1. Divergent Plate Boundaries:
* What happens: Plates move apart, allowing magma from the mantle to rise and solidify, forming new crust.
* Features: Mid-ocean ridges, rift valleys, volcanic activity, and shallow earthquakes.
* Examples: Mid-Atlantic Ridge, East African Rift Valley.
2. Convergent Plate Boundaries:
* What happens: Plates collide, resulting in one plate subducting (sinking) beneath the other.
* Features: Deep ocean trenches, volcanic arcs, mountain ranges, and deep-focus earthquakes.
* Types:
* Oceanic-Oceanic: One oceanic plate subducts beneath another, forming volcanic island arcs.
* Oceanic-Continental: Oceanic plate subducts beneath continental plate, forming volcanic mountain ranges.
* Continental-Continental: Both continental plates collide, forming massive mountain ranges.
* Examples: Andes Mountains, Mariana Trench, Himalayas.
3. Transform Plate Boundaries:
* What happens: Plates slide horizontally past each other.
* Features: No new crust is formed or destroyed, but the plates create a zone of intense seismic activity.
* Examples: San Andreas Fault in California.
Specific Features at Plate Boundaries:
* Volcanoes: Occur at divergent and convergent boundaries, where magma rises to the surface.
* Earthquakes: Occur at all types of boundaries, where plates move and create friction.
* Mountains: Formed at convergent boundaries, where plates collide and push up the land.
* Tsunamis: Can be generated by earthquakes along subduction zones.
* Rift Valleys: Formed at divergent boundaries, where the crust splits and pulls apart.
* Ocean Trenches: Deep depressions in the ocean floor, formed at subduction zones.
In summary:
The edges of tectonic plates are dynamic zones where Earth's crust is constantly being created, destroyed, and transformed. This activity shapes our planet's landscape, influences climate, and creates natural hazards.
