What human activities lead to soil erosion?

Liquefaction was one reason the kobe wharfs were destroyed and other areas nearby. what is liquefaction? a. it is when conditions in the soil send the seismic wave out to the mountains and bounce back b. it is when conditions in the soil change to vigorous p-wave shaking when the surface waves pass by c. it referes to the fact that when an earthquake occurs wet and soft soil will vibrate more vigorously then solid rocky soil strangely in kobe some streets had very bad damage but the next street over had far less damage. what caused this? a. the waves passed through the city hit the mountains and returned back to the city. at some points the incoming and outgoing waves amplified their strength b. the mountains also had a quake and sent waves into the city c. waves hit the moutains and took longer to return

The diagram below represents a marine food web and a process that can harm the human population. each circle represents an organism and the smaller dots inside them represent a toxic substance. what is being represented and how does it harm the population? the diagram represents biological half-life, in which toxins build up in organisms higher up on the food chain, and this can negatively impact humans who consume the organisms and the toxic substance. the diagram represents biomagnification, in which toxins build up in organisms higher up on the food chain, and this can negatively impact humans who consume the organisms and the toxic substance. the diagram represents the process by which different organisms prey upon each other; this can impact the human population by reducing the number of organisms that do not contain the toxin. the diagram represents the way that toxins are metabolized by living organisms, with those at greater trophic levels able to metabolize more efficiently than those at lower levels. this means that those at higher tropic levels are safer for humans to consume compared to the organisms at lower trophic levels.

In what for do plants utilize nitrogen? why do they need nitrogen?