Geological Oceonagraphy

71% of the earth is covered by water

• N. Hemisphere ~ 60%

• S. Hemisphere ~ 81%

Oceans are the main source of saltwater

• 5 oceans that scientists identified but refer to as the main bodies that create waves, currents, and other ocean phenomena

• Pacific, Atlantic, Indian, Southern, Arctic

  • Out of the 5, the Southern is the newest, relatively identified

• Pacific is the largest/deepest

• Atlantic is the second largest, and the smallest is the Arctic. The Southern Ocean is the second smallest

Earth is created based on density

• Density: how much something weighs in a particular area

• The more weight is spread out, the easier it is to manage

  • Ex) An 80-pound cell phone versus an 80-pound ceiling. You can hold up the latter in one hand

1. Oceanic Crust (Oceanic plates/Continental plates)

• Younger, thinner, but extremely heavy

2. Continental crust

• Older, thicker, but lighter

Both of them are lighter than the mantle

Diverging plates vs Converging plates

• Diverging plates:

  • Move away from each other

  • Forms mid-ocean ridge

    • Big crack in the Atlantic Ocean, from the N. Pole to S. Pole, the only part of Earth where new land is being formed constantly is in the Atlantic Ocean

• Convergent plates:

  • 2 oceanic crusts form a subduction zone

    • Deep sea trench

      • Lots of lifeforms in these environments are undiscovered

Subduction zones: The region where an oceanic plate sinks down into the asthenosphere at a convergent boundary, between continental and oceanic plates

Hydrothermal vents:

• Organisms are constantly being found and identified in the hydrothermal vents, they’re a land of their own

• Lots of bacteria and fish

The Pacific Ocean has converging plates, the Atlantic Ocean has diverging

Further elaboration: You can walk around 100 yards in the Atlantic Ocean on the East Coast and still be only ankle high. However, if you take a few steps in the Pacific, you’ll be met with a steep drop because there is only a tiny portion of the water is shallow

Earthquake activity is increased towards the Pacific, a tsunami is formed by earthquakes, and there’s more earthquake activity there

A huge amount of energy in a small space increases its pressure. The pressure creates a massive tsunami, and the drastic change of slope forces the water to be pressurized

• Earthquakes have to happen in the open ocean