GEOL 111 - Midterm

The terms 'tsunami' and 'tidal wave' mean the same thing and are interchangeable when discussing a seismic sea wave.

false

The point along a fault where movement first occurs during an earthquake is called the earthquake's ______.

focus

Landslides associated with the 2010 Haiti earthquake were

found mostly on slopes steepened at their base by road construction.

What does the Mercalli Intensity Scale depend on?

how much damage the shaking caused

What kind of natural hazards are not normally insurable?

landslides

A basalt magma typically erupts in what form?

lava flows

Which is the product of a non-explosive style of eruption?

lava flows

Fissures in the harbor area following the 2010 Haiti earthquake were caused by _____.

liquefaction of unconsolidated sediments along the coastal area.

Unlike regular ocean waves, tsunami waves are different because they ____.

move much faster

Earthquakes

occur on faults when rocks rupture, releasing stored up stress as energy

Most natural disasters are which of the following?

rarely if ever cyclic because there are too many overlapping effects

What are two main causes of tsunami?

subduction-zone earthquakes and landslide into the ocean

The 1811-1812 New Madrid earthquakes were different from most California earthquakes because

the New Madrid earthquakes were centered in a plate interior

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.

What is the principal difference between the inner core and outer core?

the inner core is solid while the outer core is liquid

How does the lithosphere differ from the asthenosphere?

the lithosphere is stronger than the asthenosphere

What does the Richter Magnitude Scale depend on?

the maximum amplitude of earthquake waves on a seismograph

A transform plate boundary involves (blank)

two plates sliding laterally past each other.

When is a large event such as a major earthquake not a disaster?

when it happens in an area without any people

Liquefaction occurs when _____.

when saturated soil and other unconsolidated Earth materials lose their strength during an earthquake and behave like a liquid.

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

About how many earthquakes occur in Japan each year?

1,000

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

25

What would the Volcanic Explosivity Index be if Yellowstone erupts?

8

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.

Which of the following is not true concerning tsunamis on the open ocean?

A tsunami in the open ocean will look like a huge wall of water to a ship in its path.

The meteorologist who originally proposed the idea of continents being able to move around on Earth's surface was _____.

Alfred Wegener

A tsunami may occur when _____.

All of the above have the potential to cause a tsunami.

How do we know about the internal structure of the earth?

By using the behavior of seismic waves as they travel through the earth.

What is the major difference between oceanic crust and continental crust?

Continental crust is less dense than oceanic crust.

Earthquakes associated with reverse faulting results in crustal shortening, which is generally found at which type of boundary?

Convergent

Which of the following is true according to the diagram below?

Deeper earthquakes are generally further from the trench than shallower earthquakes.

Earthquakes associated with normal faulting cause the extension of Earth's crust. This type of faulting is generally associated with which type of plate boundary?

Divergent

Which of the following did not occur during the Dec. 16, 1811, New Madrid earthquake?

Downed power lines caused numerous small fires along the Mississippi River.

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

False

Earthquakes occur in association with convergent and transform fault boundaries, but not divergent boundaries.

False

The Hawaiian Islands are a volcanic arc atop an oceanic subduction zone.

False

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

Which of the following would not be a part of the Ring of Fire?

Hawaii

According to the intensity map of the 2010 Haiti earthquake, the greatest intensity experienced during this earthquake was ______.

IX

If you are at the beach and feel a large earthquake, what should you do, and when should you do it?

Immediately run up slope as far as possible.

Eye witness accounts reported that the Mississippi River flowed backward during at least one of the larger earthquakes during the New Madrid 1811-1812 earthquake swarm. What is the best explanation for why the river 'flowed backward?'

Intense shaking along the river caused water to bounce from one side of the river to the other. This formed waves that flowed upriver, making it appear that the river was flowing backwards.

Why does the intensity map for the Dec. 16, 1811, earthquake not show any intensities on the west side of the map?

Intensities are not shown on the west side of the map because the population of European settlers in that part of the U.S. was sparse.

The New Madrid Seismic Zone does not include which of the following states?

Iowa

Which of the following is true?

Much of the initial problems associated with the nuclear reactors was due to flooding of the generators, brought on by the tsunami.

How does pahoehoe lava differ from aa lava?

Pahoehoe is ropy-looking, and aa is clinkery.

Using the accompanying diagram, which of the following is represented by Plate A?

Plate A is the Pacific Plate.

Most of Earth's active volcanoes are found _____.

Ring of Fire

Which of the following would be a modern analogy to the Midcontinent Rift of North America?

The East African RIft Valley

The 2010 Haiti earthquake was reported to have a moment magnitude of Mw7.1. What is the difference in the moment magnitude (Mw) and the Richter magnitude (M)?

The Richter magnitude is based on the highest amplitude of seismic waves measured on a seismogram, whereas the moment magnitude takes into account the area of rupture, the amount of movement along the fault, and the strength of the rocks that ruptured.

Which of the following is not true with respect to the San Andreas fault?

The San Andreas fault represents the convergent boundary between the North American and the Pacific plates.

What is the tectonic reason for the Sunda Strait?

The Sunda Strait formed as a result of the wrenching motion caused by the north-northeast motion of the island of Sumatra and the east motion of the island of Java.

Why is Yellowstone's supervolcano so explosive?

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

Which of the following did not occur as a result of the eruption of Krakatau?

The sound of the explosions could be heard as far away as San Francisco, California.

Which of the following is not true with respect to the strongest aftershock during the 1811-1812 earthquakes?

The strongest aftershock caused the formation of the bluffs along the Missouri River near Council Bluffs, Iowa.

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

Toba: 74,000

A rapid retreat of the shoreline can indicate a tsunami wave is imminent.

True

A tsunami ripped the Dutch ship Berouw from its moorings and deposited it 0.5 miles upstream from the ocean. A subsequent wave picked it up again and carried it another mile upstream.

True

When the Dec. 16, 1811 New Madrid earthquake occurred in Missouri, people as far away as New York and North Caroline felt the shaking.

True

Based upon the Modified Mercalli Shake Map, the highest intensity estimated for the New Madrid December 16, 1811 earthquake was _____.

X+

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.

What is Anak Krakatau?

a small volcano that has formed over the site of the original Krakatau.

Sendai and the nearby region was hardest hit by the tsunami because _______.

all of the above

The 1811-1812 New Madrid earthquakes occurred _______.

all of the above

The Reelfoot Rift formed _______.

as a result of the breakup of Rodinia over 700 million years ago.

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.

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