Natural Disasters Exam 2, Chapter 7 Exam (Volcano Case Histories:Killer Events), Chapter 6 Exam (Volcanic Eruptions:Plate Tectonics and Magma)

100 year flood probability

1% probability of that flood in any year

State with most thunderstorms

Florida

Silicon and oxygen link up to form the silicon-oxygen ______________.

tetrahedron

In Icelandic-type eruptions, low-viscosity, low-volatile content lava erupts peacefully.

True

Pyroclastic flows can travel across bodies of water.

True

Volcanic eruptions can result in the formation of tsunamis.

True

Mechanisms of controlling runoff

You are going to put up levees

You're welcome

Your lord and saviors RnB

Rock may melt by _______________.

All of these choices are correct

Spreading centers are an ideal location for volcanism because ______________.

All of these choices are correct

Greenhouse effect (definition and causes)

Warms atmosphere

Several geologic phenomena are being studied as signs of an impending volcanic eruption. These include seismic waves, ______________, and the release of gases.

ground deformation

Most of the people killed by the Mount St. Helens eruption of 1980 __________.

had gone around barriers meant to keep people out of 'harms' way

The Mt. Pinatubo endangered people, animals, and property when its 1991 eruption resulted in __________.

lahars and pyroclastic flows

Most Icelandic eruptions are __________.

peaceful fissure eruptions

Over _________ of volcanism is associated with the edges of tectonic plates.

90%

Hadley cells

The rising at the tropical/equator

The typical trend in a rising plume of subduction-zone magma is to increase the ____________.

All of these choices are correct

Why are low-latitudes the most dangerous latitudes to have a large volcanic eruption occur?

Ash and gases from low-latitude eruptions are spread around Earth to the greatest degree.

The two most active Cascade Range volcanoes over the past 4,000 years are _______________.

Mt. St. Helens and Mt. Shasta

Height of tsunami in open ocean first height of tsunami encountering land

One meter

Specific heat

Amount of heat required to raise the temperature of water

In 1985, __________ produced a minor eruption that melted part of a glacier near its summit, sending a lahar down its slopes and killing at least 22,000 people.

Nevado Del Ruiz, Colombia,

Highest wind speeds associated with

tornadoes(318)

In 1883, __________ exploded and the resulting tsunami killed 36,000 people on Java and Sumatra.

Krakatau

In the United States, there was great concern in the early 1980s when earthquakes were frequent, including harmonic tremor, and four magnitude 6 earthquakes caused damage near __________.

Long Valley Caldera in California

Seafloor spreading generates __________ magma

basaltic

Tsunami risk related to landslides and debris flows and associated with volcanic flank collapse

Hawaii

Weather event with the highest death toll

Heat related weather events

Deaths associated with flooding

50% of all deaths associated with flash flooding is vehicle related

__________ eruptions are the most violent types of explosive eruptions.

Plinian-type

Internal mechanisms within a hurricane

Warm rising air

Requirements for hurricane development

Warm water, unstable air, low wind speeds in upper atmosphere

Latent heat and condensation

Water going from vapor to liquid, that's causes storms.

Hurricane wind speeds (right-hand side of storm)

Wind speed + the speed the storm is moving in

You're welcome

Your lord and saviors :) RnB

Slow flowing, more viscous basaltic lava commonly has a rough, blocky texture called ________.

aa

A caldera collapse occurs ________________.

after the magma chamber is mostly empty

In August 1986, a gigantic volume of __________ belched forth from Lake Nyos in Cameroon and swept down the adjacent valleys asphyxiating 1,700 people.

carbon dioxide

Cyclonic rotation - northern hemisphere

Counter-clockwise

Nature of hurricane rotation (north hemisphere)

Counter-clockwise

Because volcanologists are aware of the potential hazards, no volcanologist has ever been killed studying a volcano.

False

Eruptions in Hawaii are always peaceful.

False

Scoria cones form from repeated eruptions over the course of many decades.

False

The Volcanic Explosivity Index (VEI) ranges from 1 to 100.

False

The higher the viscosity of magma, the more fluid is its behavior.

False

The most peaceful eruptions are __________ eruptions.

Icelandic type

What triggers of tsunami (not just earthquakes!)

Land slide, volcano, asteroids, earthquake

The three most recent catastrophic Yellowstone eruptions occurred at 2.06 million, 1.29 million, and 640,000 years ago.

True

The variations in the composition of magmas govern whether eruptions are peaceful or explosive.

True

The energy behind the 1902 pyroclastic flow that destroyed St. Pierre came from _________________.

All of these choices are correct

Strongest winds in the hurricane (where?)

Eye wall

Seiche

Mini tsunami in a lake

Low- and high-pressure systems - cyclonic vs anticyclonic

Areas of high pressure are called anticyclones, whilst low pressure areas are known as cyclones or depressions.

The formation of a giant continental caldera includes all but which of the following?

Basaltic eruptions begin forming circular fractures surrounding the bulge.

__________ melting occurs when a rock melts due to a lowering of pressure.

Decompression

Hot spots occur only under oceanic plates.

False

Less than 20 percent of Earth's magma extruded through volcanism occurs at oceanic spreading centers.

False

Magma at spreading centers is low-temperature, high-viscosity, and granitic, with easy escape of gases, providing all the factors that promote the peaceful eruption of magma.

False

Cause of thunder

Lightening heats up the air

Types of jetstreams

Polar and Sub-tropical jet streams, ours is polar

Month of the year for most deadly hurricane landfall?

September

Where are the major zones of volcanism?

There are three main places where volcanoes originate: Hot spots, Divergent plate boundaries (such as rifts and mid-ocean ridges), and. Convergent plate boundaries (subduction zones)

When the relative humidity reaches 100%, excess water vapor condenses and forms liquid water. This temperature is the ___________.

dew point temperature

Important requirements for hail to form are _______________________________.

1. Large thunderstorms with buoyant hot air rising from heated ground2. Upper-level cold air creating maximum temperature contrasts3. Strong updrafts to keep hailstones suspended while adding coatings of ice onto ever-growing cores

Over _________ of Earth's magma extruded through volcanism takes place at the oceanic spreading centers.

80%

What do dew point and relative humidity have to do with eachother?

Air temperature at which relative humidity is 100%, which then excess water vapor condenses and forms liquid water

The viscosity of magma is lowered by __________.

All of the choices are correct.

Why does the magma from some volcanoes flow smoothly and relatively peacefully, while the magma from other volcanoes blasts forth violently and deals death over wide areas?

All of these are correct

Mt. Rainier, Washington, is number one on the danger list of many U.S. volcanologists because of its __________.

All of these choices are correct

Violent causes of death from volcanic eruptions include _______________.

All of these choices are correct

Mineral growth in magmas at the surface with temperatures around 1,000 to 1,200°C occurs in the following way

Both of these are correct

During the 1990s, hundreds of trees were killed at Mammoth Mountain, California, by the diffuse emission of _________ gas.

CO2

Tsunami risk in the Atlantic Ocean (what is the source of the potential risk?)

Canary Islands, (Volcanic Islands)

Coriolis effect and movement of hurricanes (northern hemisphere)

Causes storms in North America that turn right

Hawaiian volcanoes unlikely to erupt include _________________.

Diamond Head, Oahu

Cause of April Fool's Day tsunami in Hilo, Hawaii

Earthquake in Alaska

Airborne pyroclasts have their finest grains settle down from the atmosphere first, closest to the volcano, followed by progressively coarser material at greater distances away.

False

All volcanic activity in a failed rift ceases once the rifting fails.

False

Antarctica does not lie above any hot spots.

False

At Lake Nyos in 1986, a gas cloud wiped out all nearby plant and animal life.

False

At oceanic spreading centers, magmas are rhyolitic in composition.

False

Gas bubbles decrease in number and volume as magma keeps rising upward to lower pressures, helping to propel magma upward through fractures or pipes toward an eruption.

False

Hawaiian volcanoes produce andesitic lava.

False

If the magma cools and solidifies below the surface, it crystallizes as volcanic rocks.

False

Lassen Peak is unusually large, SiO2-rich, lava dome in Mt. Saint Helens.

False

Most volcanism is associated with hot spots.

False

No magmas contain dissolved gases.

False

Nuee ardente (French for glowing cloud) is another term used to describe a lava flow.

False

Pyroclastic flows cannot travel down all sides of a volcano simultaneously.

False

The highest temperatures and highest SiO2 contents are in basaltic magma, giving it the lowest viscosity and easiest fluid flow.

False

Transform faults have lots of associated volcanism because the strike-slip motions keep a "lid" on the hot asthenosphere below, allowing it to melt.

False

How to protect yourself in a tsunami event

Go to higher ground and stay there!!!!!

Origin of the word "tsunami"

Harbor Wave

As minerals form in magma kept at a constant temperature, what happens to the viscosity of that magma?

It increases

Stream equilibrium controls

It is going to change its slope

Controls on the shift of the ITCZ

It is gonna shift around with the season. It moves north in the Northern Hemisphere summer and south in the Northern Hemisphere winter. Therefore, the ITCZ is responsible for the wet and dry seasons in the tropics.

What was the origin of the gas that killed 1,700 people in Cameroon in 1996?

It leaked upward from basaltic magma underlying a lake.

This volcano erupted in 1883 in the Sunda Strait between Sumatra and Java, exploding with a loudness heard 3,000 miles away, then collapsing into its magma chamber, making a caldera and setting off a tsunami that killed at least 36,000 people.

Krakatoa

During the summer of 1783, the greatest lava eruption of historic times poured forth at _________, accompanied by the release of an enormous volume of gases that enshrouded much of northern Europe in a "dry fog" or blue haze rich in SO2 (one of the visible components of today's urban smog).

Laki, Iceland

Weather conditions with different pressure systems

Low-pressure systems are associated with clouds and precipitation that minimize temperature changes throughout the day, whereas high-pressure systems normally associate with dry weather and mostly clear skies with larger diurnal temperature changes due to greater radiation at night and greater sunshine during the day.

Avulsion and channelization processes

Lower level in the flood plan

Base-level

Lowest level

On 8 May 1902, a massive eruption of __________ killed 30,000 people in the town of St. Pierre.

Mont Pelée, Martinique,

Braided stream characteristics

More sedimate than it can actually carry

Crater Lake, Oregon, fills the caldera of ____________ which collapsed about 7,600 years ago.

Mt. Mazama

A genuine success story of advance warning before a large eruption occurred in the Philippines in 1991 before the climactic eruption of _________________.

Mt. Pinatubo

On 20 February 1943, a new volcano named __________, a scoria cone, was born when an eruption rose up through a farm field near a village in Mexico.

Paricutin

The most famous of all volcanoes probably is Vesuvius, and the most famous of its eruptions are those of 79 ce, which buried the cities of ____________.

Pompeii and Herculaneum

Hydrograph plot

Rate of flow, or volume

____________ in the Aegean Sea underwent an explosive series of eruptions around 1628 bce that buried the Bronze Age city of Akrotiri on Thera to depths of 70 meters.

Santorini

Spreading centers have relatively peaceful eruptions of magma because the __________.

SiO2-poor magma is at high temperatures.

Trends in deaths associated with lightning

Steady decrease

__________ are steep-sided, symmetrical volcanic peaks built of alternating layers of pyroclastic debris capped by high-viscosity andesitic to rhyolitic lava flows that solidify to form protective caps.

Stratovolcanoes

Saffir-Simpson scale and the categories of storms

Strength of the hurricane! Measured by the wind speed.

The volcanic explosivity index (VEI) measures size of volcanic eruptions on a scale of 0 to 8. Between 1500 and 1980, one VEI 7 eruption occurred. This was ______________.

Tambora in 1815

Tsunami generation from earthquakes caused by vertical movements of the crust along subduction zones.

The crust is moving vertically and the crust is being squeezed

Enhanced Fujita scale

The way of determining tornado wind speed and better assessing the damage because of the closer relation of the wind speeds for each tornado. (google E1,E2...) (Measures tornadoes and tells you max. wind speed)

About 80 percent of the magma reaching Earth's surface is basaltic, with only about 10 percent andesitic and 10 percent rhyolitic.

True

Although there are 92 naturally occurring elements, a mere eight make up more than 98 percent of Earth's crust.

True

At Mt. St. Helens, about 60 people were killed in 1980, primarily by pyroclastic flows and effects related to lateral blast.

True

At a depth of 32 km, basaltic rock melts at around 1,400°C but this same rock will melt at only 1,250°C at Earth's surface.

True

Basaltic magma has the lowest viscosity, so more of it reaches the surface; the more viscous rhyolitic magmas are so sluggish that they tend to be trapped deep below the surface where they cool, solidify, and grow into the larger mineral crystals of plutonic rocks.

True

Below the ocean basins, basaltic magmas have low contents of SiO2, low temperature, low viscosity, and allow easy escape of gases, producing peaceful eruptions.

True

Beneath continents, rising basaltic magmas are contaminated by sediments and continental-crust rocks, altering magma compositions; the resultant andesitic-to-rhyolitic magmas have high contents of SiO2, relatively low temperatures, and high viscosity.

True

Decreasing the pressure on hot rock generates most magma.

True

Highly fluid basaltic lava may cool with a smooth, ropy surface called pahoehoe, whereas lower temperature, slower flowing, more viscous basaltic lava commonly has a rough, blocky texture called.

True

Hot spots can be under the oceans, under the continents, in the center of plates, and at spreading centers.

True

If lava reaches the sea or a lake it cools rapidly into ellipsoidal masses called pillow lava.

True

If the magma reaches the surface, it forms volcanic rocks, named for Vulcan, the Roman god of fire.

True

If two magmas have the same composition, the hotter of the two magmas will have a lower viscosity.

True

Lava domes form when high-viscosity magma with low-volatile content cools quickly, forming a hardened dome a few meters to a kilometer or so in height.

True

Magma at great depth does not contain gas bubbles because the high pressure at depth keeps gas dissolved in solution.

True

Magma rising in a subduction zone tends to get more "contaminated" with high-silica minerals than does magma rising in a spreading ridge.

True

Oxygen and silicon are so abundant in Earth's crust that their percentages dwarf those of all other elements.

True

The eruption of Nevado del Ruiz in Columbia in 1985 dropped hot pyroclastic debris onto glaciers, resulting in lahars.

True

The largest number of hot spots lies beneath Africa.

True

The lowest temperatures and highest SiO2 contents occur in rhyolitic magma, material so viscous that it commonly does not flow.

True

The most abundant dissolved gas in magmas is H20.

True

The most dangerous volcanoes tend to be in the same general plate-tectonic settings as the largest earthquakes in the world.

True

The plate-tectonic process responsible for volcanoes in the Pacific Northwest region of North America is identical to the cause of the region's great earthquakes—subduction of the Juan de Fuca Plate.

True

The primary reason magma forms at subduction zones is that the subducting plate carries a cover of sediments, water, and hydrated minerals down with it, which lowers the temperature required for the adjacent overlying mantle lithospheric rock to melt.

True

The process of mineral formation in a cooling magma is called crystallization.

True

The radiocarbon process of documenting major eruption dates for volcanoes in the past 50,000 years or so is the same as that used to work out dates of major prehistoric earthquakes.

True

Water circulating at thousands of feet below the surface can be heated to temperatures far above 100°C (212°F) without boiling because the pressure of the overlying groundwater body is so great.

True

When gas escapes quickly and violently from lava it may produce a frothy glass full of holes left by former gas bubbles; this porous material, known as pumice, contains so many holes it can float on water.

True

When it comes to volcanic hazards, the key problem is how easily the dissolved gases can escape from the magma.

True

While there are many hundreds of different minerals, the overwhelming majority of Earth's crust is composed of just eight common rock-forming minerals.

True

Period and wavelength of tsunami waves compared to wind-generated waves are

Tsunami waves are longer than wind-generated

Volcanic eruptions with which of the following VEIs happen the most often?

VEI of 3

What is the volcanic explosivity index (VEI) of a Yellowstone super-eruption?

VEI of 8

_________ eruptions are common first phases in the eruptions of volcanoes as they "clear their throats" before emitting larger eruptions.

Vulcanian-type

Formation of thunderstorms

Warm ,moist air rises into cold air

The Toba eruption 74,000 years ago may have __________.

caused a great reduction in the worldwide human population

Pyroclastic debris is __________.

chucks of magma and rocks blown into the air by gas in a volcanic eruption

A well-formed conical volcano located above an active subduction zone that has not erupted in 12,000 years is __________.

dormant, but will likely erupt again at some point

Most rifting occurs at spreading centers __________.

located below sea level

The presence of water ________ the melting point of rock.

lowers

Definition of fronts along with types of fronts

means The boundaries between different air masses. Cold Fronts Warm air in front of cold air then Warm Fronts are Cold air in front Warm air

The number of active "hot spots" on Earth over the last 10 million years active is __________.

more than 100

Which of following correctly lists the order in which the listed minerals form in a cooling magma from the first to the last to form?

olivine, pyroxene, amphibole, biotite mica, and quartz

If basaltic lava reaches the sea or a lake, it cools rapidly into ____________ lava.

pillow

Dome collapse, overspilling crater rim, direct blast and eruption column collapse are all ways to generate __________.

pyroclastic flows

If all of the following rocks were to completely melt and reach the same final temperature, which would produce magma with highest viscosity?

rhyolite

A mantle hot spot has generated a long-lived plume beneath Yellowstone National Park, and the North American continent is moving __________ above it about 2 to 4 cm/yr.

southwestward

Some of Earth's most beautiful mountains are ________, including Mt. Kilimanjaro in Tanzania, Mt. Shasta in California, Mt. Rainier in Washington, and Mt. Fuji in Japan.

stratovolcanoes

What erupts in a geyser?

superheated water and steam

What is the cause of volcanism at Italy's Vesuvius, Stromboli, Vulcano, and Etna?

the subduction of Mediterranean seafloor beneath Europe

Active volcanoes today in Oregon and Washington, including Mt. St. Helens, result from _________________.

the subduction of the Juan de Fuca Plate beneath North America

The three 'Vs' of volcanology are __________________.

viscosity, volatiles, and volume

In magma, __________ is the most abundant dissolved gas.

water vapor (H2O)

A shield volcano has a great ___________.

width compared to its height