GEO Ch1

Reid; 1906, San Francisco

The elastic rebound theory for the origin of earthquakes was first proposed by ____________ following the ____________ earthquake.

focus

When an earthquake occurs, energy radiates in all directions from its source. The source is also referred to as the __________.

S waves travel through solids and P waves travel through liquids

Which one of the following statements is correct about S and P waves

Primary waves

____________ have the highest velocities

they are started by fault-induced, horizontal shifts in the sea floor that suddenly propel great masses
of water in opposite directions

Which one of the following is true regarding tsunamis

design of structures, intensity and duration of the vibrations, nature of the surface material

The amount of destruction caused by earthquake vibrations is affected by __________.

surface waves

On a typical seismogram, ____________ will show the highest amplitudes

aftershocks

Major earthquakes are often followed by somewhat smaller events known as

Richter

The ____________ magnitude scale is a measure of the energy released. It does not directly measure the extent of building damage.

seismograph

The instrument which records earthquake events is termed a

XII

____________ is the maximum possible damage designation on the Mercalli scale.

epicenter

The position on Earth’s surface directly above the earthquake source is called the

elastic rebound

The mechanism by which rocks store and eventually release energy in the form of an earthquake is termed

surface wave

this type of seismic wave is the most destructive

30 times

Approximately how much more energy is released in a 6.5 Richter magnitude earthquake than in one with magnitude 5.5

are faster than S waves and surface waves

P waves

I to XII that rates the structural damage due to an earthquake

The Mercalli Scale is a scale from

arrival times of P and S waves

The distance between a seismological recording station and the earthquake source is determined from the

amplitude of the surface waves

The Richter magnitude of an earthquake is determined from the

they have relatively small amplitudes compared to their very long wavelengths

Which one of the following best characterizes tsunamis?

San Francisco, 1906

The ____________ earthquake was accompanied by extensive fire damage

Liquefaction

A ____________ refers to the tendency for a foundation material to lose its internal cohesion and fail mechanically during earthquake shaking

seismogram

The record of an earthquake obtained from a seismic instrument is a

seismic waves

Most of our knowledge about Earth’s interior comes from

oceanic crust is enriched in potassium, sodium, and silicon

Which one of the following statements about the crust is NOT true

iron

The dense core of Earth is thought to consist predominantly of

a rigid layer of crustal and mantle material

The lithosphere is defined as

basalt

The average composition of the oceanic crust is thought to approximate that of

granite

The average composition of the continental crust most closely approximates that of

weak electrical currents associated with fluid motions in the outer core

The Earth’s magnetic field originates by

in the upper mantle

The asthenosphere is located

strike slip

A ____________ fault has little or no vertical movements of the two blocks.

reverse

In a ____________ fault, the hanging wall block move up with respect to the footwall block.

the crust is shortened and thickened

In thrust faulting,

a hanging wall block that has moved down between two normal faults

A graben is characterized by

tensional stresses and normal-fault movements

The mountains and valleys of the Basin and Range Province of western United States formed in response to

the hanging wall block above an inclined fault plane moves downward relative to the other block

In a normal fault

a strike-slip fault that forms the boundary between tectonic plates

A transform fault is

cooler temperatures

Brittle deformation would be favored over plastic deformation in which of the following conditions?

a low-angle, reverse fault

A horst is

A syncline is

a fold in which the strata dip toward the axis

a low-angle, reverse fault

A thrust fault is best described as

dome

The Black Hills of South Dakota are a good example of a

basins

Large circular downwarped structures are called

high temperature and high confining pressure

Which of the following combinations should favor folding rather than faulting?

normal faults

Tensional forces normally cause which one of the following

San Andreas strike-slip fault

The ____________ in California is the boundary between the North American and Pacific plates.

accretionary-wedge complex

A(n) ____________ is a thick accumulation of sediments and small, tectonic blocks formed of material scraped off a descending, lithospheric plate.

fault blocks uplifted by late Tertiary to Quaternary normal faulting

The Sierra Nevada, CA, and Teton, WY ranges are examples of