ESCI 2: Plate Tectonics

continental drift theory

proposed by alfred wegener

continental drift theory

continental landmasses were drifting across the earth

african n south american coast lines seemed to fit as if they were a jigsaw puzzle; continents were 2gether then naghiwalay overtime

y did wegener conclude that continents r like puzzle

pangea

one large landmass; has upper and lower part

laurasia

upper part of pangea

gondwana

lower part of pangea

panthalassa ocean

ocean that surrounds pangea

flora n fauna

plantation, vegetation, n species na nandun sa area, fossils and plants r similar dun sa africa n america

di nya masagot kung bakit gumagalaw yung mga continents

bak8 ndi accepted ng mga scientists yung continental

nung 60s nagkaron ng progress sa theory ni wegener

seafloor spreading theory

seafloor spreading theory

proposed by harry hess; nung prinopose to, wala pa tayong plate tectonics

seafloor spreading theory

process that occurs sa mid-ocean ridges

seafloor spreading theory

new oceanic crust is formed thru volcanism then gradually moves away from da ridge

1. di kayang iexplain yung small features ng ocean natin

2. di pinaguusapan movement ng continents

3. does not speak of lithospheric regions

bak8 insufficient pa rin yung seafloor spreading theory para majustify

plate tectonics

1967

plate tectonics theory

major landforms r created as a result of earth’s subterranean movements

7 major plates

• african

• antarctic

• eurasian

• indo-australian

• north american

• pacific

• south american

tectonic plates

formed from lithosphere: crust n upper part of mantle

tectonic plates

floating on the slowly flowing asthenosphere which is yung lower part ng mantle

tectonic plates

large rigid slab of rock

convection flow

movement ng magma natin dun sa ilalim ng planet in a circular motion from pinaka mainit to pinakamalamig n bc of this naapektuhan yung lithosphere

• divergent

• convergent

• transform

plate boundaries

divergent plate boundaries

2 tectonic plates move away from each other

divergent plate boundaries

earthquakes r common, magma rises from mantle, solidifying to create new crust

african n american plates

bc of divergent plate boundaries

convergent plate boundaries

2 tectonic plates come 2gether; crust is destroyed

oceanic-oceanic convergence

2 oceanic plates converge; once is subducted under other (kung cno mas matanda, sya mapupunta sa ilalim), creates trenches n volcanoes

oceanic-continental convergence

oceanic plate converge w continental plate, op subducts under cp kasi mas lower density nya; it forms volcanic arcs

continental-continental

2 continental plates converge; neither subducts kasi parehong light, plates go downward motion n crust is pushed upward or sideways; forms mountain ranges

transform plate boundaries

2 tectonic plates slide past each other

transform plate boundaries

common din here earthquakes along sa faults

transform plate boundaries

crust is cracked n broken n transform margins but not created or destroyed

bc of the convection flow ng magma, naapektuhan yung lithosphere sa taas, causing earthquakes

bak8 nagkakaron ng earthquakes pag may volcanic eruption