GEOL 111 Quiz Questions 2

How many states were directly affected by the 1993 Flood?

9

The wetlands surrounding New Orleans are rapidly disappearing. Why?

A and B

It was assumed that Yellowstone's heat source was an extinct volcano. What event made scientists realize that Yellowstone was still active and prompted them to take a closer look at the seismic activity of the national park?

A large earthquake in Yellowstone National Park in 1959.

What caused the Industrial Canal & Intercoastal Waterway levees to fail?

The storm surge sent a huge wave of water up the Intercoastal Waterway, over-topping the canal walls and scouring away the earthen levees.

How do volcanoes form at convergent boundaries?

Volcanoes at convergent boundaries form when water in the subducted plate is squeezed out and travels into the overlying plate, where it causes minerals to melt. This melt may then rise to the surface where it will form a volcano.

Which of the following is not true with respect to water's role in mass movements?

Water in the pore spaces is the major cause of mass movements during an earthquake.

Why did the 17th Street and London Street canals fail?

Water soaked into the underlying peat layer and weakened the soft sediments beneath the levee wall.

What is Yellowstone?

Yellowstone is a caldera that overlies an active magma chamber.

What is the source of Yellowstone's volcanism?

Yellowstone sits on a hotspot.

Like all hurricanes in the Atlantic Ocean, the weather event that became Hurricane Katrina began as _____.

a storm off the west coast of Africa.

VEI stands for ______.

a volcano's explosivity index.

On average, more people die from which type of natural disaster than any other?

flash floods and flooding

One of the geologists listed some potential precursors to a Yellowstone eruption. The precursors he listed are earthquake swarms, heating of the ground, increasing hydrothermal events, and _____.

ground uplift

What keeps a stream flowing year-round, even though it may not rain for many months?

groundwater flow from the adjacent ground into the stream

Highly explosive magmas are controlled by which of the following?

high silica content and high water

Most of Earth's active volcanoes are found _____.

in the Ring of Fire.

Over the last 30 years, hurricanes have become more ______ due to _______.

intense, warmer ocean temperatures

A basalt magma typically erupts in what form?

lava flows

Select the 3 ENGINEERING flood-control methods.

levees channelization dams

Tambora formed as a result of ____.

subduction along the Java-Sunda trench.

Krakatau formed as the result of the convergence of which two plates?

the Indian-Australian and the Sunda plates

Toba formed from magma generated during the subduction of _____.

the Indian-Australian plate under the Sunda plate.

Tambora is a part of _______.

the Indonesian island arc.

The background in the painting, The Scream, by Edvard Munch is evidence of what?

the high amount of sulfur dioxide put into the atmosphere by the eruption of Krakatau in 1883.

The eruption of Tambora in 1815 indirectly led to _____.

the migration of people from family farms in the Northeast to the Ohio Valley.

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

to raise groundwater levels

Approximately 40,000 people died as a result of the 1883 eruption of Krakatau. What were the two volcanic hazards responsible for these deaths?

tsunamis and pyroclastic flows

The source of the magma for the eruption of Toba during the Younger Toba Tuff event was most likely from _____.

two shallow magma chambers

As a result of mass movements on the slope below Mt. Toc, _______.

water levels in the reservoir were raised and lowered several times in an attempt to reach hydraulic equilibrium between the water level in the reservoir and the nearby rocks.

What are the two most abundant gases in magmas?

water vapor and carbon dioxide

Yellowstone's most recent eruption was _______. There is evidence that Yellowstone has errupted _____ in the last 2.3 million years.

~600,000 years ago, 3 times

Which agency manages the rivers, dams, and levees in the United States.?

Army Corp of Engineers

How many hominin species are believed to have lived through the Younger Toba Tuff eruption?

At least four, the Neanderthals, Homo sapiens, Homo floresiensis, and Homo erectus.

How does pahoehoe lava differ from aa lava?

Pahoehoe is ropy-looking, and aa is clinkery.

Which town's levee withstood the flood?

Prairie du Rocher, IL

Besides wind, what is the biggest hazard from hurricanes?

Storm surge

Which of the following volcanic areas is not located over mantle plumes or hotspots?

Tambora

Which of the following is true with respect to the underlying geology in the Vaiont River valley?

The Vaoint River valley is underlain by rocks that dip (tilt) into the valley.

Which of the following is true with respect to the October 1963 Vaiont Dam landslide?

The initial geologic survey was conducted only after the occurrence of a landslide into a nearby reservoir.

Why is Yellowstone's supervolcano so explosive?

The magma beneath Yellowstone is full of gas and very viscous because it is silica-rich.

What was the origin of the pumice rafts associated with the 1883 eruption of Krakatau?

The pumice rafts formed when hot ash from pyroclastic flows encountered cold seawater.

Following the Younger Toba Tuff eruption, the hominin population may have decreased to as low as ______ individuals.

10,000

Global temperatures dropped by how much as a result of the 1815 eruption of Tambora?

10oC

The October 1963 Vaiont Dam landslide killed around 2,500 people. How long did it take for the mass movement to flow out of the reservoir, over the dam, and into the valley below?

12 minutes

After scientists installed seismographs, how many earthquakes per week did they record?

25

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

30 days

An unusually wet summer was the primary cause of the 1993 Flood. The jet stream became locked over the midwest and ____ inches of rain fell over ____ months.

30, 6

The 1993 Flood had a recurrence interval of ______.

500 years

What is the elevation of the city of New Orleans?

7-10 feet below sea level

According to the documentary, a supervolcano erruption will occur somewhere on earth every _______ years.

700,000

What would the Volcanic Explosivity Index be if Yellowstone erupts?

8

In the spring of 2003, some unusual events occurred in Yellowstone that caused some to worry that Yellowstone might erupt. Select the 3 events that occurred in 2003.

A pack of bison died from poisonous gas. Steamboat Geyser, a geyser that can be dormant for up to 50 years, began erupting. The ground heated up and cracks opened up.

What is the difference in a storm surge and a tsunami?

A storm surge is caused by a combination of high water resulting from a low pressure system at sea and strong onshore winds, whereas a tsunami is caused by an underwater disturbance, such as an earthquake, to the ocean floor.

The force of the October 1963 mass movement was enough to _____.

All of the above are results of the 1963 Vaiont Dam landslide.

Mass movements include _____.

All of the above.

What was (were) the cause(s) of the La Conchita mudslides of 1995 and 2005? (You might need to use the photos in the mini lecture as a guide.)

All of the above.

Why is 1816 known as 'the year without a summer?'

Because the northern hemisphere experienced snows in June, July, and August.

How were the 1925 Gros Ventre landslide and 1963 Vaiont Dam landslide similar?

Both landslides were caused by excessive water in the underlying rocks.

Which town's levee failure was credited with saving St Louis, Missouri from flooding.

Columbia, IL

Select all the engineering systems or structures mentioned in the video that were put in place in New Orleans to deal with potential flooding.

Drainage canals Levees Pumps Flood walls

Earth's active volcanoes are found at convergent boundaries, divergent boundaries, and transform fault boundaries.

False

Large volcanic eruptions can emit sulfur dioxide and cause short-term global warming.

False

The October 1963 Vaiont Dam landslide occurred without any warning.

False

The rim of the caldera from an ancient eruption of Krakatau (pre-1883) is marked by the islands of Verlaten, Lang, Rakata, and Anak Krakatau.

False

Which of the following volcanoes formed over a hot spot?

Hawaii

Which hominin species was best suited for the volcanic winter that followed the eruption of the Younger Toba Tuff event?

Homo neanderthalensis

Select the 3 methods inspired by the 1993 Flood to prevent future damage and loss from flooding.

Leaving crop residue on the land to reduce soil erosion and run-off Returning agricultural land to natural wetlands Elevating homes above flood level

After the eye of Hurricane Katrina passed over New Orleans, why did the flood waters continue to rise in the low-lying areas of the city?

Levee along two canals failed and water from Lake Ponchartrain drained into the city center.

In the days preceding Hurrican Katrina, why did many people stay in New Orleans instead of evacuate? (select all that are true)

They did not have transportation They were elderly or sick They had survived previous hurricanes without evacuating.

Why would living on a floodplain behind a levee be safe from flooding?

This statement is not true.

The most recent supervolcano to erupt was _________ and it occurred ________ years ago. This volcano may have nearly ended human life on earth.

Toba; 75,000

A tsunami ripped the Dutch ship Berouw from its moorings and deposited it o.5 miles upstream from the ocean. A subsequent wave picked it up again and carried it another mile upstream.

True

It is possible that Yellowstone will experience a supervolcano eruption but there will likely be some warning.

True

Paintings by J.M.W. Turner and other landscape artists of the early 1800s yield clues to climatic conditions of that time.

True

The signal that magma is moving upward and an eruption may be imminent would be the constant rumbling vibrations known as harmonic tremors.

True

Volcanoes with high silica magmas generally have more explosive eruptions than those with lower silica magmas.

True

Aerosols released into the atmosphere from the Toba eruption ~74,000 years ago caused which of the following?

all of the above

Eruptions dominated by basalt compositions are found where?

along divergent boundaries at mid-oceanic ridges

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

anytime

Pyroclastic flows contain _____. (select the 3 that apply)

ash hot gases rock fragments