tectonic boundaries

Tectonic Plate Boundaries

By Drew Lindow

Divergent Boundaries

• A divergent boundary is created when two plates move apart from one another.

Mid-Atlantic Ridge• The Mid-Atlantic ridge is the most famous

divergent plate boundary. The ridge is spreading at a rate of 3.5 cm/year.

South West Indian Ocean Ridge• The S. W. Indian Ocean Ridge separates the

Somalia and African plates from the Antarctic plate. It spreads at a rate of 1.5 cm/year.

Convergent Boundaries

• A convergent boundary is created when two plates push towards each other.

Himalayas • Continental - Continental• The Himalayas were formed by the converging of

the Eurasian plate and the Indian plate.

The Chile Fault

• This is a double fault. On the west is an oceanic – continental boundary and east of that is a continental – continental boundary.

• This is a convergence of the Nazca and S. American plate.

Aleutian Trench• Oceanic - Continental

• The Aleutian Trench and the Aleutian Islands were formed by the collision between the northern part of the Pacific plate and the North American plate.

Java Trench• Oceanic – Continental

• The Java trench is a convergence of the India plate on the southwest and the Burma and Sunda plates on the northeast.

Philippine Plate• Oceanic – Oceanic• The Philippine plate converges with the Pacific

plate to form the Marianas Trench.

Caribbean Fault• Oceanic – Oceanic• The American plates are converging with the

Caribbean plate from the east.

Transform Boundaries

• A transform boundary is created when two plates slide past each other. Earthquakes are commonly made when the two plates build up stress and suddenly release it.

Alpine Fault• The Alpine Fault creates a transform boundary

between the Pacific plate and the Indo-Australian plate. The average slip rate is 3 cm/year.

Alpine Fault

• This image shows the Alpine Fault line crossing the souther alps in New Zealand.

Divergent Offsetting• Many transform faults are found on the ocean floor where

they offset diverging plates in a zig-zag like motion. Below is the Mid-Atlantic Ridge and some offsetting transform faults.

Sources

• http://www.geography-site.co.uk• http://www.scarborough.k12.me.us• http://en.wikipedia.org• Google Earth