PLATE ROTATION POLE

WE CAN DESCRIBE THE MOTION BETWEEN ANY TWO PLATES AS A ROTATION ABOUT AN IMAGINARY POINT, CALLED A "POLE".

THE RATE OF PLATE MOTION INCREASES WITH DISTANCE FROM THE POLE

UPPER FIGURE: PLATE 2 ROTATES COUNTERCLOCKWISE RELATIVE TO PLATE 1

WHERE PLATE 2 MOVES AWAY FROM THE BOUNDARY THERE IS

A RIDGE (SPREADING CENTER)

WHERE PLATE MOTION IS ALONG THE BOUNDARY THERE IS

A TRANSFORM FAULT

LOWER FIGURE: PLATE 1 ROTATES COUNTERCLOCKWISE RELATIVE TO PLATE 2

WHERE PLATE 1 MOVES TOWARD THE BOUNDARY THERE IS

A SUBDUCTION ZONE (TRENCH)

WHERE PLATE MOTION IS ALONG THE BOUNDARY THERE IS

A TRANSFORM FAULT