Marine science

• 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  \n  

Pacific Ocean- Pacific=Tranquil 

Magellan- first European to complete a transpacific voyage 

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Pacific Ocean covers 1/3 of the earths surface 

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

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Hawaii island rises 10.6km  

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Atlantic Ocean  

Long, narrow s shaped ocean 

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

Relatively shallow - mid Atlantic Ridge 

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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  

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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 

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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 

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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  \n  

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 

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

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A degree of latitude is always the same  

Longitude vary depending on your latitude 

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James cook- three voyages to chart the Pacific Ocean 

1468 

1772 

17776 

Started the beginning of scientific bio’ 

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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