PUBHLTH 90- NATURAL DISASTERS

after the magma chamber is mostly empty

A caldera collapse occurs ________________.

true

A majority of earthquakes occur on or near plate boundaries.

magnetized in the direction of the Earth's magnetic field at that time and place, seafloor spreading

After lava cools, atoms in iron-bearing minerals on the seafloor become ______________ . This evidence of ____________ is just one dataset supporting the theory of plate tectonics.

released

As radioactive atoms decay, energy is ________________.

true

Hot spots have active volcanoes above them on the Earth's surface and moving plates carry the volcanoes away from their hot-spot source.

tsunamis debris avalanches lahars

In addition to lava flows, volcanic processes can cause:

false

Normal faulting occurs when the hanging wall moves upward relative to the footwall.

seismic waves, ground deformation, the release of gases

Several geologic phenomena are considered precursors of an impending volcanic eruption. These include _____________ , ____________ , and __________.

false

Shield volcanoes are steep-sided, symmetrical volcanic peaks built of alternating layers of pyroclastic debris capped by high-viscosity andesitic to rhyolitic lava flows.

a'a

Slow flowing, more viscous basaltic lava commonly has a rough, blocky texture called ________.

true

Strike-slip (transform) faults usually link spreading centers or connect spreading centers with subduction zones.

chemical, physical

The Earth's innermost layer is known as the core when considering __________ properties, but is broken into 2 layers, outer core and inner core, when discussing ___________ properties.

hypocenter, epicenter, hypocenter

The _____________ is where an earthquake starts and the __________________ is a surface point on a map directly above the ________________.

Icelandic type eruptions

The most peaceful eruptions are _____________.

true

The movements of the lithospheric plates are directly responsible for the vast majority of the earthquakes, volcanic eruptions, and mountains on Earth.

pyroclastic flows

The primary cause(s) of death from explosive volcanic eruptions is(are) _______________.

true

The rates of plate movement are comparable to those of human fingernail growth.

viscosity, volatiles, volume

The three Vs of volcanology are __________________.

true

The types of rock or sediment on which a structure's foundation sits are of paramount importance with respect to whether the structure will be damaged by shaking from an earthquake.

divergent and convergent plate boundaries

Volcanoes are formed at ____________________.

true

Volcanoes tend to occur mostly along plate boundaries.

push together

What type of motion is associated with convergent plate boundaries?

pull apart

What type of motion is associated with divergent plate boundaries?

slide past

What type of motion is associated with transform plate boundaries?

older, colder plate goes beneath the younger, warmer plate

When oceanic lithosphere collides with another plate, the ________ in the process of subduction.

Pushing together plate motions, occurrence of earthquakes, and reverse faulting

Which characteristics describe a convergent plate boundary?

Pulling apart plate motions, occurrence of earthquakes, and normal faulting

Which characteristics describe a divergent plate boundary?

Horizontal sliding plate motions, occurrence of earthquakes, and strike-slip faulting

Which characteristics describe a transform plate boundary?

is not where earthquakes occur

Which does not describe the lithosphere?

reverse

________ faults are commonly found at areas of plate convergence where subduction or continental collision occurs.