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.
Minor earthquakes happen in the Bay Area of Northern California often (there are thousands a year in fact). But the two most major earthquakes to hit the area happened in 1906 â¦ and 1989. 1906 - The San Francisco earthquake was a magnitude 7.9 and was one of the worst natural disasters in American history. Fires broke out in the city, 3,000 people were killed and 80 percent of the city destroyed. 1989 - The Loma Prieta earthquake measured 6.9 on the Richter scale and killed 63 people.