unit 1 marine science

what started scientific ocean exploration

captain James cook- scurvy

Benjamin franklin-gulf stream

Charles darwin-evolution

HMS challenger

lead by sir Charles Seville “father of oceanography”

crossed the major oceans carrying out many scientific tests

4700 new species were discovered

The meteor (1925)

German research vessel cruised the Atlantic for 25 months; mapped the seafloor using sonar technology

sea vs gulf vs bay

gulf-large body of water enclosed on 3 sides by land

bay-like a gulf but smaller

sea-partially enclosed by land, smaller and shallower than oceans

latitude

lines parallel to the equator; measure in degrees north and south

North Pole-90 degrees north

South Pole-90 degrees south

Tropic of Cancer-23.5 degrees north

Tropic of Capricorn-23.5 degrees south

equator-0 degrees

longitude

runs from both to south pole

matured in degrees east and west

0 degrees longitude-prime meridian

24 meridians; 15 degrees apart

archimedes principle

the buoyant force on any object is equal to the weight of the liquid that they displace

Ferdinand magellan

conducted first voyage across th globe

sea level

the point at which the ocean touches the shoreline

the water cycle

precipitation (watershed-land area through water flows on its way back to the ocean)

evaporation

condensation-process of cloud formation

water percentage of the earth

71% percent, 3 percent is fresh water/ 68 is salt water

geology

study of the physical characteristics of the lithosphere

the mantle is the region of geological activity below the crust; magma is within the mantle

theory of plate tectonics

earths crust is divided into plats; they float like rafts.

Continents are made ontop of the plates

how do plates move

temperature difference between the upper mantle and the lower mantle—> creates a convection current

seafloor spreading

caused by the upward movement of magma under the ridge, causes the plates to move apart.

ocean vs continental plates

ocean plates are more dense, thinner, and geologically young

continental plates are less dense, thicker, and geologically old

plate boundaries

convergent-plates collide together

subduction-one plate is pushed beneath another; causes trenches

divergent-rising magma pushes plates apart and allows for a new crust to form (rift)

transform- plates slip and grind against each other; causes earthquakes

biotic environmental factors

all living or once living organisms in th ecosystem and their interactions with each other

abiotic environmental factors

sunlight, temperature, salinity, pressure, currents

how is the sea salty?

erosion

marine organisms use the salt to clean themselves

average ocean salinity

35 ppt

(33-38 ppt)ef

freshwater salinity

less than 0.5 ppt

water between 0.5-17 ppt is considered brackish

the halo cline

salinity at the bottom of the ocean is greater than that on the top

oxygen in the water

50 percent of earth’s oxygen supply comes from the ocean

how is ocean depth calculated

by using song (speed in sound in water)7

continental shelf

shallow part of the seafloor near a continent

continental slope

where sealer drops steeply at the outer edge of a continental shelf; continental rises are at the base of a slope

seamounts

small submarine mountains; regions of volcanic activity; doesn’t break ocean surface

mid ocean ridges

continuous undersea volcanic mountain range

abyssal plains

between continental margin and mid-ocean ridge; majority of the ocean