Presentation on theme: "Plates on the Move Guide to plate movement. There are three types of plate movement."— Presentation transcript:
Plates on the Move Guide to plate movement
There are three types of plate movement
3 Types of Plate Movement Apart - Divergent Together - Convergent Side by Side - Transform
Continental & Oceanic Crust Oceanic Crust More dense (basalt) Continental Crust Less dense (granite) REMEMBER:
Divergent Boundary Plates are moving apart or separating
Divergent Boundary : Oceanic-Oceanic Also known as seafloor spreading Plates are separating from each other as a new land mass forms This is seen at mid-ocean ridges and rifts Plate separation is a slow process. For example, divergence along the Mid Atlantic ridge causes the Atlantic Ocean to widen at only about 2 centimeters per year.
Divergent Boundary: Oceanic-Oceanic
Divergent Boundary: Continental-Continental Effects that are found at this type of plate boundary include: a rift valley sometimes occupied by a long linear lakes or a shallow arm of the ocean numerous normal faults bounding a central rift valley shallow earthquake activity along the normal faults Volcanic activity sometimes occurs within the rift
Divergent Boundary: Continental-Continental African Rift Valley
Convergent Boundary Plates are moving towards each other
Convergent Boundary: Continental-Continental Two continental plates collide & crumple the edges of the plates Form mountains We can see the end result of the collision between the Indian & Eurasian plates which are the Himalayan Mountains.
Convergent Boundary Subduction: Oceanic-Continental When an oceanic plate goes underneath a continental plate called subduction This forms a trench or deep valley where the plates meet. An example of a subduction zone is the Marianas Trench in the Pacific Ocean where the Pacific Plate is subducting under the Eurasian Plate.
Convergent Boundary Subduction: Oceanic-Oceanic Older, more dense plate subducts below the other plate The subducted plate melts and begins fracturing its way through the rock above Volcanic cones form and over time grow higher than sea level—island chains are produced Examples: Japan, the Aleutian islands and the Eastern Caribbean islands of Martinique, St. Lucia, and St. Vincent, and the Grenadines