Occurs when large areas move upward.
-happens in the himalayas
-generally occurs at slow rates (a few mm/year)
-over long periods of time it is possible to move rocks over a mile verically
Uplift
Occurs when an area drops
-very common with compaction of sediments
-can also occur during tectonic events
Subsidence
generic term that geolgist use to indicate events that cause uplift and deformation
Mountain building
what causes uplift?
thrust faults that stack rocks on top of each other
piles of volcanic rock extruded onto an area
igneous activity injects magam and expands rocks upward
increased thermal activity
folding or buckling of rock
uplifts occur at convergent plate boundries
uplift generally occurs with
moutiain buliding & isostaic adjustments
isostatic adjustments can be caused by
erosion
sediment build up
glaciation
reigonal mountains result from temporally extended and l
temporally extended and laterally extensie plate interactions
reional mountains are created as
belts that trend parallel to plate boudaries
created by large upward movements of mantle ( bows the crust upward)
reigonal mountains are associated with
increases in crustal thicknesses
local mountains are examples of
individual uplift
regional mountains are
large areas of many different types of uplift
regional mountains may contain many different examples of local mountains
local mountains can be cause by volcanism. faulting folding and erosion.
Local mountains may occur in areas where regional mountains are absents
mountain types
erosional mountains (texas)
volcanic mountains (pacific nw)
fault-block mountains (nevada)
fold and thrust moutains (Georgia )
complex moutians (georgia)
how do earthquakes occur?
energy stored in rocks is released along the faults
what are seismic waves?
produced by the earth -a rapid release of energy
energy realsed durring an earthquake radiates from
the hypocenter
most earthquakes occur
along the fault zones
earthquakes can be caused by
volcanic eruptions
meteorite impacts
nuclear wepons
human induced causes
after an earthquake some rocks return
elastically to the original position after an earthquake
after large eathquakes, an ________ or ________ can occur
foreshocks and aftershocks
95% of the energy released by eathquakes originates in