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.
A) United States
He was 28th president of USA
Answer: The answer is A: get permission from the U.S. government to enter.
Explanation: I don't know why, I think it has something too do with the government being paranoid of terrorist attacks.
Answer:
c) known to have experienced numerous polarity reversals, as seen by the remnant magnetization of iron-rich minerals in rocks.
Explanation:
Paleomagnetism is the study of the Earth's magnetic fields in sediment (rocks or other archaeological material). This can be used to estimate the age of sediment (or in this case, the seafloor) because it is known that the magnetic field of Earth experienced numerous polarity reversals. This allows is to employ such sequences as a chronologic tool. Paleomagnetism has also been a significant tool in the subjects of continental drift and plate tectonics.
