Oceanography exam 1

Name one example of divergent, convergent, and transform boundaries

divergent: Mid-Atlantic Ridge convergent: Andes Mountains transform: San Andreas fault

What are major threats to the ocean?

Climate change, pollution, overfishing

How old is the Earth and the solar system?

Solar system: 5 billion years old Earth: 4.6 billion years old

How did the ocean and atmosphere originate? Where did the water on Earth come from?

- The atmosphere originated from density stratification and outgassing - The oceans and water came to Earth from outgassing releasing water vapor, comets that came from space, and water runoff from land

What were the 4 lines of evidence that Wagner identified?

- the continents fit together like a puzzle (Pangea) - mountain chains matched - fossils matched - glacial ages

What are neritic sediment deposits?

1/4 of the ocean floor, lithogenous deposits surrounding the continents

What is the average depth of global ocean?

12,100 ft

What degree is the Earth's axis of rotation?

23.5 degrees

What are pelagic sediment deposits?

3/4 of the ocean floor, biogenous deposits in the middle of the ocean

When was multicellular life introduced to Earth?

550 million years ago

What percentage of the Earth's surface is covered by ocean?

70.8%

How do hydrogen bonds form between water molecules? Are these stronger or weaker than covalent bonds?

A positively charged hydrogen end interacts with a negatively charged oxygen end to form a hydrogen bond. They are much weaker than covalent bonds

Why do volcanoes and earthquakes occur in subduction zones?

Because the plate is bending downward and slowly plunging back into the Earth's interior

Why is water the universal solvent?

Because they are attracted to other water molecules and other polar chemical compounds

What is an example of an active margin?

California

What are coral reefs made out of?

Colonial animals that live in shallow, warm, tropical seawater and produce a hard skeleton of limestone.

What is the Earth's internal structure chemically?

Crust, mantle, core

What caused the separation of the Earth into layers?

Density stratification

Why was Wagner's hypothesis rejected?

He provided no realistic evidence, no proof of the continents moving other than the Earth's spin

What patterns in ocean features did Hesse notice in his seafloor depth data? How did Hess explain how new seafloor formed and then was recycled back into the Earth? Where did these processes take place and what was the driving mechanism?

Hesse notices sea floor spreading and convection cells. He explained that a new ocean crust was created at the ridges, split apart, moved away, and later disappeared into deep Earth

Does water have a low or high specific heat capacity?

High specific heat

Where would you expect to find rocks and gravel?

High wave action

how is a hotspot different from a volcano associated with a subduction zone?

Hotspots are different because they are areas of intense volcanic activity that remain in the same location and are unrelated to place boundaries while a volcano in a subduction zone has to do with the plate moving

Where would you expect to find fine-grained silts and clays?

Low-wave action

Does science describe the absolute truth?

No

How are the continental and oceanic crust different in composition, thickness density, and age?

Oceanic crust: higher density, thinner Continental crust: lower density, thicker

Why does oil not combine with water?

Oil is less dense than water

What are the main characteristics of the five oceans that make up global ocean (including vol of water they contain)

Pacific: largest ocean Atlantic: smaller, shallower Indian: Similar to Atlantic, but in Southern Hemisphere Arctic: very small and very shallow, surface level is ice Antarctic: Antarctic convergence

When did Pangaea form and separate?

Pangea formed between 540-300 million years ago and separated starting 180 million years ago

What type of margin is off NJ's coast?

Passive margin

What are differences and features of passive and active margins?

Passive: has abyssal plain, has continental rise Active: has seamounts, has ocean trench

What are hydrothermal vents?

Sea floor hot springs created when cold seawater seeps down along cracks in the ocean crust and approaches an underground magma chamber, the water gets hot and goes back to the surface

How are seamounts and table mounts different? Where are these formed?

Seamounts are cone-shaped and table mounts are flat on the top. They are formed by volcanic activity in hotspots and processes in the mid-ocean ridge

Is seawater more or less dense compared to fresh water? Why does ice float?

Seawater is more dense than freshwater

What was Wagner's continental drift hypothesis?

That the continents are slowly drifting across the globe

What are features in deep ocean basins and along mid-ocean ridges?

The mid-ocean ridge is volcanic and is composed of basaltic lavas, a Rift Valley

What is the theory of plate tectonics?

The plates move horizontally in respect of one another

How did Vine and Matthews connect the unexplained magnetic stripes on the seafloor with Hess's idea of seafloor spreading?

Their idea is that there was above-average and below-average magnetic polarity episodes embedded in sea floor rocks that were caused by Earth's magnetic field alternating between normal and reversed polarity

What form of energy changes the state of matter?

Thermal energy

What is radiometric dating?

a process to determine the age of rocks

Why is the latent heat of vaporization greater than the latent heat of melting?

because gas molecules have the largest intermolecular space - it takes more energy to convert liquid to gas than solid to liquid

What is the hydrologic cycle?

continuous movement of water on, above, and below the surface of Earth

How did the section near the continental slope and small submarine canyons along the shelf form?

erosion

What evidence supports the Theory of Plate Tectonics?

fossil evidence, glaciers, coastlines, mountain ranges,

What are the three main layers of most of the ocean?

halocline (rapid changing salinity) thermocline (rapid changing temperature) pycnocline (rapid changing density)

What are water's unique chemical properties?

high boiling point, high specific heat, cohesion, adhesion, density

How are sediments connected to surface conditions and plankton?

idk

How do igneous rocks with magnetite record the direction of the magnetics pole?

idk

What are the 3 hypotheses that explain the origin of life?

idk

What process increases the seawater salinity? What process decreases it?

increases: formation of sea ice and evaporation because it removes water from the ocean, leaving the salt decreases: melting sea ice, precipitation, runoff

What is the Earth's internal structure physically?

inner core, outer core, mesosphere, asthenosphere, lithosphere

What are gyres and what drives them?

large circular loops of water that are driven by the major wind belts of the world

What are water's important physical properties

melting point, boiling point, density

What are the 2 main chemical components of the atmosphere?

nitrogen and oxygen

Why are some mid-ocean ridges rises, while some are ridges?

oceanic ridges have a steep rugged slope and spread slowly oceanic rises have gentle less rugged slopes and spread faster

Biogenous

origin: algae, protozoans, coral reefs example: shells

Hydrogenous

origin: precipitation of dissolved materials from seawater example: metal sulfides

Lithogenous

origin: rivers, erosion, glaciers example: clay

Cosmogenous

origin: space dust, meteors example: iron-nickel

What essential element for animals is thought to be lacking in the Earth's early atmosphere?

oxygen

How does salinity vary at the surface and with depth? Why is this different with latitude?

salinity is different at the surface due to high latitudes, precipitation, runoff, temperature Salinity varies widely on the surface but barley at all in the deep ocean

What is salinity? What is the average salinity of the ocean?

salinity is the total amount of solid material dissolved in water. 3.5% salinity in salt water

What factors affect the density of seawater?

temperature and salinity

What is ocean sustainability? What affects sustainability?

the process in keeping our oceans alive - pollution, overfishing, climate change affect sustainability

what is the Nature of Science Inquiry?

the process that scientists observe and publish a hypotheses that might later be replaced

How does salt in sea water affect the freezing point similar to putting salt on a sidewalk?

the salt makes the freezing point lower (28.4)

What makes water polar?

the slight separation of charges makes the water molecule polar

What causes Earth to have seasons?

the tilt of the Earth's axis

Where do you find brackish water?

where freshwater and seawater mix

How is sediment transported from land to ocean?

wind, ice, gravity, water