EPS 80 Midterm 1 (42 MCQ, 3 fill in)

Why do nuclei have to get really close before they can fuse? (Quiz 1)

A) They need to get close enough they physically crash into one another and that merges the atom

B) They need to get close enough that the electrons in one atom (- charged) attract the protons (+) in another atom

C) They need to overcome van de waals forces, so they stick together. This is the same force that spiders use to stick to walls

D) They need to overcome the coulomb barrier - Nuclei far apart repel each other, as they get closer, the strong interaction takes over and the nuclei begin to attract each other

D) They need to overcome the coulomb barrier - Nuclei far apart repel each other, as they get closer, the strong interaction takes over and the nuclei begin to attract each other

Explain: Protons in nuclei are + charged, and like-charges repel each other. To fuse them, you have to smash them together with enough speed and heat to overcome this barrier. Once they get close enough, the strong nuclear force pulls them together.

Difference between Fusion and Fission? (Quiz 1)

A) Fusion is used by nucleur power plants, fission is a possible future source of energy that could power the entire world

B) Fusion is when 2 atoms merge and energy is released, Fission is when an atom splits apart and energy is released.

C) Fission is when 2 atoms merge and energy is released, Fusion is when an atom splits apart and energy is released.

B) Fusion is when 2 atoms merge and energy is released, Fission is when an atom splits apart and energy is released.

Explain:

Fusion=Fusing together, Small atoms → Bigger. Fuels our sun.

Fission=Atom splits apart, energy is released. Fuels nuclear power plants.

Co-60 has a half life of 5.27 years. Initially we have 10 g of Co-60. How much remains after 21.08 years? (Quiz 1)

A) 0.625 g

B) 5 g

C) 1.25 g

D) 7.5 g

A)

Step 1-Find the number of half lives: 21.08/5.27=4 half-lives

Step 2-Cut the mass 4 times by 1/2: 10/2=5, 5/2=2.5, 2.5/2=1.25, 1.25/2=0.625 g

Why do gaps in the wavelength of starlight at Tc provide evidence for nucleosynthesis in stars? (Quiz 1)

A) Tc has a short half life. None of the isotopes have a half life longer than 4.2 million years. If Tc is still in stars, 14 billion years into the universe, it must be being produced. It cant remain from the big bang

B) Tc has a longer half life than the age of the universe

C) Tc has too high an abundance to have been made at the start of the universe

A) Tc has a short half life. None of the isotopes have a half life longer than 4.2 million years. If Tc is still in stars, 14 billion years into the universe, it must be being produced. It cant remain from the big bang

Explain: Technetium (Tc) is an element with no stable isotopes. Its longest-lived isotope has a half-life of only 4.2 million years. If all elements were made only at the beginning of the universe (Big Bang), Tc would have vanished already. When light shines from a star, elements in the star absorb specific wavelengths of light, leaving dark lines (rainbow barcode). An astronomer noticed that there is light coming from red stars, and saw it is the barcode for Tc. If an element that dies out 4.2 million years ago is sitting inside a star right now, it couldn’t be from the Big Bang, which means the star is actively making it right now, through nucleosynthesis. A simple analogy: If you find a tray of cooked bread on the kitchen counter, it cannot be a leftover from 10 years ago, someone must have baked it right now.

**Why is it challenging to make elements heavier than Fe by fusion? (Quiz 1)

A) Fe has the highest binding energy per nucleon. Fusion to iron releases energy, fusion past Fe consumes energy. Have to make it by s/r process instead

B) Fe has the lowest binding energy per nucleon. Fusion to iron consumes energy, fusion past Fe releases energy. Have to make it by s/r process instead

C)All eleme nts heavier than Fe spontaneously break apart back to Fe

A) Fe has the highest binding energy per nucleon. Fusion to iron releases energy, fusion past Fe consumes energy. Have to make it by s/r process instead

Explain: Iron is Fe. A star stays hot and doesn’t collapse because it generates heat through fusion through its core. Everytime a star fuses lighter elements into heavier ones , it releases heat to keep it burning . Iron is the most stable, tightly bound element. If you try to use lighter elements to fuse UP to heavier elements like Iron, you get energy from it. But if you try to fuse PAST Iron to create something heavier (like Gold, Uranium), the star becomes less stable, and you have to pump energy IN. The moment a star’s core turns into iron and you try to fuse it, the star has no source of heat, and then the core begins to absorb the heat like a sponge and cools down, gravity crushes it, causing a supernova.

Small, loose atoms (Hydrogen, Helium) → Fusion Releases Energy → Iron (Most stable)
Big, compact atoms (Uranium) → Fission Relases Energy → Iron (Most stable)

If you try to move towards Iron (either by fusing light elements together or splitting large elements), you will release energy. If you try to move away from iron, you will have to absorb energy. Push UPhill takes energy

Approximately how thick is the Earth's crust? (Quiz 1)

1-7 km

100-200 km

7-100 km

200-300 km

7-100 km

When did eukaryotes evolve? (Quiz 1)

3-3.5 Ga

0.5-1 Ga

~1-1.8 Ga

~2.1-2.7 Gaz

~2.1-2.7 Ga

(Prokaryotes (simple bacteria) evolved first (~3.5–3.8 Ga))

When did the first vertebrate-like creature (Tiktaalik)? (Quiz 1)

~375 Ma

~515 Ma

~50 Ga

~100 Ma

~375 Ma

When did the dinosaurs go extinct? (Quiz 1)

~ 252 Ma (end Permian mass extinction)

~66 Ma (K-Pg mass extinction)

~56 Ma (Paleocene - Eocene thermal maximum)

~66 Ma (K-Pg mass extinction)

Why has the length of a day on Earth changed over time? (Quiz 1)

The Earth's orbit has gotten smaller, so we spin faster around the Sun

The Earth's tilt has changed, affecting how fast we spin

Tidal friction has slowed Earth's rotation rate down

Tidal friction has slowed Earth's rotation rate down

Explain: Earth’s days used to be shorter (18-22 hours), the Earth was spinning faster. The moon’s gravity pulls on Earth’s oceans, creating 2 large tidal bulges (high tides). The earth rotates faster than the moon—the moon will try to pull back on the bulge, which causes friction. Fossil Proof: Rudist Bivalves (Clams) grow lines on their shell every single season in the year.

Today: 365 Days/24 Hours (365 Days x 24 Hours= 8,766 Hours)

Cretaceous Period (70 Million Years Ago): 370 Days(Rings)/around 23 Hours (8,766 Hours in Year/370 Days=Hours in a Day)

Devonian Period (400 Million Years Ago): 400 Days/21 Hours

Cryogenian Period (900 Million Years Ago): 500 Days/18 Hours

If there are few hours in a day, there will be more days in a year.

Which of the following are evidence for plate tectonics on Earth? Select all that applied.(Quiz 1)

Fossil remains that span multiple continents

Glacial striations radiating out from Antarctica

The rise and fall of glaciations in the last 50 Ma

Volcanic activity in Hawaii

The fit of the African and South American coastlines

Fossil remains that span multiple continents, Glacial striations radiating out from Antarctica, The fit of the African and South American coastlines

Which layers of the Earth are a liquid? (Quiz 1)

The inner and outer core

The mantle

The mantle and outer core

The outer core

Outer core

Crust: Solid, Mantle: Solid Rock, Outer core: Liquid iron-nickel (S-wave cannot pass), Inner Core: Solid Iron-Nickel

What is the definition of an isotope? (Quiz 1)

Atoms with the same number of protons but different numbers of neutrons

Atoms with the same number of neutrons but different numbers of protons

Elements are defined by their proton count. An isotope has the same proton number, but different amount of neutrons.

What type of radioactive decay changes the mass of the atom by 4 (2 protons and 2 neutrons) (Quiz 1)

Alpha decay - emmits a helium atom

Beta decay

Gamma decay

Alpha decay - emmits a helium atom

Explain:

If the atom has too many protons, neutrons, it is unstable (radioactive), and will spit out particles or radiation to reach a stable state.

Alpha Decay: The unstable nucleus ejects 2 protons, 2 neutrons together= Helium 4-nucleus. (4/2 He)The Mass Number drops by 4, the Atomic Number drops by 2.

Ex on slide: Uranium-235 (235/92 U) spits out an alpha particle, becomes Thorium-231 (231/90 Th). Changes element by -2 spots

Beta Decay: Nucleus has too many neutrons, A neutron turns into a proton, and spits out an electron (Beta Particle). Mass stays the same. Atomic Number increases by 1 (+ gain proton).

Ex on slide: Carbon-14 (14/6 C, 6 protons 8 neutrons) → Nitrogen-14 (14/7 N,7 protons 7 neutrons)+electron. Changes element by -1 spots

Gamma Decay: The nucleus is energized, usually right after alpha/beta decay, releases gamma photons (energy). No change in mass or atomic number. It is the same element as the result, but just in a less energized state.

Approximately how old is the universe? (e.g. how long ago did the Big Bang happen?) (Quiz 1)

20.5 billion years

13.7 billion years

10.5 billion years

13.7 billion years

How were most elements heavier than hydrogen and helium formed? (Quiz 1)

By nucleosynthesis in previous generation stars

Through processes occuring on Earth (natural nuclear reactors)

In the big bang at the start of the universe

By nucleosynthesis in previous generation stars

Explain: The Big Bang only created Hydrogen, Helium, Lithium (made the lightest stuff). Every heavier element is formed by stars (its heat and gravity force positively charged nuclei together). To get elements greater than Iron, you have to use neutrons because protons hate each other (Coulomb Barrier)→ If atom has too many neutrons, it will go through beta decay (neutron becomes proton, spits out electron). The s-process and r-process differ in how they feed neutrons into that iron core. Ex: s-process: “Feeding a toddler 1 pea at a time”, the iron only swallows 1 neutron so it has time to digest, wait, transform that neutron into a proton (Creates medium-heavy elements like Tin, Led). Ex: r-process (rapid): “A firehose blasting into a toddler’s face 1000 peas at a time”, the iron has no time to digest anything, neutrons rapidly begin changing into protons (during Supernovas, creates heavier elements like Gold, Uranium)

How old is the Earth? (Quiz 1)

3 Ga

4.5 Ga

5.5 Ga

1 Ga

7.1 Ga

4.5 Ga

Approximately when did flowering plants evolve? (Quiz 1)

 

50 Ma

 

300 Ma

 

130 Ma

 

10 Ma

 

130 Ma

What is the strongest evidence we have for the Earth's oceans becoming oxygen-rich?

Trees began to evolve

Fish suddenly got really big as there was more Oxygen available

Banded iron formations (BIFs)

Banded iron formations (BIFs)

Explain: In the early ocean, there was no free oxygen in the air or water. Because there’s literally no oxygen, dissolved iron stayed completely dissolved in seawater, so the ancient oceans were just soups of dissolved iron. Earlier Bacteria used H2S to make sulfur but NOT oxygen. Around 3.5-2.7 Ga, single-celled cyanobacteria started to generate oxygen using Water H2O + CO2 + Sun→ Sugar + Oxygen (Kept Hydrogen and Carbon to build sugar, threw away oxygen into the seawater). (( Later, a complex cell swallows the cyanobacteria and kept it inside of them, which the bacteria evolves into a chloroplast. )) When the oxygen meets the dissolved iron in the ocean, the iron rusted and turned into red/black rust flakes, and they settled down to the bottom of the ocean floor. When oxygen ran out, or there is no cyanobacteria, normal silica mud fell on top of it. This cycled repeatedly, causing layers of either rust or silica. This multi-layered stack of rock is called BIF (Banded Iron Formation)

What happens at a continental-oceanic collision boundary? (Quiz 2)

Denser continental crust subducts under less dense oceanic crust. Produces volcanoes, big earthquakes and tsunamis

Denser oceanic crust subducts under less dense continental crust. Produces volcanoes, big earthquakes and tsunamis

Denser oceanic crust subducts under less dense continental crust. No volcanoes, big earthquakes and tsunamis

Denser continental crust subducts under less dense oceanic crust. No volcanoes produced, but big earthquakes and tsunamis

B) Denser oceanic crust subducts under less dense continental crust. Produces volcanoes, big earthquakes and tsunamis

Explain: Ocean Rock (Basalt) is heavy and sinks, Continental Rock (Granite) is light and floats. The heavy ocean floor dives down, gets stuck, jerks violently (Earthquakes, Tsunami), melts mantle rock to feed volcanoes.

What happens at a continental-continental collision boundary? (Quiz 2)

The denser continental plate subducts, form big volcanoes like Mt. St. Helens and Mt. Rainier

Two continents collide, produces the largest earthquakes we see on Earth

Two continents collide, neither plate can succesfully subduct, form large mountain ranges like the Himalaya

One continent slips past the other, like the San Andreas fault

Two continents collide, neither plate can succesfully subduct, form large mountain ranges like the Himalaya

Explain: Two plates are colliding into each other, but none of them are heavy enough to sink into the water, so they just smash into each other, and pile upwards into mountain ranges.

Give an example of a place on earth where a new ocean may be forming? (Quiz 2)

East Africa

Antartica

Florida

Hawaii

East African Rift System

East Africa is tearing in half. As the ground drops into a deep valley, the ocean will eventually flood in and create a brand-new sea.

What happens at a divergent plate boundary? (Quiz 2)

Two oceanic plates slide past each other

Two oceanic plates pull apart. Makes big volcanoes like Mt. St. Helens

Two plates pull apart, New oceanic crust is made in the middle

Two continental plates come together. Makes the Himalayas

Two plates pull apart, New oceanic crust is made in the middle

What is an example of where a new ocean started to form but eventually failed

Yosemite

Florida everglades

Badlands

The midcontinental rift, near Lake Superior

The midcontinental rift, near Lake Superior

What is the distribution of hot spots around the world?

Many hot spots are clustered in the Pacific and Atlantic. They are thought to arise from large low shear velocity zones

Lots of hot spots are clustered in australia - arising from a large low shear velocity zone

Lots of hot spots are clustered around antartica - they are thought to arise from a subduction zone

Many hot spots are clustered in the Pacific and Atlantic. They are thought to arise from large low shear velocity zones

Select all volcanoes or volcanic regions that were formed by hotspot volcanism.

Kilauea Volcano, Hawaii

Iceland

Mt. St. Helens, USA

Mt Fuji, Japan

Kilauea Volcano, Iceland

Where is the Moho (Mohorovicic) discontinuity?

Inside the deep mantle

Between the mantle and outer core

Between the crust and mantle

Between the outer core and inner core

Between the crust and mantle

What is a soft story building?

Buildings with unequal levels of resistance on different floors, often with a parking garage underneath

Buildings which have been seismically retrofitted

Buildings built on soft sediments prone to liquefaction

Buildings with unequal levels of resistance on different floors, often with a parking garage underneath

When was the last major earthquake on the Hayward Fault?

1989 (M7.1)

1868 (M7)

1906 (M8.3)

1868 M7

How long might East Bay residents lose access to water in the event of a Hayward Fault earthquake?

1 day to 1 week

6 weeks - 6 months

1-5 years

5+ years

6 weeks-6 months

What is the point of getting 10 seconds warning through an earthquake early warning system? Select all answers that apply.

Time to drop, cover, and hold on

Time to put down hazardous chemicals

Time to shut off gas

Time to hold elevators at a floor

Time to evacuate buildings

Time for surgeons to drop operating instruments

Time for everyone to flee to high ground

1) Time to drop, cover, and hold on, 2) Time to put down hazardous chemicals, 3) Time to shut off gas, 4) Time to hold elevators at a floor, 5) Time for surgeons to drop operating instruments

To preserve communications after a really big earthquake, what should you do? Select all that apply.

Text but don't call, since voice calls use more of the network

 

Change voicemail to provide updates on your status

 

Post on social media

 

Call but don't text, texts overwhelm the network

Text but don't call, since voice calls use more of the network

Change voicemail to provide updates on your status

Which type of plate boundary forms the largest earthquakes (>M9)?

Continental-continental convergent boundary (e.g. the Himalayas)

Transform boundary (e.g. the San Andreas Fault)

Oceanic-continental convergent boundary

Oceanic-continental convergent boundary

Select all the factors that contribute to an earthquake's magnitude (e.g. energy released in an earthquake).

Strength of the rock along the fault

How deep the earthquake is

Area of the fault that slips

How far you are from the earthquake

Amount of slip (in meters)

Strength of the rock along the fault, Area of the fault that slips, Amount of slip

What are the first types of seismic waves to arrive at a seismic station after an earthquake?

S waves (shear waves)

P waves (compressional waves)

Surface waves

P-waves

How do we determine the location of an earthquake?

Using GPS

By measuring the time lag between the arrival of P waves and S waves at various seismometers (like thunder vs. lightning in a storm)

By looking at which direction the waves are travelling from

By measuring the time lag between the arrival of S waves and Surface waves at various seismometers (like thunder vs. lightning in a storm)

By measuring the time lag between the arrival of P waves and S waves at various seismometers (like thunder vs. lightning in a storm)

Why don't we use the Richter scale anymore?

It was updated as part of a universal move to metric measurements (e.g. meters, km, not feet and inches)

The Richter scale uses wave amplitude, but seismometers only record certain frequencies so it was doing a bad job at really large earthquakes

The Richter scale isn't very good at recording the smallest earthquakes

The Richter scale uses wave amplitude, but seismometers only record certain frequencies so it was doing a bad job at really large earthquakes

How much more energy does a magnitude 7 earthquake release compared to a magnitude 5?

32 x 32 x 32 = 32768 times more energy

10 x 10 = 100 times more energy

32 x 32 = 1024 times more energy

32 x 32 = 1024 times more energy

What affects the intensity of an earthquake?

The magnitude of the earthquake

The distance you are from the earthquake

What materials are between us and the earthquake

The depth of the earthquake

Everything

For the same magnitude earthquake, why do people feel earthquakes at a greater distance on the East Coast (e.g. central Virginia) versus in the Bay Area?

People in the bay area get more earthquakes a year, so they stop noticing the smaller ones

The east coast is made of a craton, which rings like a bell when an EQ happens. Whereas all the faults in the Bay Area dissipate the energy faster.

Earthquakes are shallower on the East coast, so you feel them more

The east coast is made of a craton, which rings like a bell when an EQ happens. Whereas all the faults in the Bay Area dissipate the energy faster.

What is the difference between magma and lava?

magma = on the surface, lava = in the subsurface (underground)

lava = on the surface, magma = in the subsurface (underground)

magma is when it has no crystals

magma is always hotter than lava

lava = on the surface, magma = in the subsurface (underground)

Which property affects viscosity more: melt composition or temperature?

Melt composition

Temperature

Melt composition

What are the primary processes that trigger an eruption? Select all that apply.

The magma solidifying

Influx of new magma at depth

Exsolution of volatiles

human activity

Influx of new magma at depth

Exsolution of volatiles

What are the main volcanic hazards at Mt. Rainier, Washington?

Toxic gases

Lahars

Lava flow inundation of Seattle

Pyroclastic flows

Lahars

Pyroclastic flows

What are the main volcanic hazards at Kilauea Volcano, Hawaii? Select all that apply.

Toxic gases

Lahars

Lava flow inundation

Pyroclastic flows

Toxic gases, Lava flow inundation

Why is rhyolitic lava more viscous than basaltic lava?

Rhyolite has more heavy metals

Rhyolitic lava is cooler than basaltic lava

Rhyolite has more SiO2

Rhyolite has less SiO2

 

Rhyolite has more SiO2

Oh no! An evil wizard is forcing you to stand near a volcanic eruption but, because they are a generous evil wizard, they are allowing you to choose the location of your own demise. Thankfully, you're taking EPS 80 and therefore know a little bit about volcanoes. Which of the following options would be least hazardous to you and possibly allow you to escape intact?

1 km away from a 20 m tall fire fountain

On a boat 300 m away from lava entering the ocean

On top of a small cinder cone where the lava is not erupting outside the cone

Inside a car just 1 km away from an approaching pyroclastic flow

 

1 km away from a 20 m tall fire fountain

What is the geothermal gradient?

The rate of change of temperature in a hot spring

The rate of change of temperature with depth in the Earth

The rate of change of pressure with depth in the Earth

The rate of change of temperature inside a volcano

 

The rate of change of temperature with depth in the Earth

In what setting do pillow basalts form?

All hotspot volcanoes

Underwater volcanoes, typically near mid-ocean ridges

Stratovolcanoes

Arc volcanoes

 

Underwater volcanoes, typically near mid-ocean ridges

Magmas with a high volatile content lead to effusive eruptions.

True

False

 

False

The crystallization of iron and titanium oxides will concentrate silica in the remaining magma.

True

False

 

True

How do we get the solid mantle to melt and produce magma to feed volcanoes? Select all that apply.

Reduce the position of the solidus by adding water (e.g. subduction zones)

Increase temperature of the mantle (e.g. at hotspots)

Have a large earthquake shake the mantle

Decrease pressure (depth) of a parcel of mantle by making it rise (e.g. oceanic-oceanic divergent boundaries)

 

Reduce the position of the solidus by adding water (e.g. subduction zones)

Increase temperature of the mantle (e.g. at hotspots)

Decrease pressure (depth) of a parcel of mantle by making it rise (e.g. oceanic-oceanic divergent boundaries)

Why does water reduce magma viscosity?

Water breaks apart chains of silica tetrahedra

Water reduces the temperature of the magma therefore reducing viscosity

Water breaks up bonds between iron and magnesium ions

Water brings dissolved minerals into the magma

 

Water breaks apart chains of silica tetrahedra

Why does the mantle melt at mid-ocean ridges?

Add water to change the position of the solidus

The portion of mantle beneath the ridge is hotter (e.g. a mantle plume)

Plates pull apart, mantle rises up, decompresses without losing much heat, crosses the solidus

 

Plates pull apart, mantle rises up, decompresses without losing much heat, crosses the solidus

Why does the mantle melt beneath Hawaii?

The Pacific Plate is pulling apart around Hawaii, so mantle rises up and melts

Adding water to the mantle because it rains a lot in Hawaii

Mantle plume is rising (decompresses), and is anomalously hot (heats surrounding mantle), double whammy to get melting

 

Mantle plume is rising (decompresses), and is anomalously hot (heats surrounding mantle), double whammy to get melting

Where does the water needed to melt the mantle in subduction zones come from?

Rainwater percolating into the continental plate above

Water being released from the altered oceanic plate being subducted

The water is already in the mantle

 

 

Water being released from the altered oceanic plate being subducted

What general compositional progression do magmas follow as they fractionally crystallize?

 

Rhyolite -> Dacite -> Andesite -> Basalt

Basalt -> Dacite -> Andesite -> Rhyolite

Basalt -> Andesite -> Dacite -> Rhyolite

Rhyolite -> Andesite -> Dacite -> Basalt

 

 

Basalt -> Andesite -> Dacite -> Rhyolite (BADR)

What happens to the silica (SiO₂) content of a magma if it incorporates and melts continental crust?

SiO2 goes down, as the continental crust is SiO2 poor

SiO2 stays the same, continental crust and primary magmas have similar compositions

SiO2 goes up, as the continental crust is Si-rich

 

 

SiO2 goes up, as the continental crust is Si-rich

What are the most abundant volatiles in magmatic systems? (Quiz 3-Volcanoes)

H2O, CO2, S

Ar, He, Ne

SO2, S, H2S

CO2, CO, CH4

Cl, F, H2O

 

H2O, CO2, S

What are the major factors affecting the viscosity of a magma? Select all that apply. (Quiz 4-Tsunamis)

How much magma there is

How deep in the crust it is

Temperature

Water content

Melt composition

Temperature

 

Water content

 

Melt composition

Approximately how many people died in the 2004 Boxing Day Tsunami in Indonesia? (Quiz 4)

50,000 to 100,000

10,000 to 20,000

1 million to 2 million

200,000 to 300,000

 

200,000 to 300,000

How do we know know the atmospheric shockwave from the Tonga volcanic eruption triggered the tsunami (not direct displacement of the water column as is normal)? Select all that apply. (Quiz 4-Tsunami)

The tsunami arrived too early, as the shockwave travels faster than water waves

Ocean basins not connected to the Pacific (e.g. Caribbean) had a small tsunami

The tsunami was too small

The tsunami traveled the wrong way

The tsunami arrived too early, as the shockwave travels faster than water waves

Ocean basins not connected to the Pacific (e.g. Caribbean) had a small tsunami

If you are on a beach, how might you know a tsunami is coming and you should seek high ground? (Quiz 4-Tsunami)

The sea level starts rising quickly

It starts to rain

You get an emergency text on your phone

Feel an earthquake

Sea starts to retreat like the tide is going out

You hear a thunderstorm

You hear a tsunami siren

 

The sea level starts rising quickly

You get an emergency text on your phone

Feel an earthquake 

Sea starts to retreat like the tide is going out

You hear a tsunami siren

If a community is on the coast, and has no high ground around, what can be done to prevent mass death in a tsunami? (Quiz 4-Tsunamis)

Fast roads away from the beach

Underground bunkers

Vertical evacuation towers

 

Vertical evacuation towers

How can we gain early warning for a tsunami? (Quiz4)

Monitor when earthquakes occur

DART buoys

Webcams on the beach

Monitor when earthquakes occur

DART buoys

Can you safely head back to the shoreline after the big tsunami wave has passed to get your stuff/find your family? (Quiz4)

Yes

No

no

What evidence do we have for a very large tsunami on the Pacific Northwest in 1700 AD? Select all that apply. (Quiz 4)

Tree rings showing sudden death at 1700 AD

Indigenous reports

Reports from European colonizers in the Pacific Northwest

Reports of a tsunami in Japan that had no local earthquake

Tree rings showing sudden death at 1700 AD

Indigenous reports

Reports of a tsunami in Japan that had no local earthquake

Which tsunami event has the tallest wave height we have evidence for?

Vajont Dam Disaster, Landslide triggered by dam building

Indian Ocean/Boxing Day Tsunami, 2004

Lituya Bay Tsunami, Rockfall triggered by an earthquake

Krakatau Tsunami, Volcanic triggered, 1883

 

Lituya Bay Tsunami, Rockfall triggered by an earthquake

How fast do tsunamis travel?

250 mph

500 mph

100 mph

1000 mph

 

500 mph

How do tsunamis differ from normal ocean waves?

Tsunami waves have very short wavelengths.

Tsunami waves are much slower than normal ocean waves.

Tsunami waves are much deeper (e.g. whole ocean depth), not just the upper few meters of the ocean.

Tsunami waves are much shallower than normal ocean waves, which is why they move so fast.

Tsunami waves are much deeper (e.g. whole ocean depth), not just the upper few meters of the ocean.

What is the run up height of a wave?

The height of the wave before breaking

How far across the ocean the wave travels

The height of the wave out to sea

The maximum height above sea level that the wave reaches after breaking

 

The maximum height above sea level that the wave reaches after breaking

How can we displace large enough volumes of water to form a tsunami? Select all that apply.

Meteorite impact into the ocean

Megathrust earthquake

Volcanic eruptions

Landslides (underwater, or into a body of water)

Heavy rain

Strike-slip earthquakes like the San Andreas Fault

Meteorite impact into the ocean

Megathrust earthquake

Volcanic eruptions

 Landslides (underwater, or into a body of water)

Mock Reading Q: What is the earthquake magnitude and fault source simulated in the USGS HayWired scenario?

An M8.2 earthquake on the San Andreas Fault

An M7.0 earthquake on the Hayward Fault

An M6.0 earthquake on the Calaveras Fault

An M9.0 megathrust rupture offshore Cape Mendocin

An M7.0 earthquake on the Hayward Fault

How does the expected shaking duration of a full-margin Cascadia subduction zone rupture compare to that of typical California strike-slip earthquakes (such as Loma Prieta in 1989)?

• A. Cascadia shaking will last roughly 5 to 10 seconds due to fast wave speeds

• B. Cascadia shaking will be approximately the same duration (~15 seconds)

• C. Cascadia shaking will last for 3 to 5 minutes over a broad regional zone

• D. Subduction earthquakes produce high amplitude displacement but zero sustained ground shaking

• C. Cascadia shaking will last for 3 to 5 minutes over a broad regional zone

Although Mount Rainier is an active composite volcano, what is considered the single most dangerous hazard it poses to downstream communities such as Puyallup and Tacoma?

• A. Fast-moving basaltic lava flows sweeping through urban streets

• B. Lahars (volcanic mudflows) generated by rapidly melting summit glaciers

• C. Toxic clouds of pure carbon monoxide gas suffocating low valleys

• D. Catastrophic caldera collapse causing an inland sea tsunami

• B. Lahars (volcanic mudflows) generated by rapidly melting summit glaciers

Which volcanic center was the site of the most recent explosive eruption sequence in California (1914–1917)?

• A. Mount Shasta

• B. Long Valley Caldera

• C. Lassen Peak / Lassen Volcanic Center

• D. Clear Lake Volcanic Field

• C. Lassen Peak / Lassen Volcanic Center

How did the Crater Lake caldera in Oregon form approximately 7,700 years ago?

• A. A giant extraterrestrial meteorite impacted the Cascade mountain range

• B. The summit of Mount Mazama was blasted away entirely into outer space by a gas explosion

• C. Mount Mazama erupted massive volumes of magma, and the mountain collapsed inward into the emptied magma chamber below

• D. Glaciers carved a deep cirque bowl that subsequently melted and dammed itself

• C. Mount Mazama erupted massive volumes of magma, and the mountain collapsed inward into the emptied magma chamber below

What is Wizard Island inside Crater Lake?

• A. A piece of the original mountain summit that failed to collapse

• B. A volcanic cinder cone built by minor eruptions on the caldera floor after the collapse

• C. A massive raft of floating pumice rock that became vegetated over time

• D. A glacial moraine deposited during the last ice age

• B. A volcanic cinder cone built by minor eruptions on the caldera floor after the collapse

What are the Deccan Traps in India, and what is their significance in Earth history?

• A. A chain of explosive composite volcanoes that erupted at 250 Ma causing the Great Dying

• B. A massive continental flood basalt province erupted around 66Ma, whose climate-altering gas emissions contributed to the end-Cretaceous mass extinction

• C. A complex system of subduction trenches formed when India collided with Asia

• D. A fossilized coral reef system that recorded the onset of the Great Oxidation Event

• B. A massive continental flood basalt province erupted around 66Ma, whose climate-altering gas emissions contributed to the end-Cretaceous mass extinction

How does the expected shaking duration of a full-margin Cascadia subduction zone rupture compare to that of typical California strike-slip earthquakes (such as Loma Prieta in 1989)?

• A. Cascadia shaking will last roughly 5 to 10 seconds due to fast wave speeds

• B. Cascadia shaking will be approximately the same duration (~15 seconds)

• C. Cascadia shaking will last for 3 to 5 minutes over a broad regional zone

• D. Subduction earthquakes produce high amplitude displacement but zero sustained ground shaking

• C. Cascadia shaking will last for 3 to 5 minutes over a broad regional zone