Earth Science 2

The apparent movement of Earth's magnetic poles over time is referred to as __________________.

Polar wandering

Which of the following are NOT associated with diverging plate boundaries?

Subduction zones

Oceanic crust is neither created nor destroyed along this type of boundary.

transform fault boundaries

If you wanted to draw the boundaries of active lithospheric plates on a globe, which of the following maps would give you the most complete information? A map showing ____________.

earthquake distribution

Along what type of plate boundary is new seafloor generated?

Divergent

The age of the deepest sediment in an ocean basin _________________ with increasing distance from the oceanic ridge.

Increases

Convergent boundaries are zones where plates ____________.

move together

Plates move apart, leaving a gap at ____________.

divergent plate boundaries

Deep-ocean trenches are associated with ____________.

convergent plate boundaries

Which of the following in NOT considered one of the seven major lithospheric plates?

Caribbean

Plate movement throughout the Earth is responsible for the development of mountain systems, earthquakes, and volcanic activity. The average rate of plate motion per year is approximately …..

2 inches

When two continental plates converge, which will subduct?

neither plate

Plates move together along ____________.

convergent plate boundaries

Oceanic crust is destroyed along _______.

convergent plate boundaries

When an oceanic plate converges with another plate, the oceanic plate bends downward as it subducts beneath the overriding plate. This bending produces the deepest features of the marine environment called ………

deep-ocean trenches

At which location would you expect to find shallow, intermediate, and deep focus earthquakes?

Along subduction zones associated with converging plate boundaries

Physical/Earth scientists conclude the breakup of Pangaea occurred about ……..

200 million years ago

Which type of plate boundary produces the most and greatest magnitude earthquakes?

convergent

Complex mountain systems such as the Alps, Appalachians, and Himalayas are the result of ____________________.

Continental-continental convergence

Radiometric dating of the ocean floor indicates that the oldest ocean seafloor is located ………………….

Near the edges of the continents

When two plates grind past one another without the production or destruction of lithosphere material, the resulting boundary is termed ____________.

Transform fault boundaries

____________ was never proposed as evidence supporting the existence of Pangaea.

Islands of Precambrian rocks along the Mid-Atlantic Ridge

The naturally occurring magnetic iron mineral that is present in most igneous rocks that is useful in paleomagnetism evaluations is called ………….

magnetite

Which one of the following most accurately describes the volcanoes of the Hawaiian Islands?

shield volcanoes fed by a long-lived hot spot below the Pacific lithospheric plate

The Aleutian Islands occur at a ____________.

 

convergent boundary on a volcanic arc above a northward-subducting Pacific plate

Linear downfolded structures with the youngest strata (rocks) in the center are called ____________.

 

synclines

Compressional stress can result in the formation of ____________.

  thrust faults and reverse faults

Which of the following combinations should favor folding (ductile deformation) rather than faulting (brittle deformation)?

high temperature and high pressure

Overall, this type of seismic wave is the most destructive.

surface waves

In a normal fault ____________.

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

This type of seismic wave travels most rapidly.

P waves

Geologically, the term deformation refers to ______________________.

Any change in the volume and/or shape of a rock body

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

reverse

A horst is ____________.

an uplifted block bounded by two normal faults

Normal faulting through time will generate elongate valleys (low areas) bounded by uplifted areas. These uplifted areas are termed _______________

Horsts

Faults having primarily vertical movement are called ____________ faults.

dip-slip

Often associated with an explosive eruption of composite cones, ______________ are characterized by gas infused with hot ash and large rock fragments that flow down the sides of the volcanic structure.

Pyroclastic flow

The term ____________ is given to any material that is ejected into the atmosphere during a volcanic eruption.

Pyroclastic material

Which kind of eruptive activity is most likely to be highly explosive?

eruptions of big, continental margin, composite cones or stratovolcanoes

Which type of volcano is the result of the accumulation of pyroclastic material violently erupted over a relatively short period of time. These volcanoes are small (between 100 & 1,000 feet in elevation) and have steep slopes (up to 40 degrees).

Cinder cones

____________ tend to increase the explosive potential of a magma body beneath a volcano.

High viscosity and dissolved gas

During some earthquakes, intense vibrations moving through unconsolidated sediments saturated with water can cause these sediments to become mobile. This process is called __________ and can cause some structures to move upward or to sink.

Liquefaction

Which type of mountain building system is associated with continental-continental convergence and is characterized by extensive folding and faulting resulting in the shortening and thickening of crustal material. Examples of this type of mountain building process include the Himalayan, Appalachian, and Ural mountains

Alpine-type

The mechanism (first recognized by Reid) by which rocks store and eventually release energy in the form of an earthquake is referred to as ____________.*

elastic rebound

The study of earthquakes is called __________________

Seismology

The lithosphere is defined as __________.

a rigid layer of crustal and mantle material

Which of the following seismic waves travels the fastest and can travel through all types of materials (solids, liquids, and gases)?

P waves

A ____________ fault has little or no vertical movements of the two blocks (the movement is primarily horizontal).

strike slip

The average composition of the upper mantle is thought to be approximately that of ____________.

peridotite

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

design of structures,

intensity and duration of the vibrations,

nature of the surface material, (all)

Which one of the following is NOT one of Earth's main layers based on mechanical strength (physical properties)?

Troposphere

The vast majority of the world's earthquakes occur in a zone known as the ____________. This region is largely bounded convergent plate boundaries.

circum-Pacific belt

____________ refers to the tendency for a foundation material (sediment) to lose its internal cohesion and fail mechanically during earthquake shaking.

Liquefaction

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

granite

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

the design of structures,

the intensity and duration of the vibration,

the nature of the surface material,

only the intensity and duration of the vibrations and the nature of the surface material, (all)

Which type of volcano would most likely be composed primarily of basaltic lava flows?

Shield volcano

When continued eruptive activity along the flank of a volcano occurs that consists only of gases, the eruptive vent is termed ___________.

fumaroles

Which of the following statements best describes the big Hawaiian volcanoes?

are situated in the interior of a large, Pacific plate above a hot spot deep in the mantle

A large depression (> 1km in diameter) at the summit of a volcano is called a _______________.

Caldera

The steep-walled depression located at the summit of a volcano is called the ____.

crater

Which statement is true about magma and volcanoes?

A low viscosity magma will flow more readily and easily than a magma with high viscosity. Therefore, the eruption will be fluid and passive.

This type of caldera-forming process occurs after a violent and large volume extrusion of molten material. The rock overlying the partially emptied magma chamber loses support and collapses suddenly.

Crater Lake-type

Crater Lake was produced when _______.

the summit of a volcano collapsed

The most violent volcanic activity is associated with ____________.

composite cones

Basaltic lava flows that resemble twisted braids of rope are termed ____________. These lava flows develop due to their high temperatures or as cooler lava flows begin to move over steeply sloped terrain.

Pahoehoe flows

Which of the following factors help determine whether a volcanic eruption will be violent or relatively quiescent?

amount of dissolved gas in the magma,

temperature of the magma,

composition of the magma,

only amount of dissolved gas in the magma and temperature of the magma, (all)

______ are tabular discordant bodies that are produced when magma is injected into fractures.

dikes

A magma's viscosity is directly related to its __________________ content.

sicila

In some instances, fissure eruptions will produce a low-viscosity lava that can flow up to 90 miles from the eruption. The term ___________ is commonly used to describe these events.

flood basalt

This volcano erupted in 79 A.D. which resulted in ash and pumice completely covering the town of Pompeii.

Vesuvius

A/an ___________ is an elongate, linear fracture in the Earth's crust through which a large volume of volcanic material is extruded.

fissure

A ____________ volcano is a very large, gently sloping mound composed mainly of basaltic lava flows.

shield

Why do magmas rise toward Earth's surface?

magmas are mainly liquid and contain dissolved fluids such as water; most are less dense than the adjacent solid rock

An undisturbed horizontal layer of basalt is confined between two sedimentary layers. The basalt exhibits a vesicular texture in its upper portion, while the sedimentary layer immediately below shows some metamorphic alteration. The sedimentary layer above shows no metamorphic alteration. Which one of the following statements is most likely to be true about the basalt?

it is a buried lava flow

____________ are usually the most abundant gases emitted during basaltic volcanism.

Water and carbon dioxide