Question | Answer |
Continental Drift | the hypotesis that continents have moved slowlyto their current locations |
Pangea | the large landmass that consisted of all the continents connected |
Seafloor Spreading | 1) hot less dense material below Earth's crust rises upward to the surface at the mid-ocean ridges 2) then it flows sideways carrying the seafloor away from the ridge 3) as the seafloor spreads apart magma moves up and flows from the cracks cools=seafloor |
Plate Tectonics | Earth's crust are broken into sections called plates which move on a plasticlike layer of the mantle |
Plate | sections of Earth's crust |
Lithosphere | plates and upper mantle form the lithosphere |
Asthenosphere | plasticlike layer below the lithosphere |
Convection Current | thought to be the force behind plate tectonics |
Earthquakes | caused by strike-slip faults |
Primary Waves | 2x faster than secondary waves |
Secondary Waves | 2x slower than primary waves |
Surface Waves | the waves we feel during an earthquake |
Epicenter | directly above the focus; at the surface |
Seismograph | measures the strength of the earthquake |
Volcano | an opening in Earht that erupst gases, ash, and lava |
Vent | the opening that magma flows out of |
Crater | the steep-walled depression around a volcano's vent is the crater |
Hot Spot | some areas at the boundary between Earht's mantle and core are unusually hot |
Sheild Volcano | quiet eruptions of basaltic lava spread out in flat layers |
Cinder Cone Volcano | when tephra falls to the ground, it forms a steep-sided, loosely packed cinder cone volcano |
Composite Volcano | the eruption can be explosive then, can switch to a quieter period, erupting lava over the top of the tephra layer |
Tephra | bits of rock or solidified lava dropped from the air are called tephra |