Alfred Wegener (1880-1930)

Mid Atlantic Ridge

Mid Ocean Ridge System

Sea Floor “Stripes”

http://atlas.geo.cornell.edu/education/instructor/tectonics/polarity.html

Convergent Margin

Major Lithospheric Plates

Source: NASA

Plate Configuration of PNW

Plate Margins

• Divergent margins: spreading centers where new lithosphere (sea floor) is created

• Convergent margins: plates are moving toward each other

• Transform margins: plates move past one another without creating or destroying lithosphere

Mantle Convection

Source: University Montpellier

Geothermal Gradient

Rate of Plate Movement

Plate Margins

Source: USGS

Juan de Fuca Ridge

Source: GSC

Plate Margins

Source: USGS

East African Rift

Plate Margins

Source: USGS

Juan de Fuca Ridge

Source: GSC

Continental-Continental Convergence

Source: USGS

Himalayas

Source: USGS

Transform Margin

Transform Faults

Left-Lateral Right-Lateral

Alpine Fault, New Zealand

Volcanism and Plate Margins

Source: Smithsonian

Earthquakes and Plate Margins

• Igneous rock types (type and location of volcanism)

• Seismic activity (type and location of earthquakes)

• Location of sedimentary basins

• Location of uplifts or mountain ranges

• Location of ocean basins

Plate Tectonics Control

Hawaii-Emperor seamount chain

Table

1 0.8 180 22.502 1.3

  

3 1.8   

4 2.6   

5 3.7   

7 10.3   

8 12   

9 18.9   

10 20.6   

11 27.2   

12 42.4   

Interval Age (my) Distance (kms) Rate (cm/yr)

6 5.1   

Chart

0.00

5.00

10.00

15.00

20.00

25.00

0 1000 2000 3000 4000

Distance (km)

Rat

e (c

m/y

r)