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43 terms

Science 3.1

STUDY
PLAY
geology
The study of the earth and its structure is called this?
Geologists
Scientists who study the structure of the earth are called?
crust, mantle, core
Geologists divide the interior of the earth into 3 major sections...What are they?
crust
The outermost layer of the earth is called the?
Sediments
The rocks of the crust are covered by a thin layer of soil and a thick layer of sand and mineral fragments called this?
by water
Most sediments are laid down by what?
eroded
In some places, this sedimentary covering has been worn away, or_________, so that the actual rock of the earth's crust can be seen.
increases
The temperature of the rocks ___________ with depth.
the warmer it gets
Finish this statement: The deeper you go...
120 degrees Fahrenheit.
2 1/2 miles beneath the earth's surface, the temperature of the rocks is over?
900 degrees Fahrenheit
AT the bottom of the earth's crust 20-25 miles beneath our feet, the rocks are hotter than what?
mantle
Beneath the earth's crust lies the ________, the middle layer of the earth.
Largest
The mantle is about 1800 miles thick and makes up the _____________ portion of the earth's interior.
Moho
The boundary between the crust and the mantle is called the ___________?
Mohorovicic discontinuity
Moho is named after the Croatian geologist who discovered it. What does Moho stand for?
hotter and hotter
If you could descend through the earth's mantle, you would find that the temperature continued to grow ___________ and ____________as you traveled deeper.
900-4000 degrees Fahrenheit
The temperature of the mantle rocks rises from about _________ at the top of the mantle to nearly ________at the bottom. This is hot enough to melt steel.
rock
Like the crust, the mantle is made of solid ______?
core
Beneath the mantle lies the____________, the innermost region of the earth.
4000
The core extends from the bottom of the mantle all the way to the center of the earth, ___________ miles beneath our feet.
iron and nickel
The core is composed of dense metals like __________ and ________________?
outer core
The white-hot __________ __________ consists of molten iron and nickel.
electrical currents
Circulating ___________ _____________ in the liquid metal of the outer core generate the earth's magnetic field.
inner core
The __________ __________ is a mass of even hotter metal, but it remains solid instead of a liquid because of the much greater pressure upon it.
Soil
__________ is essential for all plant life?
weathering
New soil is formed by ___________, a process that causes rocks to gradually break or crumble into smaller pieces.
chemical or physical
Geologists classify weathering as either what two things?
Chemical weathering
___________ ___________ occurs when natural acids slowly eat into a rock and break it apart.
oxygen and carbon dioxide
Natural acids are produced when rainwater mixes with ________ and ____________ __________ gases in the air.
Acids
__________ are also produced by mosses and lichens clinging to a rock.
Physical weathering
______________ ____________ takes place when rock is broken down by water, ice, or windblown sand.
plates
Most geologists believe that the earth's crust does not consist of one huge, unbroken shell of rock, but of several individual __________ that "float" like rafts on the soft rock of the upper mantle.
eight inches
Careful measurements show that some of the earth's plates are drifting as much as __________ ___________ per year.
seven
In all, _________ large plates and several smaller plates are thought to exist.
North American plate
Most of the United States is located on the ___________ _____________ _________, except for the southwestern California.
Pacific Plate
Southwestern California is on the ____________ ____________?
mountains
When two plates collide head-on, they may fold or buckle, producing __________.
plate boundaries.
Most of the world's large mountain ranges are located at or near?
Indo-Australian and Eurasian
The Himalayas, the highest mountains on Earth, lie on the boundary between the _________________ plate and the ___________ plate.
mid-oceanic ridges
The earth's oceans contain underwater mountain ranges called _____________ ____________ where plates of the earth's crust are moving away from each other.
rift
As these plates move apart, they create a gap, or _____, between them that is quickly filled by molten rock rising from below, forming a ridge.
trench
When one plate goes under another plate. When this happens, a deep __________, like a muddy valley, is formed in the ocean floor.
deepest
These trenches are the ________ places in the ocean.