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