Pyroclastic flow

Geologists are leading the way to discover ways to help save future lives. They reexamine the facts and geological clues that Vesuvius leaves them on regular bases. There is evidence of the volcano producing dense lava flows capable of obliterating everything in its path. The pyroclastic flow is probably its most dangerous weapon as they can generate heat up to nine hundred degrees. The pattern of the behavior of Vesuvius seems to be a period of quiet, then large explosion followed by the same.…

Most of lava flows are blocky, and pyroxene olivine basalt. (4) 3000 – 2000 years ago The activity became explosive and major pyroclastic falls were erupted intermittently mainly from the summit crater. Deposits of pyroclastic flows were found on the southern and western slopes of the volcano. (5) 2000 years ago to 1707 AD Strombolian activity occurred at the NW-SE trending flank craters, formed many scoria cones. Most of the lava flows are “aa” lava of pyroxene olivine basalt…

the Younger. At midday an explosion flung up a column where ash and pumice began to fall, covering the area. Rescues and escapes happened at this time. Sometime at night pyroclastic flows in the nearby surrounding area of the volcano began. Lights were seen on the peak interpreted as fires. People fled for their lives. The flows were quick moving, thick and very hot, bashing down most structures in their path, cremating or suffocating all inhabitants lingering and changing the landscape,…

composition was in its most recent eruption. Mt. St. Helens most recently erupted on May 18, 1980. An earthquake right under the mountain caused an enormous landslide/avalanche going close to 150 mph. A huge hazard from this event was the pyroclastic flows, which were allowed to escape because the landslide reduced the pressure keeping it in there. Extremely hot ash, poisonous gases, and lava fragments flowed down the mountain at speeds quicker than 200 mph. Mt. St…

Hood’s history is less violent or explosive than Mount St. Helen’s to the North. Characterized by four distinct volcanic behaviors, Mount Hood experiences lava flows traveling short distances in most cases less than six to eight miles from the source. These flows build up flanks one sector of the volcano at a time. At times the lava doesn’t flow but instead builds domes that can reach hundreds of feet in height. Repeatedly collapsing lava domes are responsible for…

Composite volcanoes, also known as stratovolcanoes, are “symmetrical cones of large dimension built of alternating layers of lava flows, volcanic ash, cinders, blocks and bombs and may rise as much as 8,000 feet above their bases.” (Volcanoes General FAQ’s). They are very steep and can be 10-20 miles wide. Composite volcanoes have many vents which pyroclastic flows escape from. These volcanoes usually have explosive eruptions due to their thick, highly viscous lava that moves at high speeds,…

There are over 1500 active volcanoes is the world. Sometimes we do not know when a volcano is going to erupt, but most of the times the volcano itself gives early signs of eruption. Some of those signs are small earthquakes beneath the volcano, swelling or increase heat and gases coming out of the volcano. A volcano is a mountain or hill, having a crater or vent where lava, rock fragments, hot vapor, and gases are being released from the earth's crust. One of the many active volcanos in the…

Another earthquake struck on May 18, which caused a debris avalanche that wiped out the entire north face of the mountain. In fact it was the largest debris avalanche in history. Following the avalanche, Mount St. Helens eventually erupted and its pyroclastic flow leveled the surrounding forest and any buildings in the area. Over 230 square miles (500 sq. km.) was affected by the eruption. The heat from Mount St. Helens’ eruption and the force of the avalanche caused the ice and snow on the…

Mount Tahoma is the highest mountain of the Cascade Range of the Pacific Northwest, and the highest mountain in the state of Washington. It is a large active stratovolcano located 54 miles (87 km) south-southeast of Seattle .It is the most topographically prominent mountain in the contiguous United States and the Cascade Volcanic Arc, with a summit elevation of 14,411 ft. The most recent recorded volcanic eruption was between 1820 and 1854, but many eyewitnesses reported eruptive activity in…

explode and may burst out the sides of the cone in addition to the summit crater. Mt Vesuvius is a Stratovolcano also known as a composite volcano. Stratovolcanoes are also called composite as they are made of built up of alternating layers of lava flow, ash and blocks of unmelted stone. Stratovolcanoes form above the subduction zone at plate boundaries. They are known for erupting with great violence. They are larger than cinder cones nd result from a conduit system; vents lead from magma…