Oceanography ( Plate Tectonics - waves and tides)

Convection Currents

causes tectonic plates to float on the mantle

Convection

Cycle of heating and cooling

Divergent

Two plates move opposite of each other

Convergent

Two plates come together

Transform

Two plates slide past each other

Subduction

When a plate is pushed under another plate

Basalt and Iron

Makes up the oceanic crust

Harry Hess

A proponent of the sea floor spreading theory

Mid ocean ridges

when tectonic plates converge causing hot mantle material to rise

Bathymetry

the study of underwater depths…

Sounding Line

A heavy weight hanging from a string used to measure ocean depth

Sonar sounding

modern method of determining ocean depth

Continental Margin

outer edge of the continent where the continental crust transitions into the oceanic crust

Shelf

Closest to the land with very shallow slopes due to sediments gathered

Slope

Marked by huge V shaped submarine canyons

Rise

The deep basin

Abyssal Plain

extremely flat sediment that stretch throughout the ocean floor.
Guyot

Oceanic Trenches

Narrow elongated depressions on the sea floor

Alfred Wegener

proponent of the continental drift

Subduction Zones

Active oceanic margin in the pacific

Passive oceanic margin in the Atlantic

the border between a continent and an ocean that is not an active plate boundary

Sediment

the further away from the mid ocean ridge the thicker the

Age of the sea floor

Increases the further you get from the mid ocean ridge

Magnetic Stripping

Magnetism patterns match up with the oceanic ridge

Pools

Anywhere where water is stored

Fluxes

The ways water moves between pools including changes in phases

3.5% salt content

Seawater is 96.50% water and…

Nitrogen

Incorporated into proteins and nucleic acids fundamental to the synthesis of all cellular structures found in marine organisms

Phosphorus

Integral to life found in energy molecules such as ATP

Salinity

the measure of dissolved salts in water

Freshwater

Less than 0.5 ppt

Brackish water

0.5 - 35 ppt

Seawater

Greater than 35ppt

Stenohaline

Restricted to specific water environments

Euryhaline

can tolerate a wide range of salinities

Hydrostatic Pressure

The result of the weight of the water column pressing down due to gravity

Sound Transmission

Passage of sound vibrations through water used by marine organisms

Heat capacity

The capability for a molecule to absorb heat energy

Temperature

In the ocean increases with decreasing depth. There are no seasonal changes at low depths.

Density

Affected by temperature

Light penetration

decreases with depth

Waves

A transfer of energy such as wind applying friction on water

Surface tension

returns water to its original state after being disturbed

Crest

highest point of a wave

Through

lowest point of a wave

Wave Height

the measurement from the vest to the through

Wave length

length between successive waves

Wind speed

how fast the wind blows

Wind duration

how long does the wind blow

Fetch

distance over water that the wind blows in a single direction

Wave steepness

Ratio of the waves height to the wave’s length(height/length)

Wave breaks

What happens when the crest reaches a 120 degree angle

Significant Wave Height

the average height of the highest one-third of waves measured

Universal Sea State Code(USSC)

A numerical scale used to describe wave height as a means to warn others

Deep water waves

Water deeper than one-half of the waves length and moves at an orbital motion

Storm centers

Flow in a circular pattern
Constructive interference

Destructive interference

2 waves meet and energy dissipates

Episodic Waves

exponentially large and sudden waves which can be larger than surrounding waves

Chop Waves

numerous

White caps

white foamy crests that form atop the water surface are visual indicators of strong winds

Shallow water waves

waves that appear at a depth of less than 1/20th the wavelength and have an ellipse orbit

Wave refraction

Waves interaction with landform caused energy transfer lowering the wave crests

Surf zones

areas of the coast where waves become vertically compressed

Breaking waves

wave energy is so unstable the crest curls and crashes

Standing waves

a shallow water wave inside a basin that is oscillating back and forth

Seiche

standing water occurring in a natural basin

Tsunamis

Resulting from tectonic plate movements

Tides

Alternate rising and falling of the sea due to the gravity of the sun and moon

Diurnal

A tidal pattern with 1 high tide and 1 lowtide per day

Semidiurnal

A tidal pattern with2 high tides and 2 low tides

Mixed Tides

A tidal pattern with2 high tides and 2 low tides per day with different wave heights for each successive high and low water

Spring tide

Tide formed from the combined force of moon and sun

Neap tide

tide formed the sun and moon from two sides

Tidal Bores

the incoming high tide forms a wave of water that travels
into a narrow area

Flood current

tidal current moving towards land when the tide is rising

Ebb current

tidal current moving
away from land when the tide is
falling

Rectilinear/Reversing currents

Currents that alternate direction
between flood & ebb

Slack water period

no velocity when transitioning from ebb to flood & vice versa

Atmosphere

Sheet of air surrounding the earth

Troposphere

Layer of atmosphere where weather phenomena occur

Stratosphere

Layer of atmosphere with ozone layer

Mesosphere

Layer of atmosphere where meteors burn up

Thermosphere

layer of atmosphere with satellites and auroras

Hadley cells

Warm air rises near the equator

Ferral Cells

Air moves towards the poles then sinks - mid latitude

Polar Cells

At high latitudes cold air sinks

Aerosols

tiny particles in air that can absorb or reflect sunlight

Jet Streams

fast narrow currents in upper atmosphere

Polar Jet stream

Jet stream found by the polar regions

Subtropical Jetstream

jet stream found by the tropics

Corrolis effect

deflects currents right in the north and south hemispheres

Westerlies

Habagat (Jun - Sept)

Easterlies

Aminan( Oct-Aug)

Tidal Mixing

Tidal waves come into contact with continents and mid ocean ridges

Upwelling

Forces denser water to rise to the surface. Surface water moves away the land

Downwelling

The counter result of upwelling. Surface water moves towards the land

Global conveyer belt

Formed by the deep ocean circulation

Ekman Spiral

As depth increases the speed of each layer decreases. As current moves down the water column

Gyres

is a circular ocean current formed by a combination of the prevailing
winds

Density Driven

causes deep currents
to return that water back around the globe