Module3TheViolenceofNature-FunctionPeriod3FUNCTION—Givingadefinition■Goals●Tolearntogiveadefinition■ProceduresStep1:DefiningadefinitionAdefinitionmaybeastatementoftheessentialpropertiesofacertainthing,orastatementofequivalencebetweenatermandthatterm'smeaning.Thetwoarenotmutuallyexclusive,noraretheyequivalent.Aconciseexplanationofthemeaningofawordorphraseorsymbol.AstatementthatgivesthemeaningofawordorsymbolintermsthathasbeenpreviouslydefinedorareacceptedasundefinedStep2:GivingadefinitionAnearthquakeisatremblingorashakingmovementoftheEarth'ssurface.Earthquakestypicallyresultfromthemovementoffaults,quasi-planarzonesofdeformationwithinitsuppermostlayers.Thewordearthquakeisalsowidelyusedtoindicatethesourceregionitself.Thesolidearthisinslowbutconstantmotion(seeplatetectonics)andearthquakesoccurwheretheresultingstressexceedsthecapacityofEarthmaterialstosupportit....Avolcanoisageologicallandform(usuallyamountain)wheremagma(rockoftheearth'sinteriormademoltenorliquidbyhighpressureandtemperature)eruptsthroughthesurfaceoftheplanet.Althoughtherearenumerousvolcanoes(someveryactive)onthesolarsystem'srockyplanetsandmoons,onEarthatleast,thisphenomenontendstooccurneartheboundariesofthecontinentalplates.However,importantexceptionsexistinhotspotvolcanoes.Atornadoisaviolentwindstormcharacterizedbyatwisting,funnel-shapedcloud.Theword"tornado"comesfromtheSpanishorPortugueseverbtornar,meaning"toturn."Tornadoesforminstormsallaroundtheworld,mostfamouslyinabroadareaoftheAmericanMidwestandSouthknownasTornadoAlley.Althoughinpurenumberofincidences,theUnitedStatesexperiencesmoretornadoesthananyothercountry,theUnitedKingdomisthemostproportionallytornado-pronecountryforitssize....Ahurricaneisaseveretropicalcycloneusuallywithheavyrainsandwindsmovinga73-136knots(12ontheBeaufortscale)用心爱心专心
