Volcanic hazard Nature of the hazard Effect on Effect on people environment Poisonous gases Magma contains Acid rain has a huge Respiration illness dissolved gases impact on Pulmonary which are released environment. Fertile Death into atmosphere soils. Destruction of Dizziness/headaches flora/fauna Pyroclastic flows fast moving Destroys trees and Hot gases and high superheated rock wildlife. Extensive speeds make and gas damage to pyroclastic flows environment close to lethal volcano Lahars Mudflow of debris. Kills all natural things 17% of volcanic Flow composed of in its path deaths pyroclastic, rocky, If fast can kill all in its water path Can destroy homes Lava flows Generally do not Destroys all natural Least hazardous move fast, lava flows things in its path people are generally from the volcano able to avoid lava flows Tsunamis Series of waves Can destroy the Can kill thousands of caused by environment and kill people without displacement of wildlife warning water Earthquake waves Focus The place often underground where an earthquake starts – A point on the surface of the earth which is directly above the focus of Epicentre – an earthquake and where earthquake waves reach first Primary (P) waves The first seismic wave that reaches a seismograph from an – earthquake; a compression wave. Minor tremors Secondary (S) waves The second waves to arrive at a seismograph from a – earthquake; transverse wave. Minor damage Long (L) (love) (tertiary) waves An earthquake wave that travels over the surface – of the earth. Destructive waves Rayleigh waves waves which travel vertically through ground shaking it – Intraplate and plate margin Plate margin occur on plate boundaries such as convergence. About 95% of all – earthquakes occur on plate margins
Volcanic hazard Nature of the hazard Effect on environment Effect on people Poisonous gases Magma contains dissolved gases which are released into atmosphere Acid rain has a huge impact on environment. Fertile soils. Destruction of flora/fauna Respiration illness Pulmonary Death Dizziness/headaches Pyroclastic flows fast moving superheated rock and gas Destroys trees and wildlife. Extensive damage to environment close to volcano Hot gases and high speeds make pyroclastic flows lethal Lahars Mudflow of debris. Flow composed of pyroclastic, rocky, water Kills all natural things in its path 17% of volcanic deaths If fast can kill all in its path Can destroy homes Lava flows Generally do not move fast, lava flows from the volcano Destroys all natural things in its path Least hazardous people are generally able to avoid lava flows Tsunamis Series of waves caused by displacement of water Can destroy the environment and kill wildlife Can kill thousands of people without warning Earthquake waves Focus – The place often underground where an earthquake starts Epicentre – A point on the surface of the earth which is directly above the focus of an earthquake and where earthquake waves reach first Primary (P) waves – The first seismic wave that reaches a seismograph from an earthquake; a compression wave. Minor tremors Secondary (S) waves – The second waves to arrive at a seismograph from a earthquake; transverse wave. Minor damage Long (L) (love) (tertiary) waves – An earthquake wave that travels over the surface of the earth. Destructive waves Rayleigh waves – waves which travel vertically through ground shaking it Intraplate and plate margin Plate margin – occur on plate boundaries such as convergence. About 95% of all earthquakes occur on plate margins