unit 5 Flashcards
what are igneous rocks?
rocks formed by the cooling of magma
what are sedimentary rocks?
rocks that are formed when sediments are cemented together
what are processes that make sediment into sedimentary rock?
weathering, erosion, deposition, lithification, cementation
what is metamorphic rock?
existing rocks that are changed by heat or pressure
what are convergent boundaries?
plates moving together
what are collision convergent boundaries?
two continents converging
what is created during collision convergent boundaries?
mountains
what are subduction convergent boundaries?
two plates moving together and the denser plate subducts into the mantle
what is created at an ocean to ocean subduction convergent boundary?
deep sea trenches and volcanic islands
what is created at a continental-to-continental convergent boundary?
deep sea trenches, mountain ranges, volcanoes
what are divergent boundaries?
when plates move away from each other
what is created at ocean to ocean divergent plates?
mid-ocean ridges, seafloor spreading
what is created at continental-to-continental divergent boundaries?
valleys and volcanoes
what is pyroclastic flow?
cloud of volcanic gas, dust and tephra
what is a caldera?
a large depression that forms when a volcano collapses
what is lahar?
volcanic debris within mud
what is a vent?
the opening where lava erupts from a volcano
what is viscosity?
resistance of a liquid substance to flow (thickness)
what is a shield volcano?
biggest volcano, broad-gentle slopes, non-explosive erupts, contains basaltic magma
what is a cinder-cone volcano?
smallest volcano, small and steep sides, ejected material piled high, explosive eruptions contains rhyolitic magma
what is a composite volcano?
layers of lava with fragments, large mountain, violent eruptions, contains andesitic magma
what is basaltic magma?
forms shield volcanoes, forms in the upper mantle, low viscosity, quiet explosion
what is rhyolitic magma?
forms cinder-cone volcanoes, high viscosity, high explosiveness
what is andesitic magma?
forms in subduction zones, intermediate viscosity, intermediate explosiveness
what is the crust?
the thinnest, outermost solid layer of earth
what is the mantle?
the thickest zone making up of 2/3 of earth’s mass
what is the lithosphere?
a solid layer made up of the upper mantle and the lower crust
what is the asthenosphere?
a flexible layer made up of the upper mantle
what is the core made of?
nickel and iron
what is the outer core?
a dense liquid layer that s waves can’t pass through
what is the inner core?
the dense, solid core
what is force?
any push or pull
what is stress?
force
what is strain?
bend
what are the three type of faults?
normal faults, reverse faults, strike-slip faults
what are normal faults?
the rock moves up and down, occurs at divergent boundaries
what happens at reverse faults?
rock above the fault moves up, occur at convergent boundaries
what happens at the strike-slip fault?
rock move away from each other, occur at transform boundaries
what is seismology?
the study of earthquakes
what is a focus-point?
the underground point where an earthquake originates
what is the epicenter?
the point on the earth’s surface above the focus
where does compression occur?
convergent boundaries with reverse faults
where does tension occur?
divergent boundaries with normal faults
where does shear occur?
transform boundaries with strike-slip faults
what are primary waves?
the fastest seismic waves that can travel through liquids, solids, and inbetween
what are secondary waves?
slower waves, particles move perpendicular to the waves
what are long waves?
seismic waves that move in circles and travel along earth’s surface creating the most damage
