Movement of tectonic plates over time Tectonic plates, American landform and topography.
Tectonic Plates Boundaries
description
Transcript of Tectonic Plates Boundaries
TECTONIC PLATES BOUNDARIES
DIVERGENT BOUNDARY
FEATURES
Mid-Ocean Ridges Earthquakes Volcanos Black Smoker
Rift Valley Rift Volcanos Earthquakes
Oceanic from Oceanic Crust Continental From Continental Crust
EXAMPLE
Mid-Atlantic Ridge Red Sea
East African Rift in Africa
Mid-Atlantic Ridge in Ice Land
Oceanic from Oceanic Crust Continental From Continental Crust
MOTION
Plates are pulling apart or separating from each other
Convection Currents Hot magma rises out
of the mantle and pushes the cold old lithosphere out of the way.
DENSITY Creates new crust
Plate Motion Cause of Plate Motion
CONVERGENT
FEATURES Continent to Continent
Mountain building Earthquakes
Ocean to Continent Volcanic Arc (on land) Earthquakes Mountain building Trench
Ocean to Ocean Volcanic Island Arc (ocean) Trenches
Long and narrow deep-sea Earthquakes
EXAMPLES Continent to Continent
Himalayas Ocean to Continent
Juan De Fuca and North American Plate Nazca and South American Plate Ring of Fire
Ocean to Ocean Philippians, Japan, South Sandwich Island
PLATE MOTION Continent to Continent
Plate collide and eventually the denser plate is pushed under Ocean to Continent
Oceanic crust is more dense then the continental, thus it is subducted (sinks) underneath the continental plate
Ocean to Ocean The denser plate sinks
CAUSE OF PLATE MOTION Lithosphere cools and is then pulled down into the mantle
by gravity. The denser tectonic plate is subducted (pulled down) The plate is then recycled into the mantle
Transform
Slips to the right Slips to the leftRight Lateral Left Lateral
Which is Which?
Transform FEATURES:
Lithosphere is not created or destroyed Earthquakes Found at mid-ocean ridges because of the offset (the Earth is a
sphere) EXAMPLE:
San Andreas Fault in California Romanche Fracture Zone
MOTION: Horizontal slip between two plates Slip can occur to the right or left Shear Stress
CAUSE OF PLATE MOTION: Convection currents moving plates over a round object
HOT SPOTS/Mantle Plumes
Thought to be caused by Mantle Plumes Mantle plume: narrow, tube-shaped jet of hot, solid material
rising from deep within the mantle