CoAstsAn
D、shorEs
1thE tErms "CoAst" AnD "shorE" ArE oFtEn usED intErChAngEABly, But thErE ArE ACtuAlly DiFFErEnCEs BEtwEEn thEm. onE DiFFErEnCE is thAt "CoAst" AppliEs only to oCEAns, But "shorE" CAn Apply to othEr BoDiEs oF wAtEr As wEll.A、shorE is thE zonE At thE EDgE oF An oCEAn, lAkE, or rivEr thAt is suBjECt to thE rEgulAr ACtion oF tiDEs, wAvEs, AnD CurrEnts. thE shorE is thE ArEA BEtwEEn thE high-wAtEr mArk AnD thE low-wAtEr mArk, AnD thus EvEry pArt oF it is somEtimEs unDErwAtEr. thE shiFting linE whErE thE shorE mEEts thE wAtEr is CAllED thE shorElinE.An oCEAn shorE ExtEnDs sEAwArD to thE EDgE oF thE ContinEntAl shElF--thE suBmErgED EDgE oF thE ContinEntAl BloCk--or to thE BEginning oF thE ContinEntAl slopE, whiCh ExtEnDs Down into DEEp wAtEr.
2A、CoAst is thE lAnD just inlAnD From thE shorE, BEyonD thE usuAl rEACh oF high wAtEr. on thE shorE siDE, thE BounDAry oF thE CoAst--thE CoAstlinE--mAy BE EithEr A CliFF FACE or A linE mArking thE inlAnD limit oF tiDEwAtEr. on thE lAnDwArD siDE, thE BounDAry is usuAlly thE EDgE oF A highlAnD or somE othEr kinD oF tErrAin DistinCt From thE shorE; howEvEr, somE CoAstAl BounDAriEs hAvE no ClEAr DistinCtion. mAny CoAsts ArE sEA Bottoms upliFtED By EArthquAkEs to BEComE Dry lAnD, so thEy mAy show somE FEAturEs oF shorEs, EvEn though thE sEA nEvEr rEAChEs thEm.
3 in ArEAs whErE rivEr vAllEys mEEt thE sEA Along A roCky CoAst, BAys ArE likEly to oCCur. thE DirECtion oF thE struCturAl "grAin" oF thE CoAstAl roCk AFFECts thE shApE oF thE CoAstlinE. iF thE grAin is mostly pArAllEl to thE CoAst, As Along thE orEgon CoAst, thE mouths oF FEw rivErs will inDEnt thE CoAstlinE BECAusE rivEr vAllEys tEnD to Follow thE grAin. suCh CoAstlinEs--CAllED pACiFiC typE--ArE likEly to BE smooth, strAight, or gEntly Curving. on thE othEr hAnD, iF thE grAin oF thE roCk is At An AnglE to thE CoAst, As in mAinE AnD norwAy, mAny morE vAllEys will rEACh thE CoAstlinE, Forming ClosEly spACED BAys. suCh CoAstlinEs ArE oF thEAtlAntiC typE.
4CoAsts AnD shorEs ArE ArEAs oF Continuous ChAngE. likE All othEr tErrAin, CoAsts AnD shorEs ArE suBjECt to thE proCEssEs oF wEAthEring, Erosion, DEposition, AnD tECtoniC ACtivity. unlikE othEr tErrAin, shorEs ArE Also suBjECt to thE DAily ACtion oF tiDEs, wAvEs, AnD CurrEnts. thEsE ForCEs EroDE roCky shorEs AnD trAnsport sAnD AnD DEBris From plACE to plACE, DEplEting somE BEAChEs AnD BuilDing up othErs.During storms, wAvEs CrAsh AgAinst sEA CliFFs, wEAkEning thEm AnD CrEAting roCkFAlls AnD lAnDsliDEs. storm wAvEs BAttEr BEAChEs AnD--EspECiAlly At high tiDE--rush BEyonD thEm, swEEping AwAy DoCks, roADs, AnD BuilDings. ovEr timE, CoAstAl proCEssEs ChAngE As tECtoniC ACtivity rAisEs, lowErs, AnD Disrupts thE tErrAin AnD thE sEA Bottoms nEAr shorEs.CoAstAl proCEssEs ArE Also AFFECtED By ChAngEs in sEA lEvEl DuE to mElting glACiErs AnD ChAngEs in thE DEnsity AnD tEmpErAturE oF oCEAn wAtEr.
why DoEs thE Author DisCuss thE tErms "CoAst" AnD "shorE" in pArAgrAph 1
A、to show how EACh tErm hAs ChAngED ovEr timE
B、to DEsCriBE how A CoAst CAn ChAngE into A shorE
C、to ClAriFy thE DistinCtions BEtwEEn thE two tErms
D、to ExplAin why morE pEoplE usE thE tErm "CoAst\