Keywords Flashcards
Basalt
Fine-grained, igneous rock, underlying more of the earth’s surface than any other rock type, especially ocean basins. Associated mainly with constructive plate boundaries
Andesite
Typically found in lava flows produced by stratovolcanoes. Generally formed after oceanic plate melts during its descent into the subduction zone
Rhyolite
Formed from granitic magma in continental or continent margin volcanic eruptions where granitic magma reaches the surface. Rhyolite is rarely produced at oceanic eruptions.
Benioff Zone
A dipping flat zone where earthquakes are produced by the interaction of a down going oceanic crustal plate with a continental plate.
Subduction Zone
The place where two lithospheric plates come together, one riding over the other.
Most volcanoes on land occur parallel to and inland from the boundary between the two plates.
Crustal Facturing
Occurs when the earth’s crust causes rock to break and fracture under stress and strain caused by seismic stresses
Mega-disaster
An extreme disaster which can impact globally
Resilience
The capacity to overcome or recover from a setback or hazard
Mitigation
Reducing the impact of a problem
Hazard profile
A method to help in preparing for a hazard using several key elements such as speed of onset and areal extent.
Speed of Onset
The time between an event occurring and it being felt, e.g. an earthquake can be instantaneous, while a tsunami wave may take some time to arrive.
Areal extent
The area over which damage occurs or a hazard is felt.
Spatial Predictability
The extent to which the location of a hazard can be known in advance; this is generally easy for a volcano but less so along fault lines.
PAR Model
A model developed by Blaikie et al. 1994). It depicts a disaster as a product of physical exposure and socio-economic pressure.
Threshold
In this context, the level of resilience a community has before it is overwhelmed by a disaster.
