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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)