Structure of the Earth

Crust = solid outermost layer

Mantle = middle layer

Core = inner layer outer core = liquidinner core = solid

Why do we have continental drift?Internal Heat Drives Geological Activity

Convection: hot rock rises, cool rock falls.

Why do we have continental drift?

Earth has molten centerConvection current form in mantleThe crust moves with these currents

Internal Heat Drives Geological Activity

Convection: hot rock rises, cool rock falls& the solid surface of the Earth moves

Surface of Earth Divided into Pieces called "Plates"

Figure 1-21

Surface of Earth Divided into Pieces called "Plates"

Most Volcanoes form at plate boundaries

Most Earthquakes occur at plate boundaries

Types of Plate Boundaries

Transform boundaries

Figure 1-30

Transform boundary Example: San Andreas Fault in CA

Transform boundary Example: San Andreas Fault in CA

Types of Plate BoundariesDivergent boundaries

Figure 1-25

Types of Plate BoundariesDivergent boundaries

Example: Mid ocean ridge

Types of Plate Boundaries

Continental collision

Figure 1-27

Convergent boundariescontinental collision

Types of Plate Boundaries

SubductionConvergent boundaries

Hawaii = Hot spot

What kind of plate boundaries are there off Washington’s coast?

Cascadia subduction zone in side view

http://en.wikipedia.org/wiki/Image:Subduction.jpg

http://www.nps.gov/archive/olym/geology/accretion.htm