Finally, when the plate has moved far enough, the edges unstick and an earthquake occurs. Many mountain ranges occur along these lines because when one plate doesn't completely move under the other, the earth crumbles and this uplifts the crust into mountains. In Europe, the Alps are formed from the African and Eurasian plate bumping into each other.
A transform plate boundary occurs when two plates slide past each other. Where the crust is rough, the two plates build up tension as they slide. When one plate overrides another plate the tension is released in the form of an earthquake. This occurs along the San Andreas Fault in California.
Because the plates are merely moving past each other no new crust is formed or lost at this boundary. Observe simple objects, patterns, and events and report their observations. Compare things, processes, and events. Know and explain science information specified for the grade level. Describe or explain observations carefully and report with pictures, sentences, and models. Cite examples of how science affects life.
Pre-lab discussion: Ask the students what major disaster happened in March of Remind them that it was the earthquake in Japan. Discuss with them some statistics from the earthquake: magnitude 9. After discussing this earthquake explain the theory of plate tectonics and go over the notes from the background information section.
Instructional procedure: This lab works well as stations because the "Dynamic Planet" map, fault blocks, and US relief map need to be shared. Identify the continents and review that this is a flat map and the world is round.
Notice how Europe and Asia are found on the right and left sides of the map. Point out the boundaries for the Earth's major plates. Have the students label their map. Again, notice that plates 3 and 4 occur on both sides of the map. Explain to the students that their map labels 9 of the larger tectonic plates but there are 7 major plates and about 18 minor plates under discussion how many actual plates there are. Have the students identify the symbols for volcanoes and earthquakes on the key for the map.
Look at the plate boundaries and observe that the volcanoes and earthquakes are predominantly found along the plate boundaries. Remember, where plates are pushing against each other or pulling apart - landforms change.
Identify the boundary between the Indian and Eurasian plates. These plates are bumping into each other convergent boundary and this process forms the highest mountain ranges on Earth, the Himalayas.
Find Iceland and notice all the volcanoes there. The volcanoes are due to the North American and Eurasian plates spreading apart divergent boundary. As the plates spread apart, rifts occur in the ground on Iceland, these rifts allow the crust to bubble up through a volcano. Find the San Andreas Fault along the coast of California. Notice all the earthquake activity found there. This fault line is due to the North American Plate sliding south while the Pacific Plate is sliding north transform boundary.
As these plates bump into each other tensions builds until an earthquake occurs. Find the Hawaiian Islands. These islands are found in the center of the Pacific Plate not at the edge. These islands formed over a hot spot in the ocean floor where magma rose upward until it bubbled up and formed the islands. Notice all the mountain ranges along the plate boundaries. Activity 2: Mountain Building A.
Fold Mountains -- form at convergent boundaries, or within a plate between convergent boundaries. The more heat and pressure you add, the further the rock metamorphoses until it becomes gneiss.
If it is heated further, the rock will melt completely and reform as an igneous rock. Empower your students to learn about the rock cycle with this collection of resources. These tectonic plates rest upon the convecting mantle, which causes them to move.
The movements of these plates can account for noticeable geologic events such as earthquakes, volcanic eruptions, and more subtle yet sublime events, like the building of mountains.
Teach your students about plate tectonics using these classroom resources. Weathering is the process of the weakening and breakdown of rocks, metals, and manmade objects. There are two main types of weathering: chemical and physical. An example of chemical weathering is acid rain. Caused mostly by the burning of fossil fuels, acid rain is a form of precipitation with high levels of sulfuric acid, which can cause erosion in the materials in which it comes in contact.
An example of physical weathering is wind blowing across the desert playas. This process causes rocks to form a specific pyramid-like shape and they are called ventifacts.
Select from these resources to teach about the process of weathering in your classroom. Metamorphic rocks start as one type of rock and—with pressure, heat, and time—gradually change into a new type of rock. In , after decades of tediously collecting and mapping ocean sonar data, scientists began to see a fairly accurate picture of the seafloor emerge. The Tharp-Heezen map illustrated the geological features that characterize the seafloor and became a crucial factor in the acceptance of the theories of plate tectonics and continental drift.
Today, these theories serve as the foundation upon which we understand the geologic processes that shape the Earth. The theory of plate tectonics revolutionized the earth sciences by explaining how the movement of geologic plates causes mountain building, volcanoes, and earthquakes. Join our community of educators and receive the latest information on National Geographic's resources for you and your students.
Skip to content. Twitter Facebook Pinterest Google Classroom. Encyclopedic Entry Vocabulary. The Alps are fold mountains, the most common mountain type on Earth. Photograph by James P. Blair, National Geographic. Foreland Basins. Fold mountains sometimes are characterized by foreland basins, depressions that run parallel to the mountain range. The Erbo Basin, in northern Spain, is a foreland basin that formed with the Pyrenees, a fold mountain chain created by the continental collision of the microcontinent of Iberia with the massive Eurasian plate.
The Persian Gulf is a foreland basin that formed with the Zagros Mountains, a fold mountain chain created by the continental collision of the Arabian and Iranian tectonic plates. Also called a collision zone. Media Credits The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit.
Media If a media asset is downloadable, a download button appears in the corner of the media viewer. Text Text on this page is printable and can be used according to our Terms of Service. Interactives Any interactives on this page can only be played while you are visiting our website. Related Resources. The Rock Cycle. View Collection. Crust is then squeezed upward between the two parallel lines, resulting in mountains!
And finally, the term erosional mountain describes mountains that are formed due to the erosion of uplifted rocks in the Earth's geography. This process occurs when rivers, over time, carve away at a region of uplifted geography. But bumps and hills are all over this planet — so what constitutes a mountain? Mountains are landforms that extend above their surrounding areas in a limited area.
That is a very general definition! No required elevation exists for a mountain to be called a mountain, so what makes a mountain different from a hill? Mountains are generally considered to be higher and steeper than a hill, but the definitions ultimately depend on local custom.
A hill to some is a mountain to others, and visa versa! These tunnels in Nevada enable traffic on US interstate highway 80 to continue through a mountain of rock instead of going around it. Used with permission. Geotechnical engineers study mountains and the movement of tectonic plates for a variety of purposes. They observe plate movements to design technologies to measure the movement of tectonic plates and mountain formation in order to predict earthquakes and how to best protect people from them.
Using these technologies, they develop processes and rules for developing communities and roadways around tectonic plate movement adding extra support requirements to structures on an earthquake fault line.
They also use the information to develop technologies that predict locations at which geothermal, oil, natural gas and coal resources may be located. Sometimes geotechnical engineers work with other engineers to turn the geological formations themselves into res ources for humans, such as mountain tunnels, dams and roads. After completing the lesson refer to the hands-on associated activity Tunnel Through! The Earth's internal structure makes the land and oceans prone to mountain formation.
The lithosphere, Earth's rigid top layer of rock, floats on the asthenosphere, Earth's hot, malleable layer beneath the lithosphere.
The rigid lithosphere layer is about km 60 miles thick and makes up the Earth's enormous moving rocks called tectonic plates; 14 major tectonic plates and 38 minor plates are identified. Tectonic plates are further classified into two major groups based upon their composition: oceanic crust and continental crust. Typically, a single tectonic plate can contain both oceanic and continental crust. Oceanic crust is mainly comprised of basaltic rocks, whereas continental crust is largely made up of felsic rocks, which are lower in density.
Map of the Earth's tectonic plates. Currents acting on the asthenosphere push the Earth's tectonic plates in lateral movements. Because the lithosphere essentially floats on the asthenosphere, movement in the asthenosphere gets transferred to the lithosphere, causing the Earth's tectonic plates to move in different directions.
The currents causing this movement in the asthenosphere are not entirely understood, but the Earth's internal heat engine is the hypothesized cause. Three types of tectonic pl ate boundaries exist: convergent, divergent and transform. Mountains are formed by plate convergence.
Plate convergence describes tectonic plate movement that results in the collision of two plates. These slow-moving collisions shift the plates only a few centimeters a year, but are powerful enough to form large mountain ranges over time.
Plate convergence resulting in mountain formation occurs in several ways. First, two tectonic plates can be pressed up against each other until the land lifts and folds over itself. If the two plates involved in the process contain continental crust, it is called a continental collision. Second, one plate can push on top of another, causing the latter to slide downward into the Earth. This is called a subduction zone when one plate moves underneath the other.
At that place, it begins to melt, leading melted rock to escape through cracks and weak spots, and burst out as fiery volcanoes. Third, tectonic plates can stretch until they crack and slide, resulting in fault-block mountains. And finally, underwater mountains are formed when tectonic plates spread away from one another, allowing melted rock to push up through the gap. This process is more common, as mountain formation occurs more often in oceans than on land.
Because mountain peaks experience higher elevations than their surrounding areas, they also experience cold temperatures in higher layers of the atmosphere. Mountains therefore often experience glaciation, when glaciers carve and shape mountain peaks by carrying rocks with them as their ice melts or shifts downward. This process carves sharp horns, rounded bowls, and u-shaped valleys into mountains, creating the images that come to mind when we think about mountains.
Mountains can also change shape due to other natural elements such as rain, wind or ice wearing away the rock. Eventually, previously high jagged peaks naturally become low rounded hills and ultimately wear down into soil, sand or sediments.
Watch this activity on YouTube. Highway tunnel along I in Nevada. Now that we've talked about mountain formation, describe for me the outer layers of the Earth Listen and clarify student descriptions.
Explain how tectonic plate movement is linked to the formation of mountain ranges. Listen and clarify student descriptions. How is this information important to the daily lives of many people? Listen and add to student answers. In today's fast-paced world, people who want to get from one side of a mountain to the other prefer the quickest route—driving through! Who are the people responsible for designing tunnels?
Engineers make driving directly through mountains a possibility by designing and constructing mountain tunnels, saving countless travelers, haulers, commuters, emergency vehicles, truckers and vacationers time on the road each day. This material is less dense than oceanic crust, but is considerably thicker. This crust is generally composed of mafic basaltic rocks and is denser than continental crust.
0コメント