1
5. Seismology and Plate Tectonics5. Seismology and Plate Tectonics
• Introduction
• Plate kinematics
• Spreading centers
• Subduction zones
• Ocean intraplate earthquakes and tectonics
• Continental earthquakes and tectonics
• Faulting and deformation in the earth
Plate Tectonics Summary (I)Plate Tectonics Summary (I)
2
Plate Tectonics Summary (II)Plate Tectonics Summary (II)
Plate Tectonics Summary (III)Plate Tectonics Summary (III)
3
Global SeismicityGlobal Seismicity
Deep SeismicityDeep Seismicity
4
Seismicity CrossSeismicity Cross--section (Wadatisection (Wadati--Benioff zone)Benioff zone)
Plate kinematics (Euler pole)Plate kinematics (Euler pole)
5
Relative Plate Motion and Plate BoundayRelative Plate Motion and Plate Bounday
Angular and Linear Velocity (I)Angular and Linear Velocity (I)
6
Angular and Linear Velocity (II)Angular and Linear Velocity (II)
Relative Plate Motions w.r.t North AmericaRelative Plate Motions w.r.t North America
7
PacificPacific--North American Plate BoundaryNorth American Plate Boundary
Global Plate CircuitGlobal Plate Circuit
8
Relative Plate MotionsRelative Plate Motions
Current and Historic Plate VelocitiesCurrent and Historic Plate Velocities
9
Bend at 43 Ma:
Absolute Plate Motions (I)Absolute Plate Motions (I)
Bend at 43 Ma:
Plate direction change?
Mantle wind?
Moving hot spot base?
Absolute Plate Motions (II)Absolute Plate Motions (II)
Plume?
Ri ht R ll?Richter Roll?
Basin and Range extension?
Propagating Rift?
10
Earthquakes at an oceanic spreading centerEarthquakes at an oceanic spreading center
Earthquakes on slow spreading centerEarthquakes on slow spreading center
11
Earthquakes on fast spreading centerEarthquakes on fast spreading center
Normal Faulting on slow spreading centerNormal Faulting on slow spreading center
12
Cooling of the oceanic plate (I)Cooling of the oceanic plate (I)
Cooling of the oceanic plate (II)Cooling of the oceanic plate (II)
13
14
15
16
17
18
SubductionSubduction zoneszones
Earthquakes at Earthquakes at subductionsubduction zoneszones
19
20
21
22
23
24
25
26
27
28
29
Double Seismic ZoneDouble Seismic Zone
30
31
32
33
34
35
Normal Faulting at TrenchesNormal Faulting at Trenches