BOOM !!!

 (FACTS ABOUT VOLCANOES)

The term “volcano” is from the Latin Volcanus or Vulcan, the Roman god of fire. The Romans first used the term to describe Mt. Etna, a volcanic mountain they believed was the forge of Vulcan.

Mt. Pinatubo is the world’s second biggest volcanic eruption in the 20th century. It erupted last June 1991. The worlds’ biggest is the Novarupta in Alaska Peninsula.

 Hundreds of years ago, the Aztecs of Mexico and the people of Nicaragua believed gods lived in lava lakes. They would sacrifice beautiful young girls to these powerful gods.

Many scientists believe that all the water on the earth was originally vented into the atmosphere by volcanoes.

A species of bird called a maleo uses heat given out by warm volcanic sand to incubate its large eggs. When the chicks hatch, they burrow their way to the surface of the sand.

The most dangerous volcano today is Popocatépetl, nicknamed El Popo, which is just 33 miles from Mexico City. El Popo is still active, sending thousands of tons of gas and ash into the air each year.

 Volcanologists use a special electric thermometer called a “thermocouple” to take a volcano’s temperature. Lava is so hot that a glass thermometer would melt.

 “Lava” derives from the Latin lavara, meaning “to wash,” and is magma that has erupted at the surface. Lava can flow up to speeds of 62 miles per hour.

The material ejected from a volcano is called “pyroclastic flow” from the Greek pyro (fire) and I (broken). It includes small fragments of rock, frothy pumice, and large boulders. Pyroclastic flow can reach temperatures of 212° F and can rocket down the side of a mountain at 155 m.p.h.

 Volcanoes form through subduction (when two tectonic plates smash against each other), mid-oceanic rift (when two plates drift apart), or in a hot spot (a weak spot in one of Earth’s plates).

 The three main types of volcano shapes are shield, cinder cone, and stratovolcano. Stratovolcanoes, also called composite volcanoes, are the most common type of volcanoes and often have symmetrical steep slopes. Classic examples include Mount Rainer in Washington State and Mount Fuji in Japan.

When the top of a volcano top collapses, it forms a caldera, which is Spanish for “kettle.” The largest caldera is the La Garita Caldera in Colorado which was formed 26-28 million years ago and was one of the largest eruptions—if not the largest—on Earth.

 About 20% of all volcanoes are under water.

Some volcanic islands such as Iceland and Hawaii have black beaches. Their sand is made from basalt, an igneous rock formed when lava cools and has been broken down into sand particles.

In some volcanic areas such as Iceland, heat energy from magma can be used to warm water and run power plants. This type of energy is called geothermal (earth heat) energy.

When Paricutin in Mexico erupted from 1943-1952, no one was killed by ash, rocks, lava, gases, or mud flows, though three people died from being struck by volcanic lightening. Though there were periods of violent explosions, Paricutin mainly dishcharged quiet flows of lava during its continous nine year eruption.

Iceland is made up almost entirely of volcanic rocks like those found on the ocean floor. It gradually built up above sea level through intense and prolonged eruptions.

The largest volcano found in the solar system is Olympus Mons on Mars, though it is now extinct.

While no other planet besides Earth shows active volcanoes, Io, one of Jupiter’s moons, shows volcanoes that are erupting.

Although volcanoes are all made from hot magma reaching the surface of the Earth and erupting, there are different kinds. Shield volcanoes have lava flows with low viscosity that flow dozens of kilometers; this makes them very wide with smoothly sloping flanks. Stratovolcanoes are made up of different kinds of lava, and eruptions of ash and rock and grow to enormous heights. Cinder cone volcanoes are usually smaller, and come from short-lived eruptions that only make a cone about 400 meters high.

About 30 km beneath your feet is the Earth's mantle. It's a region of superhot rock that extends down to the Earth's core. This region is so hot that molten rock can squeeze out and form giant bubbles of liquid rock called magma chambers. This magma is lighter than the surrounding rock, so it rises up, finding cracks and weakness in the Earth's crust. When it finally reaches the surface, it erupts out of the ground as lava, ash, volcanic gasses and rock. It's called magma when it's under the ground, and lava when it erupts onto the surface.

Volcanoes can be active, dormant or extinct. An active volcano is one that has had an eruption in historical times (in the last few thousand years). A dormant volcano is one that has erupted in historical times and has the potential to erupt again, it just hasn't erupted recently. An extinct volcano is one that scientists think probably won't erupt again.

Volcanoes can grow quickly. Although some volcanoes can take thousands of years to form, others can grow overnight. For example, the cinder cone volcano Paricutin appeared in a Mexican cornfield on February 20, 1943. Within a week it was 5 stories tall, and by the end of a year it had grown to more than 336 meters tall. It ended its grown in 1952, at a height of 424 meters. By geology standards, that's pretty quick.

There are 20 volcanoes erupting right now. Somewhere, around the world, there are 20 active volcanoes erupting as you're reading this. Between 50-70 volcanoes erupted last year, and 160 went off in the last decade. Geologists estimate that 1,300 erupted in the last 10,000 years. Three quarters of all eruptions happen underneath the ocean, and most are actively erupting and no geologist knows about it at all. One of the reasons is that volcanoes occur at the mid ocean ridges, where the ocean's plates are spreading apart. If you add the underwater volcanoes, you get an estimate that there are a total of about 6,000 volcanoes that have erupted in the last 10,000 years.

The tallest volcano in the Solar System isn't on Earth. That's right, the tallest volcano in the Solar System isn't on Earth at all, but on Mars. Olympus Mons, on Mars, is a giant shield volcano that rises to an elevation of 27 km, and it measures 550 km across. Scientists think that Olympus Mons was able to get so large because there aren't any plate tectonics on Mars. A single hotspot was able to bubble away for billions of years, building the volcano up bigger and bigger.