QUIZ: Volcanoes and Plate techtonics

the depression in which Crater Lake is now located is the result of the top volcano collapsing after a cataclysmic eruption

true

not a method that volcanologist use to predict volcanic eruptions?

clouds increase over the volcano due to the release of water vapor

which type of volcano is built by long lasting lava flows?

shield volcanoes

not a type of pyroclastic material?

dome

volcanoes form everywhere except:

at transform plate boundaries

mafic magmas usually contain very low amounts of silicon and low amounts of iron and are very viscous.

false

what has NO influence on the viscosity of magma?

its color

what are some volcanic hazards that could face a geologist working on a volcano?

suffocation by gases emitted by the volcano, pyroclastic flows, earthquakes caused by moving magma, and landslides triggered by the volcano.

Hawaii is an example of a/an:

hot spot

what is a lahar?

a mudslide triggered by a volcano

cinder cones are built by relatively short lasting volcanic activity.

true

how do volcanoes affect people?

houses/buildings/roads/ and fields can get covered with ash, if the ashfall is really heavy it can make it impossible to breathe, lava flows are almost always too slow to run over people but they can certainly run over houses/roads/and any other structures, and pyroclastic flows are so hot and choking that if you are caught in one it will kill you.

the most explosive volcanoes build:

stratovolcanoes

common volcanic gasses?

carbon dioxide and sulfur dioxcide

volcanic eruptions of gas and ash have virtually no affect on global climate.

false

mafic volcanoes do not have the characteristic of:

they are typically found at subduction zones

______said of material forcibly ejected from a volcano

pyroclastic

_____a plume of magma that pierces the earths lithosphere

hot spot

_____a type of rock made up of consolidated volcanic ash

tuff

_____a volcano constructed of alternating layers of lava and pyroclastic deposits

stratovolcanoes

convergent and transform plate boundaries do not generate destructive earthquakes.

false

explosive volcanoes are located near convergent plate boundaries.

true

why are reverse faults common in subduction zones?

because of compression

oceanic crust is created at _____ plate boundaries and destroyed at _____ plate boundaries.

divergent, convergent

the origin of the Himalaya Mountains

a continent-continent collision is occurring, which means that neither plate can sink into the mantle. instead, large mountains are pushed up.

the “year without a summer” was caused by

a huge volcanic eruption in Indonesia

how does continental drifting work?

continents pull apart from each other

what is the mechanism that drives continental drift?

mantle convection

describe paleomagnetism

the earths magnetic field periodically reverses over geologic time

what provides evidence for continental drift and plate tectonics?

paleomagnetism of the earths crust, sea floor spreading, earthquakes occurring along transform and convergent plate boundaries

what plate tectonic setting does this describe

convergent plate boundary

what is a subduction zone?

where one lithospheric plate is pushed/pulled beneath another

what type of plate boundary is represented by the San Andres Fault?

transform

how are mountains formed by plate techtonics?

accretion along the continental margin, magmatic processes, compression at convergent plate boundaries, and collisions of all continents

where do we see rift valleys, normal faults, black smokers, and rising magma?

at mid ocean ridges

geologist immediately accepted the theory of continental drift when it was proposed

false

volcanoes at oceanic divergent plate boundaries are not as explosive as those at ocean-continent convergent boundaries.

true

what does the pattern of magnetic stripes on the seafloor indicate?

that oceanic crust is formed at mid ocean ridges and is then pushed/pulled away from them

what is a region where two plates are moving toward each other called?

convergent plate boundary

California’s San Andres fault is typical of?

transform boundaries