Science 10 - 1st Quarter Review - Plate Tectonics & Earth's Interior PDF

Science 10 – Pointers to Review 1st Quarter Unit 1-MODULE 2: THE EARTH’S INTERIOR...

Science 10 – Pointers to Review 1st Quarter Unit 1-MODULE 2: THE EARTH’S INTERIOR Unit 1- MODULE 1: PLATE TECTONICS Summary/Synthesis/Feedback The Earth is composed of three major layers: the crust, mantle, Summary/Synthesis/Feedback and core which is subdivided into outer and inner core. According to the plate tectonics model, the entire lithosphere of the The crust is the outermost and thinnest layer of the Earth. Earth is broken into numerous segments called plates. The mantle is the middle layer of the Earth. It makes most of the Each plate is slowly but continuously moving. Earth’s volume and mass. As a result of the motion of the plates, three types of plate The crust and a part of the upper mantle make up the lithosphere. boundaries were formed: Divergent, Convergent, and Transform The lithosphere is subdivided into portions called lithospheric plates. fault boundaries. The asthenosphere is the weak layer of the mantle on which the Divergent boundary is formed when plates move apart, creating a lithosphere floats. zone of tension. The outer core is made up of molten material and accounts for the Convergent boundary is present when two plates collide. Earth’s magnetic field. Transform fault is characterized by plates that are sliding past The inner core is the deepest layer of the Earth. It is made up of each other. solid nickel and iron. The temperature in the inner core reaches as Plate tectonics give rise to several geologic features and events. high as 5000oC. The speed, reflection and refraction properties of seismic waves Glossary of Terms are used by scientists to study the structure and composition of the Continental volcanic arc mountains formed in part by igneous Earth’s interior. activity associated with subduction of oceanic lithosphere beneath a The Continental Drift Theory of Alfred Wegener states that the continent continents were once part of a large landmass called Pangaea Convergent boundary a boundary in which two plates move which drifted away from each other. The continents moved away toward each other, causing one of the slabs of the lithosphere to from each other towards their current positions. subduct beneath an overriding plate Alfred Wegener based his theory on evidences from fossils Crust the outer portion of the earth imbedded in rocks and rock formations. Continental Crust the thick part of the Earth’s crust, not located Seafloor spreading is believed to occur as hot magma rises at the under the ocean rift in the mid-ocean ridge. This magma cools down and becomes Oceanic Crust the thin part of the Earth’s crust located under the the new seafloor as it pushes the former. oceans The old seafloor is destroyed at the subduction zone and melts Divergent boundary a region where the crustal plates are moving inside the mantle. apart The age of rocks and the magnetic stripes in the ocean floor Earthquake vibration of Earth due to the rapid release of energy support the Seafloor Spreading Theory. Fault a break in a rock along which movement has The Theory of Plate Tectonics helps explain the formation and occurred destruction of the Earth’s crust and its movement over time. Fracture any break in a rock in which no significant Scientists believe that the plates’ movement is due to convection movement has taken place currents in the mantle. Geology the science that studies Earth Hot spot a concentration of heat in the mantle capable of creating Glossary of Terms magma Asthenosphere soft, weak upper portion of the mantle where the Magma a mass of molten rock formed at depth, including dissolved lithospheric plates float and move around gases and crystals. Continental Drift Theory states that all the continents were once Mid-ocean ridge a continuous mass of land with long width and one large landmass that broke apart, and where the pieces moved height on the ocean floor. slowly to their current locations Plates rigid sections of the lithosphere that move as a unit Convection current current in the mantle because of the heat from Plate tectonics a theory which suggests that Earth’s crust is made the inner layers of the Earth, and is the force that drives the plates up of plates that interact in various ways, thus producing to move around earthquakes, mountains, volcanoes, and other geologic features Lithosphere the topmost, solid part of the Earth that is Primary (P) wave the first type of seismic wave to be recorded in a composed of several plates seismic station Lithospheric Plates the moving, irregularly-shaped slabs that fit Rocks consolidated mixture of minerals together to form the surface of the Earth Secondary (S) wave second type of earthquake wave to be Mid-ocean ridge area in the middle of the ocean where a new recorded in a seismic station ocean floor is formed when lava erupts through the cracks in the Seismogram a record made by a seismograph Earth’s crust Seismograph a device used to record earthquake waves Mohorovičić Discontinuity (Moho) the boundary that separates Subduction an event in which a slab of rock thrusts into the mantle the crust and the mantle Transform fault boundary a boundary produced when two plates Plasticity the ability of solid to flow slide past each other Seafloor spreading process by which new ocean floor is formed Trench a depression in the seafloor produced by subduction near the mid-ocean ridge and moves outward process Subduction the process in which the crust plunges back into the Volcanic Island arc a chain of volcanoes that develop parallel to a Earth trench Tectonics branch of geology that deals with the movements that shape the Earth’s crust Please remember to review the notes from our previous discussions on Module 1 and Module 2, as they are included in the scope of the first quarterly examination.