1 Earthquake and Volcanic Hazards Flashcards
Earthquakes can strike any location at any time, but history shows they occur in the same general patterns year after year, principally in three large zones of the earth:
CIRCUM-PACIFIC SEISMIC BELT
ALPIDE EARTHQUAKE BELT
MID-ATLANTIC RIDGE
is a natural phenomenon that is characterized by a sudden, violent shifting of massive plates underneath the earth’s surface
earthquake
Found along the rim of the Pacific Ocean, where about 81% of our planet’s largest earthquakes occur.
The belt exists along boundaries of tectonic plates.
CIRCUM-PACIFIC SEISMIC BELT/
RING OF FIRE
The belt accounts for about 17% of the world’s largest earthquakes.
Extends from java to Sumatra through the Himalayas, the Mediterranean, and into the Atlantic.
ALPIDE EARTHQUAKE BELT
Located along the floor of the Atlantic Ocean.
Houses the longest mountain range in the world.
Most of **** is deep underwater and far from human development.
MID-ATLANTIC RIDGE
(circum-pacific belt)
Earthquakes in these subduction zones are caused by ____________
slip between plates.
is the place inside Earth’s crust where an earthquake originates.
focus/hypocenter
The point on the Earth’s surface directly above the focus is the ________
epicenter
closer to the surface where rocks are stronger and could build up greater strain
unaccompanied by volcanic activity
caused by scraping of mature plates
has friction
san andreas fault
Shallow focus earthquakes
two types of earthquake
volcanic
tectonic
are produced by sudden movement along faults and plate boundaries.
Tectonic earthquakes
Earthquakes induced by rising lava or magma beneath active volcanoes is called __________________.
volcanic earthquakes
elastic wave generated by an impulse
may travel either along or near the earth’s surface or through the earth’s interior.
radiates from the focus of an earthquake
SEISMIC WAVE
an instrument used to detect and record seismic waves caused by earthquakes
seismograph
2 types of body waves
s waves
p waves
2 types of surface waves
love waves
rayleigh waves
2 types of seismic waves
surface
body
these waves can travel through the interior of the earth from the focus to distant points on the surface
body waves
(waves)
travel the fastest
can move through all states of matter
primary
logitudinal
P waves
(waves)
can only travel through solid materials
shake the ground perpendicularly casuing more damage
secondary
transverse
S waves
these waves can only travel along the surface
confined to the outer layers of the earth
surface waves
(waves)
move transverse to the direction of the propagation but with no vertical motion
cause rocks to move horizontally or side to side at right angles
cause the most damage
Love waves
(waves)
cause rock particles to move upward, up, backward, and down in a path that contains the direction of the wave travel.
Rayleigh waves/ ground roll
earthquakes that precede larger earthquakes in the same location.
a larger earthquake comes after it at the same location.
foreshock
