GLG112 Final

1. An extremely large volcanic depression 2. in the ground was produced by the catastrophic eruption of an older steep-sided volcanoWhat are the two types of volcanoes?

1- Caldera 2- Composite

When ash breaches this altitude in the atmosphere, it will have an overall cooling effect on climate

11km

Tsunami are typically about _____ high in the open ocean, and 6-15 m high on reaching shallow water.

1m

rupture length of a M10 earthquake

40,000 km or the entire circumference of the Earth

The current size of yellowstones magma chamber

55m X 20m X 6 deep

What factors influence flood severity?

Amount and distribution of precipitation in drainage basin (valley) Rate precipitation soaks into the ground Level of soil saturation before the storm

Which of the following influences whether a flood occurs?

Amount of discharge, height of levees, urbanization, width of channel

What does the Volcanic Explosivity Index (VEI) describe?

Amount of material ejected and height of eruption column

Data recorded on a seismogram shows these two properties of seismic energy.

Amplitude and duration of shaking

Distance between arc and trench?

Angle of Subduction which is determined by the rate of movement and density of plate.

Ocean-Ocean Subduction Zones

Associated with Island Volcanic Arc, seamount, magma rising

Rheological Layers- plastic solid

Asthenosphere lower mantle

What is barometric pressure?

Barometric Pressure is the weight of a column of air that is above any given point

Where will a stream have the fastest velocity?

Before the delta where the stream has the most water

Why are shield volcanoes flat?

Composed of successive stacked mafic lava flow(lava flow had a low viscosity)

How do cyclones gain strength and lose strength?

Cyclones gain strength over warm ocean water and lose strength over land Warm sea surface water evaporates, providing more moisture to the storm. Cyclones also lose strength as they move over cold water.

steps of Earthquakes

Elastic deformation- Apply stress to rocks (compression, extension, sliding) and rocks absorb energy over time and bend (slowest process) Brittle Deformation- rock reaches critical stress and moves (moves) Elastic Rebound- rocks return to original shape but have been broken and moved )offset a long fault

Earthquakes lead to:

Fire-result of broken gas lines and electric lines Landslides- loose sediment Tsunami

Continental Drift evidence

Fit together Fossils match Rock types match Glacial Records/ striations

Normal Faulting

H.W goes down relative to footwall up

Reverse Faulting

HW. goes up relative to footwall goes down Compression causes crust thickening

Which of the following are NOT associated with a hurricane?

High atmospheric pressure

How does temperature affect viscosity of magma?

Higher temperature magmas have a lower viscosity

Which of the following occurs in a lava tube?

If it drains it becomes a long tube, insulates lava, and surface of lava flow solidifies to form a roof over flowing lava

Which of the following commonly precede a volcanic eruption?

Increased gas flow, heat flow, and stem eruptions from the volcanic eruption

whats associated with Deep Ocean Trenchs

Island Arcs

S waves

Lateral swing Shear waves(cuts through rocks) Only travels through solids

Convection

Liquids or plastic solids cycling, hot to cold and cold to hot

Rheological Layers- rigid solid

Lithosphere and inner core

Tsunami typically have _________________________ relative to wind-blown waves.

Long periods short wavelengths

Strike Slip

Look across fault to see motion Left and Right Lateral

Which of the following would not be a result of magma slowly rising through thick continental crust?

Magma viscosity increases

Which of the following typically decreases downstream in a river?

Maximum sediment grain size

The downfall of which ancient civilization in the Mediterranean closely followed the caldera-forming eruption at Santorini?

Minoan

Transform- sliding motion

No subduction, mountain building, no volcanism Transform faults link up spreading centers at divergent boundaries

Ocean-Cont Subduction Zone

Ocean trench= deepest part, where the plates meet, always where oceanic subduction Oceanic Plate subducts under cont. Plate

Rheological Layers- Liquid

Outer core

Faster: P waves or S waves?

P waves

Asthenosphere

Rigid Mantle is the uppermost part Flows and melts

How are tsunamis generated?

Rocks absorb strain and deform Brittle deformation- megathrust earthquake on reverse fault, rocks elastically rebound, pushing all water above epicenter, water rises and collapses sending tsunami out in all directions Rocks reform to original shape and may be moved up down left or right

How is magma formed at divergent boundaries, continental rifts, and hot spots?

Rocks melt as the pressure decreases

What controls wave run-up height and distance?

Slope of seafloor Topography of the shore Offshore barriers Tsunami walls Character of the streets

What would you expect a flash (rapid) flood to look like?

Small discharge, high flood level

The location of the largest and longest seismic gap in California (name the fault and region of the gap using direction e.g. Northern Cascadia fault, Southern Wasatch fault)

Southern San Andreas Fault in California

The December 26, 2004 Indonesian earthquake occurred:

Subduction along indonesian and australian plate

Choose the statement that best describes how flooding is caused by storm surge?

The ocean rises up and under the low pressure system and wind pushes the water on shore as the hurricane move

Why are there different types of volcanoes?

The type of volcano is determined by the chemistry of the magma and amount of dissolved gas in the magma and how long it erupts for

Conduction-

Transfer heat through two or more surfaces touching

Cont-Cont- Collision

Upper crust peels off and stacks on top of each other

The measure of a volume of material ejected and height of the eruption column

VEI

P Waves-

Vertical jolt Compressional Contraction and expansion Can travel through liquids, solids, and gases

What causes an explosive eruption?

Volatiles(gases) rapidly expand when a magma chamber is depressurized, causing an explosion

This type of volcano is typically associated with composite cones and calderas, as it typically form after major explosive eruptions

Volcanic Dome

a small monogentic volcano built out of lava flows

Volcanic dome

What typically happens when tributaries join the main river?

Water velocity, channel size, amount of discharge, total sediment load increase

Coriolis Effect

Wind/ocean current deflect to the right in the northern hemisphere Wind/ocean current deflect to the left in the southern hemisphere

A delta forms when:

a river slows and deposits sediment as it enters the sea

strain

absorbed

high barometric pressure

air descends and creates clear skies (hot dry)

stress

applied

The composes the mushroom cloud of a plinian eruption

ash <2mm

Where does convection occur?

asthenosphere

shield volcanos are composed primarily of _____ lava flows

basaltic

Hazards associated with basaltic lava flows and eruptions are:

burials of roads and neighborhoods by lava flows, house fires, and volcanic gases and methane

This type of volcano is created during a superpilan eruptions as a magma chamber is completely emptied and collapses

caldera

This volcano is relatively small and composed of volcanic cinders. What kind of volcano is it?

caldera

A steep-sided volcano is built from layers of loose rock by a (mostly) gas rich eruption of low viscosity magma. What type of volcano is it?

cinder

Eruptions on the islands of Santorini in Greece and Krakatau in Indonesia resulted in:

collapse of a huge caldera that caused part of an island to disappear beneath the sea, a huge ash column and pyroclastic flows, destructive waves that traveled across the sea

describe a scoria cone

composed of a pile of loose vesicular lava fragments formed from lava flows steep-sided hills

A polygenetic volcano built out of repeated, alternating effusive and explosive eruptions

composite

This relatively large, symmetrical volcano contains interlayered lava flow, pyroclastic deposits, and volcanic mudflows. What kind of volcano is it?

composite

what kind of volcano is mt. saint helens?

composite

magma becomes more felsic over time as it moves through this

cont. crust

Ingenious-extrusive

cools from lava, fast cooling

Ingenious-intrusive

cools from magma, slow cooling ex granite Slower it cools= stronger it is

How is Magma formed?

decompression melting, addition of heat and gas

The name for the stream pattern that resembles the shape of an oak tree

dendrite

The amount of water flowing through a channel over a given amount of time is called its:

discharge

an increase in water velocity and channel size will cause an increase in this

discharge

the size of this area will determine how much water enters a stream

drainage basin

Radial drainage pattern

drainage is found on symmetrical mountains such as volcanos

structurally controlled pattern

drainage occurs on eroded layers or structures and then cuts across a ridge to follow a different weak layer

The number of these per day are a good indication of how close magma is to the surface

earthquakes

a stream that doesn't flow all year round

ephemeral

Why does pahoehoe have a lower viscosity than a'a?

erupts at a high temp

What types of rocks would be common in a composite volcano?

felsic and intermediate lava flows and tephra

Strombolian eruptions are caused by?

gas rich magma

What does it mean when the amount of SO2 emitted from the vent of a composite cone or caldera quickly decreases?

gases trapped

Ash is technically this and therefore planes can't fly through ash clouds

glass

One way to monitor active volcanos

ground inflation gas flux

grain size is largest in this region of a stream

headwater

How does the addition of water cause melting?

heats the rock

run-up

height and distance

Rheological-

how the layer behaves

The eruption that occurred on Mount St. Helens was triggered by

huge landslide caused a lateral blast that knocked down trees and buildings

What happens to water velocity downstream?

increases

Focus

initial rupture

A hot mixture if ash, pumice, rock, and water

lahars

Epicenter-

land directly above focus

Volcanic mudflows (lahars) are common on composite volcanoes because:

large amounts of rain and snowmelt mix with loose ash on steep slopes

Long, thin lava flows are typically produced by:

low viscosity

One reason for santorini being a good location for the lost city of Atlantis

minoans rock white and black rocks

This process occurs when water velocity speeds up

more erosion

What tectonic setting is interpreted to be the cause of volcanism at Yellowstone?

movement of North America over a mantle plume

Convergent Boundaries

moves together

The volume of water flowing through any part of a river per unit time is calculated by:

multiplying the velocity by the cross sectional area of a river

shield volcanos are primarily built up by relatively

non-explosive outpourings of lava

Lithosphere

oceanic and continental crust and rigid mantle doesn't melt and moves in direction of convection cells in asthenosphere

A stream or river that flows all year is referred to as:

perennial

a stream that flows all year round

perennial

Standing on top of a ridge 20 km away from a volcano while its erupting and you may perish in this fast moving erratic hazard

pyroclastic flow

Ash in the troposphere will have this overall effect

regional warming

Large movement on this type of fault is most likely to generate a tsunami

reverse fault/thrust fault

Surface waves-

rolling motion traveling along surface when P&S waves combine

Which of the following accompanies urbanization (replacing farms and open areas with cities)?

runoff occurs more quickly and produces a higher peak flow

A calera forming eruption in 1613 BC

santorini

Dendrite Stream Pattern

shaped like a tree

Which of the following is NOT a hazard associated with ash clouds and ash fall?

structures catching on fire

potentially explosive composite volcanos are most common above ____ zones

subduction

What happens to a river as it flows through a delta and encounters the sea?

the total sediment load carried by the river decreases

Seismic waves slow down when they travel through less dense material (sediment or rock with pore space). What effect does this have?

time difference between p and s waves increases

Even though the land is flatter this property of a stream actually increases toward base level

velocity

This volcanic hazard cause roof collapse

volcanic ash

low barometric pressure

warm moist air rises and creates inclement (bad) weather

Liquefaction-

wet sediment liquefies due to intense shaking

Composition

what layers are made of

gas in basaltic magma is the major controlling factor that determines

what rock type will form and what landforms