Discuss the view that the impacts of volcanic hazards depends primarily on human factors
Discuss the view that the impacts of volcanic hazards depends primarily on human factors
There are a wide range of volcanic hazards associated with volcanoes, there are the obvious primary hazards; lava flows, pyroclastic activity and poisonous gas emissions. There are also secondary impacts that result from the eruption such as lahars (sometimes called mudflows), avalanches and debris flows. These are all caused by natural causes but the effects from these can be enhanced or worsened by human factors. There are many different ways that volcanoes can impact the people and environment around it. The hazards from volcanoes can cause death to surrounding populations and also destroy important buildings and the infrastructure nearby. The environment can also be affected due to the gas released from volcanoes and also destruction of environment from pyroclastic flows or lava flows. These can be compounded and the impacts will vary depending on a mixture of human and physical factors.
In 1980 in Washington State after 123 years of hibernation Mt St Helens erupted. This volcanic eruption produced many different hazards including a huge landslide, one of the largest ash clouds in recent years and a pyroclastic flow that destroyed huge areas surrounding the volcano. The most devastating of these to humans was the ash cloud. This drifted hundreds of miles and ash fell on 11 states. It also destroyed miles of highway and 20 bridges resulting in damage worth more than $1 billion. This impact as not made worse by humans as no one could predict that the ash cloud would travel so far and affect such a large area. However this problem could have been limited if humans hadn’t built further from the volcano as nearby areas were more affected by the ash. The environment was also affected by lightening created by ash swirling in the atmosphere. This lightening caused various forest fires destroying thousands of acres of forest. This was a purely physical factor as the wind caused the ash to move and travel in this way. Therefore this damage was not due to human factors. There was also the landslide that occurred on the north side of the volcano. This was one of the largest landslides in history and covered 24 square miles. This destroyed hundreds of homes and miles highways but also destroyed large areas of woodland and forest. This had purely physical causes but many of the impacts of this were due to human factors such as the building of large highways, highway 5 is less tan 30km away from the summit of Mt St Helens. This meant that the impacts of the volcanic hazards were made much worse and this applies to most volcanic eruptions.