{
 "source": "https://peabody.kids/flashcards/earth-plate-tectonics",
 "id": "earth-plate-tectonics",
 "title": "Plate Tectonics, Volcanoes and Earthquakes",
 "category": "science",
 "subject": "Earth Science",
 "levels": [
  "6-8",
  "9-12"
 ],
 "description": "How Earth's plates move and the quakes and volcanoes they cause.",
 "tags": [
  "tectonics",
  "volcanoes",
  "earthquakes"
 ],
 "frontLabel": "Term",
 "backLabel": "Meaning",
 "cards": [
  [
   "Plate tectonics",
   "The theory that Earth's outer layer is broken into moving plates"
  ],
  [
   "Tectonic plate",
   "A large slab of Earth's lithosphere"
  ],
  [
   "Lithosphere",
   "Earth's rigid outer layer: crust and top of the mantle"
  ],
  [
   "Asthenosphere",
   "The soft, slowly flowing layer of mantle below the lithosphere"
  ],
  [
   "Continental drift",
   "The idea that continents slowly move over time"
  ],
  [
   "Who proposed continental drift in 1912?",
   "Alfred Wegener"
  ],
  [
   "Pangaea",
   "The supercontinent that existed about 300 million years ago"
  ],
  [
   "Seafloor spreading",
   "New ocean floor forming at mid-ocean ridges and moving outward"
  ],
  [
   "Mid-ocean ridge",
   "An underwater mountain chain where new crust forms"
  ],
  [
   "Convergent boundary",
   "Two plates moving toward each other"
  ],
  [
   "Divergent boundary",
   "Two plates moving apart"
  ],
  [
   "Transform boundary",
   "Two plates sliding past each other"
  ],
  [
   "Subduction",
   "One plate sinking beneath another"
  ],
  [
   "Subduction zone",
   "The place where one plate dives under another"
  ],
  [
   "Ocean trench",
   "A deep, narrow valley in the seafloor at a subduction zone"
  ],
  [
   "Mariana Trench",
   "The deepest known ocean trench"
  ],
  [
   "Rift valley",
   "A valley formed where plates pull apart"
  ],
  [
   "Fault",
   "A crack in Earth's crust where blocks of rock move"
  ],
  [
   "San Andreas Fault",
   "A famous transform fault in California"
  ],
  [
   "Earthquake",
   "Shaking of the ground from sudden release of energy in Earth's crust"
  ],
  [
   "Focus (hypocenter)",
   "The point underground where an earthquake starts"
  ],
  [
   "Epicenter",
   "The point on the surface directly above the focus"
  ],
  [
   "Seismic waves",
   "Vibrations that travel through Earth during an earthquake"
  ],
  [
   "P waves",
   "Fast seismic waves that arrive first"
  ],
  [
   "S waves",
   "Slower seismic waves that arrive second"
  ],
  [
   "Surface waves",
   "Seismic waves that move along the ground and cause the most damage"
  ],
  [
   "Seismograph",
   "An instrument that records earthquake waves"
  ],
  [
   "Seismologist",
   "A scientist who studies earthquakes"
  ],
  [
   "Richter scale",
   "An older scale of earthquake size"
  ],
  [
   "Moment magnitude scale",
   "The scale scientists now use to measure earthquake size"
  ],
  [
   "Aftershock",
   "A smaller quake that follows a larger one"
  ],
  [
   "Tsunami",
   "A giant sea wave usually caused by an undersea earthquake"
  ],
  [
   "Ring of Fire",
   "A belt of volcanoes and earthquakes around the Pacific Ocean"
  ],
  [
   "Volcano",
   "An opening in Earth's crust where lava, ash and gas escape"
  ],
  [
   "Vent",
   "An opening where magma comes out of a volcano"
  ],
  [
   "Crater",
   "A bowl-shaped dip at the top of a volcano"
  ],
  [
   "Caldera",
   "A large crater formed when a volcano collapses"
  ],
  [
   "Magma chamber",
   "An underground pool of magma"
  ],
  [
   "Shield volcano",
   "A wide, gently sloping volcano like those in Hawaii"
  ],
  [
   "Composite (stratovolcano)",
   "A steep cone built from layers of lava and ash"
  ],
  [
   "Cinder cone",
   "A small, steep cone of volcanic fragments"
  ],
  [
   "Active volcano",
   "One that is erupting or may erupt"
  ],
  [
   "Dormant volcano",
   "A volcano that is quiet but may erupt again"
  ],
  [
   "Extinct volcano",
   "A volcano that is not expected to erupt again"
  ],
  [
   "Hot spot",
   "A place deep in the mantle that feeds volcanoes, like Hawaii"
  ],
  [
   "Pyroclastic flow",
   "A fast cloud of hot gas and ash from a volcano"
  ],
  [
   "Ash",
   "Tiny rock and glass pieces thrown out by a volcano"
  ],
  [
   "Mount St. Helens",
   "A volcano in Washington State that erupted in 1980"
  ],
  [
   "Mauna Loa",
   "A huge shield volcano in Hawaii"
  ],
  [
   "Mount Vesuvius",
   "The volcano that buried Pompeii in the year 79"
  ],
  [
   "Geyser",
   "A hot spring that shoots water into the air"
  ],
  [
   "Old Faithful",
   "A famous geyser in Yellowstone National Park"
  ],
  [
   "Fold mountains",
   "Mountains formed when plates push together and crumple rock"
  ],
  [
   "Himalayas",
   "Mountains formed where India's plate pushes into Asia's"
  ],
  [
   "Convection currents",
   "Slow movements of hot mantle rock that help move the plates"
  ],
  [
   "Evidence for drift: fossils",
   "The same fossils appear on continents now far apart"
  ],
  [
   "Evidence for drift: coastlines",
   "South America and Africa fit together like puzzle pieces"
  ],
  [
   "How fast do plates move?",
   "A few centimeters a year, about as fast as fingernails grow"
  ],
  [
   "Strike-slip fault",
   "A fault where blocks slide sideways past each other"
  ]
 ]
}