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69 Cards in this Set

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  • Back

How is the earths crust like a ship?

The crust floats on the mantle like a ship floats on water. The crusts vertical position, as well as the ships is determined by density

Why was the early bombardment of space debris important to differentiation?

The kinetic energy of space debris colliding with earth was transformed into heat energy. The heat melted the earths rock so it was molten and could flow. If the rock was solid it couldn't have settled into such distinct layers.

What is the order of the spheres?

Lithosphere, asthenosphere, lower mantle, outer core, inner core.

What part of the earth do S-waves not pass through?

S-waves can't pass through liquid so they can't pass through the liquid outer core.

What is the Moho how was it discovered?

The boundary between the earths mantle and crust detected my mohorovicic, who observed an increase of speed across it.

What evidence would lead someone with no scientific knowledge to suspect that the continents were once connected?

The matching lines of south america and africa on a globe

How is the seafloor recycled?

New lithosphere is created where magma wells up at a spreading center, and it is destroyed when it sinks back into the mantle at a subduction zone.

how does the theory of plate tectonics differ from the theory of continental drift?

plate tectonics states that plates not just the continents move. Also because the theory includes seafloor spreading, it provides a way for continents to move, a mechanism.

Why does the asthenosphere flow?

convection is the reason the asthenosphere flows. It is at the top of a convection cell that carried heat away from earths surface.

What role does gravity play in plate motion?

Gravity pulls the dense edge of the older sphere into the asthenosphere. this pulls the res of the plate as well


one of the earths structural layers- a layer of weak warm rock the flows slowly over geologic time.

continental drift

The hypothesis that the worlds continents move slowly over earths surface

convergent boundaries

places where tectonic plates come together


Earths innermost layer, mostly iron, includes inner and outer core


earths surface layer, consisting of oceanic and continental crust


The process by which the earth formed layers according to density.

divergent boundaries

places where plates pull apart

Earth Science

study of history structure and natural processes of planet earth


the shaking of ground that results when rock under the earths surface moves or breaks


The earth science concerned with the composition and structure of earth

Inner Core

A solid sphere of hot metal, mostly iron at the center of the earth


Earth's outermost structural layer, consisting of cool rigid rock

Lower Mantle

The lowest portion of the Mantle a zone of strong rigid rock


Molten rock in the earths Interior


Thick layer of dense, hot rock between earth's crust and core

Mid-Ocean ridge

A global system of underwater mountains created by seafloor spreading

Ocean Trenches

Long, Deep, Steep troughs in the seafloor where an oceanic plate sinks beneath an overlying plate

Outer Core

A shell of hot liquid beneath the mantle and above the inner core

Plate Tectonics

The theory that earth's lithosphere is divided into large plates that move slowly around the globe

Seafloor Spreading

The process by which new lithosphere is created at mid-ocean ridges as older lithosphere moves away


The study of seismic waves, waves that travel through the earth as a result of an earthquake or other disturbance.


the sinking of oceanic lithosphere into the mantle.

Subduction Zone

The region where an oceanic plate sinks into the asthenosphere at a convergent plate boundary

Tectonic Plates

Separate pieces of lithosphere that move on top of the asthenosphere

Transform Boundaries

Places where tectonic plates slide along beside each other as they move

The lithosphere includes the crust and top part of the


The layer of earth made up of soft rock that flows slowly over time is the


What type of plate boundary lies between two plates that are moving away from each other?


A long deep steep depression in the seafloor where subduction occurs is an

Ocean Trench

Is the earth's inner core a solid, liquid, or gas. Why?

a solid because the pressure keeps it from melting

Why is the outer core the source of the earths magnetic field?

Moving liquid iron particles there form an electric current and an electric current always produces a magnetic field.

Why doesn't the heat in Earth's core melt the earth?

Heat escapes slowly because rock is a poor conductor

Why is the inner core earths most dense region?

The inner core is made mostly of iron

dense material sank toward the earth when it was molten

pressure packs atoms in the inner core tightly together

Fossils such as glossopteris and mesosaurus have been found in widely separate continents because

The continents were once connected in a supercontinent called pangea

Plate Tectonics Explains

How seafloor spreading and subduction account for the movement of tectonic plates

Why the continents move

Why plate boundaries are such active geologic regions

Chemical Rocks

Sedimentary rocks formed from minerals precipitated out of solution

harry hess

seafloor spreading




proves earth is layered


crust and mantle


father of modern geology

how do scientists study the earths layers?What role do seismic waves play?

Scientists study the earth through seismic waves created by earthquakes

What layer creates the magnetic field how?

The outer core creates the earths magnetic field

because it is full of heated moving particles that are creating a magnetic field

How does the crust makeup differ from the core in respect to the elements found there?

The crust has lighter elements like oxygen or hydrogen while the core has more dense elements like iron.

What are the two types of crust? where do they occur? Which is more common? Why is the continental crust thicker?

Continental- makes you the landmass

oceanic-underlies the ocean (most common)

Continental crust thicker because it has roots that go down under the earth

Where do you find the youngest oceanic crust?

near mid-ocean ridges where it is created

Describe the process of seafloor spreading? who discovered it?

harry hess, new lithosphere is created at midocean ridges

how are earthquakes and volcanos related? How do we measure earthquakes? what scale is used?

earthquakes and volcanos both occur at plate boundaries. The ricter scale is used to measure earthquakes.

What are the three different types of faults?

divergent, convergent, transform


plates moving away from each other

ex: seafloor spreading


plates moving toward each other. One plate ends up overtaking the other one.


plates sliding against each other

the san adreas fault line

What are minerals? What are they composed of?

material that has 5 characteristics

naturaly occurring


crystal structure



chemical comp

what is the most common mineral on earth?


how are minerals formed? how do we measure hardness? what scale is used? why is color not a good identifier of mineral indentification?

crystalization, resistance to scratching, mohs scale, some minerals can exist in different colors

Describe the different types of minerals with regards to how they are formed?

Cooling magma, Hydrothermal solutions, Evaporation, Pressure and temp change

What is the difference between intrusive and extrusive rock?What are their other names? What is stone mountain? Which ones are created from a volcano?

intrusive, plutons, forms from magma underground

Extrusive igneous or volcanic rock

stone mountain intrusive

Describe the three types of rocks. How do they differ? How are each of them formed?which is the most common at earths surface?

sedimentary igneous metamorphic

Describe the two types of weathering that can occur to rocks? How do they differ?

Clastic- Formed when bits and pieces of weatherd rocks to hold together

Chemical- when minerals percipitate out of a solution