Natural Disasters Exam 1 Flashcards
(60 cards)
In silicate minerals, isolated silicate tetrahedra and three-dimensional networks of silicate tetrahedra are example of _____________.
Defining anions
The shape that a crystal of a particular mineral takes is determined by the ______________ of the mineral.
crystal system
A partly-molten of the Earth that the tectonic plates of the Earth move over is called the _____________. This is located in the upper mantle.
The asthenosphere.
The tectonic plates of the Earth are contained in a layer called the ______________. This layer is contained in the crust and uppermost mantle.
The lithosphere.
_____________ is hotter than the outer core, and is solid because it is under greater pressure.
The inner core.
Where does the Earth’s magnetic field originate? The ____________ is completely molten.
In the outer core.
Where do most of Earth’s volcanism happen?
At transform tectonic plate boundaries.
At divergent tectonic plate boundaries
These are the seafloor spreading center. This is where 80% of Earth’s volcanism happens because volcanism happens all along the many thousands of miles of divergent seafloor spreading centers.
Where are Hawaii and Yellowstone volcanoes located?
The _____________ are the exception to the fact that Earth’s volcanism happens at the margins of tectonic plates.
Over mantle plumes.
When the westward moving North American continental plate overrode part of the Earth Pacific Rise, that part of the East Pacific Rise was replaced by ________________.
A transform plate boundary.
The point of origin of an earthquake along a fault plane is called the _____________. Site of first motion along the fault. Located at some depth below the surface.
focus
Point on the surface directly above the focus.
Epicenter
_________________ is the scale currently used by the United States Geological Survey (USGS) to rank an earthquake by size, and provides a more complete estimate of the energy released by an earthquake than did the original earthquake scale used by the USGS. This is more of a complete measure of the intensity of an earthquake.
Moment Magnitude
How does faulting happen?
It happens under low pressure, near the surface, where brittle rock failure occurs.
It is believed that movement along a fault dies out at depth when rock deformation along the fault becomes ______________ due to higher pressure at greater depths in the Earth.
Plastic deformation
All rocks initially undergo elastic deformation when stress first applied.
Brittle Deformation
Rocks undergo _____________ when the “elastic limit” of the rocks is exceeded, resulting in faulting and permanent rock movement.
Brittle Fracture
_______________are the fastest type of seismic wave and can pass through an medium (solid, liquid or gaseous), including through solid, molten, and semi-molten layers of the Earth.
P-waves body seismic waves
__________ have most of their energy from p-wave body waves
underground nuclear explosions
___________________ have most of their energy in s-wave body waves
natural earthquakes
We know that the outer part of the Earth’s core is completely molten because is completely blocks _________________ seismic waves that pass through solid layers of the Earth but cannot travel through liquids.
S-wave body seismic waves
What kind of faulting happens under tension (stretching) of the crust?
Common at divergent plate tectonic boundaries.
Normal dip-slip faults.
What kind of faulting happens under compression of the crust?
reverse dip-slip faults
What kind of faulting happens under shearing of the crust?
common at transform plate tectonic boundaries
left-lateral and right-lateral strike-slip fault
