Geology 1400 - earthquake

Slab pull occurs because subducting slabs are _________, and therefore are _________ dense than the surrounding asthenosphere.

cooler; more

Normal, reverse, and thrust are all examples of ____________ faults.

dip-slip

Which basic type of plate boundary is shown in the image below?

divergent

The distribution of _________ around the globe provides the primary indicator of the boundaries between lithospheric plates.

earthquakes

Which of the following is a type of convergent plate boundary?

subduction zone

In the image below, the rocks have been bent into an elongate trough. This is a(n) ________.

syncline

In plate tectonics, a triple junction is a place on the earths surface where

the boundaries of three lithospheric plates meet at a single point.

Hypocenter

the underground focus point of an earthquake.

Mid-ocean ridges are

underwater volcanic mountain ranges

Tsunamis are most commonly generated by sudden _________ movement of the seafloor during an earthquake.

vertical

Seismic retrofitting is the process of

strengthening existing buildings and structures.

Lithospheric plates move relative to other along plate boundaries at velocities between _________

1 and 20 centimeters per year

According to the moment magnitude scale (Mw), the amplitude of ground shaking during a magnitude 8 earthquake would be 1,000 times greater than a magnitude ________ earthquake.

5

A tsunami is

A seawave generated by an earthquake, landslide, or submarine volcanic eruption that may destroy coastal cities thousands of kilometers from its source

Who first proposed the theory of continental drift?

Alfred Wegener

___________ propose the continental- drift hypothesis, suggesting that the arrangement of continents on the planet has changed over geologic time.

Alfred wegener

Sea floor spreading is associated volcanic activity

Along mid-ocean ridges.

In the image below, the rocks have been bent into and elongate arch. This is an example of a(n)___________.

Anticline

The majority of new oceanic crust is created

At mid-ocean ridges.

Most of the polling force driving plate motion is produced

At subduction zones.

The graph below shows the change in velocity of seismic waves depth in the crust. Why does the velocity of the P-wave drop drastically at the core-mantle boundary?

Because the outer core is liquid and seismic waves travel slower in liquids

Sort-term predictions of earthquake behavior have

Been largely unreliable

Continental lithisphere does not subduct because it is too

Buoyant.

Mountain ridges formed along production zones are formed, in part, by__________ in the crust.

Compression

As shown in the figure below, a coil spring would be useful in illustrating any _________wave.

Compressional

Large, thick-crusted, nonvolcanic mountain belts, like the Himalayas, are associated with

Continent-continent collisions.

Which concept/Hypothesis was developed first?

Continental drift

Which of the following is true of continental lithosphere compared to oceanic lithosphere?

Continental lithosphere is thicker than oceanic lithosphere.

A ____________ is a linear feature in Continental lithosphere where a plate is pulling apart, resulting in a deep Valley, extensive faulting and volcanism, if substained, division into two plates separated by a new oceanic lithosphere

Continental rift

Most medium- and deep-focus earthquakes occur at

Convergent-plate boundaries

Which of the following is true about the lithosphere?

It is composed of a crust and the uppermost rigid part of the mantle.

Designing and retrofitting building to withstand The effects of earthquakes is a type of

Earthquake engineering.

Add transformation plate boundaries,

Earthquakes are common but volcanoes are absent.

The point in the earths surface directly above the point where the earthquake occurs as termed

Epicenter.

At the subduction zone where the Pacific plate is abducting under the islands of Japan, the Wadati-Benioff is deep earthquakes

Extends from the trench westward underneath Japan

Movements along faults often produces a rock formed from sharply angled rock fragments termed __________.

Fault breccia

The distinction between joints and faults is that_______.

Faults are fractures along which displacement has occurred; displacement does not occur along joints

The idea that the continents had once fit together as a simple supercontinent called Pangaea was rejected when first proposed because.

Geologist did not know of a force great enough to move continents.

At any point along the surface of any non-vertical fall, as is shown in the figure below, the

Hanging wall lies vertically above the footwall.

The portion along a fold where curvature is the greatest and termed the fold __________.

Hinge

Hotspots are caused by

Hot plumes of mantle that rise up through cooler, denser surrounding rock.

The point within the earth where the earthquake originates is termed the

Hypocenter (focus).

With increasing distance of mid ocean ridge, the age of oceanic crust

Increases.

____________ is the balance between the Weight of the mountain range and booyancy provided by the underlying mantle.

Isostasy

It's a P-wave is traveling through the earth and encounters the molten magma chamber, what will happen to the velocity of the P-wave?

It will decrease.

If an S-wave is traveling through rock win it encounters a mountain magnet chamber, what will happen to the velocity of the S-wave?

It will not travel through the magma.

Marine magnetic anomalies in oceanic crust result from sea floor spreading in conjunction with

Magnetic polarity reversals

Which earthquake scale is used to assess the effects of an earthquake on humans and human-made structures

Mercalli scale

Which of the following is a divergent plate boundary?

Mid-Atlantic Ridge

Marine magnetic anomaly belts run parallel to

Mid-ocean ridges.

Which of these properly illustrates the principal of isostasy?

Mountains stand high because they are gravitationally balanced by there deep crustal roots.

During an earthquake, if a hanging wall slides down words relative to a foot wall, The fall is termed a ________ fault. Refer to the figure below for an example of such a feature.

Normal

In a __________ fault, the fault plane is non-vertical and the hanging wall block moves downward relative to the foot wall block.

Normal

What type of a fault is the result of deformation to accommodate tensile stresses such as those that occur during rifting?

Normal

What kind of fault is shown in the image below?

Normal fault

Which type of seismic wave has the fastest velocity?

P-wave

What is the correct order of arrival for seismic waves?

P-wave, S-waves, surface waves

Magnetic strips on the sea floor are roughly _________ about the ridge access along which they were created.

Parallel to and symmetric

According to the theory of plate tectonics, plates are

Pieces of lithosphere that move over the surface of the earth with respect to one another.

Epicenter

Point on Earth's surface directly above an earthquake's focus

Which is not one of the ideas that A. Werner used to support his theory of continental drift?

Polar wander from paleomagnetism

During an earthquake, if the hanging glass slides upwards relative to the football, the fall is termed a _________ fa if the fault is steep (closer to vertical than horizontal). Refer to the figure below for an example of such a feature.

Reverse

If a fault plane is greater than 30° from horizontal and then hanging wall block moves upward relative to the foot wall block, the fault is called a ________ fault.

Reverse

What kind of fault is shown in the image below?

Reverse fault

What type of fault is illustrated in the figure to the left?

Right lateral strike slip

In the following graph, why does the line of S-wave not appear in the outer core?

S-waves can't travel the outer core because it is liquid.

Which of the following best describes how scientist study the interior of the earth?

Scientist use seimic waves, gravity, and magnetism to study the earth's interior.

Which of the following best describes how scientist study the interior of the earth?

Scientists use seismic waves, gravity, and magnetism to study the earths interior.

What kind of process is shown in the image below?

Sea floor spreading

A _________ is a scientific insurance used to record the ground motions produced by an earthquake.

Seismometer

What kind of stress is associated with the fault shown in the figure above?

Shear

On either side of the mid-ocean ridge, Oceanic lithosphere slowly_________

Sinks into the atmosphere because it cools and thickens, increasing in density.

What is the most important driving force for the plates in plate tectonics?

Slab pull

Periods of intermittent sliding on a fault because of stress released during episodes of slip, followed by stress buildup on the point that the fault is reactivated, are termed

Stick-slip behavior

How is stress different from strain?

Strain is the change in shape of a rock due to applied stress.

How is stress different from force?

Stress is the force applied per unit area.

We can describe the orientation of planar features such as faults and joints using measurement of the ________.

Strike and dip

If a fall is nearly vertical in orientation and the two walls of rock on opposite sides slide past one another horizontally, the phone is termed a _________fault. Refer to the figure below for an example of such a feature.

Strike-slip

The only place where we can have deep earthquakes is where?

Subduction zone

Deep-sea trenches are likely to be located near

Subduction zones.

Earthquake waves that travel along the earth's surface are termed.

Surface waves.

What kind of fold is shown in the picture below?

Syncline

Oceanic lithosphere thickens as it moves away from mid-ocean ridges primarily because of

The addition of new lithospheric mantle as a result of cooling

In a hot-spot volcanic island chain, such as the Hawaiian islands, which of the following is true?

The ages and distance between volcanoes can be used to calculate plate velocities.

The map below depicts the locations of earthquakes in the ocean basins. Which of the following locations is most likely to be located along a plate boundary?

The middle of the north Atlantic ocean, where there is north-south belt of earthquakes

A long delay the arrival of p-waves and s-waves at a seismometer means that

The seismometer is located far from the earthquake.

What can be said about the ocean sediments collected from location B as compared to location D?

They are thicker and older

Which of the following best describes the distribution of earthquakes around the globe?

They occur in distinct zones.

Which of the following is a conservative plate boundary?

Transform

The time it takes for seismic wave to travel from the focus of an earthquake to a seismometer is called the _________.

Travel time

Earthquakes that occur in a band called the ________ can be used to track the motion of subducted oceanic lithosphere.

Wadait-Benioff zone

Faults that have moved recently or are likely to move in the future are referred to as ____________ faults.

active

The vast majority of earthquakes occur

along any plate boundary.

The rock produced at mid-ocean ridges consists of

basalt at shallow depths and gabbro at deeper depths.

On a geologic map, if the contacts between sedimentary rock units form a bull's-eye pattern of concentric circles, with the youngest unit in the center, the underlying structure is a(n) ________.

basin

Body waves include

both S- and P-waves

Faulting and earthquakes are examples of what type of deformation?

brittle

Subduction zones are found at _____________ plate boundaries.

convergent

Before an earthquake, the rocks can respond to applied stress to a small degree by bending and warping without breaking. This is termed _________.

elastic behavior

Seismic waves travel _________ in solids than in liquids; however, unlike P-waves, S-waves __________ travel through liquids.

faster; can't

At a subduction zone, the downgoing (subducting) plate

is always composed of oceanic lithosphere

If you stand on one side of a strike-slip fault and the block on the other side of the fault has moved to your left, this is known as a(n) ________.

left lateral fault

The sides of a fold, where curvature is at a minimum, are termed _________.

limbs

Wet and unconsolidated substrates are uniquely susceptible to ________ during an earthquake.

liquefaction

Aftershocks after a major earthquake

may continue for days, weeks, or years after the initial earthquake.

Most earthquake are a result of

movement of rocks along faults.

If compressive stresses acting on a rock are greatest in a north-south direction, the rock will likely deform by shortening in a _________ direction.

north-south

Transform plate boundaries are unlike other plate boundaries because

old plate is not consumed nor is new plate created.

On a geologic map, the beds of an eroded anticline will be _________ near the fold hinge compared to further from the hinge.

older

An episode of mountain building is termed a(n) ____________.

orogeny

Continental coastlines that occur within the interior of a lithospheric plate are called ________ margins.

passive

Surface waves

produce most of the damage to buildings during earthquakes.

The average length of time between earthquakes along a fault is termed the __________

recurrence interval

The energy that is released during an earthquake travels through the earth as vibrations termed _________.

seismic waves

A body of rock affected by compressive stress will likely undergo ____________.

shortening

The core consists of two layers: a(n) ________ inner core and a(n) ________ outer core.

solid; liquid

Which of the following is NOT associated with convergent plate boundaries?

spreading centers

The term for a change in shape induced by a stress is _________.

strain

The term for a change in shape induced by stress is ________.

strain

Which of the following is NOT an example of deformation?

stratification