Analyse the Factors That Cause Differences in the Hazards Posed by Volcanoes Around the World

Analyse the factors that cause differences in the hazards posed by volcanoes around the world (40 marks)

All volcanoes can cause many hazards to occour, both during and after their eruptions, such as pyroclastic flows, ash clouds and landslides. However, the severity of these hazards varies greatly depending upon physical, economical and social factors.

One physical factor which can have a major impact upon the hazards posed by volcanoes, is the type of lava associated with them. If the volcano has highly acidic lava (Andesitic or Rhyolitic), then it will be much cooler and more viscious (800 degrees), meaning it will most likely solidify while travelling down the sides of the volcano, resulting in little/no damage caused by the lava flow itself. However if the lava type is Basaltic, then it will be much hotter and less viscous (1200 degrees), meaning it will take longer to cool and will be able to flow great distances resulting in the increased likelihood of damage to property and wildlife in the surrounding areas. For example, when Mount Nyiragongo last erupted in 2011, its Basaltic lava reached speeds of up to 60mph causing major destruction to houses, however this hazard would be much smaller if the volcano's lava type was more acidic. Also, the lava type of a volcano can determine the type of eruption it will have. A volcano with Basaltic lava will typically eject lava and steam, meaning there will be a much smaller pyroclastic flow due to the lack of debris caused in the eruption, however a volcano with andesitic lava typically ejects ash, rock, gases, steam and lava meaning it's pyroclastic flow will be much more severe, therefore the potential hazard caused will be increased.

Another factor that can influence the hazards caused by a volcanic eruption is the population density of the country it is situated in. If the population density is extremely high, then there is a greater chance of fatalities