Volcanic eruptions occur when magma pressure beneath the volcano needs to be released. Magma is melted surface crust or upper mantle that begins to pool beneath the volcano. The eruption spews out the magma and dissolved gasses associated with it. Scientific advancements in the study of volcanic eruptions allow scientists to notice the signs before a volcano erupts. Residents in the vicinity of a volcano will receive advanced notice before the volcano erupts and will be moved to safety. The damage that follows an eruption effects both physical property and atmospheric conditions.
Physical Property Damage
Major volcanic eruptions throw a large amount of ash into the atmosphere. The ash slowly descends back to Earth and collects on the roofs of buildings. The threat of a roof collapse is potentially dangerous especially after heavy rain that would turn the ash into a heavy mud-like substance. Lava flowing from the volcano centre can cause a fire hazard as it comes in contact with plant life and buildings.
Ash from a volcano is actually made of fine glass particles. Ash that is breathed in by humans and animals may cause respiratory problems. Falling ash on exposed skin may cause irritation and rashes. Since the ash from an eruption can spread miles relative to wind direction, residents are encouraged to wear respirators or damp cloths over their mouths. Lava can emit toxic gases that can cause asphyxia or death.
Threats to Wildlife
Local wildlife in the vicinity of a volcano is at risk after an eruption. Faster moving animals such as birds have a higher survival rate than other local animals. The fumes from lava beds in addition to falling ash and rock may force wildlife to seek safety nearer to humans. The devastation caused to their habitats and the years it may take before they can return, may force confrontations with humans as they seek sustenance.
Lava and fallen ash will destroy local plant life and vegetation. Flowing lava causes fires as it comes in contact with trees and other dry plants. Potential mud or rock slides crush and cover plants and farmlands. After lava cools, it forms a hard black sheet of rock. The rock has to be broken through and removed before attempts are made to repair the damage caused to agriculture.
Atmospheric and Other Damage
During massive eruptions large amounts of ash, aerosol droplets and volcanic gas are injected into the stratosphere. The ash tends to fall back to Earth within a few days but gases such as sulphur dioxide can cause cooling in the atmosphere. Volcanic eruptions can also trigger potentially dangerous electrical storms, hurricanes and tsunamis, which can cause significant damage to humans and property around coastal areas.