SMCHS Earth Science Sem 1 Final

Places where two tectonic plates are moving away from each other are called _____________________________.

Divergent Boundaries

Fractures in rock where sections of rock might suddenly move to create and earthquake are called _________________

Faults

What evidence did Wegener use to estimate the time of the continent Pangaea's break up into smaller continents?

Fossil data

Why does magma move up and through the Earth's crust?

It is less dense than the surrounding rock

When magma reaches the surface it is called___________________

Lava

What is the study of earthquakes called?

Seismology

A wide, dome shaped volcano built from thin, freely flowing lava is called a(n) __________ _________

Shield Volcano

Hawaii, which sits over a HOT SPOT located near the center of the Pacific Plate, is which type of volcano?

Shield Volcano

What is the rating from the Richter Scale based on?

Size of the largest wave

___________________ is the force per unit area acting on a material.

Stress

What type of fault is the San Andreas Fault

Strike Slip

What is an isochron ?

a line on a seafloor map that connects points of equal age

What is a pyroclastic flow?

a mixture of volcanic gas, ash, and other tephra

Where is andesitic magma found?

at the margins of the continents

A _________ is the unaltered remains of a once-living organism.

fossil with original preservation

What is the Earth's core composed of?

iron and nickel

During the time of Pangaea, what had the greatest impact on Earth's climate?

it was a time of a giant global ocean

What two topographic features of the ocean floor were discovered only with the use of sonar?

mid-ocean ridges and deep-sea trenches

Where do most volcanoes form?

plate boundaries

What causes the seafloor to spread?

rising molten magma

Much of the Earth's internal heat comes from ________________________

the decay of radioactive materials

How many times larger is a magnitude 3 than a magnitude 1 earthquake on the Richter Scale?

100 times

How old is a mammoth's tusk if there is only 25 percent Carbon -14 remaining in the sample?

11,400 years

the figure, after four half-lives (22,820 years), how much C-14 would be left?

6.25%

What is the name for an igneous intrusion that is smaller than a batholith but similar in shape?

A Stock

How is a volcanic crater connected to a magma chamber?

A Vent

What characterizes an index fossil?

All of the above

What is the longest division of time in the geologic time scale?

An Eon

What is the shortest division of time in the geologic time scale?

An Epoch

Where does an earthquake originate?

At the Focus

Where are the youngest rocks on the ocean floor located?

At the Mid-ocean ridges

What type of magma has the lowest silica content and is the least explosive?

Basaltic

A _________________ is a large intrusive rock body that covers at least 100 square kilometers.

Batholith

What happens as a lithospheric plate moves over a HOT SPOT?

a chain of volcanoes form

What is the name for a large crater formed when a magma chamber collapses?

Caldera

What is the name of a large volcanic crater over 1 km in diameter?

Caldera

What isotope is used for finding the age of materials that are organic in origin?

Carbon-14

The subduction of an oceanic plate beneath a continental plate produces a(n) ____________________________

Chain of volcanic mountains

What texture do most plutons have?

Coarse

What type of volcano forms from alternating layers of tephra and non explosive lava?

Composite Volcano

What is the name of Alfred Wegener's hypothesis about moving land masses?

Continental Drift

The subduction zone in the figure is?

D

Which mineral may preserve magnetic patterns on the ocean floor, in support of tectonic plates?

Magnetite

A ___________________ is a device that can detect changes in the strength of the Earth's magnetic field.

Magnetometer

Which scale measures the damage done by an earthquake to determine an earthquake's intensity?

Modified Mercalli Scale

Which type of wave arrives first at a seismic facility?

P

Most of the world's major earthquakes occur in the areas bordering the _________________________

Pacific Ocean

What is the study of the Earth's ancient magnetic record?

Paleomagnetism

What era of geologic time ended with the largest extinction event in Earth history?

Paleozoic

The supercontinent from Wegener's theory of continental drift is called ___________________________.

Pangaea

Petrified wood is an example of __________.

Permineralization

What are most earthquakes associated with?

Plate Boundaries

The tremendous amount of heat within the Earth powers ___________________

Plate Tectonics

_______________ push and pull rocks in the same direction along which the waves are traveling.

Primary Waves

Which feature shown in the figure is the oldest?

Q

What method is used to determine the exact age of a rock or fossil?

Radiometric Dating

Which type of fault results in horizontal shortening?

Reverse

When a divergent plate boundary forms on a continent, (land), a ___________________forms.

Rift valley

Harry Hess's theory of _________________________ explained how ocean crust is generated and destroyed.

Seafloor spreading

Which factor could give scientists a clue about changes in Earth's atmosphere over time?

Sedimentary Rock Layers

What geologic principle states that in an undisturbed rock sequence, the oldest rocks are on the bottom and the youngest are on the top?

Superposition

Which waves are called body waves?

Surface waves only

Which type of stress pulls a material apart?

Tension

Rock fragments thrown into the air during a volcanic eruption are called _______________

Tephra

What are shallow, intermediate, and deep earthquake classifications based on?

The depth of the focus

Why does knowledge of Earth's interior come from seismic waves?

They change speed and direction when they encounter different materials

A place where two plates slide laterally past each other is called a _______________________________

Transform Boundary

(LAB reference) What type of material is used in the dating technique of Dendrochronology?

Tree Growth Rings

An earthquake on the ocean floor can produce ______________________________

Tsunami

The Principle of __________ states that the processes that have been occurring today have been occurring since Earth formed.

Uniformitarianism

____________________ is the internal resistance to flow of a liquid.

Viscosity

What are large, angular fragments thrown from a volcano called?

Volcanic Blocks

When does magma form?

When temperatures are hot enough to melt rock (1000 degrees)

Rocks close to the mid-ocean ridge are _____________________ rocks far from the mid-ocean ridge.

Younger than