Answer:
The mean center of population is the place where an imaginary, flat, weightless, and rigid map of the United States would balance perfectly if all residents were of equal weight. Historically, the movement of the center of population has reflected the expansion of the country, the settling of the frontier, waves of immigration and migration west and south. Since 1790, the center of population has moved steadily westward, angling to the southwest in recent decades.
SOURCE: Geography Division, "Centers of Population Computation for the United States 1950-2010," issued March 2011, available at www.census.gov/geo/www/2010census/centerpop2010/COP2010_documentation.pdf. Consulted for historical reference: Historical Atlas of the United States, National Geographic Society, 1988.
NOTE: The Proclamation Line of 1763 limited British settlement to areas east of the Appalachian Mountains. Alaska and Hawaii were not included in the calculation of the mean center of population until 1950. Puerto Rico was not included in any decade. For more information on the mean center of population, an animated map, and other resources. This graphic is adapted from the "Census Atlas of the United States" published by the Census Bureau in 2007.
Explanation:
Answer:
The crust size remains constant because the older crust is melted at subduction zones.
Explanation:
The crust is constnatly created on Earth, but the crust is constantly getting destroyed as well. This situation leads to the total size of the crust being roughly at the same level, or rather constant, as one side a new one emerges, while at the same time, on the other side it gets destroyed.
The vast majority of the new crust is formed where there are divergent plate boundaries. Here, a gap opens up between the plates that move away and magma is constantly rising to the surface and creates new crust. When it comes to the destruction of crust, it occurs at subduction zones. Here, one plate moves below another plate, and as it does it reaches the upper mantle where it gets melted and recycled because of the high temperatures and pressure.
The Mediterránea sea is the answer
This should be under mathematics not geography.
