plate boundaries

• Convergent boundary


  Two plates are pushing toward each other
• Convergent boundaries


  • The boundary between the Eurasian Plate and the Indian Plate at the Himalayas
  • The boundary between the Nazca Plate and the South American Plate along the west coast of South America
• Divergent boundary


  Two plates that are moving apart from each other
• Divergent boundaries


  • The boundary between the African Plate and the Arabian Plate in the Red Sea
  • The boundary between the Pacific and Antarctic Plates
  • The Mid-Atlantic Ridge, made up of the boundary between the North American and Eurasian Plates in the North Atlantic, crossing Iceland, and the South American and the African Plates in the South Atlantic
• Transform boundary


  Two plates slide past each other
• Transform plate boundaries


  • The boundary between the Pacific Plate and the Australian Plate, crossing New Zealand
  • The boundary between the Pacific Plate and the North American Plate in California
• Convergent Plate Boundary: Continental-Continental collision


  • The rock making up continental plates is generally lighter and less dense than oceanic rock, so it is too light to get pulled under the earth and turned into magma
  • A collision between two continental plates crunches and folds the rock at the boundary, lifting it up and leading to the formation of mountains and mountain ranges
• Convergent Plate Boundary: Continental-Continental collision

  • The Himalayan range in southern Asia
  • The Alps in south-central Europe
  • The Andes Mountains in South America
• Mountain range


  A series of connected mountains close to each other geographically or of common origin
• Continental crust


  The earth's crust that makes up the continents
• Lithosphere


  Rigid outer layer of the earth broken up into the tectonic plates
• Asthenosphere


  A hot, semiliquid zone on which the tectonic plates float
• Boundary


  The border between two tectonic plates
• Mountain


  A high, large mass of earth and rock that rises above the earth's surface with steep or sloping sides
• Magma


  Molten rock, gases, and solid crystals and minerals
• Convergent Plate Boundary: Oceanic-Continental collision


  • The denser oceanic crust undergoes subduction, where it bends and is pulled under the continental crust
  • This leads to the formation of a volcanic arc near the edge of the continental leading plate
• Volcanic arc


  An arc-shaped chain of volcanoes formed above a subduction zone
• Trench


  A steep-sided depression in the ocean floor
• Subduction zone


  The area where one plate is being pulled under the edge of another
• Oceanic crust


  The earth's crust found underneath the oceans
• Volcano


  A vent in the earth's surface through which magma and gases erupt
• The world's deepest parts of the ocean are found along trenches, e.g. The Mariana Trench is 11 km deep
• Underwater earthquakes, especially the stronger ones, can generate tsunamis, which are a series of ocean waves with very long wavelengths caused by large-scale disturbances of the ocean
• When two oceanic plates collide, trenches are formed, which become the sources of earthquakes
• The leading edge of the subducted plate will eventually reach the mantle, causing it to melt and turn into magma, which will rise to the surface creating an island arc parallel to the trench