Answer:
Density is one of the most factors that play a key role in plate tectonic activities. Some of the ways in which density is important in the field of plate tectonics are as follows-
- The convergent plate boundaries are responsible for the creation of a subduction zone, where the high-density lithospheric plate subducts below the less dense one. It is because the heavier plate is comprised of heavy minerals thereby forming heavier rocks as a result of which its density increases. Due to these differences in density, there occurs a subduction zone.
- The divergent plate boundary forms where two plates move away from one another. This type of plate motion is responsible for the eruption of magma on the seafloor. As the plates diverge, the lithosphere becomes eventually thin, and with more progressive spreading, the magma comes out to the seafloor. This is because the hot magma is less dense, and forms convection cells as they rise upward. This is how the density helps in the upwelling of magma at the mid-oceanic ridge in a divergent plate boundary.
- When there collide two plates of equal densities, then it gives rise to the formation of huge mountains, because neither of them is heavy to get sink. So it uplifts the crust, forming a sandwich-type pattern.
Geologic maps are most recognized by their contour lines which represent different elevations. The correct option among all the options that are given in the question is the last or the fourth option. Geologic maps are important for all geologists around the world. I hope the answer comes to your help.
Answer:
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Explanation:
Answer:
Human activity - Produces greenhouse gasses.
Greenhouse gasses - Cause atmosphere to trap more heat.
Sun's output - Can vary.
Ice age - Peaked 20,000 years ago.
Explanation:
Human activity includes the usage of fossil fuels on a very large scale, and by using them we release huge amounts of greenhouse gasses into the atmosphere.
The greenhouse gasses have the ability to trap the heat that is reflected from the surface of the planet, thus keeping more of it in the atmosphere and causing global temperature rise.
The sun is technically a star, thus an object that produces energy and light, and like every star, it has variations in its activity in accordance with the processes going on on it.
There have been numerous ice ages through the geological past, and the last one of them ended only around 10,000 years ago, with its peak being just 20,000 years ago.
