PLATE TECTONICS

A PRIMER

PLATE TECTONICS

• Heat flowing from the interior of the earth through the mantle and lithosphere to the surface is the engine that causes major and minor portions of the Earth’s crust (i.e., tectonic plates) to slowly converge, diverge, or slide past each other over time.

• The relative movement of plates causes compression, tension, or shear, which causes faulting and earthquakes.

TECTONIC PLATES TWO EARTH DAYS AGO

PLATE TECTONICS

• Plate boundaries are defined by seismic activity (i.e., seismicity) .

• Plate boundaries are often marked by prominent fault zones that may in some cases cause notable surface faulting.

Plate Movement Causes Three Primary Kinds Of Faulting

Strike-SlipReverse

Normal

EARTHQUAKES DEFINE PLATE BOUNDARIES: PACIFIC, EURASIAN, NA, SA, NASCA, CARIBBEAN,

COCOS, AND PHILIPPINES PLATES

JUAN DE FUCA PLATE IS SUBDUCTING BENEATH NORTH AMERICAN PLATE

COCOS PLATE IS SUBDUCTING BENEATH NORTH AMERICAN PLATE

MOTAGUA FAULT:1976 GUATEMALA QUAKE

SAN ANDREAS FAULT: PACIFIC AND NORTH AMERICAN PLATE BOUNDARY

1,000-KM-LONG SAN ANDREAS FAULT SYSTEM

SURFACE FAULT RUPTURE: 1906 SAN FRANCISCO QUAKE

Schematic Diagram of the Schematic Diagram of the Earthquake MechanismEarthquake Mechanism

Schematic Diagram of the Schematic Diagram of the Earthquake MechanismEarthquake Mechanism

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Schematic Diagram of the Strike-Slip Earthquake Schematic Diagram of the Strike-Slip Earthquake Mechanism: 1989 Loma Prieta, CAMechanism: 1989 Loma Prieta, CA

Schematic Diagram of the Strike-Slip Earthquake Schematic Diagram of the Strike-Slip Earthquake Mechanism: 1989 Loma Prieta, CAMechanism: 1989 Loma Prieta, CA

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ARABIAN, AFRICAN, ANATOLIAN, INDIAN, AND EURASIAN PLATES

DEAD SEA RIFT: BOUNDARY OF ARABIAN AND AFRICAN PLATES

NORTH ANATOLIAN FAULT: EURASIAN AND ARABIAN PLATES

NORTH ANATOLIAN FAULT: 1999 KOCALEI, TURKEY QUAKE

NORTH ANATOLIAN SURFACE FAULTING: 1999 KOCALEI QUAKE

COLLISION OF INDO-AUSTRALIAN AND EURASIAN PLATES

COLLISION OF INDO-AUSTRALIAN AND EURASIAN PLATES

250-KM-LONG LONGMENSHAN FAULT ZONE: CHINA QUAKE OF MAY 12, 2008

250-KM-LONG LONGMENSHAN FAULT ZONE: CHINA QUAKE OF MAY 12, 2008

PAKISTAN EARTHQUAKE: OCTOBER 8, 2005