God bless America !

Welcome to our crater !


Worldwide almost 800 volcanoes are active ** Molten lava can flow as fast as 35 MPH, outrunning most animals ** There are 10 times as many submarine volcanoes as on land ** Ash and lava dust are rich in plant nutrients and make excellent fertilizer ** Liquid lava is 10 times hotter than fresh brewed coffee, 800'C to 1200'C (1500-2000'F) ** Manila, Philippines is just a short drive between 13 active volcanoes ** Incredible as it may seem, the most abundant volcanic gas is Carbon Dioxide ** Even when buried deep underground, all magma has contains some WATER ** Pumice is used as fine abrasives in hand soaps and even some toothpastes ** Lava has an odd aroma, (metallic sulfurous) rubbing two rocks together until friction warms them up and smell quickly **


Far below the surface, and area of superheated rock begins to move upward. Hot enough to be molten yet due to enormous pressure, it remains a solid. The mass finds its way to cooler rocks in the area so very slowly because of the fact that it is still solid. As it creeps toward the surface, pressure and temperature changes lower and the mass melts becoming magma. It is now a liquid trapped inside of solid rock. Being more than just melted rock, it now contains various gases. These gases become superheated to 1,000's of degrees able to become incandescent. Most of it is steam, but sulfur and carbon dioxide are also present. Only now since the rock is molten, the gases attempt escape creating tremendous pressures in the underground magma chamber. Temperatures are now around 2000 C / 3000 F. Then due to this tremendous pressure, weak spots in the crust rupture or old solid lava plugs in the volcano's throat explode causing an eruption. The magma is now called lava (above ground) and begins cooling, flows down the mountain's side and may eventually cool enough to form plugs in the vent until the next eruption.


Each volcano has it own characteristics of growth due to the chemistry of the magma and how it reaches the surface. This determines how steep or tall the mountain may be and if it will erupt quietly or violently. Andesitic volcanoes usually are taller than basaltic volcanoes due to the fact that andesitic magma is less dense. Summits can reach as high as 4 miles! A large volcano would then indicate that the magma keeps taking the same route to the surface. (Andesitic volcano) If the passage is blocked by solidified rock, the pressure builds until sufficient force causes the volcano to erupt explosively "clear it's throat". Hawaii's (Basaltic volcanoes) on the other hand, have so much magma coming up that this cannot happen because the basaltic magma is "fluid". Kilauea is a "safe" volcano to watch since the eruptions are mild and non-explosive.

Links to other sites on the Web


Enjoy learning about volcanoes? Please click here for "our" Recommended books ! So far, we have had visitors to date. Thanks for stopping by !

01/2005 volcanologist@reocities.com

Sign Guestbook -- View Guestbook

This page hosted by GeoCities Get your own Free Magmatic Smile Here