An yirdquauk (kent as a quauk, tremor or temblor an aw) is the result o a suddent release o energie in the Yird's crust that creates seismic waves. The seismicity, seismism or seismic activity o a aurie refers tae the frequency, teep an size o yirdquauks experiencit ower a period o time.
Yirdquauks are measured uisin observations frae seismometers. The moment magnitude is the maist common scale on which yurdquauks lairger than approximately 5 are reportit for the entire globe. The mair numerous yirdquauks smawer than magnitude 5 reportit bi naitional seismological observatories are measured maistly on the local magnitude scale, referred tae as the Richter scale an aw. Thir twa scales are numerically seemilar ower thair range o validity. Magnitude 3 or lawer yirdquauks are maistly amaist imperceptible or waik an magnitude 7 an ower potentially cause serious damage ower lairger auries, dependin on thair deth. Intensity o shakin is measured on the modifee'd Mercalli scale.The shallaeer a yirdquauk, the mair damage tae structurs it causes, aw else bein equal.
- "Earthquake FAQ". Crustal.ucsb.edu. Retrieved 24 Julie 2011.