Key Terms Flashcards
Asthenosphere
The upper layer of the earth’s mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.
Lithosphere
The rigid outer part of the earth, consisting of the crust and upper mantle
Basaltic eruptions
Basaltic eruptions are volcanic events characterized by the eruption of basaltic magma, which has relatively low viscosity and low gas content.
Benioff zone
The narrow area where earthquakes tend to occur in the subduction is known as the Benioff Zone
Risk sharing
Sharing knowledge and human response strategies will enable all countries to prepare for a hazard event in a better way.
Convection column*
A convection column in the mantle is responsible for the vertical transferring of heat from the core to the surface.
Convection currents
Hot material rises from the core-mantle boundary due to reduced density.
As it loses heat near the surface, it becomes denser and sinks back down.
These circulating cells of molten rock contribute to volcanic activity, earthquakes, and continental drift.
Coriolis effect
An effect whereby a mass moving in a rotating system experiences a force acting perpendicular to the direction of motion and to the axis of rotation.
deflects wind to the right in the north hemisphere/the left in the south
Crowdsourcing
Crowdsourcing is the collection of information, opinions, or work from a group of people, usually sourced via the Internet.
Denudation
Denudation is a geological process that shapes our Earth’s surface.
It involves the gradual removal of material from landforms and landscapes due to the actions of moving water, ice, wind, and waves.
Disaster hotspot
Areas at relatively high risk of loss from one or more natural hazards.
Effusive eruptions
Effusive eruption is a type of volcanic eruption in which lava steadily flows out of a volcano onto the ground, gruadual release of volcanic material
Environmental degredation
Environmental degradation refers to the deterioration of the environment/ depletion of natural resources due to various factors.
Fatalism
Fatalism refers to a viewpoint that considers natural hazards as uncontrollable events.
- any losses resulting from these hazards should be accepted because there is nothing that can be done to prevent them.
Ridge push/Gravitational sliding
Occurs at mid-ocean ridges as the result of the rigid lithosphere sliding down the hot, raised asthenosphere below mid-ocean ridges.
-It primarily occurs at mid-ocean ridges
Slab pull
Slab pull is a geophysical mechanism whereby the cooling and subsequent densifying of a subducting tectonic plate produces a downward force along the rest of the plate.
Ground deformation
Refers to changes in the shape or position of rocks. Deformation of rocks occurs as a result of stress
HDI
The Human Development Index (HDI) measures a country’s average achievements in three basic aspects of human development
- it looks at life expectancy at birth, mean years of schooling, expected years of schooling, and Gross National Income per capita.
Intraplate
Volcanicity thats distant from a plate boundary at locations called mid-plate hotspots, such as Hawaii and the Galapagos Islands.
Lahar
A violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano.
Latent heat
The heat required to convert a solid into a liquid or vapour, or a liquid into a vapour, without change of temperature
Magnitude
The size of the hazard, usually
this is how a hazard’s intensity is measured
Mitigation
Strategies carried out to lessen the severity of a hazard (e.g. sandbags to offset impact of flooding)
NGO
a non-profit organization that operates independently of any government, typically one whose purpose is to address a social or political issue:
Nuee ardente
An incandescent cloud of gas, ash, and lava fragments ejected from a volcano, typically as part of a pyroclastic flow.
Phreatic eruption
When magma heats ground or surface water it results in an explosion of water, steam, rock, and ash,
Paleomagnitism
The magnetism in rocks that was induced by the earth’s magnetic field at the time of their formation.
Pyroclastic flow
Dense, destructive mass of very hot ash, lava fragments, and gases ejected explosively from a volcano and typically flowing at great speed.
Pyrophytic vegetation
Plants that have adapted to tolerate fire.
They are important for nutrient cycling, improving biodiversity and other factors.
Retardants
A fabric or substance that prevents fires
Retrofitting
When a machine is provided with a part, or a place is provided with equipment, that the machine or place did not have
Storm surge
A rising of the sea as a result of wind and atmospheric pressure changes associated with a storm.
Stratovolcanoes
Stratovolcano is a conical-shaped volcano that forms by layering lava, ash, and tephra.
Tephra
Rock fragments and particles ejected by a volcanic eruption.
Unconsolidated sediment
Sediment that has not yet been cemented to form solid rock (lithification)
Volcanicity Explosivity Index
A scale that describes the size of explosive volcanic eruptions based on magnitude and intensity. The numerical scale (from 0 to 8) is a logarithmic scale,
Vulnerability
Vulnerability refers to how susceptible a human society is to damage and stress
