• What is marine science- The process of discovering unifying principle in data obtained from the ocean

• The goal of science is to learn more about the natural world

• Scientific method- A systematic process for obtaining and interpreting knowledge- Ask a question, for a hypothesis, observe or experiment, form theories and laws, test repeatedly

• Not a easy process to do

• A hypothesis can be revised

• Scientific method in a nutshell

• 1.Observe

• 2.hypothesize/ model

• 3.test and criticize

• 4.Refine (until you get it right)

• Quantative data (number)

• Precise and easily compared, good for measuring change

• Statutes and probability- measure of how likely something is high degree of scientific certainty: 95% probability

• You must repeat it multiple time if you are testing someone to make sure you have accurate information.

• Also do it under different condition

• Scientist communicate their science primarily to other scientist, not specifically for the general public

• How do you know a science paper is legit?

• Depends on where it is published

• Science and nature are the best journals for all scientific disciplines

• Look for evidence on how the science might be real by using the scientific method

• World ’s Ocean- we have 5 oceans

• Pacific Ocean, Indian ocean, Southern ocean, Atlantic ocean, Artic ocean

• Total Earth surface are 70% ocean and 30% land.

Ocean and society lecture 3 

Pacific Ocean- Pacific=Tranquil

Magellan- first European to complete a transpacific voyage

Pacific Ocean covers 1/3 of the earths surface

Surrounded by the “ring of fire”= lots of volcanic activity

Hawaii island rises 10.6km

Atlantic Ocean

Long, narrow s shaped ocean

Named by the roman (from atlas mountain in NW Africa)

Relatively shallow - mid Atlantic Ridge

Indian Ocean

Mostly in the southern hemisphere

Average depth 3.9km

Important trade route for Egypt, Mesopotamia

Egyptian sailed this ocean 2500 years ago

Arctic ocean

Shallow and small relative to other ocean

Separated from Atlantic by a submarine ridge

Most surrounded by lands and contains the North Pole

Least studied of all ocean, cause it’s hard to get there- uncharted until the 1800s

Souther (Antarctica) Ocean

Surrounds the continent of Antartica north to 60 s latitude

History of marine science

Paleolithic humans developed barbed spears and harpoons

Neolithic human used bones fish hooks and nets

Copper fish hook’s

Hunter - haters along the sea shore

Sailing vessel in Egypt

Eratosthenes- Greek mathmatician

Calculated earths circumference, to within 1% of the true value

established or global grid system of charts

Hipparchus- Introduced the regular grid

Ptolemy- Charts with 360 divisions and north at the top

Produced the first world atlas

415 ce- the library was burned and Europe enter the dark age

Mid pacific island have been colonized for about 2500 years

Hawaii was colonized around 450 - 600 ce

Colonized and commuted long distances

Used stick charts showing oceanic wave refraction patterns to help navigate to small atolls over great distance

The Marshall Islands consist of two parallel island chains called rattan and ralik, which can be seen quire clearly on the map below

Chines voyages of discovery

Chines navigators became more skilled and vessel became better 

European renaissance leads to voyage of discovery

Prince Henry of Portugal

Columbus sought a route to the east

Ferdinand Magellan voyage was the first to circumnavigate the globe

Latitude and longitude are the grid which a ship uses to know its location and navigate safely

A degree of latitude is always the same

Longitude vary depending on your latitude

James cook- three voyages to chart the Pacific Ocean

1468

1772

17776

Started the beginning of scientific bio’

Charles Darwin (1809- 1882)

Student at Cambridge

Was at sea for 5 years

One of the best scientists of his time

Challenge expedition- ocean exploration was for navigation

Modern Era

In the 20th century the military studied winds and currents to improve safety and navigation

Economic needs- fisheries, oil. And minerals

Technology- Remotely operated vehicles, Underwater vehicles

DSV Alvin specification vehicle

Operating depth-45000 meters

Life support 216 hours

Capacity- 3 people

Remote sensing- Collecting data from aircraft or satellites

Ocean age is 4 billion years

The formation of the earth and the ocean

The big bang is the concept used to the beginning of the Universe 14 billion years ago.

Where did earth come from? The mass of the universe was concentrated at a single, incredibly hot point.

Most substances of earth were formed by stars

Stars form from hydrogen and stars produce heavy elements

The Milky Way- earth has rotated around this 20 times since the ocean formed

Heavier elements condense from supernovae (exploding stars) - Most chemical elements heavier than Fe were formed in explodering stars or supernovae

Most chemical elements heavier than Fe were formed in exploding stars or supernovae.

Formation of earths- Compress of this material by gravity, bombardment cause the planet to melt.

Density of stratification- results in a an inner and outer core, a mantle and a crust

First “surface” formed 4.6 billion years ago

½ of the water came from the volcanoes

½ of the water came from the outer space

Solar wind

How the salty ocean is formed

When the earth is cooled enough

Rain eroded the minerals in the rocks

Ocean was formed 2.8 billion years ago

Mille Urey Experiment- a chemical experiment that stimulated the condition of how life originated.

Earth rocks formed 4 billion years ago

Our sun will die in 5 million years

6 million years from now the sun will enter the red giant phase

97% of the water on earth is In the ocean

1.9% of ice on land, ground water 0.5%

Earth structure and plate tectonics

Earth is composed of different layers... layers have different chemical and physical properties

Plate tectonic explains the large-scale features of life

AL Wegener- the concept of continental drift

Evidence- fossils, corals, mountains

Wegner's hypothesis was not well received by the scientific community

Early mid 1900s- A technological revolution in science

Seismic waves bend as they encounter different density of rocks

Radioactive decay is the primary heat source inside the earth

Heat moved by

Conduction- movement of heat

Convection- when fluid moves away from the source.

The heat powers plate tectonics

The center of the earth is hot and molten

Why doesn’t the lithosphere sink into the atmosphere- Buoyancy- ability of an object to float in a fluid.

First time we really explored all the details of the pacific

Sea floor spreading- key idea

Convection currents in the mantle were proposed as the force that caused the ocean to grow and continents to move.

Wegener's ideas- Echo sounder- revealed the shape of the mid Atlantic ridge

Seismic studies also indicated the plasticity of the upper mantle

Radiometric dating of crustal rocks revealed something very unexpected... young ocean crust

Youngest crust Pleistocene

Oldest crust late

Active margins (Pacific Type)- associated with plate boundaries; high degree of tectonic activity

Leading edge margins created by collision of oceanic and continental

Passive margin (Atlantic type)

Are contained withing the lithospheric plates and are not next to a plate boundary

Continental shelf= Shallow submerged edge of thhe continent

Shelf break- abrupt transition from continental shelf to continental slope

Continental slope- transition between continental shelves and continental slope

Distance from shore varies, depending on location

Submarine canyons are common features of continental slopes

• Resembles larger river cut canyons on the continent

• More than 100 canyon nick edges of earth shelves

• Frequently seen on the edges of western U.S mountains, although the erosion here was caused by moving water during precipitation event and snow melting

Turbidity current- is the major mechanic of the formation of submarine canyons.

The topology of deep ocean basin differs from that of the continental margin

Features of the deep ocean floor

Ocean ridges

Hydrothemal vents

Abyssal plains abysall hills

Seamounts and guyots

Treanches and island acres

Seamounts- Are steep sided volcanoes

Reaching the sea surface to form islands

Guyots- are submerged, flat topped seamounts are most common in the pacific ocean at a depth of 1300 m

Abyssal hill- lower relife bumps 1000m, 3300 ft) high that are scattered across the abyssal plain

Trench- arc shaped depression in the deep ocean, Some of the most tectonically active features on earth, Deepest place on the earth crust

The greatest known trench is the Mariana Trench in West pacific

Mariana trench- Deepest part of the world ocean,

Island arcs- forms when two oceanic plates converge and island arc is formed by volcanic activity

Ocean ridges and rises- the longest and most continuous mountain belts on Earth

Intraplate- means with a single plate

Hot Spots- associated with development of island and seamount chains, Hawaii island

Charles Darwin (1842) proposes a mechanism for the formation of coral atolls

Hydrothermal vents- featured of rift valleys, temperature can be at 350 C

Formed by rising superheated seawater at the spreading centers.

Bob Ballard discovered hydrothermal vents in 1977.

Hydrothermal is based on chemosynthesis not photosynthesis