Quiz 12

A hypsographic curve is

a generalized curve showing the earth's surface by elevation in relation to sea level.

Along the trough of a fold, layers that seem to slope downward toward the axis of a fold produce

a syncline

The greatest amount of crustal shortening would be associated with

a thrust fault

Which of the following can lead to the formation of mountains?

all of the above: plate collisions and volcanic activity, exposure of plutons by erosion of surrounding landscape, and faulting

The San Andreas system in California is an example of a

all of there are correct: a strike-slip fault, transform fault, and right-lateral motion

The variety of surface features on the Earth results from

all of these: tectonic activity, gravity, weathering and erosion

Which of the following is true regarding the Richter scale- a scale which quantifies the amount of energy released by an earthquake?

an 8.0 on the scale is equal to 31.5 times more energy release than a 7.0

Volcanoes formed from silica-rich magma

are highly explosive and dangerous

The area at the surface directly above the subsurface location where seismic waves are initiated is termed the

epicenter

The motion of seismic waves is initiated in a subsurface area long the fault plane called the

focus, or hypocenter

Molten rock that pours forth on Earth's surface is called

lava

Pulverized rock and clastic materials ejected violently during an eruption are called

tephra, or pyroclastics

Fault types are defined by

the relative motion of the hanging wall and footwall

Which of the following is incorrect relative to the principal locations of volcanic activity?

they occur around the perimeter of the Atlantic Ocean Basin

The wave amplitude associated with a magnitude 8 quake on the Richter scale is how many times greater than that of a magnitude 6 quake?

100

A brittle rock is likely to respond to stress by_____, whereas a ductile rock is likely to respond by____.

breaking, bending

Explosive eruptions tend to build up

composite volcanoes

Reverse and thrust faults are associated with

compressional forces

Tensional stress along a fault can result in a dropped hanging-wall block relative to the footwall side, producing a

normal, fault

An instrument used to record vibrations in the crust is the

seismograph