Volcanoes

    Volcanoes are formed where? Between the iron core in the earth there is a solid rock called the mantle. When rock melts from the mantle it moves to the surface. It releases gases that have been pressured up. This is when volcanoes erupt.
    What is the difference between magma and lava? The molten rock inside the earth is called magma. Magma is formed inside the earth and is extremely hot. Lava is the one that you see coming from the volcano. Lava is the stuff that is on the outside of the volcano. Lava is formed form magma after it is on the outside of the earth's crust.
    There are many different lava types. There are also different kinds of magma. The different kinds are called compositions. The different rocks melt at different temperatures. Since the rocks that are melted by the magma the different kinds of minerals affect the magma results.
    Mount St. Helens was first observed by George Vancouver in May of 1792. He was calculating the inlets of the Puget sound. He didn't name the mountain until October of that year. He named it when his ship sailed across the mouth of the Columbia River.
    About three or four years later Mount St. Helens erupted. Lots of people were reporting what they had heard and what they had seen. Some people had reports about the ash fall. Later people studied the eruption and they said that Mount St. Helens eruption occurred in 1800.
    Mt. Vesuvius had the plinian stage of a volcanic eruption. It was named after a guy who helped people fleeing from the volcano. His name was Pliny. Ash and rock and stuff go high into the air at the plinian stage of a volcanic eruption. There is no lava flow at this time. It may last hours or days.
    Mt. Vesuvius is a composite volcano. Composite types have only two different eruptions. Ash and Cinders are produced for one. The other produces lava. In Vesuvius both haven't been seen happening together.