Earth's Crust in Motion (10th Grade) PDF
Document Details
Uploaded by Deleted User
Tags
Summary
These notes cover the earth's crust and plate motion as an introduction to plate tectonics, earthquakes, and volcanoes. It discusses different types of mountains, seafloor spreading, and earthquakes.
Full Transcript
10th grade EARTH’S CRUST IN MOTION PASA The structure of the Earth The outermost and thinnest layer of the Crust earth. The thickest and has hot gooey magma Mantle rock that slowly circulates in giant...
10th grade EARTH’S CRUST IN MOTION PASA The structure of the Earth The outermost and thinnest layer of the Crust earth. The thickest and has hot gooey magma Mantle rock that slowly circulates in giant convection currents. Outer coreThe liquid outer core is mostly molten iron and nickel. Iron and nickel remain solid Inner core because of the immense temperature and pressure. The earth's crust and the rigid layer of the mantle that is connected to the crust are together called the LITHOSPHERE The earth's lithosphere is broken like an eggshell into large parts called PLATES (also known as TECTONIC PLATES). These plates move around on top of a plastic-like layer of the mantle called the ASTHENOSPHERE. MOUNTAIN BUILDING Different kinds of plate activity create different kinds of mountains, like the following:; When plates move away from each other, they create FAULTS, rock layers that are pulled apart. This sometimes causes large FAULT-BLOCK MOUNTAINS: blocks of rock to tilt and separate, forming parallel ridges and valleys.Mountains with sharp, jagged ridges above wide, flat valleys are most characteristic of fault-block mountains. Plates moving together exert an enormous amount of pressure on rock from different sides, causing it to fold and squeeze FOLDED MOUNTAINS: together. You can usually see all of the rock layers if you look at an exposed face of a folded mountain When the lava from a volcano cools,it creates another hard layer. After layers and layers of hardened lava pile up, the VOLCANIC MOUNTAINS: volcano can form a cone-shaped mountain, like Mount Saint Helens and dozens of other volcanoes in the Cascades. Underwater volcanic eruptions can build mounds under UNDERWATER VOLCANIC water.As more lava piles up, eventually the mountain reaches MOUNTAINS: the water's surface, forming a volcanic island, such as Hawaii. German meteorologist, came up with a theory of CONTINENTAL DRIFT to explain this. It suggests that originally these continents were connected as a huge landmass, which Wegener called PANGAEA. Plate Tectonics The shifting and moving of plates affects the earth's surface and appearance. At the plate boundaries (where the edges of plates meet), plates can move apart, collide, overlap, or scrape past each other. Uneven heating of the mantle causes CONVECTION CURRENTS, or the cycling of heat that drags the plates Plates Moving Apart The boundary between plates moving apart is called a DIVERGENT BOUNDARY. When plates move apart, magma from the mantle gets pushed up and forms new crust to fill the gaps between the plates. This new magma is less dense than the surrounding area, so it usually lifts up and forms ridges in the seafloor. Plates that move apart can also form rift valleys, SEAFLOOR SPREADING Using sound waves, scientists mapped the seafloor and discovered a bunch of underwater ridges. This led to a theory of SEAFLOOR SPREADING: As plates along the ocean bed spread apart, hot magma is forced upward and flows through the cracks, forming ridges of igneous rock called BASALT. Plates Colliding The boundary between plates moving toward each other is called a CONVERGENT BOUNDARY. Massive earthquakes occur along these boundaries, often deep under the crust. There are two types of plates: OCEANIC PLATES and CONTINENTAL PLATES. Oceanic plates are denser than continental plates, so when an oceanic and a continental plate collide, the denser oceanic plate When two continental plates collide, because they are of equal density, one doesn'+get subducted. Instead, the crusts get compressed into each other, forming folds and crumples, which we see as mountains. Oceanic plates occur at mid ocean ridges where molten rock has cooled and solidified. As more molten rock erupts in the ridge, it pushes the oceanic plate away from the ridge. As it gets farther away, it gets colder and denser. So when two oceanic plates collide, whichever plate is older (and therefore colder and denser) will sink underneath the younger (and therefore warmer and less dense) plate. One oceanic plate is always a bit less dense than the other. The area around the sinking plate is called the SUBDUCTION ZONE. The rock around the subducting slab melts into magma. Magma, or molten rock, is not as dense as the solid rock of the crust and lithosphere. So, the magma rises to the surface, creating a volcano. Volcanoes spew magma- when magma reaches the earth's surface, however, it Plates Sliding Past Each Other when plates slide past each other in different directions,their edges can scrape, causing EARTHQUAKES. Places that experience frequent earthquakes, like California, are located on top of plate boundaries. Plates sliding past each other can also form FAULTS or enormous fractures in the rock bed. The boundary between plates sliding past each other is called a TRANSFORM BOUNDARY. 0 1 EARTHQUAKES PASA EARTHQUAKES As rocks get strained from rubbing against other tectonic plates, they build up potential energy....until they break and move, releasing all this stored potential energy. This movement and breaking causes vibrations that move outward like a wave-that's an earthquake, SEISMIC WAVES and SEISMOGRAPHIC DATA The energy in earthquakes is released in the form of vibrations called SEISMIC WAVES, which travel outward in all directions. The source the energy waves released by earthquakes of the seismic wave, which is where the movement originates, is called the FOCUS. The point on the earth's surface that's closest to the focus is called the EPICENTER. P-Waves and S-Waves There are two kinds of underground seismic waves. 1. PRIMARY 2. SECONDARY WAVES WAVES called P-WAVES which called S-WAVES,which vibrate in the same vibrate perpendicularly direction as the wave is to the direction the traveling wave is traveling SURFACE WAVES which are the seismic waves that travel on the earth's surface, are slow-moving, large, and can be very destructive. Measuring earthquakes Magnitude Intensity measure measure the size of the earthquake the amount of how much energy is groundshaking raleased change with distance e To measure strength, or MAGNITUDE of seismic waves, scientists use a SEISMOGRAPH which records the seismic waves from all over the world. Using distance information from different seismograph stations, they can figure out the epicenter of the earthquake. RICHTER SCALE The magnitude of an earthquake is measured using the RICHTER SCALE. Richter magnitudes are based on the magnitude of the seismic wave. Most major earthquakes are in the to 9 range on the Richter scale. For every I-point increase on the scale, the ground shakes 10 times as much and the earthquake carries 32 times more energy! //World Tsunami Awareness Day Tsuna mi! PASA What is a tsunami? Earthquakes that happen under water can create seismic sea waves, called TSUNAMIS. Tsunamis, like regular waves, consist not of moving water, but the movement of energy through water. When there is less water to move through, wave speed slows down but the height of the wave rises to as high as 100 feet, about the height of a 10-story building. Main causes of tsunamis Earthquake – Tsunami is generated by the earthquake because of the disturbance of the seafloor and is formed generally with vertical displacement. Most Tsunami is generated by earthquakes that occur along the subduction boundaries of plates along the ocean trenches. The size of the Tsunami is related to the size of the earthquake. Volcanic eruption – Volcanoes that occur along the Coastal waters can cause several effects that can cause a tsunami. Landslides – Earthquake and volcanic eruptions generally generate landslides, these landslides when moving into the Oceans, bays and lakes can generate Tsunami. Earthquake Eruptions Landlsides As these tsunamis approach land, they can become enormous- sometimes as tall as a nine- story building-and can cause a lot of destruction. In 2004, Sumatra, Indonesia, experienced one of the worsttsunamis in history, which killed roughly 230,000 people. In 2011, a devastating tsunami swept over Japan's North Pacific Coast. Carefully examine the statements below. Put them in the order in which they occur to create a tsunami: 1.Sea movement causes Tsunami 4.Sea above earthquake forced upwards 2.Plate movement causes earthquake 5.Plates move towards each other 3.Waves crash onto shore 6.Tsunami waves spread quickly outwards Make a larger, neater (better) coy of the diagram below. Use the material on this page to fully annotate the diagram in order to fully explain how tsunamis form. Remember to give the diagram a title, to use a ruler for arrows, to draw a frame around your diagram; draw only in pencil and write in blue or black pen. VOLCANOES When rising high-pressure magma finds an opening, it explodes to the surface, creating a VOLCANO. Some of the magma is under so much pressure that a volcanic eruption can push lava, rock, ash, and hot gases thousands of meters into the air. Magma, or molten rock, is less dense than the solid rock of the crust and lithosphere, so it constantly wants to rise to the surface. When rising high- pressure magma finds an opening to the surface, the magma explodes out of it. Volcanoes usually form as tectonic plates collide or drift apart to form a long crack, or RIFT. Or they can just "pop up"at a HOTSPOT, where tons of boiling magma pushes toward the surface in one spot. Volcanoes are categorised into three main categories: Active volcanoes have a recent history of eruptions; they are likely to erupt again. Dormant volcanoes have not erupted for a very long time but may erupt at a future time. Extinct volcanoes are not expected to erupt in the future. Classifications Shield of volcanoes Composite Volcano Volacano are built almost entirely of fluid They are usually tall with steep lava flows. Lava pours out of vents even sides and are made out of in all directions, either from the repeating layers of lava flows, summit (top) or along two to three volcanic ash, cinders, blocks, and rift zones (fractures) volcanic bombs. PARTS OF A VOLCANO Crater a funnel-shaped opening at the top of a volcano. Conduit connects the magma chamber to the crate Main Vent through which magma travels. the main opening on the surface of a volcano that emits lava, gases, ash and other volcanic Magma A region beneath the vent where magma is materials.Chamber deposited before eruption. Parasitic Cone a small cone-shaped Ash and Gas volcano formed by an Cloud accumulation of A mixture of rock, volcanic debris. minerals and gases expelled out of the Secondary volcano. Vent a pathway where magma reaches the Throat surface without going through the main part of the conduit vent. that ejects lava and volcanic ash. a flat piece of rock formed when magma Sill hardens in a crack of a volcano. Cinder Cone are the simplest type of volcano. They are made of small pieces of solid lava, called cinder, that are erupted from a vent. are technically lava flows made up of lava that is too Lava Dome thick to flow away from the vent. Transformation of plate Plate boundaries Descriptio Process and transformation n 1. Tensional forces pull plates apart. 2. Magma Plates move Divergent rises from the mantle, creating new crust. 3. away from boundary Formation of mid-ocean ridges and rift valleys. 4. each other Earthquakes due to crustal stretching. 1. Compression forces push plates together. 2. Plates move Convergen Subduction of denser oceanic plates. 3. Formation toward each t boundary of deep ocean trenches. 4. Earthquakes along other subduction zones. Plates slide 1. Shear forces cause plates to move laterally. 2. Transform past each other Plates grind against each other 3. Formation of boundary horizontally strike-slip faults. 4. Little to no volcanic activity. 1st activity Case and effect of earthquakes Instructions: complete the table by matching the causes of earthquakes on the left with their corresponding effects and description on the right Brief Causes Effects description Tectonic plate Your answer here Your answer here movements Volcanic activity Your answer here Your answer here Human activities Your answer here Your answer here Other natural Your answer here Your answer here phenomena Zones of interaction Your answer here Your answer here Thanks! Do you have any questions? [email protected] +34 654 321 432 yourwebsite.com CREDITS: This presentation template was created by Slidesgo, and includes icons by Flaticon, and infographics & images by Freepik Please keep this slide for attribution Icon pack Alternative resources Here’s an assortment of alternative resources whose style fits that of this template: Free vector hand drawn l ayers of the earth Gradient heat map backg round Did you like the resources on this template? Get them on our other websites: Vectors: Gradient heat map background Free vector hand drawn layers of the earth Free vector hand drawn layers of the earth I Free vector hand drawn layers of the earth II Resources Free vector hand drawn layers of the earth III Icons: Icon Pack: Geology | Lineal color Photos: Free photo destroyed home russian's war in u kraine Free photo cracked concrete wall Free photo college students of different ethnic