8th Grade Science Test 2 Flashcards
the most abundant element in the earth’s crust
oxygen
in what type of fault do rocks along one side of the fault move horizontally along the fault
strike-slip fault
85% of all earthquakes are
shallow-focus earthquakes
a bowl-shaped hollow more than 2 miles wide, formed by the collapse of an underground magma chamber
caldera
the point deep in the earth at which an earthquake begins
focus
the large almond- or teardrop-shaped pieces of ejecta formed when lava solidifies
volcanic bomb
the narrow zone of active volcanoes that nearly encircles the Pacific basin
Ring of Fire
About 80% of the world’s earthquakes occur
in the circum-Pacific belt
the bending or buckling of rocks under great force produces
a fold
the inner core of the earth is thought to be
solid
an inactive volcano that can erupt again
dormant
the middle of the earth’s three main layers
mantle
an instrument used to record the vibrations caused by earthquakes
seismograph
a large, well-known strike-slip fault in western California
San Andreas Fault
the study of the earth
geology
the study of earthquakes
seismology
all the present-day continents are thought to have been one land mass called
Pangaea
an earthquake caused by sudden movements of rock beneath the earth’s surface
tectonic earthquake
a domelike igneous instrusion formed when magma bulges overlying rocks upward
laccolith
type of volcano consisting primarily of erupted volcanic ash and rock fragments held loosely together
cinder-cone volcano