Iceland sits on a divergent boundary between the North American Plate and the Eurasian Plate that has formed the Atlantic Ocean. The island also sits over a hot spot. The frequent volcanic eruptions are a result of hot spot activity and separating plates.
ammunition image by Chris from Fotolia.com. Artillery shells generally come with a lot of different markings on them. These markings have several different purposes, but the main purpose for the labels is safety. The markings identify data that is crucial to both the government and the person using the artillery shell. A casual observer, or ammunition collector, might enjoy knowing a little bit about the markings and what they mean as well.
Caliber is a term used to indicate the diameter of a bullet in hundredths of an inch. A bullet that is 30 hundredths of an inch (.30) in diameter is called a 30 caliber bullet. The term caliber is of English origin and is used by ammunition and firearm manufacturers in the United States.