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Middle school Earth and space science - NGSS
Course: Middle school Earth and space science - NGSS > Unit 4
Lesson 3: Plate tectonicsPlate tectonics and the ocean floor
Review your understanding of plate tectonics and the ocean floor in this free article aligned to NGSS standards.
Key points:
- There are two types of tectonic plates: oceanic and continental. Oceanic plates make up the ocean floor. Continental plates make up the continents.
- Both oceanic and continental plates are topped by crust. On average, oceanic crust is denser than continental crust.
- A trench forms when an oceanic plate collides with another plate at a convergent boundary. When this happens, the denser plate is subducted, or pushed under, the less dense plate.
- A mid-ocean ridge forms when two oceanic plates move apart at a divergent boundary.
- New oceanic crust is created at mid-ocean ridges. As it ages, it moves away from the ridge and becomes cooler and denser. Eventually, the crust reaches a trench and is destroyed.
Want to join the conversation?
- why do waves in the ocean happen(5 votes)
- The common, constant waves that you see in the ocean are caused by wind. Storm surges, underwater earthquakes, and underwater landslides also generate waves, but those are relatively rare events.(11 votes)
- Will the people go and look in the trench for other animals that haven't been seen before.(5 votes)
- yes they will so we don't face them in the near future(4 votes)
- can people go in a trench, find megalodon DNA, and bring it back?(5 votes)
- In simple words, yes.(2 votes)
- Why do tectonic plates crash into one another(3 votes)
- Why this that(3 votes)
- How are tectonic plates formed(3 votes)
- Is it safe for people to just go in the Mariana Trench ?
Like will we be safe and be able to get out of it safely ?
Is there any restriction for it ?(2 votes)- Look it up on Google, Safari, Microsoft Edge, etc.(2 votes)
- Can people go can see the plates move.(1 vote)
- No, they move too slowly, and are underground, or rather, are the ground(3 votes)
- How hot does the sun have to get to boil the ocean?(1 vote)
- we would have to be really close to venus to make our water boil(3 votes)
- How do scientists believe that the world would fit together and make a giant country/puzzle basically(1 vote)
- Because, proof shows that all of the contents would fit together!(3 votes)