volcanoes

• A stratovolcano is a tall, conical volcano characterized by alternating layers of lava and ash.
• A shield volcano is a type of volcano characterized by its broad, gently sloping shape and built up by successive lava flows.
• volcanic gases occur on sheild volcanoes due the the consatnt relase of pressure. they release co2 and so2 which make acid rain. heavy co2 sinks into valleys and suffocates people, it also accumaltes in lakes
• lava flows are found at sheild volcano eruptions, they are slow moving so do not pose immediate threat to people but they do destroy properties and farm land
• pyroclastic materials include ash, lapilli and bombs. when lithified they form rock tuff, lapilli tuff and agglomerate tuff. they are in size order
• ash particles travel very far and have the ability to cause breathing problems and stop air travel. in less developed countries it land in flat roofs making them collapse it also conaminates water supplys and farmland
• pyroclastic flows are found at strato and are high density flows of hot ash, pumice, lava and volcanic gases. they travel very fast down steep volcano sides. they can be mapped on isopach maps. they melt snow and ice causing lahars
• lahars are water based flows of volcanic material (ash boulders ect) from stratovolcanoes. they travel very fast down steep slopes and valleys. they are often caused by recent heavy rainfall and melted ice
• blast/explsion damage caused by an eruption happens at high pressure releases on stratovolcanoes. it affects areas close to eruption and destroys trees and buildings
• tsunamis occur when explosive eruptions cause large amounts of land to fall into the ocean on islands. this causes displaced water to return back to land in large powerful waves
• volcanic landslides are lots of loose material displaced due to heavy rainfall and earthquakes down steep slopes