Plate Tectonics What is it and what makes it work? Steven Earle, Geology Department Malaspina University-College

1
Plate Tectonics What is it and what makes it
work?Steven Earle, Geology DepartmentMalaspina
University-College
2
The Earths interior
1000 C
4000 C
7000 C
3
Pea-soup analogy
4
mantle convection

• Heat transfer from the core to the
• mantle produces slow convection
• of the mantle material

(in the order of centimetres per year)
5
Mantle convection produces lateral forces at the
boundary between the mantle and the crust
6
Lateral forces at the crust-mantle boundary push
the crust around in different directions and
this leads to the motion of crustal plates. The
plates are moving at rates of cm/year
7
Plate motions
8
Divergent boundary
9
Convergent boundary
Subduction
10
Transform boundary
11
Plates of the Earths crust
12
Plates around North America