Epicenter October 30, 2009

The epicenter or epicentre is the point on the Earth‘s surface that is directly above the hypocenter or focus, the point where an earthquake or underground explosion originates. The word derives from the Neolatin noun epicentrum^[1] from the Greek adjective ἐπίκεντρος (epikentros) “central”, from ἐπί (epi) “on, upon, at” and κέντρον(kentron) “centre“.

In the case of earthquakes, the epicenter is directly above the point where the fault begins to rupture, and in most cases, it is the area of greatest damage. However, in larger events, the length of the fault rupture is much longer, and damage can be spread across the rupture zone. For example, in the magnitude 7.9, 2002 Denali earthquake in Alaska, the epicenter was at the western end of the rupture, but the greatest damage occurred about 330 km away at the eastern end of the rupture zone

Ring of Fire October 30, 2009

Pacific Ring of Fire

From Wikipedia, the free encyclopedia

The Pacific Ring of Fire

The Pacific Ring of Fire (or sometimes just the Ring of fire) is an area where large numbers of earthquakes and volcanic eruptions occur in the basin of thePacific Ocean. In a 40,000 km horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and/or plate movements. The Ring of Fire has 452 volcanoes and is home to over 75% of the world’s active and dormant volcanoes. It is sometimes called the circum-Pacific belt or the circum-Pacific seismic belt.