Science Forces in Earth's Crust

seismic/epicenter

Geologists use __________ waves to locate an earthquake's __________.

Seismic

__________ waves carry energy from an earthquake away from the focus, through Earth's interior and across the surface.

Base-Isolated Building

a building mounted on bearings designed to absorb the energy of an earthquake

Seismograph

a device that records ground movements caused by seismic waves as they move through Earth

Syncline

a downward fold in rock formed by compression in Earth's crust

Syncline

a downward fold in rock formed formed by compression in Earth's crust

Stress

a force that acts on rock to change its shape or volume

Stress

a force that acts on rocks to change its shape or volume

Folds are bends in rock that form when ________ shortens or thickens part of Earth's crust?

compression

the force that causes the earth's crust to become shorter and thicker is_

compression

Where the rock of the crust is pushed together, __________ causes _______ faults to form

compression, reverse

which of the following is a rating of earthquake damage at a particular location_

mercalli scale

What type of fault is at an angle, so one block of rock lies above the fault while the other lies below the fault?

normal fault

when the hanging wall of a fault slips down with respect to the footwall, the result is a _

normal fault

List the waves in order they occur

p waves, s waves, surface waves

Sometimes _______ _______ causes the crust to __________.

plate movement, fold

A _____ fault has the same structure as a normal fault, but the blocks are in the _______ direction.

reverse, opposite

Shearing

stress that pushes masses of rock in opposite directions, in a sideways movement

Compression

stress that squeezes rock until it folds or breaks

Tension

stress that stretches rock so that it becomes thinner in the middle

the largest waves on a seismogram are_

surface waves

A fold in rock that bends downward to form a valley?

syncline

Footwall

the block of rock that forms the lower half of a fault

Hanging Wall

the block of rock that forms the upper half of a fault

Friction

the force that opposes the motion of one surface as it moves across another surface

Magnitude

the measurement of an earthquake's strength based on seismic waves and movement along faults

Focus

the point beneath Earth's surface directly above an earthquake's focus

Epicenter

the point on Earth's surface directly above an earthquake's focus

Liquefaction

the process by which an earthquake's violent movement suddenly turns loose soil into liquid mud

Seismogram

the record of an earthquake's seismic waves produced by a seismograph

Earthquake

the shaking that results in the movement of rock beneath Earth's surface

Strike-slip faults occur at ________ ________.

transform boundaries

Tsunamis are triggered by earthquakes originated beneath the ocean floor

true

The rock on either side of the fault slips past each other sideways, with little ______ or ______ motion.

up, down

The rocks on both sides of a fault can move_____ or_____ or _____.

up, down, sideways

The rock forming the hanging wall of a reverse fault slides ______ and ______ the footwall.

up, over

plate/Reverse

Faults usually occur along __________ boundaries, where the forces of plate motion push or pull the crust so much that the crust breaks. There are three main types of faults: Normal faults, __________ faults, and Strike-Slip faults.

What can only be a few centimeters across or hundreds of kilometers wide?

Folds in the Earth's crust

What is an example of a strike-slip fault?

San Andreas Fault in California

Geologists

__________ can determine earthquake risk by locating where faults are active and where past earthquakes have occurred.

________ and ________ are found where compression forces have ________ the crust. Where collisions of two plates happen?

Anticlines, synclines, folded/Convergent Boundaries

damage

Causes of earthquake __________ include shaking, liquefaction, aftershocks, and tsunamis.

drum

During an earthquake, seismic waves cause the seismograph's __________ to vibrate. The suspended weight with the pen attached move very little. Therefore, the pen stays in place and records the drum's vibrations.

What are some examples of folds in the Earth's crust?

Mountain Ranges like the Himalayas in Asia and the Alps in Europe. Central Appalachian Mountains in Pennsylvania.

What is a FAULT that creates TENSION and happens on a HANGING WALL that moves DOWN?

Normal Fault

What are 3 types of faults?

Normal Faults Reverse Faults Strike Faults

What is an example of a reverse fault?

Northern Rocky Mountains in the western United States and Canada

synclines/plateaus

Over millions of years, the forces of plate movement can change a flat plain into land-forms such as anticlines and __________, folded mountains, fault block mountains, and __________.

What is a FAULT that creates COMPRESSION and happens on a HANGING WALL that moves UP?

Reverse Fault

What is an example of a normal faults?

Rio Grande rift valley in New Mexico

faults/earthquakes

Seismographs and fault monitoring devices provide data use to map __________ and detect changes along faults. Geologists are also trying to use these data to develop a method predicting __________.

What is a FAULT that creates SHEARING and moves SIDE-TO-SIDE with very little UP/DOWN motion.

Strike-Slip Fault

_______ _______ faults are created where two plates move past each other, called _________.

Strike-slip, shearing

__________ in Earth's crust pulls rock apart causing normal faults.

Tension

Shearing

Tension, compression and __________ work over millions of years to change the shape and volume of rock.

drop/cover/hold

The best way to protect yourself is to _____, _____, and _____.

Footwall

The block of rock that forms the lower half of a fault

What happens when movement occurs along a normal fault?

The hanging wall slips downward

Magnitude

Three commonly used ways of measuring earthquakes are the Mercalli Scale, the Richter Scale, and the Moment __________ Scale.

faults

To monitor faults, geologists have developed instruments to measure changes in elevation, tilting of the land surface, and ground movements along __________.

stronger/flexible/modified

To reduce earthquake damage, new buildings must be make __________ and more __________. Older buildings may be __________ to withstand stronger quakes.

Plateau

a large area of flat land elevated high above sea level

Tsunami

a large wave produced by an earthquake on the ocean floor

Richter Scale

a scale that rates an earthquake's magnitude base on the size of its seismic waves

Mercalli Scale

a scale that rates earthquakes according to their intensity and how much damage they cause at a particular place

Moment Magnitude Scale

a scale that rates earthquakes by estimating the total energy released by an earthquake

Strike Slip Fault

a type of fault in which rocks on either side move past each other sideways with little up or down motion

Strike-Slip Fault

a type of fault in which rocks on either side move past each other sideways with little up or down motion

Normal Fault

a type of fault where the hanging wall slides downward; caused by tension in the crust

Reverse Fault

a type of fault where the hanging wall slides upward; caused by compression in the crust1

Reverse Fault

a type of fault where the hanging wall slides upwards; caused by compression in the crust

P Wave

a type of seismic wave that compresses and expands the ground

Surface Wave

a type of seismic wave that forms when P Waves and S Waves reach Earth's surface

S Wave

a type of seismic wave that moves the ground up and down or side to side

in the hours after an earthquake, people should not go inside a building, because of_

aftershocks

Aftershock

an earthquake that occurs after a larger earthquake in the same area

Anticline

an upward fold in rock formed by compression of Earth's crust

A fold in rock that bends upward into an arch?

anticline

What terms do geologists use to describe upward or downward folds in rock?

anticline and syncline

Over millions of years, the forces of plate movement can change a flat plain into land-forms such as ____________ and __________, folded mountains, fault-block mountains, and plateaus.

anticline, syncline

Folds in the Earth's crust are made up of parallel ridges called ________ and valleys called ________.

anticlines, synclines

Normal faults occur where plates__________, or pull apart.

diverge

Best way to stay safe during an earthquake

drop, cover and hold

An earthquake's epicenter is located deep underground

false

As S waves move through the ground, they cause it to compress and then expand

false

Liquefaction forces squeeze or pull the rock in earth's crist

false

Rock uplifted by normal faults creates fault-block mountains

false

A__________is a break in the rock of the crust where rock surfaces slip past each other.

fault

Most__________occur along _______ ________, where forces of plate motion push or pull the crust so much that the crust breaks.

faults, plate boundaries

The forces produced by the movement of Earth's plates can _______, ________, and _______ the crust.

fold, stretch, uplift

What is the block below the fault?

footwall

What is the block above the fault?

hanging wall