Cultural erosion is the process through which a culture loses many of its essential components. This is frequently due to the advent of a new culture that replaces the old one. The new culture may have similarities to the original one, but because it lacks some important aspects, it is able to replace the old one. Cultural erosion can be natural or intentional. Where nature takes its course, cultures and their elements disappear when they are no longer viable options for survival. For example, when a glacier melts or volcanoes erupt, they leave behind evidence of what used to be there - rock formations, caves, etc. People then use this information to create art, architecture, tools, and more. These are all examples of natural cultural erosions. Intentional cultural erosions occur where people choose to destroy parts of their own culture for the purpose of replacing them with another. This can be done by individuals who seek out new ways of doing things or groups of people who decide that the existing culture is not viable and work together to create a new one. There are cases where entire societies have chosen cultural erosion over other options available to them. One example is the American Indian population in the West, who were given several opportunities to stop cultural erosion from happening but instead decided to continue on with it.