GEOL Natural Disasters

How are electrical charges distributed in storm clouds and on the ground below?

"+" charges are in the upper part of a cloud and on the ground, whereas "-" charges are near the base of a cloud.

After major hurricanes like Katrina and Ike, some insurance companies have imposed deductibles as high as ________.

$20,000

Nor'easter wave heights are commonly ___________ high.

1.5-10 meters

"The Perfect Storm" was a nor'easter that occurred in _______ and producing waves that were __________ high.

1991, 10.7 m

Roughly what depth of flowing stream is dangerous to drive through?

30 cm (1 foot)

How long before a flood can someone purchase insurance from the National Flood Insurance program?

30 days

How many people died in the 1999 Venezuela mudslide and flood?

30,000

How fast do tornadoes move along the ground?

50 to 80 km per hour

Did you know water is most dense at 4°C (39°F)? That is why lakes don't freeze to the bottom. If water was most dense at 32°F then lakes would freeze to the bottom in the winter. Considering the density of water changes as its temperature changes, what percentage of sea level rise is from the expansion of sea water as its temperature rises (vs. melting glaciers)?

70%

What causes a cold front?

A cold air mass moves in against a warm air mass.

What is avulsion?

A flooding stream permanently leaves its old channel to form a new floodplain channel.

Look up the "Channeled Scablands" of eastern Washington. We see river landforms on massive scales. For example, ripple marks which are normally a few centimeters high are several meters high. How could a river create river formations on a such a large scale?

A major ice dam broke and Glacial Lake Missoula flooded the landscape in short period of time.

What is a hydrophobic soil?

A soil containing hydrocarbon residue that does not allow for infiltration of water after a forest fire.

What local circumstances also raise the height of a storm surge onshore close to the beach?

A surge moving into a bay funnels the water and raises the surge.

What causes cover collapse?

A thick clay layer above a limestone cavern settles down into the cavern, leaving a soil cavity above. That cavity may collapse to form a sinkhole.

What is NOT among the solutions to reducing beach erosion?

Add rip-rap off shore to make the continental shelf flatter reducing the speed of the wave.

Oxygen isotope analysis is the measurement between the ratio of the two isotopes of oxygen. The lighter isotope, O16 (oxygen-16), ________.

All of these: evaporates more readily from the oceans, is more prevalent in precipitation, is more prevalent in glaciers

The movement of sand parallel to the shore ________.

All of these: is created by waves approaching at an oblique angle, may create spits, is achieved by longshore currents

Proxy data for climate change detection comes from ________.

All of these: seafloor sediments, glacial ice, fossil pollen, tree growth rings

The natural cause(s) of climate change is(are) ________.

All of these: variability in Earth's orbit, movement of lithospheric plates farther/closer to the equator, volcanic activity, variability in Earth's orbit and volcanic activity

The ________ river has the largest discharge of any in the world. (You may need to look up the information on a reputable website).

Amazon

The Morganza Floodway takes water from the Mississippi River and diverts it to the _____________.

Atchafalaya River

When is hurricane season (which months), and why then?

August-Nov, because it takes all summer to warm the ocean

Which gas is the most responsible for the ozone hole?

CFCs

Which of the following is a variable gas?

Carbon Dioxide

Which of the following areas has NOT seen major subsidence from groundwater withdrawal?

Charleston, South Carolina

Why are skies clear in the eye of a hurricane?

Cold, dry air is descending.

What should you do to avoid being killed by lightning if caught out in the open in a storm with no place to take cover?

Crouch down on the balls of your feet with your feet together.

Santa Ana winds and Chinook winds spread forest fires due to their warm dry winds. Why does this happen? (You may need to view other parts of the textbook).

Descending air is compressed and heated. Humidity is decreased.

Desertification in the Sahel was caused by the all of the following EXCEPT:

El Nino

Why does Venice, Italy, have canals for gondolas and boats instead of normal streets for cars?

Extraction of groundwater below the city caused subsidence of the city below sea level.

Alluvial fans develop at locations where stream gradients abruptly increase (get faster) for a short distance.

False

El Nino is caused by humans.

False

Limestone is only moderately soluble and usually produces very subdued karst topography (virtually flat surfaces).

False

Nor'easters are named because of the region of the US at which they occur (New England).

False

Pure water is an excellent solvent.

False

The use of aerosols and refrigerants is the most prominent means by which humans add carbon dioxide to the atmosphere.

False

Why are ocean waves generally larger than those on lakes?

Fetch length is much longer in the ocean.

As snow melts in MN in the spring, think about what happens to snow at the base of a stop sign, telephone pole, tree, etc. The sun warms the pole and the heat travels through the metal. What would happen to the Trans-Alaska pipeline if the posts were solid metal? How does a thermosiphon work?

Heat dissipaters at the top allow the heat to escape into cooler air. The vapor cools, condenses at the top, then sinks to the bottom where it is heated.

All of the following are effects of a hurricane. But which of the following damages do NOT accompany the surge of a hurricane?

Heavy sand is deposited on beaches, partly burying some homes.

Let's consider greenhouse gases and a feedback effect. We are in a global warming period currently. What effect does water vapor on Earth's climate and why?

Higher atmospheric temperatures increase the rate of evaporation, which causes a greater amount of water vapor in the air which in turn heats the atmosphere even more.

What is the approximate diameter of most hurricanes and of a hurricane's eye?

Hurricane diameter is about 160 to 800 km with an eye about 20 to 50 km.

How would a hydrograph for a drainage basin change if major urban growth were to occur upstream?

Hydrograph would be higher and narrower.

What are the main differences in a stream hydrograph after a large fire?

Hydrograph would be higher and narrower.

Which one of the following best describes how urbanization affects small-stream watersheds?

Infiltration decreases; lag time between storms and peak runoff is shortened.

If your neighbor, Jane, installed a groin upcurrent of your property, what would you most like do assuming you like your beach sand?

Install a groin on the downcurrent side of your property to trap sand.

What is the motion of a stick (or a water molecule) in a deep-water wave?

It moves in a circular motion in a vertical plane, with the top of the wave moving in the direction of wave travel.

Why does a stream bottom erode more deeply when its water level rises in a flood? (Hint: think about the speed of water).

Its water level rises, so water velocity increases and it can carry more sediment.

Tornado Alley is centered on ____.

Kansas and Oklahoma

________ is the term for solution topography in areas of limestone bedrock.

Karst

How would you recognize a karst landscape?

Karst has an extremely ragged surface dissolved on the surface of limestone bedrock.

What is karst and how does it form?

Karst is the ragged surface dissolved on the surface of limestone bedrock formerly buried under soil.

Why does sea level rise during a near-shore storm?

Low atmospheric pressure of the storm permits sea level to rise.

Which of the following is not a source of data used to understand climate?

Magma temperatures

Let's consider albedo and a feedback effect. If we were in a global cooling, what effect would more ice have on Earth's climate and why?

More ice will cool Earth's climate even more because it has a high albedo.

What effects do levees NOT have on a stream?

Natural levees downstream will lower in height.

Nor'easters are most common from ___________.

October-April

What are oxbow lakes and how do they form?

Oxbow lakes are cut off meanders, left behind as a flooding stream takes a shorter path downstream.

A delta protects the shoreline from a storm surge from a hurricane. The Mississippi Delta, however, is shrinking which is why New Orleans had so much damage from Hurricane Katrina. What is one reason why the delta is shrinking?

People further upstream put in dams and weirs which trap some of the sediment that would normally make it to the mouth of the river.

Which of the following statements about sinkhole formation is incorrect?

Permafrost thaw is a way that a sinkhole can form.

What causes caverns in limestone?

Rainwater dissolves carbon dioxide to make weak carbonic acid that dissolves limestone.

Why are inlets through barrier bars or barrier islands not closed by longshore drift of sand?

Rapid flow of water back and forth through the inlet as tides rise and fall keeps it clear.

Why do such lightning strikes in high mountains often NOT produce major fires?

Since fire moves more easily uphill, there is not much fuel above them.

Which is NOT a method for recognizing the presence of swelling soils?

Since they deform elastically, the ground feels spongy or bouncy underfoot.

The best-known features on the surface of the Sun are dark blemishes called ________.

Sunspots

Which of the following is correct?

The United States has more tornadoes than any other country in the world.

See Figure 16-19 in the textbook. Why do you think the home made out of wood was safe in the forest fire?

The homeowners had cleared fuels near the home so that the radiant heat was far enough away to not allow the home to catch on fire.

How does urbanization affect the lag time of streamflow peak? (Lag time is the time between a rainfall and peak stream flow).

The lag time is shorter and the peak is higher.

What measure was taken during the 1993 Mississippi River flood to protect the town of Prairie du Rocher, IL?

The levee was blasted upstream of Prairie du Rocher to allow water on the floodplain to flow back into the main channel.

How can there often be big waves at the coast when there is little or no wind?

The storm generating the waves is far offshore.

I've taken my kids tubing near Black River Falls, WI. My son kept saying, "Whoa, Mom, why do we keep going to the side of the stream and not down the middle?" Which is the correct response to his question?

The stream flows the fastest on the outsides of the meanders.

How does the relationship between ignition time and radiant heat change with distance?

The time it takes for wood to ignite increases with distance from radiant heat.

Why is storm damage of a westward-moving hurricane generally less on the south side of the eye?

The winds are moving offshore there, so the waves are smaller. The storm surge is north of the eye.

Storm chasers that study tornadoes try to avoid being victims of those tornadoes by doing what?

They approach tornadoes from the southwest.

What physical effect do most bridges have on the streams they cross?

They cause more flooding upstream.

Why do grass, needles, and shrubs burn easier and faster than trees?

They have a large surface area compared with volume of solids.

Gradients usually decrease downstream in a major river system.

True

Methane is produced by anaerobic bacteria.

True

Oxygen isotope analysis is the precise measurement of the ratio between two isotopes of oxygen.

True

Which of the following is not true about how hazards are related to climate?

Volcanoes are related to wetter climates

Why does removal of logs and rocks from a beach endanger the sea cliffs behind them?

Wave energy is taken up in moving the logs and rocks.

What causes swelling soils to swell?

When they get wet, water enters the clay mineral structure to cause swelling.

Which of the following is NOT found in a cloud that might develop a tornado?

a dark, stationary cloud with a rounded bulbous top

What shape of roof is most susceptible to being lifted off by a hurricane?

a gently sloping roof with one slope facing toward the wind

Over the ENTIRE past 70 million years there has been ________.

a global cooling

With urbanization of the upstream drainage area, what changes can be expected in the height of the 100-year flood?

a greater height

What shape of roof is least vulnerable to being pulled off?

a hip roof (sloping to all sides)

A cause of the 1993 Missippippi River flood was ________.

a persistent high pressure in the southeastern US which stalled summer storms over the Mississippi River valley.

See "Cases in Point." What was the early development along a New Jersey coastline which eventually led to extreme beach hardening?

a railroad

What is the significance of a sand boil?

a sign of seepage under a river levee

What caused the Oakland-Berkeley Hills, CA fire in 1991?

a single ember from a small grass fire that was thought to be completely put out by firefighters

What is a wall cloud?

a slowly rotating cloud that sags below the main storm cloud base

To what depth of water do waves commonly move sand?

about 10 meters

What is the approximate forward speed of a hurricane (how fast does it approach the coast)?

about 25 km/hour

Flood insurance in Florida is only possible for those living on barrier islands who _______.

adopt government construction requirements

What are the suspended solid and liquid particles suspended within the atmosphere called?

aerosols

Why are fires more frequent and hotter now than they were several decades ago?

aggressive fire suppression for many decades

Which of the following is designed to prevent or retard shoreline erosion?

all of these: groin, beach nourishment, jetty

Part of Kentucky has karst topography. Knowing this, it would be logical to find _________ there.

all of these: sinkholes, stalactites, soluble bedrock

All of the following lead to the failure of a river levee EXCEPT:

allowing water to flow in sand boils to the adjacent floodplain

What are the best detection devices to warn people of an already moving debris flow?

an acoustic flow monitor

If a 100-year floodplain was flooded in 2003, when should we expect the next 100-year flood?

anytime

In order for Denver to reduce damage to homes from swelling soil, there has been a regulation for new subdivisions to excavate to a depth of ____________.

at least 3 m.

What is the greatest danger (what causes most deaths) from a tornado?

being struck by flying debris

What effects does the wind NOT have on buildings during a hurricane?

blows down (collapses) roofs

Which one of the following structures is built parallel to the shoreline which trap sediment on the landward side?

breakwater

How does a fire generate its own winds?

by strong convective updrafts creating a low pressure and drawing in new air from all sides

Which gas is the most responsible for human-induced global warming?

carbon dioxide

What is in water in the ground that helps it dissolve limestone?

carbonic acid formed from carbon dioxide in air combining with rainwater

What is riprap?

coarse rock built parallel to the shoreline placed at the base of a cliff to absorb wave energy and retard erosion

What creates the electrical charges in clouds that characterize lightning storms?

collisions between falling ice particles and water droplets carried in updrafts

When a stalactite meets a stalagmite the result is a ________.

column/pillar

In the Northern Hemisphere, we can use the right-hand rule. Consider descending air. Point your right thumb straight down at the table. Notice which way your fingers curl. Now consider ascending air. Point your right thumb straight up towards the ceiling. Notice which way your fingers curl. Knowing this information, would you expect hurricanes to rotate?

counterclockwise

Which way do winds move at the base of a hurricane?

counterclockwise, inward toward the eye

If floodwaters have 50% sediment and 50% water the flood/flow is termed a _________.

debris flow

What type of drainage pattern would you expect to find in Minnesota?

dendritic

This drainage pattern looks like the veins on the underside of a leaf:

dendritic.

Which of the following helps determine past climate on the basis of tree rings?

dendrochronology

What was the reason the 2000 Montana Bitterroot forest fire was so disastrous?

dense understory from a lack of burning since 1910

Santa Ana winds are caused by:

descending air over Nevada pushing air towards southern California

The total volume of flow in streams is termed ________.

discharge

During climatic cooling sea level ___________ because __________.

drops, more water is locked on land in the form of ice

What weather conditions are most likely to foster the formation of sinkholes? (Weather is short-term, climate is long-term. Climate would refer to desert, tropical, etc. The question is asking about weather).

dry weather, because that lowers the water table so the cavern roofs are not supported and may collapse

Which area of the US is most prone to lake-effect snow?

eastern sides of the Great Lakes because of the westerly winds

Waves begin to "feel bottom" when the depth of water is ________.

equal to one-half the wavelength

Which is not a technique used in swelling soils?

extracting groundwater in that area

Santa Ana winds often cause forest fires in the __________.

fall to early winter

Where do people most commonly get the material to build an artificial river levee?

from the river channel, by dredging

What would you expect to happen after the next major Yellowstone eruption and why?

global cooling because of the increased amount of ash and sulfur dioxide

Like limestone, ________ is highly susceptible to subsurface erosion.

gypsum

What is LEAST necessary to start and maintain a fire?

high atmospheric pressure

What significant effects does faster forward speed of a hurricane have on coastal areas? (Refer to the "Storm Surge" section of the textbook).

higher level surge and less rain

Modern climate change is dominated by ________.

human influences that exceed the bounds of natural variability

Which of the following conditions result in land subsidence?

human overuse of groundwater, loosely packed sediment

Oxygen isotope analysis is used when studying ________ and climate change.

ice cores

Which of the following techniques are NOT used to fight fires?

igniting a fire adjacent to (without a gap in between the burnout and main fire) and directly upwind of the wildfire

Wildfires are beneficial to forests in all of the following ways EXCEPT:

improving views.

Where in North America are sinkholes most prevalent and why?

in Florida, because it is almost all limestone and has abundant groundwater

Where does a tropical cyclone or hurricane get its energy?

in the heat and moisture rising from a low pressure cell of the equatorial ocean

Which part of a storm is the area that is likely to form tornadoes?

in the tailing part of the area of heaviest rain

Where is a relatively safe place to be in a lightning storm?

in your house

How does urbanization (introducing more pavement, buildings, etc.) affect runoff and infiltration in a previously forested, drainage basin?

infiltration decreases; runoff increases

If you lived near a river, based on erosion and deposition where would your home be the safest?

inner edge of a large meander

After we were done tubing, we got out and played at a beach (natural sand bar). Where do you think we were on this meandering stream and why is sand deposited here?

inside of the meander since this is where the stream slows down and sediment is deposited

Which of the following does NOT cause increased erosion in a stream channel?

installing riprap at the toe (lower bank) of a stream

Global warming would cause

inundation of coastal plains.

Where in a hurricane are the winds strongest?

just outside the eye (in the eye wall)

Which of these effects on coastal areas is NOT caused by heavy rain during a hurricane?

large storm surges

What condition does NOT lead to more fire-prone forests?

larger trees

Caverns most commonly develop in ____.

limestone

Prime conditions for the development of karst topography include the following: (Hint: think about why the jello instructions ask you to boil water).

limestone, warm groundwater, abundance of groundwater

The movement of water within the surf zone that parallels the shore is termed ________.

longshore current

Streams which are at or above the water table are known as ________.

losing streams

What two main factors cause increased height of a storm surge?

low atmospheric pressure and strong hurricane winds

Where in a hurricane is the atmospheric pressure lowest, and approximately how low can that be?

lowest in the eye; as low as 960 millibars

If you do not have a storm shelter or a basement, where in a home is the safest place to be?

lying in a bathtub

Which type of stream channel pattern is most common in MN?

meandering

Wind shear associated with several major airline crashes is believed to be caused by which of the following?

microbursts

What is the principle cause of increased fire hazard to members of the public?

more people building in or next to forests or other wild lands

What aspect of roads is most important for evacuation in case of a forest fire?

more than one evacuation route

Refer to Figure 16-11. If you were caught in a forest fire in southern Alberta you should try to:

move downslope and towards the southwest

Where do hurricanes striking North America originate?

near-equatorial latitudes off the west coast of Africa

What was not a reason that led to the 1976 Teton Dam failure in Idaho?

no concrete was used in the earth-fill dam

Why was the 1997, $53 million of renourishment of sand in NY considered a success?

no major storms struck Long Island in the 5 years after the project

Variations in the angle that Earth's axis makes with the plane of it's orbit is called ________.

obliquity

What is La Nina?

ocean water off of South America becomes unusually cool, the trade winds are stronger than normal

One result of wave refraction is that wave energy is concentrated ________.

on headlands projecting into the water

Where is erosion concentrated along a meandering stream?

on the outer parts of the meander loops or bends

Which of the following is not a benefit of vegetation near a riverbank?

overgrazing of domesticated cattle is decreased since animals prefer shade and need the vegetation for food.

A(n) ________ is an abandoned, cutoff, meander loop.

oxbow

After forest fires people may have trouble breathing because of all of the following reasons EXCEPT:

ozone in the stratosphere

When development on an alluvial/debris fan is necessary, how should the streets and buildings be oriented?

parallel to the downslope direction of flow

Which of the following would NOT minimize fire danger to houses for people living in the woods?

piling firewood next to the house

What human action does NOT negatively impact stream processes and cause excessive erosion?

planting trees

Wildfires can be quite beneficial. Which of the following is NOT a benefit of wildfires?

reducing the amount of carbon dioxide in the atmosphere

How do aerosols affect climate?

reflecting sunlight back to space, therefore cooling Earth's climate

When waves reach shallow water, they are often bent and tend to become parallel to the shore. This process is termed ________.

refraction

If the Yellow River in China has had a 4000-year history of flooding, why do you think the lower portions of the river (greatest volume of water) are densely populated?

rich agriculture due to alluvial plain sediments

What is NOT a structure used to trap debris flow?

riprap

Other than limestone, what other types of rocks are soluble and can form cavities that collapse?

salt and gypsum

If a stream is flowing at 1 cm/sec, which size(s) of particles would be deposited?

sand and gravel

What causes cover subsidence?

sandy sediment which overlies limestone, slowly settles into cracks in dissolving limestone, sinkhole forms slowly

Good uses for floodplains do NOT include which of the following?

shopping centers

In what direction do most mid-continent tornadoes travel along the ground?

southwest to northeast

Deposition of dissolved minerals in caverns leaves deposits such as the icicle-like ________.

stalactites

Most of Earth's ozone, is found in the ________.

stratosphere

What causes the loud boom that we hear as thunder?

supersonic expansion of air heated by a lightning bolt

What caused the catastrophic 1997 flood along the Red River in North Dakota?

thawing to the south of the frozen north-flowing river backed up water behind the ice to the north

What is a rain shadow?

the leeward side of a mountain range that is very dry

What about being in a car generally protects you in a lightning storm?

the metal frame around the car

What led to the deaths of 1,000,000 Chinese people in 1887?

the river breached its levee and changed its course, causing famine downstream

Which region in the United States has the greatest annual frequency of hailstorms?

the western Great Plains

How did 11 firefighters die in the Storm King Fire, Colorado in 1994?

they moved upslope to try to escape flames

What are the main characteristics of soil above a limestone cavern that lead to the formation of dangerous, quickly-forming sinkholes?

thick, clay-rich, and cohesive enough to develop a large cavern before it collapses

Why are houses in hurricane areas generally on tall posts?

to keep them above the level of the storm surge

Which of the following is NOT a common reason cited for building large dams on rivers?

to raise groundwater level upstream to benefit agriculture

What is the main purpose of a floodway?

to store flood waters on the floodplain to protect cities up and downstream

Earth's atmosphere is divided vertically into four layers on the basis of temperature. The layers, in order from bottom to top, are ________.

troposphere, stratosphere, mesosphere, thermosphere

If you wanted to live in woods in a fire prone area, all of the following will lessen your risk of losing your home in the case of forest fire EXCEPT:

use propane heat instead of a wood to heat the home

When is the main tornado season in the central United States?

varies upon location

Most waves are generated by ________.

wind