Plate Tectonics - AP Environmental Science
- Identify the process where oceanic crust sinks beneath a trench.
- Subduction. Oceanic plates are recycled into the mantle at trenches.
- What is the primary source of heat driving mantle convection?
- Radioactive decay in Earth's interior. Uranium, thorium, and potassium decay provides internal energy.
- Identify the three types of plate boundaries.
- Convergent, divergent, and transform boundaries. The three ways plates can interact at their edges.
- What is the primary cause of earthquakes?
- Movement along faults at plate boundaries. Sudden release of stress accumulated along plate boundaries.
- What occurs at a divergent boundary?
- Plates move apart, forming new crust at mid-ocean ridges. Separation allows magma to rise and solidify into new seafloor.
- What is the average rate of plate movement?
- Several centimeters per year. Similar to fingernail growth rate, measurable by GPS.
- What is slab pull?
- A force exerted by a sinking plate during subduction. Gravitational force from dense subducting slabs pulls plates down.
- How does plate tectonics contribute to biodiversity?
- By forming diverse habitats through geological activity. Mountain building and volcanism create varied environments for life.
- What is the significance of paleomagnetism in plate tectonics?
- It records the history of Earth's magnetic field and supports seafloor spreading. Ancient magnetic patterns preserved in rocks show plate motion.
- What is a rift valley?
- A deep valley formed as tectonic plates move apart. Continental divergence creates elongated depressions.
- What is the role of volcanic arcs in plate tectonics?
- They form above subducting plates and indicate active convergence. Curved volcanic chains mark active subduction zones.
- What is a tectonic plate?
- A rigid segment of the lithosphere that moves over the asthenosphere. Large pieces of lithosphere that act as single units.
- What is ridge push?
- A force exerted by cooling, sinking lithosphere at mid-ocean ridges. Cooling lithosphere at ridges slides down and pushes plates.
- What is the Pacific Ring of Fire?
- An area with frequent earthquakes and volcanic eruptions around the Pacific Ocean. Results from numerous subduction zones around the Pacific.
- What type of crust is denser, oceanic or continental?
- Oceanic crust. Higher density causes oceanic crust to subduct beneath continental.
- Identify the process that recycles oceanic crust back into the mantle.
- Subduction. Oceanic plates sink back into mantle, completing the cycle.
- What is subduction?
- The process where one plate moves under another into the mantle. Denser oceanic plates sink beneath less dense continental plates.
- Explain continental drift.
- The hypothesis that continents move across Earth's surface over time. Early theory explaining why continents fit together like puzzle pieces.
- Name the geological feature formed by oceanic-continental convergence.
- Volcanic mountain ranges. Oceanic plate subduction creates coastal volcanic chains.
- What evidence of tectonic activity is found in oceanic crust?
- Magnetic striping and age differences of rocks. Patterns show symmetric spreading from mid-ocean ridges.
- What evidence supports the theory of plate tectonics?
- Fossil distribution, rock formations, and seafloor spreading. Multiple lines of evidence confirm plate movement theory.
- What drives the movement of tectonic plates?
- Convection currents in the mantle. Heat-driven circulation in the mantle pushes plates around.
- What type of boundary is the San Andreas Fault?
- A transform boundary. California's major fault where plates slide horizontally.
- Name the geological feature formed by continental-continental convergence.
- Mountain ranges. Continental collision creates folded and uplifted terrain.
- Who proposed the theory of continental drift?
- Alfred Wegener. German meteorologist who first proposed continental movement.
- What occurs at a transform boundary?
- Plates slide past one another, causing earthquakes. Lateral motion creates friction and sudden release of energy.
- What is the asthenosphere?
- A semi-fluid layer of the mantle on which tectonic plates move. The plastic layer beneath plates that allows movement.
- Which layer of Earth is involved in plate tectonics?
- The lithosphere. The rigid outer shell that breaks into moving plates.
- What occurs at a convergent boundary?
- Plates collide, leading to mountain formation or subduction. Collision creates compression and vertical crustal movement.
- How are ocean trenches formed?
- By subduction of oceanic plates beneath continental or other oceanic plates. Subduction creates deep depressions in the ocean floor.
- What is the theory of plate tectonics?
- Earth's lithosphere is divided into plates that move on the asthenosphere. The fundamental principle describing how Earth's surface moves and changes.
- How do tectonic plates affect climate?
- By altering ocean and atmospheric circulation patterns. Continental positions affect global weather and ocean currents.
- What is a hotspot?
- A location where magma rises to Earth's surface independent of plate boundaries. Fixed volcanic source creates island chains as plates move.
- Which geological feature results from a transform boundary?
- Fault lines. Fractures where plates slide past each other horizontally.
- Name the geological feature formed by oceanic-oceanic convergence.
- Island arcs. Chains of volcanoes form when oceanic plates converge.
- What is the lithosphere?
- The rigid outer layer of Earth, comprising the crust and upper mantle. Earth's strong outer layer that forms tectonic plates.
- What is the role of mantle plumes in plate tectonics?
- They create hotspots and volcanic activity. Rising columns of hot rock create volcanic activity.
- What is the significance of the Mid-Atlantic Ridge?
- It is a divergent boundary where new oceanic crust forms. Demonstrates active seafloor spreading in the Atlantic.