#Quake definition crack

#Quake definition crack

The epicentre usually registers the strongest shaking.įault = a crack in the Earthâ€™s crust along which the rocks slide. directly above the true centre of the seismic disturbance from which the shock waves of an earthquake seem to radiate. This is defined by the amount a reference point is affected by an earthquake or moved from itâ€™s original position before the earthquake.Įarthquake = shaking or slipping movement of the earthâ€™s crust, followed by seismic waves and vibrations.Įarthquake Fault = earthquake faults are fractures where displacement is on either side relative to one another and parallel to the fracture.Įpicentre = the point on the Earth's surface vertically above the focus of an earthquake, i.e. This is called convection.ĭeformation = deformation is a change to the original shape of material and in earthquakes this is due to stress and strain.ĭisplacement = displacement is a change in the initial reference point or later position. The area of fluid which is colder and denser sinks,occupying the area of the warmed fluid. spring bobbing, up and down.Ĭonvection = as a fluid is warmed it expands and rises as the density decreases. Affect and can pass through only solid materials (only solids offer resistance to change in shape).Also called Transverse Waves = wave motion (amplitude) is perpendicular to direction of travel, e.g. They are not as fast as P-waves and result in changing only shape of material they travel through. They are shake-waves (shear waves), vibrating side-to-side. Secondary waves or S waves = vibrations occurring at right angles to direction of wave propagation. Also called Longitudinal Waves= wave motion (amplitude) is parallel to direction of travel, e.g. Affect and can pass through solids, liquids, and gasses (as they all exhibit resistance to change in volume).

Change both volume and shape of material in which they pass. Primary waves or P waves: push-pull waves, waves move back and forth in the direction in which the wave is travelling. Aftershocks are linked to the size of the mainshock and if this is large can continue for many weeks, months or years.Īmplitude = the size of the wiggles on an earthquake recording.Īsthenosphere = the asthenosphere is the ductile part of the Earth just below the lithosphere, which includes the lower mantle and is about 180km thick.īody waves = seismic vibrations that move through the Earth's interior. Active fault = an active fault is one that has moved once or more times in the past 10,000 years and therefore likely to move sometime in the future.Īftershocks = smaller earthquakes that occur after the main earthquake in the same place as the mainshock.