The Observatory Of USGS in Volcanoes

II THE OBSERVATORY OF USGS IN VOLCANO Volcanoes are built by the accumulation of their own eruptive products-lava, bombs (crusted over ash flows, and tephra (airborne ash and dustl. A volcano is most commonly a conical hill or mountain built around a vent that connects with reservoirs of molten rock below the surface of the Earth. ASH CLOUD A cloud of ash formed by volcanic explosions. CRATER Mouth of a volcano. Surrounds a volcanic vent. Volcanoes erupt because of density & pressure. The lower density of the magma relative to the surrounding rocks causes it to rise Clike alr bubbles In syrupl. It will rise to the surlace or to a depth that is determined by the density of the magma and the weight of the rocks above It. ASH Fragments of lava or rock smaller than 2 mm in size that are blasted into the air by volcanic explosions. The "velcano" has Its origin DID YOU KNOW name from the name of Vulcan. In Roman mythology, Vulcan is a ged of fire. LAVA Centuries ago, the people living in the island of Vulcano in the Mediterranean Sea of believed that Vulcano was the chimney of the torge of Vulcan-the blacksmith of the Roman gods. They thought that the hot lava fragments and Molten rock that erupts from a volcano that solidifies as it cools. clouds of dust erupting from Vulcano came from Vulcan's forge as he beat out thunderbolts for Jupiter, king of the gods, and weapons for Mars, the god of war. FLANK MAGMA 6 REMEMBER Molten гock Earth's surface. Velcanoes are meuntains but they are very different from other mountalns. beneath The side of a volcano.