oceanography

Hyrdosphere

All the water based parts of the earth, rain, snow, sediments and nutrients going into the water, evaporation, etc

Geosphere

Internal and surface parts of the earth, submarine volcanoes emit magma and other fluids that causes sea water to circulate

Biosphere

Life in ocean and on surface

All the earth systems are____

Connected through the flow of water and recycling of carbon

Earth external power plant and what it does

Solar radiation, heats up atmosphere and ocean

Earths internal power plant

Radioactive decay, releases the heat stored in the earth center

Isotope

Variant of a chemical element that has the same number of protons but different number of neutrons

Isotope

Variant of a chemical element that has the same number of protons but different number of neutrons

How has the earth been losing its heat?

Radioactive decay of unstable isotopes

Conduction

Transfer of heat through one atom to another. Done between physical contact

Convection

Heat transfer that causes motion, done through movement of fluids like liquids or gases

earths tilt

23.5 degrees

Tilt of the sun at the equator, during summer solstice

0 degrees

Tropic of Cancer and Tropic of Capricorn tilt of sunlight, during summer solstice

23.5

North and South Pole tilt of the sun, during summer solstice

66.5 degree of sunlight

Line of latitude/parallels

Parallel to the equator and perpendicular to earth axis. The distance between them are spaced equal,

1 degree of latitude

60 nautical miles

1’ (1 angle of latitude)

1 nautical mile (nm)

1 nautical mile

1.15 mile

Longitude

Meridians, vertical lines on a map, 0-180, 180 is other side of class. 0-180 of the west is the western hemisphere. 0-180 east is the eastern hemisphere

Prime meridian

Greenwich England, 0 degree

Tropical belt

Equator

Temperate belt

Tropic of Capricorn and Tropic of Cancer

Polar belt

North and South pole

Piloting

Judging location by landmark

Dead reckoning

Using direction, speed, and even the sun moon and stars to navigate (uses estimation)

Determining latitude

The angle between the horizon and North Star (only northern hemisphere)

Determine longitude

(the degree of your location) /15= time difference between you and Greenwich England

Ahead of Greenwich England

Eastern Hemisphere

Behind Greenwich England

Western Hemisphere

Determine longitude

(Time difference) x 15

Who created the first coordinate system

Ptolemy

Astrolobe

Later basis of the sextant, uses stars and the sun to get your latitude

Sextant

Navigation tool, uses 2 mirrors to reflect light twice allowing the user to measure the angle between a celestial body (usually North Star) and horizon to get latitude

Longitude and latitude are measured in

Degrees

1 degree

60 “minutes”

1 “minute”

60 “seconds”

Temperate zone

Tropics of cancer and Capricorn (23.5 degree tilt of sun light)

Tropical zone

Basically equator

Polar zone

Poles

Higher latitude means closer to the

Poles

Formula for the worlds circumference

360 degrees/angle of shadow difference = whole world /difference in shadow location

LORAN

Radio navigation system that uses the time difference in arrival time of radio waves to determine distance and location (only near coast)

GPS

Like LORAN but instead of the coast it uses 7 satellites and can be used anywhere

Who made the chronometer

John Harrison

What is used to map the sea floor

Longitude, latitude, depth, usually via a bathymetric map

Sounding

Using weighted lead lines and letting them drop until it stops to measure depth, took forever

Mathew Maurer

Pioneer in hydrography, mapped lots of the sea, big deal guy

Bathymetric maps

Maps that let use 3d visualize a surface

Isopoints

Connecting points of equal depth like contour lines on a topographic map

Wider contours

Shallow

Narrower and jagged contours

Deeper

Continental shelf

Shallow gently sloping submarine zone, first to appear

Continental slope

Steep drop off that connects the continental shelf to the sea floor, transition zone between continental and oceanic crust

Continental shelf

Wide gently sloping area of the ocean inbetween the continental slope and abyssal plain, thick accumulation of the terrigenous sediments at base of the slope

Accretionary prism

Zone at trench where sediments are squeezed due to convergence of two plates

Key things to remember about ocean basin

Abyssal plains, volcanoes, ocean ridges and ocean rises

Atoll

Submerged volcano island with reef, enclosing the shallow lagoon

Guyot

Drowned atoll with a flat top and reef

Abyssal plain

Flat smooth area of the sea between 3000-6000 meters deep

Modern sea depth measurement tools

Echo sounders with a hydrophone, they send high frequency sound waves from the ship, to the sea floor, and return to the ship

Equation for echo sounders

Speed x time/2

Side scan sonar and multibeam echo sounder

Like the other echo sounder but covers more area and is 3D, uses overlapping swaths to allow for a 3D bathymetric map, takes a while, swaths up to a 100m wide

seismic profile/seismic reflection survey a

Low frequency echo soundingPenetrates beneath the ocean floor, can disturb animals

Exclusive economic zone(EEZ)

Rules that country can access and own resources at or less then 200 nautical miles from their coast

P wave

Primary seismic wave from earthquake, travels fast through the earth

S wave

Secondary wave, is ½ slower then P wave, can’t travel through liquid

Ryleigh wave

Travels across the surface of the earth

how can we tell the distance from the surface to the epicenter of the earthquake

Time difference in arrival of P and S waves

When do P and S waves refact

When passing through an object of different density

How do we know part of the outer earths core is liquid

S waves aren’t read on the other side of the earth after earthquakes

What floats higher

Thicker and less dense things float higher

What happens when 2 plates converge

Dense one gets subdued

Passive continental crust

Quiet transition zone between the continental and oceanic crust where no active collision or subduction is occurring

Active continental crust

A boundary where tectonic plates collide or slide past each other causing high levels of earthquakes, volcanoes, and mountain building

Lithosphere

Crust and upper mantle, tectonic plates here

Asthenosphere

Beneath lithosphere, lots of convection, more dense, putty like

Isostasy

Condition of equilibrium being maintained between crustal blocks of different thickness (ice floating on water) the lithosphere on the asthenosphere

3 ways the plate boundaries

Convergent, divergent, and strike slap

Subduction zone

Marked by a trench, volcanism on the over riding plate, deep focus earthquakes along the slope of the subducting

What do trenches mark

Subduction cones and plate boundaries

Divergent boundaries

2 plates move apart as new oceanic crust is produced at spreading centers by material introduced from the mantle(upwelling) this is marked by volcanism in or near the central rival

Rift stage

Continental break up

Drift stage

Sea floor spreading

3 things cause plates to move

Convection, ridge push, slab pull

Ridge push

Hot magma rising and cooling

Slab pull

Gravity pulls heavy slab down

Passive continental margins

Continental shelf, slope, and rise

What is the distance limit from the coast that determines what nations legally have control over?

12 miles

When are coastal states obligated to share some of their revenue from the ocean?

If the material is on their continental shelf but over 200 miles away

What are the earths 4 parts?

The iron nickel core, a dense silicate mantle, A less dense silicate crust, A gaseous atmosphere

How did we get oceans from the Earth internal water?

Volcanic activity released gases from the earths interior produced in atmosphere rich in water vapor CO2 and nitrogen as the surface cooled down that water vapor condensed into liquid, which formed the ocean

Chemical weathering

Breaking down and dissolving via acid

Excess volatiles

Substances that occurred far further amounts than what could be accounted for by a chemical weathering of crustal rocks

Oxygen is a byproduct of

Photosynthesis

Radioactive dating

Using the number of carbon left in, then using its half life to figure out when the object formed

When can carbon 14 no longer be detected

Rock is over 50,000 years old

Sedimentary rocks

Rocks broken down through weathering

How are sedimentary rocks dated

Volcanic ash fall deposits in nearby sand and min