Unit 2 Flashcards
instrument used to measure volcanic gases
correlation spectrometer
vertical intrusion of magma between rock layers
dike
immediate return of deformed rock to its natural shape
elastic rebound
location on the earth’s surface directly over the focus of an earthquake
epicenter
specific point in the earth where the rock layers along a fault move, producing an earthquake
focus
semi-dark line that indicates the ridge of a fold on a geologic map
fold axis
block of rock below the slant of a fault
footwall
mini-quakes that usually occur before a major earthquake
foreshocks
shows locations and types of rocks and other features, like faults and folds
geologic map
energy produced from the heat of magma and other volcanic materials
geothermal energy
What causes an earthquake
Heat from Earth’s mantle
Plate tectonics
What causes an volcanic activity
fault lines
the Ring of Fire
plate boundaries
When stress on rocks becomes too great, they break, and then undergo:
elastic rebound
Magma that is highly viscous with a high silica and gas content creates an eruption that is _____.
very explosive
a scale of magnitude used to measure the relative size or strength of an earthquake
Richter scale
newer magnitude scale that measures the amount of moved or displaced rock along a fault to determine the strength of an earthquake
moment magnitude scale
scale that measures the effects or severity of damage from an earthquake
Mercalli intensity scale
instrument used to measure and record vibrations that result from earth movements
seismograph
instrument used to measure ground swelling, which usually occurs from magma building in the magma chamber of a volcano
tiltmeter
earthquake with magnitude of 2.0 in a Richter scale can….
be barely felt
earthquake with magnitude of 8.0 in a Richter scale can….
destroys cities
In order to locate an earthquake’s epicenter, seismology centers compare the arrival times of:
P and S waves
To predict earthquakes, geologists look for a combination of the following signs:
foreshocks
decreases in well water levels
increases in radon gas in ground water
A vast plain of rolling hills are actually folds of _____.
anticlines and synclines
fold where hills arch up
anticline
simplest type of fold, where rock layers incline in the same direction
monocline
broad, gentle fold of a large area that occurs from rock layers upwarping; looks like an upside-down bowl
dome
broad, gentle fold of a large area that occurs from rock layers downwarping; looks like a* bowl right-side up*
basin
What type of mountains occur at normal faults from the footwall being thrust upward along the hanging wall.
Fault-Block
horizontal intrusion of magma that builds and bubbles like a dome within the rock layers
laccolith
horizontal intrusion of magma into rock layers
sill
massive layer of magma underneath sedimentary rock that usually forms the base of mountains
batholith
The capital letter(s) that label a rock unit (e.g., KJk) on a geologic map represents the rock unit’s _____.
age range
Volcanoes that are tall, steep, and made of both lava and volcanic material are
composite
Tall, gradually sloped volcanoes made mostly of lava flow are _____ volcanoes.
shield
what are the basic features of a map
title
scale
legend
compass
What type of maps include colors, letter symbols, fault lines and contact lines?
geologic maps
What type of map focuses geological features’ shapes, elevations, and steepness of slopes
Topographic Maps
Earthquakes can be predicted. T/F
False
What could help create a volcano
cracks in Earth’s crust
plate tectonics
built up magma
The Pacific plate collides with and is subducted under four other crustal plates. The area where this happens has lots of volcanic activity. This area is called the _____.
Ring of Fire
A volcano with basaltic magma would probably _____.
erupt with a gradual lava flow
This feature occurs in an area where water is heated under ground to the point of boiling. When the water and steam build, they finally rise through a vent on the surface, spraying water and steam high up into the air. This feature is a _____.
geyser
Naturally hot water containing many minerals and found on the surface of the earth is called a _____.
hot spring
A natural disaster produced by volcanic activity that has killed more people than lava flows is _____.
a landslide or mudslide
Mount Tambora in Indonesia erupted and caused the “Year without a Summer.” Over 100,000 people died from starvation because of the resulting _____.
climate change
A tiltmeter is a volcanic monitoring tool that measures _____.
ground swelling
Volcano eruption can be predicted
True
