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
