Answer: e. The photic zone is where most primary production occurs.
Explanation:
The photic zone can be define as the sunlight or photosynthetic zone. It is the uppermost layer of the water body like lake, ocean, pond or others. This zone receives the maximum sunlight in the entire water body. Thus this facilitates the growth of large number of plants and other autotrophs like diatoms. This is called as the zone of primary productivity because in water the sunlight and dissolved atmospheric carbon dioxide are available for conducting the process of photosynthesis.
South Africa is the most stable.
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.
