question

What are the principal oceans of Earth? How to they compare in size, location, and depth?

answer

1.Pacific Ocean - largest, deepest 2.Atlantic Ocean - about half size of Pacific 3.Indian Ocean - slightly smaller than Atlantic; mostly in Southern Hemisphere 4.Arctic Ocean - about 7% size of Pacific; shallower than other oceans 5.Southern Ocean (Antarctic Ocean) - portions of Pacific, Atlantic, and Indian Oceans south of 50 degrees South latitude

question

What percentage of Earth is covered by oceans?

answer

71%

question

How does a sea differ from an ocean?

answer

smaller and shallower than ocean; composed of salt water; usually enclosed by land; directly connected to World Ocean (Mediterranean Sea)

question

Name and locate the deepest ocean trench and describe its exploration by humans.

answer

Mariana Trench (Pacific Ocean) - deepest part of ocean (36,161 ft. below sea level) Visited by humans in 1960 in a deep-diving bathysphere. No mountain on Earth is taller than Mariana Trench is deep

question

Who were some of the early explorers and what were some of their contributions?

answer

Mostly searching for new food sources -Pacific Navigators - Polynesians - great distances were challenging -Early European Navigators - Phoenicians (first western hemisphere), Greeks (followed the north star), Romans -Middle Ages - Arabs (dominant navigators in the Middle East), Vikings (established temporary settlements in North America), Chinese (Ming Dynasty)

question

Who made one of the first scientific ocean explorations? What were some of his contributions?

answer

Captain James Cook - 3 scientific voyages between 1768 and 1779; created longitude, mapped previously unknown islands including Hawaiian Islands, died in Kona, Hawaii

question

List and describe the systematic steps of the scientific method.

answer

1.Observation - Collection of facts 2.Hypothesis - preliminary explanation for observations or data (educated guess) Must be subject to testing and falsification, must be tested repeatedly and systematically 3.Testing - Development of observations 4.Theory - well tested, widely accepted explanation of some aspect of natural world that can incorporate facts, laws, logical inferences 5.Law - descriptive generalizations about behavior in natural world

question

Distinguish between a hypothesis and a theory. Give some examples of each.

answer

hypothesis becomes a theory only after extensive testing. Examples: Big Bang, Plate Tectonics, Evolution

question

What is the difference between a scientific laws and theories?

answer

Laws describe while theories explain

question

Compare and contrast the protoearth and the modern Earth.

answer

Protoearth - more massive and larger than present Earth; molten; homogeneous

question

Describe the process by which the protoearth formed a layered, internal structure. What is the basis for this layering?

answer

Density Stratification - protoearth formed a layered internal structure based on density (bombarded by meteorites)

question

Distinguish between continental and oceanic crust. What is the composition of each?

answer

Oceanic crust - basalt (dense); Continental crust - granite (thicker, less dense)

question

Describe the process that led to the formation of Earth's early atmosphere. How was Earth's early atmosphere different from the present atmosphere?

answer

Outgassing - process by which gases are expelled from Earth's interior. Primordial atmosphere = Low density gases mostly water vapor (H2O) and CO2 with small amounts of H, CH4, NH3 and others

question

What process led to the formation of Earth's current oxygen-rich atmosphere?

answer

Photosynthesis

question

Describe the formation of Earth's oceans and discuss the origin of salts in ocean water.

answer

Water vapor from outgassing condensed and fell to Earth forming oceans about 4 billion years ago. Ocean Salinity - abundant acidic rainfall on surface dissolved compounds that when carried to ocean made it salty

question

Discuss the implications of Stanley Miller's 1952 experiment. What did he demonstrate?

answer

Demonstrated that UV radiation from sun (with an electric spark to simulate lightning) and H, CO2, CH4, NH3 and inorganic molecules from oceans may have combined to produce organic molecules such as amino acids (prebiotic soup)

question

What is the age of the Earth and how was it determined?

answer

Radiometric dating of rocks determine Earth's age to be 4.6 billion years old

question

Describe Alfred Wegener's hypothesis of Continental Drift.

answer

Super continent called Pangaea began breaking apart about 200 mya. Continents drifted to their present positions and broke through oceanic crust.

question

List the evidence Wegener used to formulate his hypothesis.

answer

Evidence included puzzle-like fit of continents, matching fossils, matching rock sequences, matching mountain chains, climate evidence

question

State the modern theory of Plate Tectonics.

answer

Lithosphere is divided into 3 plates. Divergent, Convergent, transform. Volcanism and earthquakes are the result of the plates.

question

Describe the evidence on continents and the sea floor that supports the modern theory of Plate Tectonics. What is the most persuasive evidence?

answer

Paleomagnetism - most persuasive evidence. Apparent polar wandering (continental rocks). Magnetic anomalies on ocean floor (sea floor spreading)

question

What is sea floor spreading and why is it an important piece of evidence supporting plate tectonics?

answer

formation of magma that rises to Earth's surface and solidifies at a mid-ocean ridge.

question

How did the work of Vine and Matthews confirm sea floor spreading?

answer

They examined a magnetic pattern on the sea floor which determined a new crust created at mid-ocean ridges

question

Why does a map of worldwide earthquakes closely match the locations of worldwide plate boundaries?

answer

Most earthquakes occur along the edge of the oceanic and continental plates. **Earthquakes usually occur where 2 plates are running into each other or sliding past each other.**

question

List the features found in the following type of plate boundary and give a geographic example: Divergent

answer

Sea floor spreading forms ridge crest fractures, which fill with molten material. *On continents rift or rift valleys form (e. g. East African rift- Red Sea)(spreading) continental rifting, splits landmasses into 2 or more smaller parts. mid ocean ridge, new ocean floor, shallow focus on earthquakes.

question

List the features found in the following type of plate boundary and give a geographic example: Convergent Oceanic - Continental

answer

ocean plate is subducted, continental volcanic arcs generated, explosive andesitic volcanic eruptions. Example: Cascade Randge, Andes Mountains.

question

List the features found in the following type of plate boundary and give a geographic example: Convergent Oceanic - Oceanic

answer

Forms volcanoes on ocean floor that merge as volcanic island arc (convergence), Denser plate is sub ducted, Deep trenches generated, Volcanic island arc generated -Ex. Aleutian Islands, Japan Arc

question

List the features found in the following type of plate boundary and give a geographic example: Convergent Continental - Continental

answer

Often produces mountains (no subduction), Tall mountains uplifted Example: Himalayas, (India-Asia collision), Other possibilities Alps, Appalachians, Urals

question

List the features found in the following types of plate boundaries and give a geographic example of each: Transform

answer

Oceanic transform fault- ocean floor only, Continental transform fault - cuts across, Transform faults occur between mid - ocean ridge segments * Plates slide past one another a.) No new crust created b.) No crust destroyed, *Most in oceanic crust, *Join two segments of mid ocean ridge, *Parallel motions of plates; same direction plates are spreading. Example: San Andreas Fault

question

What are the differences between oceanic ridges and oceanic rises? Why do these differences occur? Give an example of each.

answer

Oceanic Rise - Fast spreading, Gentle slopes, East pacific. Oceanic Ridges - Slow spreading, Steep slopes, Mid Atlantic

question

Distinguish between mantle plumes, and hot spots.

answer

Rising plume of mantle material forms hot spots.

question

Describe how the occurrence and distribution of mantle plumes and hot spots supports the theory of Plate Tectonics.

answer

Rising plume of mantle material forms hot spot

question

Explain the stages of coral reef development form fringing to barrier reef to atoll?

answer

Fringing reefs - develop along margin of landmass. Barrier reefs - separated from landmass by lagoon. Atolls - Atolls are a round reef with nothing in the middle and form on flanks of sinking volcanic islands.

question

Who was the first scientist to explain atoll formation?

answer

Charles Darwin

question

Anaerobic

answer

A bacteria that lives without oxygen.

question

Heterotroph

answer

An organism that cannot make its own food.

question

Mantle

answer

Thickest layer, made up of hot rock. has plasticity

question

Nebular Hypothesis

answer

All bodies of the solar system are formed from the nebula (mainly hydrogen & helium)

question

Photosynthesis

answer

A process by which plants use the sun's energy to make food.

question

Scientific Method

answer

A series of steps followed to solve problems including collecting data, formulating a hypothesis, testing the hypothesis, and stating conclusions.

question

Theory

answer

A hypothesis that has been tested with a significant amount of data

question

Hypothesis

answer

(educated guess) A preliminary explanation for observations or data

question

Autotroph

answer

An organism that makes its own food

question

Evolution

answer

A change in a species over time

question

Continental Crust

answer

Granite - Intrusive, igneous rock. Less dense, light colored. A solid, thicker layer.

question

Oceanic Crust

answer

Basalt. Earths crust located under the ocean that is usually thinner.

question

Isostatic

answer

Vertical movement of sections of Earth's crust to achieve balance. rises or sinks due to loading or unloading

question

Density Stratification

answer

The process by which matter became layered by density during Earth's formation.

question

Earths Core

answer

The extremely hot and dense center of the earth, which is believed to be composed of iron and nickel

question

Crust

answer

Earth's outermost layer. Basaltic/Granitic Rock

question

Protoearth

answer

The protoplanet Earth- was much larger than today's earth and didn't contain life or water. Was homogenous and was bombarded by meteorites. One theory states that the Moon was born after Protoearth collided with a planet.

question

Granite

answer

A usually light colored igneous rock that is found in continental crust

question

Density

answer

Mass per unit volume

question

Basalt

answer

A dark, dense, igneous rock with a fine texture, found in oceanic crust

question

Outgassing

answer

the process by which water vapor and other gases and compounds are brought to Earth's surface by volcanism and released into the atmosphere

question

Lithosphere

answer

A weak, cool, rigid layer made up of the uppermost part of the mantle and the crust. Thinner in oceans and thicker on continents.

question

Asthenosphere

answer

The solid, plastic layer of the mantle beneath the lithosphere; made of mantle rock that flows very slowly, which allows tectonic plates to move on top of it

question

Define bathymetry

answer

The measurement of depth of water in oceans, seas, or lakes.

question

Name the techniques used by early ocean navigators to estimate ocean depth.

answer

Echo Soundings & Precision depth recorder

question

Name some modern techniques used to map the ocean floor.

answer

Multi beam sounders, side scanning sonar, Satellite Mapping,

question

Describe the differences between Passive and Active continental margins. List and describe the features associated with each type. Explain how these features relate to plate tectonics.

answer

Passive: not close to plate boundary; lack major tectonic activity; wide continental shelf, continental slope, continental rise. Active Margins - associated with plate boundaries; high degree of tectonic activity

question

Differentiate between continental shelf and continental slope. Which has the steeper gradient?

answer

Continental shelf - flat zone (gentle slope) from shoreline to shelf break (deep ocean basin); Continental slope- steep gradient; beyond the shelf break where deep ocean basins begin

question

What are turbidity currents and what type of deposits do they generate?

answer

move under the force of gravity, graded bedding. underwater avalanches; sediment from continental shelf

question

Explain what graded bedding is and how it forms.

answer

material that settles out and larger particles on the bottom smaller ones stay on top

question

How are submarine canyons created?

answer

formed by turbidity currents which carve out the submarine canyons in the continental shelf.

question

What are some differences between a submarine canyon and an ocean trench?

answer

submarine canyons - deep, narrow, v-shaped; carved by turbidity currents. Ocean Trenches: convergent boundaries; deepest part of oceans; most in Pacific; example Mariana Trench

question

What are abyssal plains and describe the process by which they are formed.

answer

is the end result of spreading of the seafloor basaltic material reaches the surface at mid-ocean ridges it forms new oceanic crust.

question

What is the origin of the various volcanic peaks of the seamounts?

answer

below sea level

question

What is the origin of the various volcanic peaks of the table mounts?

answer

below sea level

question

What is the origin of the various volcanic peaks of the abyssal hills?

answer

above sea level

question

What is the origin the various volcanic peaks of the sea knolls ?

answer

above sea level

question

Where are the majority of the world's earthquakes and active volcanoes located?

answer

Pacific Ring of Fire

question

Describe characteristics and features of the mid-ocean ridge.

answer

Earth's longest mountain chain; entirely volcanic; basaltic lava; divergent plate boundary

question

List and describe the different type of hydrothermal vents. What is the water temperature associated with each type?

answer

Warm Water Vents: lowest temperature; clear water (86 degrees). White Smokers: Intermediate temp. White water (light compounds) (86-662 degrees). Black Smokers: highest temp. Black water; metal sulfides (Fe, Ni, Cu, Zn) 662 degrees

question

Name the three basic types of oceanic islands. Describe the origin and name an example of each type.

answer

hot spots - form at one time, hawaiian islands. volcanic activity - Ascension island among the mid-atlantic ridge (iceland). Island arcs - Convergent plate boundaries - aleutian islands, Japan forms at the same time because of subduction and bc they move away from the hot spot.

question

Abyssal clay

answer

fine-grained sediment

question

Radiolarian

answer

protozoans; hard shells made of silica (glass)

question

Quartz

answer

A very hard mineral composed of silica

question

precipitate

answer

A solid that forms and settles out of a liquid mixture

question

phosphorite

answer

phosphates, fertilizers

question

phosphate

answer

useful as a fertilizer

question

petroleum

answer

mainly from continental shelves

question

pelagic deposit

answer

Sediments cover about 3/4 of the sea floor. Lithogenous sediment- found in deep ocean basins and are fine grained

question

paleoceanography

answer

study of how ocean, atmosphere, and land interactions have produced changes in ocean chemistry, circulation, biology, and climate

question

ooze

answer

accumulates when rate of deposition exceeds rate of dissolution (to leak out slowly)

question

neritic deposit

answer

lithogenous sediment, may contain biogenous sediment, on continental shelves and shallow water near islands.

question

nannoplankton

answer

(coccolithospore) Photosynthetic algae, individual plates from dead organisms

question

microscopic biogenous sediment

answer

Must use a microscope to see. Organisms create tiny shells called tests, which sink to the bottom of the ocean and form biogenous sediment. mainly algae and protozoans.

question

manganese nodule

answer

under a microscope. found in deep sea floor (abyssal plains), hydrogenous sediment, Fist-sized lumps of manganese, iron, and other metals

question

macroscopic biogenous sediment

answer

large enough to be seen without a microscope, shells, bones, teeth

question

lysocline

answer

The depth in the ocean in which the pressure is high enough and the amount of carbon dioxide in deep ocean water great enough to begin dissolving calcium carbonate.

question

lithogenous sediment

answer

(terrigenous) eroded material carried by wind, glaciers, and gravity, on continents.

question

limestone

answer

hydrogenous sediment, CaCO3

question

gas hydrate

answer

a gas; such as methane, trapped in a lattice-like structure of water molecules

question

foraminifera

answer

(Microscopic zooplankton) One of a group of tiny single-celled organisms that live in surface waters and whose secretions and calcite shells account for most of the ocean's carbonate sediments.

question

evaporite mineral

answer

A hydrogenous sediment Minerals form when seawater evaporates in restricted ocean. Halite (common table salt) and Gypsum, high evaporation rates.

question

diatomaceous earth

answer

a light soil consisting of siliceous diatom remains and often used as a filtering material

question

diatom

answer

class of algae with silica tests which contain a single cell

question

cosmogenous sediment

answer

derived from outer space (meteorite, space dust)

question

coccolithospore

answer

photosynthetic, microscopic, made up limestone (calcite), live mainly on the surface

question

chalk

answer

A type of limestone; a powdery, fine-grained rock composed of almost pure calcite.

question

carbonate

answer

CO3

question

calcium carbonate

answer

CaCO3

question

calcite compensation depth (CCD)

answer

depth where CaCO3 produced can dissolve. rate at which the shells dissolve

question

calcareous ooze

answer

50% of shallow oceans with warm surface water, mostly the hard remains of cocci, forminfera containing calcium carbonate

question

biogenous sediment

answer

Sediment that is made up of the skeletons and shells of marine organisms.

question

algae

answer

photosynthetic, biogenous sediment

question

Fathom

answer

standard unit of the ocean depth

question

Echo Soundings

answer

or fathomer, reflection of sound signal; lacks detail, may provide inaccurate view of sea floor

question

Precision Depth Recorder (PDR)

answer

1950's good resolution; reliable sea floor maps; confirmed sea floor spreading, focused on high frequency sound beam

question

Multibeam echo sounders and side scan sonar

answer

precise pictures of ocean floor; computer generated sea floor maps

question

Satellite mapping

answer

detect irregularities in height of ocean surface caused by gravitational attraction of sea floor features, indirectly reveal bathymetry

question

Seismic reflection profiles

answer

air guns, strong, low frequency sounds, details ocean structure beneath the sea floor, structure of rock layers beneath sea floor; used in oil, gas, and mineral exploration

question

Hypsographic curve

answer

relationship between height of land and ocean depth

question

HMS Challenger

answer

(1872) - first systemic measurements

question

What is the difference between oceanic ridges and oceanic rises?

answer

ridges=steep, slow with rugged slope. rises= gently sloped, rapid, less rugged

question

Describe features of the mid-ocean ridge.

answer

caused by the divergent movement of plate tectonics and it is characterized by spreading sea-floor,shallow earthquakes and rising magma. (Mid-Atlantic ridge.)

question

Hydrothermal vent

answer

unusual ecosystems; sea floor hot springs, foster unusual deep-ocean ecosystems able to survive without sunlight.

question

What is one example of a passive margin?

answer

East coast of the US. Florida

question

What are 2 examples of an active margin?

answer

Western South america (nazca plate) and cascades

question

Name two types of active margins.

answer

Convergent and transform margin

question

Describe the features of a convergent active margin

answer

continental volcanic arc, narrow shelf, steep slope, offshore trench, oceanic trench

question

Transform active margin

answer

associated with transform plate boundaries. Linear islands, banks, and deep basins close to shore (less common)

question

What is an example of a transform active margin

answer

coastal California along the san andreas fault

question

Continental borderland

answer

islands, shallow banks, deep basins, transform active margins (san andreas fault)

question

Example of a volcanic arc

answer

japan, aluetian islands

question

example of a ocean trench

answer

mariana trench

question

example of continental arcs

answer

cascades, andes mountains

question

Oceanic crust is dense and composed of rock _____ while continental crust is less dense and composed of rock _____.

answer

basalt, granite

question

Plate tectonics is an example of a scientific ____ which is well tested, widely accepted.

answer

theory

question

Lithosphere is sub ducted into the mantle at ______ plate boundaries.

answer

convergent

question

__________ is the most persuasive evidence for plate tectonics.

answer

paleomagnetism

question

The cool, rigid, solid outer portion of earth consists of the crust and upper mantle is known as the _________ which rides on a weak, plastic layer in the upper mantle known as the ________.

answer

Lithosphere, asthenosphere

question

Iceland is located over the mid atlantic ridge which is a _____ plate boundary.

answer

divergent

question

Many lines of evidence supported the hypothesis of ________________ but the inability to provide plausible mechanism caused most 20th century geologists to reject the idea.

answer

Continental drift

question

The san Andreas fault in california is a _________.

answer

continental transform fault

question

The ________ depicts stages of ocean basin evolution

answer

wilson cycle

question

Mid ocean ridge

answer

divergent plate boundaries, volcanic magma rises creating new crust

question

hot spot

answer

magma rises, intense volcanoes, associated with plate boundaries

question

What is the difference in spreading rates of mid ocean ridges and a mid ocean rise?

answer

mid ocean rise is at a fast pace and is flat. mid ocean ridge is a slow, rigid, solid and tall.

question

List the origin and characteristics of the four types of marine sediment.

answer

Lithogenous, biogenous, hydrogenous, cosmogenous

question

How does lithogenous sediment originate? Where is most of it found?

answer

eroded material from continents carried to the oceans by streams, glaciers, wind and gravity. found around continental margins

question

What is mineral that makes up most lithogenous sediment?

answer

Quartz (SiO2)

question

Differentiate between sediment types found in neritic and pelagic deposits?

answer

Neritic is near shore, close to land, shallow water, deposited quickly. Pelagic is farther shore, deeper water and is finer sediment, deposited slowly

question

How does biogenous sediment originate?

answer

from remains of hard parts of once living organisms

question

Explain the difference between macroscopic and microscopic biogenous sediment and give and example of each.

answer

macro- large enough to see without microscope, shells, bones, teeth. micro- tiny shells called tests accumulate to form ooze

question

Define ooze.

answer

algae and protozoans

question

What is the most common type of pelagic deposit?

answer

abyssal clay (red from iron)

question

What type of organism is a diatom?

answer

photosynthetic algae (plankton)

question

If siliceous ooze is constantly dissolving in sea water, how can deposits of it accumulate on the sea floor?

answer

Ooze accumulates when rate of deposition exceeds rate of dissolution

question

Discuss the distribution of biogenous sediments in neritic and pelagic environments including carbonate deposits such as limestone and stromatolites, siliceous ooze, and calcareous ooze.

answer

limestone contains fossil shells, stromatolites are fine layers of carbonate in warm, shallow high salinity oceans.

question

Outline the relationship between the calcite compensation dept (CCD) and the formation of calcareous oozes.

answer

they both dissolve with warm ocean water

question

Manganese Nodules

answer

very slow rates, not sure why hey are not buried on seafloor, fist sized lumps of manganese, iron and other metals

question

Define cosmogeneous sediment and discuss the origin cosmogenous sediment.

answer

Macroscopic meteor debris

question

what controls this distribution of pelagic and neurotic sediments?

answer

depth of water and sea floor features

question

List some commercially important resources provided by ocean sediments.

answer

petroleum, gas hydrates, sand and gravel, evaporite salts, etc.

question

Distinguish between calcareous and siliceous oozes.

answer

Calcareous=CaCoO3 Silicous=SiO2

question

Lithogenous

answer

derived from land, produced by weathering: breaking of rocks into smaller pieces

question

biogenous

answer

derived from organisms

question

hydrogenous

answer

derived from water

question

cosmogenous

answer

derived from outer space

question

Neritic: What are the different mechanisms that transported the sediment and the energy conditions under which they were deposited?

answer

Beach deposits- wave deposited (quartz). Continental shelf- relict sediments. Turbidite- Graded bedding. Glacial- high latitude, ice rafting.

question

Pelagic

answer

slowly on deep ocean floor, volcanic ash, wind-blown dust

question

What is the composition of diatoms?

answer

silica

question

Neritic covers about _____ of he sea floor.

answer

1/4

question

Pelagic sediments cover about _____ of the sea floor.

answer

3/4

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