science quiz Flashcards
explain that the lithosphere and the asthenosphere are involved in tectonic plate movement.
lithosphere- a solid brittle divided into tectonic plates
asthenosphere- soft solid that flows moving the lithosphere plates
kinds of lithosphere that make up tectonic plates
oceanic- young, dense, thin
continental- old, not dense, thick
theory of plate tectonics
the theory of plate tectonics states that when plates move stress builds up and when much builds up deformation occurs
how do folds form
when rock bends; syncline in v shape and anticline in A shape
main stresses in crustal deformation
compression, tension, sheer stress
types of volcanic land forms
-shield volcanoes
-cinder cone
-composite volcanoes
-lava plateaus
-craters
-calderas
types of mountains
fold-convergent; fault block- convergent+divergent; volcano-convergent
faults
-fault= break in rock
-compression cause reverse fault
-sheer causes strike slip
-normal fault- tension
viscosity
the shape and explosiveness of a volcano depends on the lavas viscosity or resistance to flow. low viscosity lava flows easily, forms low slopes, and erupts without large explosions. high viscosity lava does not flow easily, forms steep slopes, and can erupt explosively.
types of viscosity
basaltic=most explosive
rhyolitic=least explosive
pyroclastic material
pyroclastic material or hot ash and bits of rock may also be ejected into the atmosphere
compression/convergent landforms
volcanoes, fold mountains, ocean trenches
hot spot
a place of significant activity or danger.
boundaries
divergent, convergent, transform
what happens on earths surface during an earthquake
structures break, deformation occurs, tsunamis, and fires
deformation
process by which rocks become deformed and change shape due to stress
soil type importance
geological variations known as site effects which are based on two general characteristics
1. the softness of the soil or rock
2. total thickness of the sediment above the bedrock
earthquakes affect on people and structures
buildings fall and humans are crushed by unsecured/structurally unsound objects/buildings. tsunamis also drown people
where do earthquakes happen
near boundaries of tectonic plates where pressure builds on the edges causing them where stress occurs
epicenter and focus
focus- place WITHIN earth along a fault at which the first motion of an earthquake occurs
epicenter- directly above the focus on earths surface
why do earthquakes occur
blocks of rock in earth move suddenly and release energy as seismic waves
