Volcanic Materials and Health Concerns
Volcanic Materials and Health Concerns
Introduction: Basic Geology of Volcanoes
A volcano can be a mountain like structure or a wide sloping hill that opens downwards to a pool of molten rock below the surface of the earth. When a break in the earth’s surface allows molten rock material to come up from the earth’s core, a volcano is formed. Volcanic eruptions can cause lateral blasts, lava flows, hot ash flows, mudslides, avalanches, falling ash and floods. These eruptions can also trigger tsunamis, flash floods, earthquakes, mudflows and rock falls. Examples of volcanic mountains are Mount St. Helens, Mount Fuji, and Pinatubo. (Kusky, 2010).
The earth’s crust is made up of huge slabs known as plates. Plates fit together like a jigsaw puzzle and float on the mantle. They are in constant motion, either towards each other or away from each other. Plate tectonics is considered to be the main theory currently used by most Earth Scientists to describe motion within the outer-most layer of the sold Earth, which is also known as the lithosphere. It is this movement that induces friction that causes earthquakes and volcanic eruptions. Volcanism is associated with two of the plate boundary types, divergent and convergent margins. Volcanoes are formed when two tectonic plates meet; the heavier plate slides underneath the light plate and melts down to become magma. This mixes with trapped gases and steam in the magma chamber (Gates, 2009). Pressure from surrounding rocks forces the magma to the surface through weak points, such as fractures and when it reaches the crust an explosion occurs with regard to the amount of pressure available and the viscosity of magma creating a subduction volcano. Volcanoes can additionally be formed when two tectonic plates move away from each other. The impact of the divergence of these plates leads to the melting of rocks in the mantle that melt from beneath the earth’s upper mantle and find
Introduction: Basic Geology of Volcanoes
A volcano can be a mountain like structure or a wide sloping hill that opens downwards to a pool of molten rock below the surface of the earth. When a break in the earth’s surface allows molten rock material to come up from the earth’s core, a volcano is formed. Volcanic eruptions can cause lateral blasts, lava flows, hot ash flows, mudslides, avalanches, falling ash and floods. These eruptions can also trigger tsunamis, flash floods, earthquakes, mudflows and rock falls. Examples of volcanic mountains are Mount St. Helens, Mount Fuji, and Pinatubo. (Kusky, 2010).
The earth’s crust is made up of huge slabs known as plates. Plates fit together like a jigsaw puzzle and float on the mantle. They are in constant motion, either towards each other or away from each other. Plate tectonics is considered to be the main theory currently used by most Earth Scientists to describe motion within the outer-most layer of the sold Earth, which is also known as the lithosphere. It is this movement that induces friction that causes earthquakes and volcanic eruptions. Volcanism is associated with two of the plate boundary types, divergent and convergent margins. Volcanoes are formed when two tectonic plates meet; the heavier plate slides underneath the light plate and melts down to become magma. This mixes with trapped gases and steam in the magma chamber (Gates, 2009). Pressure from surrounding rocks forces the magma to the surface through weak points, such as fractures and when it reaches the crust an explosion occurs with regard to the amount of pressure available and the viscosity of magma creating a subduction volcano. Volcanoes can additionally be formed when two tectonic plates move away from each other. The impact of the divergence of these plates leads to the melting of rocks in the mantle that melt from beneath the earth’s upper mantle and find
References: Barr, L. (2003), Volcano: When A Mountain Explodes, Capstone Classroom, Bloomington, Minnesota Ciottone, G. (2006), Disaster Medicine, Elsevier Health Sciences, Philadelphia, PA Duncan, R Ganeri, A. (2012), Volcano, Britannica Digital Learning, Mankato, Minnesota Gates, A Kungolos, A. (2006), Environmental Toxicology, WIT Press, Southampton, UK Kusky, T Zuehlke, J. (2008), Landslides, Learner Publications, Minneapolis, U.S.A