ESC2000, Module 2 Test

Magma is

the mixture of molten rock, suspended mineral grains, and dissolved gas that forms in the crust or mantle when temperatures are sufficiently high

Non-explosive eruptions are characteristic of the following:

-Low viscosity magmas -Low-dissolved gas levels

Based on the map in the Explore: Earthquakes, Volcanoes, and Plate boundaries select the active volcanoes in Washington state

-Mt. Rainier -Mt. Baker -Mt. St. Helens

Which of the following plates are considered "Fast Moving"?

-Pacific -Nazca

Which of the following is not a common sign of an imminent eruption?

A blanket of fresh new lava or tephra spreads across the land

An assemblage of cratons and orogens is called a

Continental shield

The principle mechanism by which heat is transferred from deep inside Earth to the base of the lithosphere is __________ .

Convection

Can occur between plates carrying either oceanic crust, continental crust, or both; because of their very different properties, the results of the convergence will be fundamentally different.

Covergent Plate Margins

When two continental plates converge the _________ plate subducts under the other plate.

Crust is too buoyant to descend into a subduction zone

A change in shape or size of a body:

Deformation

What is the sum of the weathering, mass-wasting, and erosional processes that result in the progressive lowering of the Earth's surface?

Denudation

After transport, the sediment accumulates in its new location as a result of ________.

Deposition

Ground movement displaces stoves, breaks gas lines, and loosens electrical wires, thereby starting

Fire

Sometimes lava reaches Earth's surface through a vent that is an elongate fracture in the crust; this type of eruption is called a ________

Fissure eruption

The magma gradually cools and solidifies from the outside inwards causing different minerals to form in a process called _______

Fractional Crystallization

The common plutonic rock associated with basaltic magma is

Gabbro

Isostatic rebound is caused when what feature is no longer present on a continental plate?

Glacier

Clastic sedimentary rocks are classified based upon

Grain Size

The common plutonic rock associated with rhyolitic magma is

Granite

________________ are primary effects that cause direct damage to buildings, infrastructure, and the landscape.

Ground motion and disruption of ground surface

Which ocean is shrinking because its underlying crust is being subducted under other plates?

Pacific Ocean

The variation of magnetic mineral directions between sections of oceanic crust of varying ages, which preserves a record of Earth's magnetic field at the time of rock formation.

Paleomagnetism

The disintegration of rock as a result of physical breakup.

Physical Weathering (mechanical weathering)

For the May 22, 1960 Tsunami, what was the location of the recorded Tsunami wave height of 12.2 recorded at the 8 hour mark?

Pitcairn Island

A unifying theory that explains hundreds of years of independent observations of Earth's topographic features.

Plate Tectonics

All bodies of igneous rock that solidify underground, regardless of shape or size, are called

Plutons

Is based on the observation that sediment is deposited in more or less continuous layers.

Principle of lateral continuity

States that sediment is deposited in a layer that is horizontal, or nearly so, and parallel to Earth's surface.

Principle of original horizontality

States that in any sequence of sedimentary strata the order in which the strata were deposited is from the bottom to the top.

Principle of stratigraphic superposition

Distinctive landscape elements result from the activity of various surface processes.

Process

The active process and depositional environment combine to result in a unique end product, or landform.

Process

Another way that lithification can occur is through __________ , in which mineral grains that were once separate can grow to become interlocked.

Recrystallization

_______ occurs when the speed of a wave changes as it passes from one medium to another, causing the wave path to bend.

Refraction

The irregular blanket of loose, uncemented rock particles that covers Earth's surface.

Regolith

Another factor in landscape development, is related to tectonic environment.

Relief

______ magma is thought to form as a result of the partial melting of the relatively silica-rich continental crust.

Rhyolitic

Contains about 70 percent SiO2 and the highest gas content

Rhyolitic Magma

___________ travel around Earth, rather than through it, and they are guided by Earth's surface

Surface waves

Although some landscape features can develop rapidly, even catastrophically, others develop only over long geologic intervals.

Time

Shallow earthquakes, but can be very powerful

Transform Fault Boundary

Fractures in the lithosphere where two plates slide past each other, grinding and abrading their edges as they do so.

Transform Fault Plate Margins

Seismic sea wave

Tsunami

_________ contain patches of vegetation on the bare granite summit that develop in depressions formed by weather over thousands of years.

Vernal Pool

Soil Removal

Water and/or wind erosion, chemical leaching

Inorganic Enchriment

Water or wind deposition of materials

The result is conspicuous decomposition and disintegration of the rock by processes

Weathering

What is a subduction zone?

Where one oceanic plate is dragged or pushed below another lithospheric plate.

How can we tell that the magnetic field has flipped?

magnetic minerals orientation shows changes in the layers

A landscape ______ achieves a state of equilibrium, it is, and likely always has been, a _______ surface

never;dynamic

The __________ involves the movement of material through the geosphere as a result of the formation, breakdown, rearrangement, and reformation of rock.

rock cycle

Which of the following are the potential ways that the lithosphere move?

-Rising magma pushing on plates -Parts of a plate that is sinking into the asethonsphere drag the rest of the plate with it. -An entire plate slides into the asethenosphere.

Sedimentary rocks provide clues about

-Surface conditions at the time of deposition -Past climates -Geologic activity at the time of deposition

Which of the following influence the formation of metamorphic rocks? (choose 1 or more)

-Temperature -Pressure -Fluids

What was the water height (m) for 2015 Central Chile Earthquake & Tsunami recorded on Easter Island, Chile at the approximate 5 hours and 30 minute travel mark? (The information can be found in the interactive map under the Distant Tsunami Impacts)

0.9

Rank the following clastic sediment types by the largest (1) to smallest (4) grain size.

1) Gravel 2) Sand 3)Silty Mud 4)Clayey Mud

How quickly are the North American and African plates diverging at Mid-Atlantic Ridge?

1.8 cm / year (I say 2.5 cm / year)

Our planet's crust is made up of about _____ major tectonic plates.

12

What year was the first tide gauge records of a tsunami obtained?

1854

A S wave, or secondary wave, moves between _______

2 - 5 km/sec

In Explore: Sedimentary Rock Simulation what is the velocity for coarse sand (cm/s)?

359

In addition to the mid-ocean ridge volcanoes, there are at least how many active volcanoes?

500

The last major eruption of the Yellowstone Caldera occurred how many years ago?

640,000

Every month, the earth is shaken by approximately ___________ earthquakes.

80,000

Volcanoes that have erupted within historic times are said to be

Active

What is obsidian?

An extrusive (volcanic) igneous rock that cooled rapidly

Contains about 60 percent SiO2 and a lot of dissolved gas

Andesitic Magma

Contains about 50 percent SiO2 and little dissolved gas

Basaltic Magma

_______ are similar to stocks, but they are huge (up to 1000 km in length and 250 km wide); these enormous plutonic bodies are fundamental building blocks of continental crust.

Batholiths

What are seismic discontinuities?

Boundaries where the velocity of seismic waves changes suddenly rather than smoothly.

Which of the following is not evidence supporting plate tectonics?

Changes in lunar tides

The decomposition of rocks and minerals as chemical reactions transform them into new chemical compounds that are stable at or near Earth's surface.

Chemical Weathering

What is the smallest size category of a clast?

Clay

It helps determine which processes are active in any area.

Climate

Intrusive igneous rocks are generally

Coarse-grained

What is the name of the plate that is beneath the Pacific Ocean and off of the west coast of Central America?

Cocos Plate

What occurs when hot magma intrudes into a cooler rock?

Contact metamorphism

What are the three most important kinds of metamorphism?

Contact, burial, and regional

Earthquakes can be deep and also very powerful

Continental Collision Boundary

Which of the following is not a method used to measure the speed of plate movement?

Continental Cores

Wegener's hypothesis of plation motion. The process by which Pangea was separated.

Continental Drift

Surface processes interact with exposed rock in various ways, depending on rock type.

Lithology

The common plutonic rock associated with andesitic magma is

Diorite

Earthquakes tend to be fairly weak and shallow

Divergent Boundary

Fractures in the lithosphere where two plates move apart.

Divergent Plate Margins

Volcanoes that have not erupted in recent memory but still exhibit some signs of volcanic activity are said to be

Dormant

What is the Benioff Zone?

Earthquakes along a ocean-ocean subduction zone

any change of shape or size that reverses when the deforming force is removed:

Elastic Deformation

The predominant hypothesis of earthquake formation:

Elastic Rebound Hypothesis

The weathered particles sometimes move under the influence of gravity, but often they are carried or pushed by a medium such as water, wind, or ice.

Erosion

Volcanoes that appear to be completely dead are referred to as

Extinct

With temperature _______, the low melting-point components are removed as magma, leaving the higher-melting point minerals behind.

Increase

Sheetlike fractures.

Joints

According to Footage of the 1980 Mount St. Helens Eruption, what did the icy melt water on Mount St. Helens cause?

Lahar

Earthquake vibrations may cause soil to slip and cliffs to collapse.

Landslides

Igneous rocks are also classified by their silica content, which of the following is true for high silica Igneous rock?

Lighter in color.

The sudden disturbance of water-saturated sediment and soil can turn seemingly solid ground to a liquid-like mass of quicksand.

Liquefaction

Which of the following metamorphic rocks is non-foliated?

Marble

The class of rocks formed by subjecting existing rock to extreme heat and pressure (but not to the point of melt) is called:

Metamorphic Rock

The source of Earth's magnetic field lies in its ____________?

Molten Outer Core

Translocation

Movement of fine particles down the soil column

When two oceanic plates converge the _________ plate subducts under the other plate.

Older

What feature marks the divergent plate boundary?

Rifts

Regolith that has undergone erosional transport.

Sediment

Clastic rocks are classified as which type of rock?

Sedimentary

_______ is a measure of the energy released by an earthquake, taking account of the fact that energy may be released over a large area of a fault

Seismic moment magnitude

Rapid cooling causes what types of crystals to form?

Small, only distinguishable through a microscope

A part of the regolith that can support plants.

Soil

What was the location for the earthquake with the highest magnitude?

Southern Chile Earthquake and Tsunami

Deepest and most powerful earthquakes

Subduction Zone Boundary

What is the primary method to distinguish volcanic and plutonic rocks?

Texture

Andesitic volcanoes have a restricted geographic distribution. A well-known ring of andesitic volcanoes that surrounds the Pacific is called ______

The Ring of Fire

Transformation

The chemical convention of minerals in the soil column

What is the geologic time scale generally based upon?

The layering of rocks and sediments

Gabbro is coarser than basalt because

The magma that formed the gabbro cooled slower than the basalt magma.