Chapter 6- 5 combine

Match the magma type with the corresponding eruption type.

- Basaltic magma: fluid lava flows from shield volcanoes; low viscosity - Felsic magma: expolsive eruptions from composite volcanoes; high viscosity

Contrast eruption columns with pyroclastic flows by putting the description in the category.

- Eruption column: > Tephra erupts high into the atmosphere along with large amounts of hot volcanic gases > Ash particles drift back down to Earth hundreds of kilometers or more from the volcano - Pyroclastic flow: > Ash layers are deposited only on and adjacent to the slopes of the volcano > Tephra billows down the slopes of the volcano in ground -hugging flows at speeds of over 100 km/hr

Match the magma type with its gas bubble behavior.

- Felsic magma = gas bubbles cannot escape easily; high pressures build up in the magma; typically explosive eruptions; magma is high viscosity - Basaltic magma = gas bubbles escape easily; little pressure builds in the magma; typically nonexplosive eruptions; magma is low viscosity

Match the volcanic feature with the hazard.

- Scoria cone: > falling volcanic cinders and bombs > volcanic ash and gases - Lava flow: > burial of roads > bulldozing and crashing of houses and other structures

Which of the following accurately describe most shield volcanoes?

- broad and gently sloping form - composed of a succession of lava flows

which of the following accurately describe a scoria cone?

- composed of a pile of loose, vesicular lava fragments - steep-sided hill - formed from lava fountains

Which of the following are properties characteristic of calderas?

- form from collapse of overlying ground into emptied magma chamber - bounded by steep escarpments - large, basin-shaped volcanic depression

Which of the following were warning signs prior to the catostrphic eruption of Mount St. Helens in May 1980?

- formation of a bulge on its flanks - earthquakes

Which of the following are characteristics of actively erupting volcanoes?

- glowing orange lava flowing downhill - fragments of molten rock blasting into the air - billowing clouds of ash rising into the air

Which of the following phenomena are monitored to predict volcanic eruptions?

- heat flow changes - changes in gas output - ground shaking - changes in topography

Due to their large size and the volume of erupted gases, which of the following are likely true for flood basalts?

- highly reflective sulfuric acid droplets in the atmosphere could lead to global cooling' - such eruptions could lead to increased greenhouse warming

Which of the following events accompanied the caldera-forming eruption at Santorini, Greece, about 3,500 years ago?

- huge ash column forms - pyroclastic flows occur - caldera collapse drops island beneath the sea surface - tsunami travels south and hits Crete

Which of the following commonly precede a volcanic eruption?

- increased heat flow from the volcano - steam eruption from the volcanic crater - increased gas flow from a volcano

Which of the following are locations where flood basalts are known to have occurred?

- india - siberia - oceanic plateaus - brazil

Which of the following are responsible for the huge size of flood basalts?

- large (long and wide) fissures from which the lava spews - multiple eruption events in the same area - low viscosity of the basaltic magma

Which of the following best describe a young scoria cone?

- little soil buildup on slopes - dark, fresh-looking lava - central crater at top of a conical hill

Which of the following are the two main factors controlling volcanic eruption style?

- magma composition - volatile content of the magma

Which of the following are hypothesized sources of the magma that produce flood eruptions?

- melted asthenosphere from around the plume in the shallow mantle - melted lithosphere over a mantle plume - plume material from deep in the mantle that melts at shallow depths

Select from below the typical components of a composite volcano.

- mudflow deposits - lava flows - pyroclastic flows

Volcanic vents can take which of the following forms?

- narrow linear fissures - roughly circular craters

Which of the following rock types are associated with basaltic volcanoes?

- nonvesicular basalt - scoria - volcanic bombs - vesicular basalt

Which of the following are characteristics typical of volcanic domes? Assume a relatively young dome.

- often occur in clusters - rubble-covered surface - steep-sided

Which of the following are erupted by volcanoes?

- pumice - lava - ash

Which of the following processes contribute to the growth of composite volcanoes?

- pyroclastic flows - ash column eruptions -eruption of lava flow

Which of the following volcanic hazards are posed to the surrounding areas by Mount Rainier?

- pyroclastic flows - lava flows - mudflows

Which of the following were hazardous effects produced in mainland Europe by the huge 1783 eruption at Lake, Iceland?

- reduced summer sunlight - unusually cold winter - crop failures and famine

Which of the following accurately describe young lava flows?

- rough upper surface - steep flow fronts

rank the following volcanoes in order of increasing average size. Put the smallest volcano on top and proceed to the largest.

- scoria cone - composite volcano - large shield volcano

The potential hazards associated with a volcano can be assessed by studying various characteristics and the history of the volcano. Match the characteristics with what type of information it provides.

- shape: steep slopes indicate high viscosity, explosive magma; gentle slopes indicate less explosive magma - rock type: chemical analysis determines magma composition and potential for explosiveness - history: the sequence of layers and isotopic dating can indicate the timing and frequency of eruptions

Which of the following are two ways in which volcanic domes grow?

- thick flows of lava break out and flow down the steep surface of the dome - magma injected into the interior expands and breaks up the overlying cooled lava

Match the eruption products with their appropriate magma descriptions.

- thin lava flows: low-viscosity magmas with relatively low volatile contents - lava domes: high-viscosity magmas with relatively low volatile contents - lava fountains: low-viscosity magmas with relatively high volatile contents - eruption columns: high-viscosity magmas with relatively high volatile contents

Which of the following techniques are used to monitor changes in the shape of volcanoes that may indicate magma movement and imminent danger of eruption?

- tiltmeter usage to determine changes in slope - radar imaging to detect small changes in topography - GPS station monitoring

Which of the following situations would represent the highest level of volcanic hazard to a population?

- town located along a river drainage directly downhill from a volcano - town located very near to a volcano

Which of the following are typical hazards associated with scoria cones?

- toxic volcanic gases - falling cinders and volcanic bombs - volcanic ash

Which of the following materials commonly are found in composite volcanoes?

- volcanic tephra - volcanic tuff - andesitic lava flows - lahars and landslide deposits

Gas in basaltic magma is the major controlling factor that determines _____

- what rock types it will form - what landforms it will create

Which of the following are processes that can occur in large magma chambers?

-A partially crystallized magma could be heated by a new, hotter magma entering the chamber -Crystals that form may sink or rise in the chamber -Magma may partially melt the chamber's rock walls, forming a new magma composition

Which of the following are tectonic settings where large magma chambers can form?

-Above subduction zones -in areas of continental collisions -In the oceanic lithosphere above hot spots and within mid-ocean ridges -In the continental lithosphere within regions of hot spots and rifts

Which of the following statements about James Hutton are correct?

-Argued that the time required for geologic processes was much greater than currently perceived -Reasoned that ancient geologic features can be explained by present geologic processes -Realized that layers of sedimentary rock are products of sediment removal and deposition -Worked in scotland

Which of following accurately most shield volcanoes?

-Broad and gently sloping form -Composed of a succession of lava flows

Which of the following produced significant amounts of heat during the early formation of Earth which started approximately 4.5 billion years ago?

-Collision and compression of materials by gravity -Sinking of the molten iron and nickel into Earth's interior -Impacts of meteors and asteroids

Select the factors that directly control the viscosity of magma

-Composition -Crystal content -Temperature

Which of these are ways in which lava flows destroy human-made structures?

-Crushing/bulldozing buildings -Burning buildings -Covering roads

Which of the following are attributes that are evaluated to classify crystalline and clastic rocks?

-Crystal/clast size -Minerals present -crystal/clast shape -Presence/absense of layers

Which of the following best describes a young scoria cone?

-Dark, fresh-looking lava -Central crater at top of a conical hill -Little soil buildup on slopes

Evidence for the cause of the dinosaurs' extinction at the end of the Mesozoic era can be found at

-Deccan Traps, India -Chicxulub crater, Mexico

Which of the following were warning signs prior to the catastrophic eruption of Mount St. Helens in May 1980?

-Earthquakes -Formation of a bulge on its flanks

Which of the following are true of the organization of rows and columns in the Periodic Table?

-Elements in the 1st column have only one electron in their outer shell -Rows indicate the number of electron shells -Elements in the last column are noble gases and have full outer shells

Which of the following are ways in which minerals are used for items typically found in a medicine cabinet?

-Emery boards have wither garnet or corundum -"Scouring agents" in toothpaste contain calcite -Fluoride in toothpaste is derived from fluorite

Which of the following are ways in which older calderas typically become harder to recognize?

-Erosion -Burial by younger rocks -Disruption by faulting

What events occurred at the beginning of the Cambrian Period, approximately 542 million years ago?

-Explosion in the amount of diversity of life -Evolution of more organisms with hard parts -Rapid evolutionary change

The principle of Faunal succession states that ________

-Fossil species show a systematic change with time -Fossil species change upward from older layers of sedimentary rock to younger layers

Which of the following are characteristics of actively erupting volcanoes?

-Fragments of molten rock blasting into the air -Glowing orange lava flowing downhill -Billowing clouds of ash rising into the air

Which of the following phenomena are monitored to predict volcanic eruptions?

-Ground shaking -Changes in topography -Changes in gas output -Heat flow changes

Select all the statements that are correct for cooling magma

-Groundwater can receive heat from magma by conduction -When magma reaches the surface of Earth, thermal energy is transferred to the atmosphere and land surfaces by conduction and radiation -Magma can lose heat when it releases gases either underground or above ground -At depth magma loses thermal energy to the surrounding rocks by conduction

Due to their large size and the volume of erupted gases, which of the following are likely true for flood basalts?

-Highly reflective sulfuric acid droplets in the atmosphere could lead to global cooling -Such eruptions could lead to increased greenhouse warming

Which of the following help determine the outward shape of a crystal?

-How the crystal's growth was affected by the material around it -The arrangement of atoms in the crystal

Why is the lower density of ice compared to liquid water so important?

-Ice floats in water; if it didn't, lakes would freeze solid in winter as surface ice sinks to the bottom -It aids in weathering, as water freezes and expands can pry apart rocks and soil

Which of the following US states were covered by parts of the large Columbia Plateau flood basalts?

-Idaho -Oregon -Washington

What happens at the atomic scale when a mineral cleaves or fractures?

-If all bonds have the same strength, the may be arranged in such a way that the mineral cleaves along 3 planes without passing through an atom -If different bonds between atoms have different strengths, the mineral will cleave along the weakest bond directions -If all bonds have the same strength, they may not be arranged in such a way as to allow cleavage planes to form; mineral fractures

Name the 4 most abundant elements in the entire earth.

-Iron -Oxygen -Silicon -Magnesium

Which of the following statements are true regarding the geologic timescale?

-It is based on data from fossils -It was first created using relative dating and correlation

Which of the following are properties characteristic of calderas?

-Large, Basin-shaped volcanic depression -Bound by steep escarpments -Form from collapse of overlying ground into emptied magma chamber

Which of the following are erupted by volcanoes?

-Lava -Pumice -Ash

Which of the following are volcanic hazards made worse by being located along a river valley directly downhill from a volcano?

-Lava flows -Mudflows -Small pyroclastic flows

Select the three ways in which magma can travel through Earth's crust

-Magma can travel upward as rocks above magma chambers collapse -Magma can travel in regions where tectonic forces have newly fractured solid rocks -Magma can travel through existing fractures in rock, forming fissures and dikes

Identify possible causes of the Great Dying, the mass extinction at the end of the Paleozoic.

-Major changes to ocean structure -Formation of the supercontinent Pangaea -Outpouring of lava -Large meteorite impact

Which of the following are principles of relative dating?

-Original horizontality -Superposition -Cross-cutting relations

Select the correct eras that are used in the geologic timescale from the choices below.

-Paleozoic -Mesozoic

Which of the following factors influence the composition of a magma?

-Partial crystallization -Assimilation and magma mixing -The completeness of the melting of the parent rock -The type of source area

From the list below select the terms that are associated with igneous rocks that have crystals observable by the unaided eye.

-Porphyritic -Pegmatite -Phaneritic

The melting of rock to form magma is influenced mainly by which of the following three factors?

-Pressure -Temperature -Water content

Which of the following settings may be associated with magmatism?

-Rifts -Fractures -Faults

Volcanic vents can take which of the following forms?

-Roughly circular craters -Narrow linear fissures

Which of the following are characteristics typical of volcanic domes?

-Steep-Sided -Rubble-covered surface -Often occur in clusters

Which of the following accurately describe a scoria cone?

-Steep-sided hill -Formed from lava fountains -Composed of a pile of loose, vesicular lava fragments

The common non-silicate mineral groups include which of the following?

-Sulfates -Sulfides -Oxides -Halides -Carbonates

Select four factors that can directly determine how far a magma can rise toward Earth's surface

-Tectonic stresses -Magma pressure -Gas pressure -Density of magma

Which of the following may be said about the mineral whose atomic structure is represented in the image?

-The crystal shape former by the mineral is a cube -The represented mineral is Halite -Na and Cl atoms alternate in the crystal lattice structure

What may be said of the mica mineral in the image?

-The mineral cleaved along one set of planes to split into thin sheets -Bonds between atoms within sheets are stronger than those between atoms linking the sheets

The age of Earth is estimated to be 4.55 billion years. This is determined by dating ________

-The moon -Meteorites

Rocks contain evidence that which of the following processes occurred throughout Earth's history?

-The seas advanced and retreated -Mountains were uplifted and eroded -Different types of creatures lived and became extinct

Which of the following types of data could be used by geologists to estimate the age of past earth events?

-Tree rings -Ice cores -Lake varves

What geologic features could cut across sedimentary rocks and therefore are younger than the rocks they cut across?

-Veins -Dikes -Fractures

Which of the following rock types are associated with basaltic volcanoes?

-Volcanic bombs -Scoria -Nonvesicular basalt -Vesicular Basalt

Gas in basaltic magma is the major controlling factor that determines ___________

-What rock types it will form -What landforms it will create

Isotopes are different forms of an element that have different ___________

-atomic weights -number of neutrons

Rocks are composed of minerals, and minerals are composed of elements

-minerals -elements

Relative dating __________ to determine the order in which geologic events occurred

-uses common sense -uses geologic principles

Rank the following eruption styles in order of increasing explosively. Start with least explosive.

1. Lava flows 2. lava fountains 3. Eruption columns

Put the events of the 1980 Mount St. Helens eruption in order. Begin with the earliest event on top and proceed to the latest.

1. earthquake 2. landslide 3. lateral blast and eruption column

Put the events of the 1980 Mount St. Helens eruption in order. Begin with the earliest event on top and proceed to the last.

1.) earthquake 2.) landslide 3.) lateral blast and eruption column

Put the events of caldera formation in order. Begin with the first event, and end with the last.

1.) magma erupts as ash column, emptying a shallow magma chamber 2.) overlying material collapses into emptied chamber in a series of fault blocks 3.) ash and other pyroclastics fill the subsiding crater 4.) small rhyolite domes form in caldera

Put the events leading to the formation of Crater Lake as we see it today. Put the first (earliest) event on top and proceed to the latest.

1.) massive ash column eruption of a composite volcano empties the magma chamber 2.) overlying volcano collapses into the resulting void 3.) scoria cone forms in the caldera 4.) rain and snowmelt fill the caldera, producing a large and deep lake

List the rocks typically found in calderas, from the top downward. Begin with the rocks at the surface and continue to the rocks the farthest below the surface

1.) volcanic tuff 2.) hard, welded volcanic rock 3.) finely crystalline granite

An unknown mineral sample is scratched by copper wire, but not by a fingernail. Based upon the Mohs Hardness Scale, what is the likely identity of this mineral?

Calcite

Which of the following is not a typical eruption style during the growth of a composite volcano?

Caldera collapse

_____ eruptions are among the world's most lethal natural disasters

Caldera-forming

_____ eruptions can erupt more than 1,000 cubic kilometers of magma, resulting in the collapse of the overlying ground into a large crater.

Caldera-forming

Which of the following are ways in which volcanic domes are commonly destroyed?

Collapse of the steep flanks into block and ash flows Internally derived explosions from trapped gas pressure

The following is a location in which flood basalts erupted:

Columbia Plateau

Which of the following plate boundaries is least likely to produce composite volcanoes?

Continent-continent convergent boundary with a high mountain range (Himalaya)

The ways in which lava flows destroy human-made structures:

Covering roads Burning buildings Crushing/bulldozing buildings

Which of these are ways in which lava flows destroy human-made structures?

Covering roads Burning Buildings and Crushing/bulldozing buildings

Which of the following is a characteristic of crystals and/or clasts that is not used in classifying a rock?

Density

Which of the following are ways in which older calderas typically become harder to recognize?

Disruption by faulting Burial by younger rocks Erosion

Match the eruption style with its description

Eruption column: Ash particles drift back down to Earth hundreds of kilometers or more from the volcano. Tephra erupts high into the atmosphere along with large amounts of hot volcanic gases. Pyroclastic flow: Ash layers are deposited only on and adjacent to the slopes of the volcano. Tephra billows down the slops of the volcano in ground-hugging flows at speeds of over 100 km/hr

Which of the following best describes the temperature of materials typically erupted from volcanoes?

Extremely hot

T/F: A typical volcanic eruption is likely to kill millions of people at a time.

False

T/F: Nearly all volcanic domes are highly symmetrical in shape

False

True or False: A typical volcanic eruption is likely to kill millions of people at a time.

False they typically kill thousands

felsic magma - gas bubbles cannot escape easily, high pressure builds in the magma; typically explosive eruptions; magma is high viscosity basaltic magma - gas bubbles escape easily; little pressure builds in the low magma; typically nonexplosive eruptions; magma is low viscosity

Felsic magma or basaltic magma Gas bubbles escape easilty, little pressure builds in the magma; typically nonexplosive eruptions magma is low viscosity gas bubbles cannot escape easily; high pressure builds in the magma; typically explosive eruptions; magma is high viscosity

Basaltic magma

Fluid lava flows from shield volcanoes; low viscosity

Which of the following are properties characteristic of calderas?

Form from collapse of overlying ground into emptied magma chamber Large, basin-shaped volcanic depression bounded by steep escarpments

Felsic Magma Basaltic Magma

Gas bubbles cannot escape easily; high pressure builds in the magma; typically explosive eruptions; magma is high viscosity Gas bubbles escape easily; little pressure builds in the magma; typically nonexplosive eruptions; magma is low viscosity

What landforms it will create what rock types it will form

Gas in basaltic magma is the major controlling factor that determines _____________________. (Select all that apply) what landforms it will create what race elements will be present in the magma how much silica is present in the molten rock what rock types it will form

high

Gases more easily remain dissolved in liquids at _________pressures.

What is the most abundant mineral in the universe?

Hydrogen

Why is burial necessary for fossil preservation?

It doesn't allow the organism's remains to decompose or be scavenged

1. Volcanic tuff 2. Hard, welded volcanic rock 3. Finely crystalline granite

Lise the rocks typically found in caleras, from the top downward. Begin with rocks at the surface and contine to the rocks the farthest below the surface. Hard, welded volcanic rock Finely crystalline granite Volcanic tuff

baslatic magma: fluid lava flows from shield volcanoes, low viscosity felsic: explosive eruptions from composite volcanoes, high viscosity

Match the magma type with eruption type Basaltic magma/felsic magma fluid lava flows from shield volcanoes, low viscosity explosive eruptions from composite volcanoes, high viscosity

Scoria: Volcanic ash and gases, falling volcanic cinders and bombs Lava: Bull dozing crushing of houses and other structures, burial of roads

Match the volcanic feature with the hazard either lava flor or scoria cone Bull dozing crushing of houses and other structures Burial of roads Volcanic ash and gases Falling volcanic cinders and bombs

convergent

Most composite volcanoes are found along ____________ plate boundaries.

The following events accompanied the 1883 eruption at Krakatau, Indonesia:

Most of a large island collapses into a caldera Tsunami waves strike ships and nearby coastline Largest and loudest explosion in recorded hisotry occurs HIgh eruption column and pyroclastic flows form

Studies of Archean sedimentary rocks indicate that this gas was absent from Earth's atmosphere for most of the Archean

Oxygen

Why are silicate minerals the most abundant minerals in the Earth's crust?

Oxygen and silicon are the most common elements in Earth's crust and are two of the most common elements in Earth's mantle

The largest concentration of composite volcanoes on Earth is located along the _____.

Pacific Ring of Fire

Which chapter of geologic history is the earliest and represents 90% of geologic time?

Precambrian

plate

Proximity to certain types ________ boundaries is the major factor making some places more prone to volcanic hazards than others. plate compositional climate national

1.Massive ash column eruption of a composite volcano empties the magma chamber 2.overlying volcano collapses into the resulting void 3.scoria cone forms in the caldera 4.rain and snow melt fill the caldera, producing a large and deep lake

Put the events leading to the formation of crater lake. put the earliest on top scoria cone forms in the caldera overlying volcano collapses into the resulting void rain and snow melt fill the caldera producing a large and deep lake massive ash column eruption of a composite volcano empties the magma chamber

1. earthquake 2. landslide 3. lateral blast and eruption colummn

Put the events of Mount St. Helens eruption in order. landslide lateral blast and eruption column earthquake

1. Scoria Cone 2. Composite volcano 3. Large shield Volcano

Rank the volcanoes in order of increasing average. Smallest on top and largest on bottom composite large shield volcano scoria scone

Which of the following commonly preceded a volcanic eruption?

Steam eruptions from the volcanic crater Increased gas flow from a volcano Increased heat flow from the volcano

Shape

Steep slopes indicate high viscosity, explosive magma; gentle slopes indicate less explosive magma.

Which principle is used to determine the age of rocks by ordering them from oldest on the bottom to the youngest on the top?

Superposition

composite

The deadly volcanic disasters at Pompeii, St. Pierre, and Mount St. Helens occurred at _______ volcanoes scoria cone shield composite

hazard, risk

The existence of a potentially dangerous situation or even is known as a ________ whereas the likelihood and magnitude of its impact on society is known as its __________.

Basaltic

The largest eruptions on Earths are floods of _________ magma. andesitic basaltic rhyolitic

subduction, convergent

The magma feeding Mount Rainier and the other Cascade volcanoes results from melting associated within the Cascadia _______ zone, which is an ocean-continent ___________ boundary.

If a mineral lacks planes along which it may cleave, what will occur?

The mineral will fracture in an irregular pattern

composite

The steep symmetrical shape of andesitic Mount Rainier indicates that it is a ________volcano. composite shield scoria cone

steep-sided cone

The typical form for a composite volcano is steep sided cone broad circular crater steep-sided dome shallowly sloping shield

andesite

The volcanic rocks associated with domes are felsic to intermediate in composition, and hence are classified as rhyolite and ___________.

What does this ancient sedimentary rock rich in iron indicate about the conditions in which it was deposited?

There was oxygen

Which of the following is not true of calderas?

They are cone-shaped

Which of the following is not true of basaltic lava flows?

They pile up in steep, cone-shaped hills

volcanic hazards

This type of volcano uniquely determines the ______________ likely to be experience by local populations long-term climate volcanic hazards tectonic activity

Fossils can include traces and imprints of plants and animals as well as their remains

True

T/F: A hot, solid rock can melt if water is introduced into the system without a change in temperature or pressure

True

T/F: Proximity to certain types of plate boundaries is the major factor making some places more prone to volcanic hazards than others

True

T/F: Scientists used various techniques to date the age of Earth before the discovery of radioactivity

True

T/F: The complete melting of a source area to form igneous rocks is rare

True

T/F: The volcanic hazards associated with a volcano are dependent upon the type of volcano

True

T/F: You can use both superposition and contact effects to determine that the light-colored volcanic rock is younger than the underlying unit

True

The same volcano may produce both explosive and nonexplosive eruptions.

True

The volcanic hazards associated with a volcano are dependent upon the type of volcano.

True

True or False: The volcanic hazards associated with a volcano are dependent upon the type of volcano.

True

True or False: The volcanic hazards associated with a volcano are dependent upon the type of volcano.

True Different types of magmas produce different types of hazards

Mount St. Helens is a volcano located in which state?

Washington

Which of the following would be evidence that a volcano has been inactive for a long period of time?

Well-developed soils on volcanic rocks

rough upper surface steep low fronts

What describes young lava flows? rough upper surface significant plant cover steep flows fronts sediments in low spots on the surface

totally covered in a fresh blanket of clean, white snow

What is a NOT a characteristic of an actively erupting volcano rapidly melting glaciers/snowpack producing massive mudflows totally covered in a fresh blanket of clean white snow glowing lava flows moving down mountain slopes billowing ash columns risking into sky

town located very near to a volcano town located along a river drainage directly downhill from a volcano

What situation would represent the highest level of volcanic hazard to population? Town located very near to a volcano town located below the flattest slope of a volcano town located directly upwind from a volcano town located along a river drainage directly downhill from a volcano

Why is ice less dense than water?

When water freezes, the molecules arrange into a crystal form in which they are farther apart than in liquid water

lava flows mudflows small pyroclastic flows

Which hazards are made worse by being located along a rive valley driectly downhill from a volcano? lava flows mudflows small pyroclastic burial by falling ash

Ash, Lava, Pumice

Which of the following are erupted by volcanoes? Ash Limestone Lava Pumice

Which of the following is the parameter least likely to provide useful information in assessing the level of danger posed by a volcano to a nearby population center?

age of the oldest volcanic layer present

isotopes that decay slowly are used to date

ancient rocks

The most common volcanic rock found in lava flows on composite volcanoes is _____.

andesite

The volcanic rocks associated with domes are felsic to intermediate in composition, and hence are classified as rhyolite and ____.

andesite

The volcanic rocks associated with domes are felsic to intermediate in composition, and hence are classified as rhyolite and _____.

andesite

Which of the following are erupted by volcanoes?

ash pumice lava

Shield volcanoes are composed primarily of ____ lava flows.

basaltic

Shield volcanoes are composed primarily of _____ lava flows.

basaltic

The largest eruption on Earth are floods of _____ magma.

basaltic

Reduced temperatures and growing seasons in Europe following the 1783 Lake eruption were primarily caused by _____

blocking of sunlight by volcanic ash and aerosols

_____ forming eruptions are the largest and most violent volcanic phenomena.

caldera-

_____ eruptions can erupt more than 1,000 cubic kilometers of magma, resulting in the collapse of the overlying ground into a large crater.

caldera-forming

Huge circular depressions from which volcanoes erupt are called _____.

calderas (or crater)

Volcanic mudflows can be detected remotely by monitoring _____

characteristic rumbling produced as they rush down valleys

Rock Type

chemical analysis determines magma composition and potential for explosiveness

Which of the following is not a way in which volcanic domes are commonly destroyed?

collapse into emptied magma chambers below

Mount Pelée, which killed about 30,000 people with pyroclastic flows in 1902, is a _____ volcano located over a subduction zone.

composite

The deadly volcanic disasters at Pompeii, St. Pierre, and Mount St. Helens occurred at _____ volcanoes.

composite

The steep symmetrical shape of andesitic Mount Rainier indicated that it is a ____ volcano.

composite

What type of volcano is Mount Rainier?

composite

_____ volcanoes produced pyroclastic flows that killed tens of thousands of people at Pompeii and St. Pierre

composite

Almost 40,000 people were killed by the 1883 eruption of Krakatau, Indonesia. Krakatau was a _____ that formed a caldera.

composite volcano

Which of the following plate boundaries is least likely to produce composite volcanoes?

continent-continent convergent boundary with a high mountain range (Himalayas)

Most composite volcanoes are found along _____ plate boundaries.

convergent

Over 90% of Earth's crust is composed of silicate minerals

crust

_____ are common on composite volcanoes because of their abundant clay, loose rocks, moisture, and steep slopes.

debris flows, landslides, and lahars

such eruptions could lead to greenhouse warming highly reflective sulfuric acid droplets in the atmosphere could lead to global cooling

due to their large size and the volume of erupted gases, which of the following are likely true for flood basalts? such eruptions could lead to increased greenhouse warming they produce large amounts of felsic ash, which adds to the fertility of soils worldwide. highly reflective sulfuric acid droplets in the atmosphere could lead to global cooling such eruptions in the future are likely to result in the loss of all life on Earth, as they did in the past

Scoria cones are composed primarily of ____.

ejected fragments of vesicular lava

eruption: tephra erupts high into the atomosphere along with large amounts of hot volcanic gases ash particles drift back down to Earth and hundreds of kilometers or more from the volcano pyroclastic flow: ash layers are deposited only on and adjacent to the slopes of the volcano tephra billows down the slopes of the volcano in ground-hugging flows at speeds of over 100 km/hr.

eruption vs phyroclastic flow tephra erupts high into the atmosphere along with large amounts of hot volcanic gases tephra billows down the slopes of the volcano in ground-hugging flows at speeds of over 100 km/hr ash layers are deposited only on and adjacent to the slopes of the volcano ash particles drift back on Earth hundreds of kilometers or more from the volcano

Felsic Magma

explosive eruptions from composite volcanoes; high viscosity

Which of the following best describes the temperature of materials typically erupted from volcanoes?

extremely hot

Which of the following are typically hazards associated with scoria cones?

falling cinders and volcanic bombs toxic volcanic gases volcanic ash

True/False: A typical volcanic eruption is likely to kill millions of people at a time.

false

True/False: All hills made of volcanic rocks are volcanoes

false

Which of the following is not a hazard typically associated with scoria cones?

fast-moving lava flows

Which of the following accurately describe a scoria cone?

formed from lava fountains steep-sided hill composed of a pile of loose, vesicular lava fragments

Caldera

forming eruptions are the largest and most volcanic phenomena shield dome caldera scoria cone

Carbon dioxide, hydrogen sulfide, and sulfuric acid are ____ associated with volcanic eruptions that are hazardous to humans, livestock, and crops.

gases

Shield volcanoes typically have ____ sloes than composite or scoria cone volcanoes.

gentler

The existence of a potentially dangerous situation or event is known as a(n) _____, whereas the likelihood and magnitude of its impact on society is known as its _____.

hazard and risk

The existence of a potentially dangerous situation or event is known as a(n) _____, whereas the likelihood and magnitude of its impact on society is known as its _____.

hazard; risk

Gases more easily remain dissolved in liquids at ____ pressures.

high

Gases more easily remain dissolved in liquids at _____ pressures.

high

Which of the following is not a typical hazard posed to human-made structures by lava flows?

high winds

Volcanism culminating in the Yellowstone eruptions of the past 2 million years has produced a set of overlapping calderas that stretch in an arc to the southwest from Yellowstone to southeastern Oregon, suggesting that North America has been riding to the southwest over a _____ for at least the past 12.5 million years.

hot spot

Which of the following commonly precede a volcanic eruption?

increased heat flow from the volcano increased gas flow from a volcano steam eruptions from the volcanic crater

Of the 4 most abundant elements in the entire Earth, which is the most common?

iron

When fluid lava erupts onto the surface, it typically produces _____

lava flows

Lava flowing in _____ in Hawaii can remain hot and fluid for so long that it flows all the way to the ocean.

lava tubes

Lava flows are produced by basaltic magmas that contain _____ than those that produce scoria cones.

less gas

Flood-basalt eruptions are fed by _____

long fissures/dikes

Long, thin lava flows are typically produced by _____.

low-viscosity lavas

According to the fossil record, _____ events have coincided with the approximate times when flood basalts were erupting.

mass extinction

Volcanic eruptions can produce huge floods by _____.

melting ice sheets

An older scoria cone would have _____ compared to a younger scoria cone.

more soil and plants

Older lava flows tend to have surfaces that are _____ than younger lava flows.

more subdued and have more soil and plants

Volcanic vents can take which of the following forms?

narrow linear fissures and roughly circular craters

Which of the following rock types are associated with basaltic volcanoes?

nonvesicular basalt scoria volcanic bombs vesicular basalt

Proximity to certain types of _____ boundaries is the major factor making some places more prone to volcanic hazards than others.

plate

Rhythmic seismic activity tends to _____ volcanic eruptions.

precede and accompany

In A.D. eruption at Mount Vesuvius in Italy, which killed about 25,000 people in Pompeii and Herculaneum, consisted mainly of _____ that roared down the slopes of the composite volcano.

pyroclastic flows

The A.D. 79 eruption at Mount Vesuvius in Italy, which killed about 25,000 people in Pompeii and Herculaneum, consisted mainly of _____ that roared down the slopes of the composite volcano.

pyroclastic flows

The typical components of a composite volcano.

pyroclastic flows lava flows mudflow deposits

flood basalts

represents the largest igneous eruptions on Earth, with some covering ten of thousands of square kilometers. Curtains of fire rhyloite ash columns flood basalts

Which of the following materials is not produced by erupting volcanoes?

sandstone

Which of the following are typically erupted from a volcano?

scalding hot ash, lava, and gases

scoria cones: steep sided, cone-shaped hill hundreds of meters high, with a small crater at the summit; composed of cinders and volcanic bombs shield volcano: broad, gently sloping conical hill or mountain, with fissures along its summit; composed of basaltic lava flows composite volcano: moderately steep, cone shaped mountain thousands of meters high with a crater at the top; composed of interlayered lava flows, pyroclastics, and volcanic mudflows volcanic dome: steep-sided, dome-shaped hill hundreds of meters high; composed of felsic lava

scoria cone, shield volcano, composite volcano, volcanic dome moderately steep, cone-shaped mountain thousands of meters high with a crater at the top, composed of interlayed lava flows, pyroclastic, and volcanic mud flows steep-sided, cone-shaped hill hundreds of meters high, with a small crater the summit, composed of cinders and volcanic bombs steep-sided, dome-shaped hill hundreds of meters high; composed of felsic lava broad, gently sloping conical hill or mountain, with fissures along its summit; composed mainly of basaltic lava flows

Which of the following lists the four types of volcanoes shaped like hills and mountains?

scoria cone, shield, composite, dome

Magma rising through the crust fractures rocks, producing rhythmic, repeating

seismic shaking

non explosive outpouring of lava

shield volcanoes are built up primarily by relatively high viscosity, dome forming eruptions explosive ash forming eruptions nonexplosive outpouring of lava

When lava flows reach the ocean, they _____.

solidify and add land to an island

Which of the following commonly precede a volcanic eruption?

steam eruptions from the volcanic crater increased gas flow from a volcano increased heat flow from the volcano

The typical form for a composite volcano is a _____.

steep-sided cone

Which of the following is a recognizable characteristic of recent calderas?

steep-sided, basin-shaped depression

A composite cone would be expected to have slopes that are _____ than those of a shield volcano.

steeper

The magma feeding Mount Rainier and the other cascade volcanoes results from melting associated within the Cascadia _____ zone, which is an ocean-continent ______ boundary.

subduction and convergent

The magma feeding Mount Rainier and the other cascade volcanoes results from melting associated within the Cascadia _____ zone, which is an ocean-continent _____ boundary.

subduction; convergent

A large volcanic eruption in a populated region could kill _____ of people at a time. Choose the most likely, or common, answer.

tens of thousands

Which factor below largely controls what rock types and landforms develop from basaltic magma?

the characteristics and behavior of the gas in the magma

Decreasing pressure on a liquid that contains dissolved gases will result in _____.

the formation of gas bubbles

Shield volcanoes have low slopes primarily because _____.

the low viscosity of basaltic magma allows it to flow downhill for long distances

The higher the gas pressure builds in magma, _____.

the more explosive an eruption it is likely to produce

History

the sequence of layers and isotopic dating can indicate the timing and frequency of eruptions

Which of the following is not evidence of recent volcanic activity?

thick, well-developed soil

thin lava flows - low viscosity with low volatile contents lava domes - high viscosity with low volatile contents lava fountains - low viscosity with high volatile contents eruption columns - high viscosity with high volatile contents

thin lava flows, lava domes, lava fountains, eruption columns low viscosity magmas with relatively high volatile contents low viscosity magmas with relatively low volatile contents high viscosity magmas with relatively high volatile contents high viscosity magmas with relatively low volatile contents

Which of the following is not a characteristic of an actively erupting volcano?

totally covered in a fresh blanket of clean, white snow

Volcanic domes form from the accumulation of ____ lava over a volcanic vent.

viscous

Volcanic domes form from the accumulation of _____ lava over a volcanic event.

viscous

Volcanic domes form from the accumulation of _____ lava over a volcanic vent.

viscous

Steep-sided hills of viscous lava that pile up over volcanic vents are known as ____.

volcanic domes

Changes in topography, water chemistry, and gas output all are used to help predict ____.

volcanic eruptions

scalding hot ash, lava, and gases

which of the following are typically erupted form a volcano? scalding hot ash, lava, and gases large quantities of liquid water ice and snow, combined with stream

continent-continent convergent boundary with a high mountain range

which of the following plate boundaries is least likely to produce composite volcanoes? continent-continent convergent boundary with high mountain range ocean-continent convergent boundary with a subduction zone ocean-ocean convergent boundary with a subduction zone

crushing/bulldozing buildings burning buildings covering roads

which of these are ways in which lava flows destroy human-made structures? crushing/bulldozing buildings burning builds blowingd down buildings with winds covering roads

pyroclastic flows mudflows lava flows

which volcanic hazards are poses to the surrounding areas by Mount Rainier? pyroclastic flows mudflows lava flows basaltic floods