You couldn't sit down and watch it happen. Or can you? You could watch it happen if you watched an earthquake. They Really Float? These plates make up the top layer of the Earth called the lithosphere. Directly under that layer is the asthenosphere. It's a flowing area of molten rock.
There is constant heat and radiation given off from the center of the Earth. That energy is what constantly heats the rocks and melts them.
The tectonic plates are floating on top of the molten rock and moving around the planet. Think of it as ice floating at the top of your soda. When the continents and plates move it's called continental drift. Think of the molten rock in the asthenosphere, not as rock, but as a liquid. It has currents and it flows just like any other liquid. When the floating plates spread apart, it's called a spreading center.
The New Zealand team suggests the jelly rock gains its consistency from a higher concentration of water or magma than is present in the lithosphere above it. But it would not have to be too high. While the lithosphere contains 0.
The finding of the jelly channel might also help resolve a year debate about whether the plates move as a result of being pushed or pulled. An early idea was that magma being extruded from the mid-oceanic ridges was pushing the plates apart. Another pushing force might come from slowly creeping convection currents beneath the plates that act like rollers beneath a conveyer belt.
On the other hand the major force might be a pulling one. As one edge of an oceanic plate dives back into the mantle beneath — as the Pacific one is doing — it pulls the rest of the slab after it.
The finding of the jelly layer makes the pushing and rolling mechanisms less likely, says Gleadow. On the other hand, the jelly layer adds weight to the idea that gravity is the driving force pulling the plates along. As one edge of the plate is being dragged under, the low friction jelly layer means the rest of the plate just slithers after it like a ski on snow. The next question is how this channel was formed and if it is present all over the world, says Moresi.
Evidence from previous studies hints at a similar structure beneath the coast of Norway and another off Costa Rica. It is likely getting some additional impetus from the adjacent African plate. The iceberg model therefore has some validity, but is not the whole story.
Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Do tectonic plates "float" over the mantle and "collide" like icebergs? Ask Question. Asked 2 years ago. Active 1 year, 11 months ago. Viewed times. Improve this question. Swike Swike 1 1 silver badge 6 6 bronze badges. That doesn't change your small energy calculation all that much, but worth noting.
Energy is very low, due to the slow velocity squared but momentum is still quite high only one multiple of the slow velocity. Similarly the ability to do work energy over time is low but the force is high.
If you trace the movement back to the circulating convection inside the mantle, not the plate riding on the mantle, you would probably get better numbers but still low energy, high momentum. It's important to differentiate between standard and 'food' calories since they differ by a factor of and it's usually done by capitalising the name of 'food-calorie'. Add a comment. Active Oldest Votes. Improve this answer.
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