor is created (continental rifting) Rift valley
Convergent: move together
Ocean-continent: old sea floor is destroyed (subduction) Trench. Explosive andesitic
volcanic eruptions Ocean-ocean: old sea floor is destroyed (subduction) Trench. Denser plate subducted. Volcanic island arcs generated.
Continent-continent No subduction (collision) Tall mountains
Transform: they past each other
Oceanic: (transform faulting) Fault. Ocean floor only
Continental: (transform faulting) Fault.cuts across continent. Shallow but strong earthquakes

Hot spots are locations on Earth's surface where an unusual amount of volcanism, not associated with subduction processes are focussed. These spots are often at the head of a track of volcanic activity that has "burned through" the lithosphere. The large number of hot spots in the Atlantic ocean are suspected to have played a role in the breakup of Pangaea.
Seamounts - Rounded tops
Tablemounts - Flattened tops

The Atlantic is getting larger than the pacific because most of the subduction is in the pacific that mean that the sea floor of the pacific is getting subducted

ContinentalDeep-ocean basinsMid-ocean ridge

Passive continental margins: develop along coastlines that are not tectonically active, including much of the Atlantic Ocean coastline.

Active continental margins: are those that are tectonically active, such as along much of the Pacific coast.

Convergent active margins:A subduction zone is formed at a convergent plate boundary when one or both of the tectonic plates is composed of oceanic crust.
The denser plate, made of oceanic crust, is subducted underneath the less dense plate, which can be either continental or oceanic crust.

Transform active margins: since these faults neither create nor destroy lithosphere, end abruptly and are connected on both ends to other faults, ridges, or subduction zones.

Features found along continental margins:

Continental shelf (shelf break: marked increase in slope, continental borderland)

Continental slope: Where deep ocean basins begin

Submarine canyons and turbidity currents

How are submarine canyons formed?
Narrow, deep, v-shaped in profileSteep to overhanging wallsCarved by turbidity currents: Underwater avalanches

Continental rise:Transition between continental crust & oceanic crust (graded bedding: Marked by turbidite deposits, turbidite deposits: Deposits generate submarine fans, submarine fans become abyssal plains)

Deep-ocean: Abyssal Plains
Extend from base of continental rise
Some of deepest, flattest parts of Earth
Suspension settling
Atlantic & Indian oceans
Features found in deep-ocean basins: Abyssal plains (suspension settling, volcanic peaks, abyssal hills)

Mid-Ocean Ridge
Longest mountain chain
Basaltic lava
Divergent
Features found at the mid-ocean ridge: Rift valley, oceanic ridges Volcanic features (pillow basalts) Hydrothermal vents: Sea floor hot springs/unusual deep-ocean ecosystems