It's an elastic wave in the earth produced by an earthquake or other means. hope it helps!
The levels of greenhouse gases in the atmosphere have been increasing due to the widespread burning of fossil fuels by the growing human populations.
18 States - North Carolina, Ohio, Alabama, Connecticut, New York, Georgia, Kentucky, Maine, Maryland, Massachusetts, Tennessee, New Jersey, New Hampshire, Pennsylvania, South Carolina, Vermont, West Virginia, and Virginia. The Appalachain mountains are found in these states, so it is only logical sediments could be found inside of them.