What happens at tectonic plate boundaries Three types

What happens at tectonic plate boundaries?

Three types of plate boundary • Divergent • Convergent • Transform

Different Types of Boundaries http: //pubs. usgs. gov/gip/dynamic/understanding. html

Divergent Boundaries • Spreading ridges (sea floor spreading) – As plates move apart new material is erupted to fill the gap – Mid-ocean ridges form

Iceland: An example of continental rifting • Iceland has a divergent plate boundary running through its middle

Another example: Arabian and African Plates Arabian Plate Red Sea African Plate

Convergent Boundaries • There are three styles of convergent plate boundaries – Continent-continent collision – Continent-oceanic crust collision – Ocean-ocean collision

Continent-Continent Collision • Forms mountains • Examples: European Alps, Himalayas

Himalayas

Continent-Oceanic Crust Collision Causes subduction zones

Subduction • Oceanic plate moves (subducts) underneath the continental plate • Oceanic plate heats and melts • The magma rises forming volcanoes • Example: The Andes

Ocean-Ocean Plate Collision • One plate runs over the other causing a subduction zone. • Forms a very deep depression in the ocean floor called a trench. • Example: The Mariana Trench is 11 km deep!

Transform Boundaries • Where plates slide past each other Example : San Andreas transform fault

All types of boundaries • Could cause earthquakes as the plates move