The glossary below consists of terms used in the standard background pages and easy background pages.

active fault
A fault that is likely to have another earthquake sometime in the future. Faults are commonly considered to be active if they have moved in the last 10,000 years.

atomic clock
Very accurate clock which uses the known properties of certain atoms to record time.

cadastral maps
Maps which show who owns land.

The process of drawing or making maps.

A chemical element that can be added to city drinking water supplies to kill harmful bacteria.

Where something unwanted or harmful enters something useful e.g. sewage contaminating the drinking water.

Legal agreements to do with land use.

The weight of a known volume of material.

The legal right to do something on your own or someone else's land.

The point on the earth's surface vertically above the hypocentre.

Process of wearing away and transporting of rocks by wind, rain or ice.

A break in rock across which there is observable movement.

A long narrow crack in the ground caused by earthquakes.

A sport where people use GPS to hide and seek containers called caches or geocahces anywhere in the world.

A scientist trained in the study of the Earth.

The science of the make-up, shape and history of the Earth.

To do with location.

geospatial data
Data or information about the location of specific things.

Global Positioning System - uses the known distance between satellites to calculate exact locations.

Geographic Information Systems - maps that combine sets of information.

Green Zone
Housing areas in Canterbury where houses are able to be rebuilt.

The point on the fault plane where the rupture starts.

Services such as roads and water systems.

Sometimes called triangulation. Where the known angles and distance between points is used to calculate the location of a distant point.

A measure of how strongly an earthquake manifests at the surface, based on its observable effects on people, buildings and the environment. Intensity is usually ranked using the 12 point Modified Mercalli Intensity (MMI) scale.

lateral shear
Sideways separation or break caused by land movement.

lateral spread
Where land slips downhill due to liquefaction below the surface.

Distance from the equator in degrees, shown as horizontal lines on a map.

A process in which water-saturated sediment temporarily loses its strength and acts as a fluid.

Distance east or west from Greenwich, England, in degrees shown as vertical lines on a map.

A measure of the energy released by an earthquake at its source. Magnitude is commonly determined from the shaking recorded on a seismograph. Each unit of magnitude on the scale represents a substantial increase in energy, for example a magnitude 5 releases 30 times more energy than a magnitude 4.

nautical charts
Charts or maps of features at sea such as reefs, coastlines, shipping hazards and sometimes water depths and currents.

Red Zone
Housing areas in Canterbury where land damage was so severe from the quakes that houses will not be rebuilt in the near furture.

Resource Consent Applications
Used to apply for the legal right to use a resource.

Rūaumoko (or Rūamoko)
According to Māori tradition earthquakes are caused by Rūaumoko - the god of earthquakes and volcanoes.

rū whenua
The Māori word for earthquakes, which translated means the shaking of the land.

When waves from a large earthquake pass though wet, loose sand, patches of sand erupt from below the surface onto the ground and form sandblow deposits, also nicknamed miniature sand volcanoes.

Objects sent into space which orbit the earth and send and receive information.

Stronger Christchurch Infrastructure Rebuild Team - an alliance of construction companies working together to rebuild Christchurch's services such as roads and water systems.

When loosely consolidated materials or rock layers move a short distance down a slope.

A particular layer of a rock.  

storm water
Rain water that has drained off buildings, solid surfaces and roads.

People who specialise in making accurate measurements on the surface of the earth to make maps.

An optical instrument used by surveyors to measure angles to give exact locations of distant points.

The shape of the earth's surface.

topographic map
Shows the shape of the surface, including altitude as well as natural and physical features - sometimes called a contour map.

A type of maths that measures the angles and sides of triangles and uses this information and set formula to find the unknown sides and angles. This type of maths can also be used to find the location of distant points.

Services such as water pipes and power lines.

Used water that needs treatment such as sewage and grey water.

An activity where people can locate and log interesting locations anywhere in the world.