Chapter 3 Tectonic Forces Flashcards
two ways of reshaping Earth’s crust
diastrophism and volcanism
what is the earth force that folds, faults, twists, and compresses rock called
diastrophism
geohazards resulting from diatrophism
earthquakes, landslides, tsunamis
plate boundary movements that result in diatrophism
convergent, divergent, and transform (all three)
True or false: Diastrophism can only happen at a boundary
False: can happen on a plate
Two examples of diatrophism
folding and faulting
The earth force that transports magma and lava to (or toward) the surface of the earth
volcanism
geohazards resulting from volcanism
volcanic eruptions and landslides (tsunamis can occur but are not as common)
boundaries that cause volcanism
convergent subduction and divergent (NOT COLLISION AND TRANSFORM)
Folding. What is it and what state was the rock in?
A bend or wrinkle in a rock resulting from compression and formed when the rock was in a plastic state.
Three examples of landforms that resulted from folding
himalayas, andes, and alps
Fault. What is it and what boundary types can it occur at?
break or fracture in rock along which movement has taken place; all boundary types
Where is the ring of fire? What percentage of earthquakes occur there?
Pacific Ocean, 90 Percent
Why are so many large cities located near volcanoes in central america?
the volcanic ash and rock create exceptionally fertile soil, making the surrounding areas ideal for agriculture, which in turn attracts large populations to settle and build cities in these regions
The richter scale (earthquake magnitude scale) goes from what to what?
1 (micro) to 10 (great)
what boundary types do earthquakes occur at?
all three (divergent, convergent, and transform)
what boundary types do volcanoes occur at?
divergent, convergent, and hotspots
volcanoes are located near ____
magma
Ocean borders can be found where?
Subduction zones
What percentage of volcanoes occur at the ring of fire? (remember 90 is earthquakes)
75 percent
what are the three observations of volcanoes?
extinct, dormant, active
name the volcano observation: no eruptions
extinct
name the volcano observation: no eruptions in 10k years
dormant
name the volcano observation: erupted within 10k years
active
the greatest geohazard is what? give an example
active volcanoes
kilauea, hawaii
difference between shield volcanoes and composite volcanoes
shield - large broad slopes with fluid lava flow (large and fluid)
composite = steep and symmetrical, explosive eruptions (steep and explosive)
composite volcanoes are also known as
stratovolcanoes
difference between low and high silica content
low - effusive (shield)
high - explosive (strato)
low silica content = low
high silica content = high
viscosity
a dome-shaped volcanoes that form when thick lava piles up around a volcanic vent and solidifies into a domed structure
lava domes
a lava dome with low viscosity
low = effusive = dome pileup
a lava dome with high viscosity
high = explosive = dome collapse
a small, cone-shaped volcano consisting of pyroclasts that become existinc after a few years/decades and often form caldera (collapse of mouth of volcanoe)
cinder cones
a broad, domed volcano formed from innumerable layers of ______ lava accumulated over tens to hundred of thousands of years
basaltic, shield
largest volcanoes on earth
shield volcanoes
effusive > ___ silica content > lava ____
low, flows
large, potentially explosive cone-shaped (steep) volcano composed of alternating layers of lava and solid rock material ranging in size from ash to boulders (pyroclasts)
stratovolcanoes
what is the difference between pyroclasts and volcanic ash?
pyroclasts- fragmented solid material ejected from a volcano (ranging from ash to boulders)
volcanic ash - pulverized rock particles and solidified droplets of lava
what is involved in a pyroclastic flow?
pyroclasts and volcanic ash
how fast can a pyroclastic flow move?
more than 50 mph
yellowstone is an example of a
hotspot
how does a caldera form
lava extrudes into a chamber, gas expands and lava explodes, the magma chamber collapses and forms a caldera
a large ocean wave generated by underwater earthquakes, landslides, and volcanoes
tsunami
