Answer:
Option (4)
Explanation:
Seismic P and S waves are generated during an earthquake that has the potential to propagate through the interior of the earth. P waves are also known as the primary waves and they move in a compression and extension way in their direction of propagation. S waves are shear waves. This P waves travel faster than the S waves and can travel in both solid as well as in liquid. Whereas the S wave can travel only through solids. They get absorbed when they reach the core-mantle boundary. These two waves are helpful in determining the epicenter of an earthquake by recording the arrival of these waves.
Hence, the correct answer is option (4).
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 Consulted for historical reference: Historical Atlas of the United States, National Geographic Society, 1988.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:
Organic and traditional farming are fundamentally different in that conventional farming depends on chemical intervention to combat pests and weeds and provide plant nutrition. Organic farming, on the other hand, produces balanced, abundant food by relying on natural concepts such as biodiversity and composting.
