Oceanography test 1

What are the five main oceans of the world?

Pacific, Atlantic, Indian, Antarctic, Arctic.

Why aren’t the Pacific and Atlantic just “Seven Seas”?

The oceans are interconnected; divisions are human-made for convenience.

Average ocean depth vs average land elevation?

Ocean = ~3,800 m deep.

Land = ~840 m high.

Ocean is ~4.5x deeper.

Where is most of Earth’s water stored?

Inside Earth’s rocks and interior (but oceans = liquid water on surface).

What is oceanography?

The multidisciplinary science of studying oceans, combining geology, biology, chemistry, physics, meteorology, astronomy, and engineering.

What is the Big Bang Theory?

Universe began ~13.8 billion years ago, expanding from a single dense point.

How old is Earth?

~4.6 billion years.

How old are Earth’s oceans?

~4.0 billion years.

How was the Moon formed?

A Mars-sized body collided with Earth; debris collected into the Moon.

Why is the Moon important?

Stabilizes Earth’s tilt, regulates tides, prevents extreme climate shifts.

What is density stratification?

Heavy materials sink inward (core); light materials float outward (crust).

What’s inside Earth’s core?

Mostly iron and nickel.

How are heavy elements formed?

Through nuclear fusion inside stars and supernova explosions.

What is a supernova?

A massive star’s death explosion scattering elements into space.

Where did Earth’s water come from?

Volcano outgassing + icy comets/meteors delivering water.

What was Earth’s first atmosphere like?

Mostly gases from volcanoes (CO₂, water vapor, nitrogen).

Where did free oxygen in the atmosphere come from?

Photosynthesis by primitive organisms.

Why are oceans important for Earth’s climate?

They regulate temperature, weather, and circulation; support life with food + oxygen.

How do oceans support human life?

Provide food, oxygen, trade routes, regulate climate, and shape history.

What is outgassing?

Release of gases from Earth’s interior (volcanoes).

What’s the average depth of the ocean?

~3,800 m.

What’s the average elevation of land?

~840 m.

Universe age vs Earth age vs Ocean age?

Universe: 13.8 billion yrs, Earth: 4.6 billion yrs, Oceans: 4 billion yrs.

Careers that study the ocean?

Marine Biologist, Marine Geologist, Physical Oceanographer, Chemical Oceanographer, Marine Engineer.

Steps of the Scientific Method (cycle order)?

1. Ask Questions → 2. Formulate Hypothesis → 3. Conduct Experiments, Observations, Collect Data → 4. Formulate Conclusions → 5. Develop Theories.

What percent of Earth is covered in water?

71%

What percent of Earth’s water is in the ocean?

97%

Where is the other 3% of Earth’s water found?

Lakes, rivers, groundwater, ice.

How old are the oceans?

~4 billion years old.

Greek origin of the word “ocean”?

Okeanos.

Order of star formation?

Nebula → Protostar → Star (fusion begins) → Red Giant → Supernova Explosion.

Order of solar system formation?

A. Flattened solar nebula forms (cloud spinning).

B. Condensation nuclei form clumps (moonsize planetesimals).

C. Solar wind blows out remaining gas.

D. Planetesimals collide & grow.

E. Planets form (~100 million years).

Order of Earth’s formation?

A. Meteorites, radioactive material melted Earth.

B. Heavy (iron) sank → core; light floated → crust.

C. Gases (H₂O vapor, CO₂) outgassed via volcanoes → atmosphere.

D. Gases condensed → clouds → heavy rains.

E. Rain collected in basins, dissolved minerals.

Who proposed biosynthesis in 1953?

Stanley Miller.

What did Miller’s experiment produce?

Amino acids (building blocks of proteins) & simple sugars.

Where might life have originated?

Shallow tidal pools OR hydrothermal vents (~3.5 billion years ago).

Necessary conditions for a life-supporting planet?

• Circular orbit around stable star.

• Right distance from star (liquid water).

• Materials for solid crust & water.

• Volcanoes/steam vents to release gases.

• Enough gravity (keep atmosphere, not crush life).

• Magnetic iron core → deflect radiation.

• Single moon → gentle tides.

• Clear atmosphere for sunlight.

• Moisture → winds/rains → currents.

Ozone layer → shield UV.

Special Earth features that allowed life?

• Circular orbit around Sun.

• Right distance for liquid water.

• Sun not a double star.

• Gravity strong but not crushing.

• Magnetic iron core → radiation shield.

• Single moon → gentle tides.

• Clear atmosphere → sunlight.

• Ozone layer → UV protection.

What is the Crab Nebula?

Remains of a star that exploded in 1054 (supernova remnant).

What is the Condensation Theory?

Stars & planets formed from contracting clouds of dust, gas, debris that clumped together.

Did Earth have oceans when first formed?

No — surface too hot, thick clouds blocked sunlight, water couldn’t condense.

Gases in Earth’s early atmosphere?

Methane, ammonia, carbon dioxide, water vapor.

Benefits of voyaging?

Mobility, sea power, more food, military/economic/nutritional advantages, curiosity, adventure.

Who were first regular ocean traders?

Cretans & Phoenicians (dual-hulled ships, navigated by stars, resource storage).

Who predicted planetary motions, calculated π, oriented maps with east right, north top?

Claudius Ptolemy.

Who sponsored voyages & created first navigation/science center?

Prince Henry (the Navigator).

Who divided Earth into 360°?

Hipparchus.

Who commanded the greatest fleet?

Zheng He (China).

Who proposed continental drift?

Alfred Wegener.

Famous Viking explorers?

Bjarni Herjolsson (saw North America— newfound land), Leif Erikson (landed).

Why did Vikings abandon colonies in North America?

Conflict with Indigenous peoples, lacked numbers/weapons/trade goods.

Who was father of physical oceanography?

Mathew Murray

Who published first current chart (Gulf Stream)?

Benjamin Franklin.

Who calculated Earth’s circumference, invented latitude/longitude?

Eratosthenes

Who discovered North America (European credit)?

Christopher Columbus (misusing Ptolemy’s charts).

Who led first expedition around the world?

Ferdinand Magellan.

Who is called first marine scientist?

James Cook (mapped NZ–Hawaii, prevented scurvy w/ cleanliness & vitamin C diet).

Who invented marine chronometer?

John Harrison.

Who organized Nile River trade?

Egyptians.

Who influenced modern naval strategy?

Alfred Thayer Mahan.

Which expedition drilled seafloor, found plate tectonics evidence?

Glomar Challenger.

Which expedition discovered trenches & measured ocean depths?

Challenger II.

Which vessel reached deepest ocean point?

Trieste

Which expedition explored Antarctica, whales, hollow earth myth?

U.S. Exploring Expedition.

Which German expedition mapped seafloor w/ echo sounder?

Meteor

Which was first voyage purely for science?

HMS Challenger (longest scientific expedition).

Technologies used today in oceanography?

Submarines, Satellites, GPS, Improved engines/ships, Computers, ROVs (remotely operated vehicles).

Polynesian survival observations?

Wave patterns, ocean currents, bird/sea life variation, star navigation.

3 groups who mapped early Mediterranean?

Egyptians, Phoenicians, Cretans.

Viking name for Newfoundland?

Vinland (“Wineland”).

Chinese navigation inventions?

Compass, central rudder, watertight compartments, multi-mast sails.

5 oceans of global ocean?

Atlantic, Pacific, Indian, Arctic, Antarctic.

SONAR acronym?

Sound, Navigation, and Ranging.