Interactions between the asthenosphere and the lithosphere create most of the major features at the surface of the earth. Upwelling and convection cells in asthenosphere cause the lithosphere to break into pieces called plates, that move, and, in turn, interact mostly at their boundaries.  This creates distinctive sets of features associated with each type and allows recognition of the type of boundary involved.

I. INTER-PLATE ACTIVITY (activity at edges of plates due to interaction between plates; (Occurs at PLATE BOUNDARIES (3 major types of boundaries between plates))
Type of Boundary	Associated Features	Where can you see this?
A. DIVERGENT either on continent or  in the ocean	Ridge systems; Rift Rift Vulcanism- ranges from isolated volcanos  to basalt plateaus Shallow focus Earthquakes***	E. Africa Rift Valley Red Sea Mid Ocean Ridges in all oceans
B. CONVERGENT 1. Ocean/ Ocean Convergence	Oceanic lithoshere subducted Subduction Zone Accretionary wedge (=prism) Vulcanism on up plate creating a Vulcanic Island Arc w/ associated trench Trench Shallow, Intermediate and Deep focus Earthquakes	Aleutians Islands Phillipines Islands Mariannas Islands Windward Islands of Carribean
2. Ocean/Continent Convergence	Oceanic lithosphere subducted Subduction Zone Accretionary wedge (=prism) Vulcanism on up (=cont.) plate creating Volcanos along the continental Margin Marginal Mountains on up plate (=cont) Trench Shallow, Intermediate and Deep focus Earthquakes	Andes Alaska Peninsula SE Asia: Java, Sumatra , etc
3. Continent/Continent Convergence	Neither plate subducted  Internal Mountains Underplating Shallow and Intermediate focus Earthquakes (No vulcanism)	Himalayas Urals Appalachians
C. TRANSFORM	Transform Faults Shallow focus Earthquakes	California Central America
II. INTRA-PLATE  ACTIVITY  (activity within the plate itself rather than at its edges)
Hot Spots.	On continents: Vulcanism.  In oceans:   Vulcanic Island arcs  w/o associated trenches or basaltic plateaus.	Yellowstone Iceland Hawaiian Islands and Emperor Sea Mounts
Transform Faults Allow motion within segments of a plate	Transform Faults also called Fracture zones	Asian Continent Across ridges in oceanic plates

***Shallow focus earthquakes originate between the surface and ~60 mi.down, intermediate focus earthquakes between ~60 and ~175 mi. in depth, and
      deep focus earthquakes, deeper than ~175 mi.