There are generally two types of hay bales. With quite different weights. The most common ones that people buy at feed stores or the farmer, and can be moved by one person, are the type you may have bucked into the barn for your uncle who had a farm when you were a teenager. They are around 3-4 feet long by 24x18 inches square.
How Earthquakes Happen. An aerial view of the San Andreas fault in the Carrizo Plain, Central California. An earthquake is the vibration, sometimes violent, of the Earth's surface that follows a release of energy in the Earth's crust. This energy can be generated by a sudden dislocation of segments of the crust, by a volcanic eruption, or event by manmade explosions.
1 Alaska, California and Hawaii have the most earthquakes in the U.S. 2  Other western states, like Nevada, Idaho, Washington and Oregon are prone to earthquakes or can be damaged by earthquakes that happen in Alaska and California.3  Alaska has more earthquakes than any other U.S. state. When they move again, they cause an earthquake. 2  Scientists who study earthquakes are called seismologists. 3  Seismologists can tell how serious an earthquake is by a machine called a seismogram, which rates the intensity of the quakeâs shaking. 4  Scientists can use special instruments to record an earthquakeâs strength.