Understanding plate boundaries

• How do the processes at divergent and convergent plate boundaries differ in terms of their effects on the Earth's surface?

  Divergent boundaries create new oceanic crust and rift valleys, while convergent boundaries lead to mountain building, volcanoes, and earthquakes
• What is the lithosphere?

  The Earth's outer layer divided into plates
• Why do volcanoes and earthquakes tend to occur at plate boundaries?

  Because this is where the plates interact and move relative to each other, causing deformation and melting of the crust
• What does plate tectonics explain?

  Movement of Earth's lithosphere plates
• What characterizes divergent boundaries?

  • Plates move apart
  • Can create new oceanic crust
• What is the name of the deep ocean trench shown in the image?

  Deep ocean trench
• What occurs at convergent plate boundaries?

  Two plates collide
• How does the flattening of the geothermal gradient relate to the processes occurring at the mid-ocean ridge?

  The flattening of the geothermal gradient is caused by the cooling of the lithosphere as new oceanic crust is formed
• What are the three different configurations of the diamond-shaped objects shown in the image?

  • Configuration A
  • Configuration B
  • Configuration C
• What are the abbreviations "Plag + Cpx" and "Ol + Opx" referring to in the image?

  Plagioclase + Clinopyroxene and Olivine + Orthopyroxene
• How does the movement of Earth's plates shape the planet's surface?

  It creates mountains, valleys, and earthquakes
• What process occurs at divergent boundaries?

  Seafloor spreading
• If you wanted to study the detailed surface features of a volcanic island, which type of microscope would you use?

  Scanning electron microscope (SEM)
• What happens at plate boundaries?

  Plates collide, separate, or slide past each other
• What is a transform boundary?

  A boundary where plates move sideways
• How do the different plate boundaries affect the Earth's surface?

  • Convergent plate boundaries lead to mountain building, volcanoes, and earthquakes
  • Transform plate boundaries cause horizontal sliding motion and earthquakes
  • Divergent plate boundaries create new oceanic crust and form rift valleys
  • Continental rift zones are young plate boundaries where the continental crust is being pulled apart
• What geological events are caused by plate movements?

  Earthquakes, volcanoes, and mountain formation
• What is a divergent boundary?

  Where plates move apart
• What type of geological feature is a "hot spot"?

  A hot spot is a stationary plume of hot mantle material that rises through the Earth's crust, causing volcanism at the surface.
• How does plate tectonics contribute to the formation of mountains and volcanoes?

  Colliding or diverging tectonic plates push up mountains and create volcanic activity
• What are the features associated with divergent boundaries?

  • Mid-ocean ridges
  • New oceanic crust formation
  • Basaltic rock
  • Characteristic U-shaped structures
  • Black smokers
• How do the shallow earthquakes and deep-focus earthquakes differ in their locations relative to the subduction zone?

  Shallow earthquakes occur closer to the surface, while deep-focus earthquakes occur deeper in the subduction zone
• What type of earthquakes are shown in the image?

  • Shallow earthquakes
  • Deep-focus earthquakes
• Why do Earth's plates move?

  They float on the molten asthenosphere
• How do the configurations of the diamond-shaped objects differ from each other?

  • Configuration A has the diamonds arranged in a single row
  • Configuration B has the diamonds arranged in two rows
  • Configuration C has the diamonds arranged in three rows
• What characterizes transform boundaries?

  • Plates slide past each other
  • Can cause earthquakes
• How do the processes at divergent and convergent plate boundaries differ in terms of their effects on the Earth's surface?

  Divergent boundaries create new oceanic crust and rift valleys, while convergent boundaries lead to mountain building, volcanoes, and earthquakes
• What is the shape of the objects shown in the image?

  Diamonds
• How do the directions of the arrows in the image indicate the movement of the tectonic plates?

  The arrows show the plates are diverging, or moving apart, from each other
• What are the key features of the continental lithosphere and oceanic lithosphere shown in the image?

  Continental lithosphere:

  • Thicker and less dense

  Oceanic lithosphere:

  • Thinner and more dense
  • Subducted under continental lithosphere
• What is the name of the boundary between the lithosphere and asthenosphere?

  Plate boundary
• What is a feature associated with transform boundaries?

  Offset rivers
• What is the process of subduction shown in the image?

  • Oceanic lithosphere is pushed under the continental lithosphere
  • This leads to melting of the mantle and rising magma
  • Causes metamorphic dewatering of the crust
• How does the depth of earthquakes vary at convergent plate boundaries?

  • Varies from shallow near the surface
  • Becomes deep as the plate moves downward
• What is the purpose of the different layers shown in the image?

  They represent different stages or configurations of the diamond-shaped objects
• What characterizes convergent boundaries?

  • Plates move together
  • Can form mountains or trenches
• How do the different plate boundaries and geological features interact to shape the Earth's surface?

  • Convergent plate boundaries lead to mountain building, volcanoes, and earthquakes
  • Transform plate boundaries cause horizontal sliding motion and earthquakes
  • Divergent plate boundaries create new oceanic crust and form rift valleys
  • Hot spots create volcanic islands and seamounts as the plate moves over them
  • The interaction of these processes shapes the continents, oceans, and overall topography of the Earth's surface
• How is new oceanic crust formed?

  Magma rises and cools to form basaltic rock
• What is an ocean feature associated with divergent boundaries?

  Ocean ridge
• What landform is created at divergent boundaries?

  Rift valley