Definitions for Test #2 Flashcards
Continental drift
A theory that explains how continents shifted position on Earth’s surface. (Alfred wegner)
earthquake
Intense shaking of Earth’s surface, caused by movements in Earth’s outermost layer.
seismic waves
Waves that travel through Earth generated by movements in the tectonic plates. can also be caused by explosions, volcanoes. and landslides.
seismogram
A result from a seismograph, records the ground’s motions in an earthquake.
shearing
deformation of a materials substance where the parallel internal surfaces slide past another.
hanging wall
the rock above fault plane
normal fault
hanging wall moves down
Pangaea
a former “supercontinent” on Earth, when all continents were once connected.
epicenter
Point on Earth’s surface directly above an earthquake.
Seismology
the branch of science concerned with earhquakes and related topics.
body waves
seismic wave that moves through the interior of the earth, rather than on the surface (P and S waves)
compression
decrease in volume of any object or substance resulting from applied stress.
footwall
the block of rock that lies on th underside of an inclined fault or of a mineral deposit.
thrust fault
reverse fault in which the angle between the horizontal and the plane is small
plate tectonics
A big slab of solid rock composed of both continental and oceanic lithosphere.
focus
Origin of earthquake
seismologist
Earth scientists specialized in geophysics who study the propagation of seismic waves.
Surface waves
Mechnaical wave that goes along the interface between two different material. (Elastic surface waves can travel along the surface of solids)
aftershock
a smaller earthquake following the first big earthquake as a shock.
strike-slip fault
a. fault planes are nearly verticle
b. movement is horizontal
anticline
up folded (arch) rock layers
supercontinent
the assembly of most or all of the earth’s continental blocks to form a single large landmass.
fault
fracture or zone of fractures between two blocks of rock, faults allow the blocks to move relative to each other.
seismograph
an instrument that measures and records details of earthquakes. such as force and duration.
extension
the movement by which the two elements of any jointed part are drawn away from each other.
foreshock
an earthquake that happens before a larger seismic even, related to both of its time and space.
reverse fault
hanging wall moves up
syncline
down folded (through) layers
