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26 Cards in this Set
- Front
- Back
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What is the structure of Earth?
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The earth is made of 4 different layers which are the crust, mantle, outer core, and inner core.
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What is the crust?
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The crust is the outermost and thinnest of Earth's layers. The crust is the outermost and thinnest of Earth's layers. Continental crust makes up al the lands of the continents. It can be 75 km thick and is mainly granite. Oceanic crust is beneath most of the ocean floor. It is made up of different kinds of rock than the continental crust. Oceanic is mainly made of basalt and the crust is about 6 to 11 km thick. The continental crust meets the oceanic crust about 100 km from a coast. The continental crust dips underwater to form the continental shelf. The edge of the continental crust is seen at a steep drop off called the continental slope. The bottom of the slope is the continental rise and the beginning of the oceanic crust.
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What is the mantle?
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The mantle is the layer that makes up most of Earth's material. The top is solid hot rock and it forms the lithosphere along with the crust. Most of the lithosphere is under the oceans of the hydrosphere. The mantle could go up to 360 to 2500 degrees C. The mantle does have some liquid properties and flows slowly when the forces of Earth act on it. Convection currents flow slowly in the mantle. In the currents, cooler rock flows down and hot rock goes up. High temperatures inside Earth give energy needed for the currents to move. The lithosphere floats on the top of the convection currents in the mantle.
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What is the core?
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The core is the center of the Earth and hottest part. It is mostly made of iron. The temperatures can go up to 7000 degrees C. The inner core is solid and the outer is liquid. The liquid flows in currents and make Earth's magnetic field.
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How do scientists study Earth's layers?
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Scientists can study material that has been pushed up through cracks from the mantle. This can occur in the deep ocean floor. Different kinds of vibrations from earthquakes are another way to study the layers. Vibrations vary as it passes through different layers. A tool called a seismograph measures earthquake waves. It moves when an earthquake occurs and shows how strong the earthquake is.
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What is a plate?
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It is a section of lithosphere.
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What causes earthquakes and volcanoes?
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The Earth is moving all the time, even when you don't notice it. The lithosphere is broken up into many small sections which are plates. Some plates are larger than continents or part of the ocean floor. Earth's plates slowly move. As they move, they could hit each other, pull apart from each other, or grind past each other. They slowly move, sometimes very lightly or roughly and cause big earthquakes. Generally, earthquakes strike, mountains form , and volcanoes also erupt. This happens in some places in the world. When gravity pulls down on the ocean plate, the rest of the plate is pulled down to the mantle with it.
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What are plate boundaries?
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The edges of plates are called plate boundaries. They meet each other at these boundaries. There are three main kinds of plate boundaries. Two plates collide. Mountains are made when the collides, tilts, and lifts as the plates meet. A spreading plate boundary may form when plates form when plates move apart from each other. One spreading plate is under the Atlantic Ocean. The edges of the plates at the ocean floor looks like a mountain range. It is known as the mid-Atlantic ridge. The low area between the plates is a rift valley.
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How are earthquakes caused?
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There are many processes that change Earth's surface. Constructive forces and processes create new things on Earth's surface. Mountains form because of the bending and folding of colliding plates. They wear away due to destructive processes, especially earthquakes. They usually happen near faults which are cracks in Earth's crust where the surrounding rock has been moved or shifted. Faults can form in lots of ways and basically anywhere. Earthquakes occur the most at faults along plate boundaries. The plates shift from its old spot to a new place by a bit and cause the vibrations we feel. The place where the earthquake starts is called the focus. The spot on Earth's surface above the focus is the epicenter. Earthquakes can cause lots of damage and make other things occur like landslides. To prevent injuries that can happen before, buildings have been improved to resist earthquakes more and make it stronger. These buildings are very flexible and stay standing.
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What are tsunamis?
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They are earthquakes that happen underwater and the waves can crash into coastlines.
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What are volcanoes?
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Most volcanoes form near colliding plate boundaries. Every time a plate moves below another, rock welt melt slowly into magma. It is sometimes forced to the surface through a weak spot in the crust. Sometimes oxygen and carbon dioxide get mixed with the magma. This causes the magma to blow up very fast. Volcanoes can create islands like Hawaii. When a volcano reaches the surface, the island forms.
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What is weathering?
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It is a slow and destructive process that changes rocks into sediments. There are 2 types of weathering: mechanical weathering and chemical weathering.
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What is mechanical weathering?
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It is the process of rock breaking into small pieces over time. In a process called ice wedging, water freezes in rock cracks and forces the rock to split. Pressure can make rock break. When wind and water destroy lots of dirt on a mountainside, this causes the rocks to be under very little pressure. Rocks slowly expand at different speeds. Lastly, cracks form in the rocks and water seeps into it.
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What is chemical weathering?
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It is the process of materials changing by chemical processes. e.g. Raindrops can absorb carbon dioxide and become carbonic acid. This can dissolve rocks a little by a little and eventually form caves. Other organisms like fungi can do this as well. Some rocks dissolve faster than others though.
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How does soil result from weathering?
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Soil can form after mechanical and chemical weathering. It is made of sediments which are very small weathered rock. Soil contains other material including dead organisms, water, and gases. Soils can come in different colors depending what is in it. Sometimes soils will have different sediments like clay which does not let water pass faster. How much water there is is another way to determine soil. Plants grow best in soil with lots of decayed matter.
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What is erosion and what does it cause?
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Erosion is the movement of material from one place to another. It is a destructive process. It is not the same as deposition. Erosion can form sand dunes, valleys, and deltas. Gravity is what is mainly causing erosion. They cause things like earthquakes. Gravity causes rivers to flow downhill and pick up sediments. The sediments erode and the faster the river, the more sediments get picked up and can form canyons. Oceans can cause erosion too and erode deep valleys called submarine canyons in the continental shelf.
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What is deposition?
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Sometimes water becomes slower and can't carry many sediments. The sediments are deposited in where it stops and can change a lake's shape. When rivers hit oceans, they slow down faster and he sediments are deposited. The deposits eventually form a delta and it can branch out as the delta grows. Glaciers can carry sediments as they slowly move.
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What are some kinds of erosion?
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Wave erosion is when waves near coastlines hit beaches or rocks there which will turn into sand. Wave erosion can also make the beach look different. They can also cause damage. Wind erosion is caused by wind blowing dust, soil, or sand from one place to another. Pieces are broken off and that's it. Field erosion is like wind erosion, except just on fields where farmers farm. They can prevent plowed fields from becoming dry by planting trees to reduce the dust.
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What are sand dunes?
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Sand dunes result from large deposits of sand. If wind blows sand in a smooth direction can move a dune. It will take the sediments and put it on the other side.
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How are minerals identified?
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Minerals are identified depending on their properties. Minerals can be identified easily in some ways like smell or touch. There are 6 ways to identify minerals. There is magnetism, hardness, streak, luster, shape, and texture.
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How can minerals be identified using properties?
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When scientists find new minerals, they compare observations with known minerals to new ones. Scientist refer to the Mohs scale to make their comparisons.
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How are rocks classified?
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Rocks are classified by how they are formed and how they look. There are three types of rock: igneous, sedimentary, and metamorphic rock.
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What is igneous rock?
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Igneous rock forms when melted rock cools and hardens. As hot liquid rock cools, crystals of minerals form. Some examples of igneous rock include granite, basalt, and pumice.
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What is sedimentary rock?
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Sedimentary rock forms when layers of materials and rock particles settle on top of each other and harden. Sandstone and conglomerate are examples of sedimentary rock. Fossils of plants and animals are often found in sedimentary rock.
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What is metamorphic rock?
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Metamorphic rock forms when particles inside the rock change as it is heated in high temperatures. Examples of metamorphic rock include gneiss and slate.
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What is the rock cycle?
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The rock cycle is a chain of many paths of how rocks change over thousands of years or stay the same. Rocks found on the surface are younger than rocks deeper in the ground.
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