Oceans Chapters 1-6

What is the primary force that causes Earth to have a greater equatorial radius than the polar radius?

The force of rotation causes Earth to have a greater equatorial radius than the polar radius.

The hydrologic cycle involves ______.

a constant movement of water into and out of reservoirs

The youngest sea floor can be found ______.

at spreading centers

The rate at which each oceanic plate (sea floor) moves away from the ridge is known as the ______.

half spreading rate

Select the correct order of layers from the middle of Earth outward as modeled by the strengths and physical properties of their materials.

inner core, outer core, mesosphere, asthenosphere, and lithosphere

The thickness, composition, distribution, and source of ______ provide oceanographers with valuable information on how Earth functions over long time scales.

ocean sediments

Rank the five parts of the world's oceans from largest at the top to smallest at the bottom.

- Pacific - Atlantic - Indian - Southern - Arctic

Select the two ideas below that plate tectonics incorporates and builds upon.

- continental drift - seafloor spreading

The characteristics listed below apply either to active or passive margins. Select all the characteristics of active margins.

- ocean trenches possible - modified by tectonic movement and volcanoes - represents a plate boundary

The most probable (original) sources of the water in Earth's ocean are ______. (Mark all that apply.)

- the Earth's mantle, some of which is brought to the surface through volcanic activity- continual addition of water from outer space

Rank Earth's layers by their average densities. Place the least dense on top.

-Crust -Mantle -Core

boundaries in marine settings create new sea floor at the centers.

-divergent -spreading

The mid-ocean and systems are the most notable features of the ocean floor.

-ridge -rise

Identify the ways in which ocean sediments can be used as direct evidence in solving different type of issues. (Select all that apply.)

-to find offshore mineral resources -to map offshore pollution patterns -to identify sites for underwater construction projects

The Earth can be modeled with 5 layers based on the strengths and physical properties of the materials in them. Put the layers in order with the outermost surface of the Earth on top. The two layers of the core have been lumped together here.

1. Lithosphere 2. Asthenosphere 3. Mesosphere 4. Core

Transform boundaries occur where two tectonic plates past each other. This motion does not always occur freely, and thus faults are formed.

1. move 2. transform

Approximately ______ years ago, the Big Bang initiated the formation of the universe.

13.8 billion

Which of the following is the scientifically accepted age of Earth?

4.5 to 4.6 billion years

The abyssal plain, or flat portion, of the sea floor is littered with hills and mountains, many of which are volcanic in origin. Which of the following are the names of some of these features? (Select all that apply.)

Abyssal hills Guyots Seamounts

The Ocean is the smallest.

Arctic

Put the following sediments in the correct order according to size, with the largest particle type on the top and the smallest on the bottom.

Boulder Pebble Sand Silt Clay

Tectonic plates move toward each other at boundaries. (Use only one word in the blank.)

Convergent

True or false: The position of the north and south magnetic poles is constant over human time scales.

False

______ result in volcanic activity that may operate independently of plate boundaries. These volcanoes can form anywhere on a tectonic plate.

Hotspots

Most of the world's landmasses are located in the ______ Hemisphere.

Northern

What features of the ocean floor are over 40,000 miles (65,000 kilometers) long and are found running through every ocean?

Ridge and rise systems

Which of the following of Earth's radii is greater?

The equatorial radius is greater than the polar radius.

Continental shelf

The submerged flat borders of the continent that slope very gently away from the shoreline

If Earth's axis were not tilted, what would happen to the seasons?

There would be no perceived seasons on Earth and global day lengths and temperatures would uniform.

During the winter solstice for the Northern Hemisphere, the Sun is directly overhead at which of the following locations?

Tropic of Capricorn

Which of the following describe weathering of the sea floor? (Choose all that apply.)

Weathering is more rapid along coastlines. Weathering occurs more slowly than on land.

Continental margin

Where land meets the ocean

Active margin

Where the continent-land transition is a plate boundary

Passive margin

Where the continent-land transition is not a plate boundary

The repeated opening and closing of ocean basins and the associated formation and breakup of supercontinents is known as the cycle.

Wilson

Residence time is the average length of time that ____.

a water molecule spends in any one reservoir

Approximately 13.8 years ago, the Big Bang initiated the formation of the universe.

billion

The most widely accepted age of Earth is between 4.5 and 4.6 years.

billion

Physical weathering of the ocean floor occurs primarily ______, whereas dissolution of minerals dominates chemical weathering.

by waves and currents

The deep-sea floor receives a ______ supply of sediment.

constant but slow

A ______ cell is the pattern mantle material takes as it rises when heated, then moves laterally as it cools, and sinks once its density is great enough.

convection

The two natural periods of time caused by the movement of Earth are the and the .

day; year

At convergent plate boundaries, the tectonic plates are moving toward each other. What happens at these boundaries depends heavily on the ______ of each plate.

density

New oceanic crust is created at some ______ boundaries, as the plates move in opposite directions.

divergent

Seismic waves travel though Earth. The waves form when ______.

earthquakes occur

Geologic time is divided into four major : the Hadean, Archean, Proterozoic, and Phanerozoic.

eons

The two major models for a mechanism to drive plate tectonics are the ridge-push, slab-pull and the convection models. The convection model relies on ______ between the top of the convecting cell and the base of the lithospheric plate, and the push/pull model relies on the ridge ______ and pushing the plate outward as the ridge falls in elevation.

friction; cooling

A(n) is composed of clumps of stars, and one example is the Milky Way.

galaxy

The Milky Way is a(n) composed of about 200 billion stars.

galaxy

The Milky Way is our ______.

galaxy

The four eons: the Hadean, the Archean, the Proterozoic, and the Phanerozoic, collectively make up what scientists refer to as ______ time.

geologic

The image depicts the cycle.

hydrologic

The point within Earth where an earthquake occurs is called the , and the point on Earth's surface directly above this location is called the .

hypocenter; epicenter

If a(n) _______ is supported consistently, it may be advanced to the level of a theory.

hypothesis

Earthquakes that occur deeper than 100 km are generally found ______.

in subduction zones

A major difference between the ridge-push, slab-pull model and the convection model is the ridge-push, slab-pull model ______.

includes the decrease in elevation from the ridge to the rest of the plate as a factor

The age of the sea floor ______ away from the ocean spreading centers.

increases

The balance of forces between internal pressures under continents and those under ocean basins is called ______.

isostasy

The principle of describes the balance of forces between internal pressures in the lithosphere and mantle. It allows for the less dense continental material to float on the denser mantle.

isostasy

GPS (Global Positioning System) navigation is widely used because ______.

it is worldwide now and extremely accurate

To determine , you would need to know the angle your location (line) makes with the equatorial plane at Earth's center.

latitude

The three states of water, , , and . are possible on Earth's surface because Earth's mean surface temperature is about 61°F.

liquid, gas, solid

Because the lines rotate with Earth, 360 degrees in twenty-four hours, it is necessary to know the time of day and the position of the Sun or the stars relative to one's line.

longitude

Which of the following time periods is based upon the lunar cycle?

month

A rotating interstellar cloud of gas and dust is referred to as a ______.

nebula

The origin of our solar system is attributed to the collapse of a single, rotating interstellar cloud of gas and dust known as a(n) .

nebula

The magnetic field of Earth is ______.

not constant.The locations of the north and south magnetic poles change over time as does their strength

The difference between an earthquake's epicenter and hypocenter (focus) is an epicenter is the point ______.

on Earth's surface directly above an earthquake, and the hypocenter is the point within Earth where the earthquake occurs

The difference between the full and half spreading rates is the half spreading rate is the rate at which ______.

one plate moves away from the ridge, whereas the full spreading rate is the rate at which two plates move away from each other

The evolution of photosynthetic organisms on the early Earth resulted in an increase in the levels of the gas in its free or "pure" form.

oxygen

The most important gaseous element to accumulate in Earth's atmosphere, which had to await the evolution of photosynthesis in order to exceed its loss to space, is ______.

oxygen

Lines of latitude, also known as , are referenced to the equator.

parallels

The relatively calm trailing edge of continents are called ______ margins, while the leading edge of continents are called ______ margins.

passive; active

A convection cell in the mantle is the ______.

pattern of movement mantle material takes as it heats and cools

The theory of incorporates the ideas of both seafloor spreading and continental drift into a unified model.

plate tectonics

The length of time that a given water molecule spends in any one of Earth's water reservoirs is called its .

residence time

Hotspot volcanoes are likely the result of ______.

rising magma from the mantle

Old maps are accurate in their north and south depictions of Earth's surface, but many are badly distorted by their east and west dimensions of geographic forms. This is because ____.

sailors have been able to calculate latitude since ancient times

Earth's tilt of 23.5 degrees as it orbits the Sun is responsible for the , which occur in both the Northern and Southern Hemispheres at opposite times of the solar year. (Hint: The answer is just one word.)

seasons

Select the statement that best describes the distribution of earthquake depths.

shallow earthquakes are common around spreading centers and under continental crust, and deep earthquakes generally occur in subduction zones.

Marine sediments are classified according to grain , geographic location, and origin and composition.

size

The Sun is directly over the two tropics, Cancer and Capricorn, at two times during the solar year. These two dates are called ______.

solstices

Measurements of ocean depth have occurred using various techniques for over 2000 years. These measurements are called .

soundings

A galaxy is composed of clumps of ______.

stars

The major changes in the state of the universe that occurred immediately after the Big Bang were in ______ and ______.

temperature; size

The thickest deposits of ocean sediment are generally found near ______.

the continental margins

A sounding is a measurement of ______.

the depth of the ocean

It is necessary to know the time of day and the position of the Sun or the stars relative to one's longitude line because ____.

the longitude line rotates with Earth, 360 degrees in twenty-four hours

If a hypothesis is supported consistently by different observations or experiments, it may be advanced to the level of a(n) .

theory

Convergent plate boundaries are where tectonic plates move one another; plate boundaries are where the plates slide past each other; divergent plate boundaries are where plates move away from each other. (Use only one word per blank.)

toward; Transform

Divergent boundaries are broken into sections and connected by boundaries; these are the areas where the new crusts slide past one another.

transform

The Big Bang is the currently accepted theory about the origin of the ______.

universe

Because Earth's mean surface temperature is about 61°F, naturally exists in all three states.

water

The Southern Hemisphere is sometimes called the hemisphere because it contains so much more than the Northern Hemisphere.

water

Two potential sources of the on Earth include the mantle and continual addition from outer space by icy comets.

water

The energy that is released when an earthquake occurs travels though Earth in the form of vibrations known as seismic .

waves

Latitude can be calculated by measuring ___.

your angle in reference to the bright star, Polaris

The hypsographic curve indicates that only ______ percent of Earth's surface is above sea level.

29

The hypsographic curve compares which of the following?

Land and water elevation relationships