Structure of the Earth Crust = solid outermost layer Mantle = middle layer Core = inner layer outer core = liquid inner 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 center Convection current form in mantle The 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 Boundaries Divergent boundaries Figure 1-25

Types of Plate Boundaries Divergent boundaries Example: Mid ocean ridge

Types of Plate Boundaries Continental collision Figure 1-27 Convergent boundaries continental collision

Types of Plate Boundaries Subduction Convergent boundaries

Hawaii = Hot spot

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

Cascadia subduction zone in side view