Glossary

• Hazard: A natural hazard is a threat of a naturally occurring event that will have a negative effect on people or the environment.
• Tectonic event:  A tectonic event is an occurrence caused by tectonic activity
• Disaster: any event or force of nature that has catastrophic consequences, such as avalanche, earthquake, flood, forest fire, hurricane, lightning, tornado, tsunami, and volcanic eruption
• Risk: the exposure of people to a hazardous event and the process of establishing the probability that a hazard event of a particular magnitude will occur within a given period.
• Vulnerability: is the potential for losses or other adverse impacts. People, buildings, ecosystems and human activities threatened with a disaster are vulnerable
• Capacity to cope: The way in which a community uses it's tools, skills and money in order to deal and cope with a disaster.
  (Skinner, M. (2003) Hazards. Abingdon, Oxon)
• Pyroclastic Flow: is a ground-hugging avalanche of hot ash, pumice, rock fragments, and volcanic gas that rushes down the side of a volcano that can travel at speeds as fast as 100 km/hour or more. The temperatures can reach greater than 500° C, sufficient to burn and carbonize wood.
• Lahar: is a rapid flowing mixture of rock debris and water that is created on the slopes of a volcano.
• Ash: Volcanic ash is created during explosive eruptions by the shattering of solid rocks and violent separation of magma (molten rock) into tiny pieces.
• Volcanic bombs:  are lava fragments that were ejected during viscous  eruption
• Tephra: is a term used for fragments of volcanic rock and lava of any size that are catapulted into the air by explosions or carried vertically by hot gases in eruption columns or lava fountains.
• Eruption cloud: is a cloud of tephra and gases that forms downwind of an erupting volcano is called an eruption cloud. The vertical pillar of tephra and gases rising directly above a vent is an eruption column.
• Frequency: Is the distribution of the hazard event through time
• Magnitude: assesses and judges the size of the impact e.g. Richter scale
• Duration: the time in which it took for the incident to occur
• Areal Extent: To what extent the precipitation covers a land area.
  
  (Skinner, M. (2003) Hazards. Abingdon, Oxon)