With reference to two volcanic events that you have studied from contrasting areas of the world, compare the nature of the volcanic hazard and its impact.
With reference to two volcanic events that you have studied from contrasting areas of the world, compare the nature of the volcanic hazard and its impact.
Mount St Helens erupted on the 18th May 1980 at 9am and is an active strata volcano Washington State USA, a MEDC. Where as on 18th July 1995, during the daytime, Montserrat, a LEDC during the day, Montserrat's Soufrière Hills composite volcano of a height 1050m, meaning sulphur hills, dormant for centuries, erupted and produced a phreatic eruption. The volcano is a strata volcano also. Mount St. Helens is a composite volcano which lies near to a destructive plate boundary where the small Juan de Fuca Plate is being subducted underneath the North American Plate where as the eruption in Montserrat was due to subduction, but the Atlantic tectonic plate subducts beneath the Caribbean plate.
Mt St Helens went on to erupt in a Plinean style, spewing out ash and produce pyroclastic flows -currents of hot gas and ash. The magma burst out causing large pyroclastic flow flattening vegetation and buildings for over 230 square miles (600 km²). There were volcanic Mudflows- Due to collapse of northern side mixed with ice, snow and water. These flowed many miles down the Toutle and Cowlitz Rivers. This led to 3 million m³ of material being transported 7 miles (27 km) south into Columbia River by mudflows. The actual eruption itself lasted for roughly 9 hours, of which is released much gas, such as SiO2 and also over 4km³ of rock, gas and steam exploded from the northern side of the mountain. Ash which was thrown vertically into the atmosphere was found over 15km above ground level. The blast crater averaged about 8 miles (13 km) in radius. The Montserrat eruption was of a very similar nature and erupted into in a Plinean style. Huge pyroclastic flows were produced and also masses of ash reached the surrounding areas and left the capital, Portsmouth covered in meters of ash. The lava was spewed out at 600 mph.
There
Mount St Helens erupted on the 18th May 1980 at 9am and is an active strata volcano Washington State USA, a MEDC. Where as on 18th July 1995, during the daytime, Montserrat, a LEDC during the day, Montserrat's Soufrière Hills composite volcano of a height 1050m, meaning sulphur hills, dormant for centuries, erupted and produced a phreatic eruption. The volcano is a strata volcano also. Mount St. Helens is a composite volcano which lies near to a destructive plate boundary where the small Juan de Fuca Plate is being subducted underneath the North American Plate where as the eruption in Montserrat was due to subduction, but the Atlantic tectonic plate subducts beneath the Caribbean plate.
Mt St Helens went on to erupt in a Plinean style, spewing out ash and produce pyroclastic flows -currents of hot gas and ash. The magma burst out causing large pyroclastic flow flattening vegetation and buildings for over 230 square miles (600 km²). There were volcanic Mudflows- Due to collapse of northern side mixed with ice, snow and water. These flowed many miles down the Toutle and Cowlitz Rivers. This led to 3 million m³ of material being transported 7 miles (27 km) south into Columbia River by mudflows. The actual eruption itself lasted for roughly 9 hours, of which is released much gas, such as SiO2 and also over 4km³ of rock, gas and steam exploded from the northern side of the mountain. Ash which was thrown vertically into the atmosphere was found over 15km above ground level. The blast crater averaged about 8 miles (13 km) in radius. The Montserrat eruption was of a very similar nature and erupted into in a Plinean style. Huge pyroclastic flows were produced and also masses of ash reached the surrounding areas and left the capital, Portsmouth covered in meters of ash. The lava was spewed out at 600 mph.
There