tectonics

• Natural Hazard


  A natural process/event that has the potential to threaten life and property
• Natural Disaster


  T realisation of a hazard when it causes damage/injury (e.g. 10 or more people are killed, or 100 people or more are affected - Source: CRED)
• Vulnerability


  The ability to anticipate, cope and recover from a natural hazard/disaster.
• Resilience


  The ability to protect lives, livelihoods and infrastructure from damage and to repair damage.
• Hazard risk equation


  Risk (R) equals hazard (H) multiplied by vulnerability (V), divided by the capacity to cope (C)
• Pressure and Release Model (PAR)


  A model which examines the underlying causes of a disaster - 1) the factors affecting vulnerability, and 2) the natural processes/hazard itself.
• Social impact


  The effects of an event/process on people and their health, livelihoods and wellbeing.
• Economic impact


  The effects of an event/process on business, trade, industry, employment and infrastructure.
• Environmental impact


  The effects of an event/process on the landscape and ecology.
• magnitude


  The size of the tectonic event - either the size of the volcanic eruption (VEI) or the amount of energy released from the hypocentre during an earthquake (MMS)
• intensity


  The strength of shaking and resulting damage from an earthquake (e.g. Mercalli scale)
• Moment Magnitude(Mw) Scale


  Based on measurement of the maximum motion recorded by a seismograph, and also based of the concept of seismic moment (Source: USGS)
• Mercalli scale


  Measurement of the effects of an earthquake experienced by people. Lower values generally deal with the manner in which the earthquake is felt by people. Higher values are based on observed structural damage.
• Volcanic Explosivity Index (VEI)

  A relative scale that enables explosive volcanic eruptions to be compared with one another. It considers the volume of pyroclastic material ejected (e.g. tephra, ash), the height of the eruption column and the duration of the eruption.
• Speed of Onset


  How quickly the peak of the hazard event occurs
• Areal extent


  The size of the physical area affected by the event.
• duration


  The length of the event
• frequency


  The number of events in a given period of time.
• spatial predictability


  How easy it is to pin point/estimate when an event will happen
• Hazard Profile


  A diagram that illustrates the main characteristics of different types of tectonic hazards)
• Governance


  The way in which local and national governments plan for, and respond to, tectonic hazards. This can contribute to an areas vulnerability and resilience.
• Inequality of access


  The way in which not everyone has the same opportunities regarding education, healthcare, housing and income. This can affect people's vulnerability and resilience.
• Population density


  The number of people per sq. km of land area
• degree of urbanisation


  The proportion of people living in urban areas. Also closely linked to higher population densities.
• Seismic moment


  a measure of the size of an earthquake based on the area of fault rupture, the average amount of slip, and the force that was required to overcome the friction sticking the rocks together that were offset by faulting (Source: USGS)
• Slip


  the relative displacement of formerly adjacent points on opposite sides of a fault (Source: USGS)
• Strike-slip fault


  vertical (or nearly vertical) fractures where the blocks have mostly moved horizontally (Source: USGS)
• Dip slip fault


  inclined fractures where the blocks have mostly shifted vertically. If the rock mass above an inclined fault moves down, the fault is termed normal, whereas if the rock above the fault moves up, the fault is termed reverse. (Source: USGS)
• Thrust fault


  A reverse fault with a dip of 45 degrees or less. (Source: USGS)
• Accuracy of data


  The closeness of a quantity to the quantity's actual value. It relies on the quality of the equipment and skilled persons to operate the equipment. Inaccurate data may result in the wrong decisions being made about planning/response/evacuation.
• Reliability of data


  The consistency/reproducibility of a measurement.
• Mega-disasters


  Large scale disasters (areal scale or economic/human impact), difficult to manage effectively to minimise impact (long and short term), and scale of impact may require international support. They can affect more than one country (directly or indirectly) - e.g. Japanese earthquake and tsunami, and Eyjafjallajokull eruption.
• Multiple hazard zone


  An area that is at risk from multiple natural hazards - e.g. hurricanes, earthquakes, volcanic eruptions, floods etc
• Hydrometeorological hazard


  Natural hazards caused by climate processes (e.g. droughts, floods, hurricanes and storms)
• Prediction


  Attempting to estimate the location, time, magnitude and intensity of an event. It is impossible to say precisely when an event will occur, however monitoring certain factors (e.g. gas output such as radon or sulphur, seismic activity, geological changes and rock stress) can give an indication that an event is imminent.
• Hazard management cycle


  The process by which governments and other organisations work to avoid/reduce loss of life or property, help those affected, and ensure rapid/effective recovery.
• Response


  Coping with the disaster - save lives, protect property, reduce economic loss (e.g. search and rescue, evacuation, restoring infrastructure)
• Recovery


  Rebuilding homes and services, restoring power and water supplies, reopening businesses and schools, repairing infrastructure.
• Mitigation


  Prevention of events or minimising effects - e.g. land-use planning and zoning, building codes, protective structures
• Preparedness


  Developing emergency plans and early warning systems, educating communities about hazards and conducting drills, creating evacuation routes.