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Middle school Earth and space science - NGSS
Course: Middle school Earth and space science - NGSS > Unit 4
Lesson 3: Plate tectonicsIntroduction to plate tectonics
Review your understanding of plate tectonics in this free article aligned to NGSS standards.
Key points:
- Earth’s lithosphere, or outermost shell, is broken up into large pieces called tectonic plates.
- These plates move slowly over the asthenosphere, a layer of softer rock below the lithosphere. On average, tectonic plates move a few centimeters per year.
- The place where two plates meet is called a plate boundary. There are three main types of plate boundaries.
- Divergent boundaries occur where two plates are moving away from each other. Along these boundaries, rift valleys and mid-ocean ridges are common.
- Convergent boundaries occur where two plates are moving toward each other. Along these boundaries, mountains and trenches are common.
- Transform boundaries occur where two plates are moving past each other. Along these boundaries, earthquakes are common.
- Evidence for plate motion can be seen in various features on Earth. For example, some of the continents have complementary coastlines. This suggests that the continents were once joined together.
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so will we every get to explore all the creature and find ones who are thought to be exstint animals under the sea bed kinda like the movie godzilla where there an whole other world(15 votes)- We might, you never know what technology gets us to!(9 votes)
What does asthenosphere mean?(5 votes)
"Asthenosphere" literally translates to "weak sphere", so it makes sense that the asthenosphere is the less rigid part of the mantle. It's right under the lithosphere. The tectonic plates drift on currents in the asthenosphere.
Does that help?(21 votes)
Why do they move and why do they transform into different things.(11 votes)- The tectonic plates move because the heat from radioactive processes within the planet’s interior causes the plates to move, sometimes toward and sometimes away from each other. This movement is called plate motion, or a tectonic shift.(5 votes)
What will Earth look like 200 years from now? Will there be a part of a volcano somewhere, like by a Walmart?(7 votes)
That's a good question.. for your great great great (and so on, I'm not about to calculate how many greats' ) grandkids. As for if there will be a volcano next to a Walmart, I guess that's up to mother nature. ;)(7 votes)
- What does asthenosphere mean?(4 votes)
There are different ways to divide the earth into layers. I'm sure you've heard of the crust, mantle, and core. Those layers are differentiated based on chemistry. Said differently, the crust, mantle, and core are distinct because they are made out of different stuff.
We can also divide the earth into layers based on physical and mechanical properties. Those layers are called the lithosphere and asthenosphere. The lithosphere is the outermost layer of earth (including the crust and upper mantle) where the rock is hard, rigid, and brittle. The asthenosphere is below that and is where the rock is hot, ductile, and slowly circulating. Circulating rock in the asthenosphere is the mechanism that drives plate tectonics.(10 votes)
Does America get earthquakes because I have lived here all my life and never felt any vibrations(5 votes)- America does get earthquakes. The most seismically active areas are: the west coast including Alaska, the areas of Tennessee, Kentucky, Illinois, Missouri, and Arkansas near the Mississippi river, the coast of South Carolina, the big island of Hawaii, and the area stretching from Salt Lake City to Yellowstone National Park. The likelihood of other parts of the country producing an earthquake strong enough for you to feel is quite low.(7 votes)
- how was all of this discovered?(4 votes)
plate tectonics theorys started in 1915 when Alfred Wegener proposed his theory of the "continental drift" Wegener proposedthat the continents plowed through "crust of ocean basins" wich would explain why the outlines of many coastlines, like south america and africa look like they could fit together like a puzzle
Keypoints:
#1) 1596 recognition that the plates moved
#2) 1858 Correlating rock type and fossils across the ocean
#3) 1872 Mapping the atlantic Mid-ocean ridge
#4) 1896 Discovery of radioactivity
#5) 1897-1911 Delineating Earths layered interior
#6) 1915 Alfred Wegener nonsense (look at the top)(3 votes)
- why are the tectonic plates named?(3 votes)
- So we can keep track of them easier(4 votes)
- how was all of this discovered(4 votes)
- plate tectonics theorys started in 1915 when Alfred Wegener proposed his theory of the "continental drift" Wegener proposedthat the continents plowed through "crust of ocean basins" wich would explain why the outlines of many coastlines, like south america and africa look like they could fit together like a puzzle
Keypoints:
#1) 1596 recognition that the plates moved
#2) 1858 Correlating rock type and fossils across the ocean
#3) 1872 Mapping the atlantic Mid-ocean ridge
#4) 1896 Discovery of radioactivity
#5) 1897-1911 Delineating Earths layered interior
#6) 1915 Alfred Wegener nonsense (look at the top)(0 votes)
what if there are more earths outside the solar system but we don't have the right technology to get there so on other earths/planets that do stuff differently then we do they may have stuff that can kill us or hurt us so we should take caution.(3 votes)
