Ukukhuphuka kwe-periodic kanye nokuwa komyalo kuthwala amagagasi. Zenzeka cishe njalo emahoreni angama-24. Abangelwa amandla adonsela phansi enyanga nelanga olwandle olwandle. Amandla adonsela phansi eLanga, nakuba emakhulu kunalawo eNyanga, anomphumela omncane kumagagasi ngenxa yebanga lawo ukusuka eMhlabeni. Ukusondela kweNyanga eMhlabeni, ngakolunye uhlangothi, kunomphumela obaluleke kakhulu kumagagasi. Ngakho-ke, amagagasi nenyanga kunobudlelwano obubaluleke kakhulu.
Kulesi sihloko sizokutshela konke okudingeka ukwazi mayelana namagagasi nenyanga nokuthi luthinta kanjani ulwandle.
Amagagasi nenyanga
Njengoba uMhlaba ujikeleza, amandla adonsela phansi adonsela amanzi ohlangothini olubheke eNyangeni, okubangela igagasi eliphezulu. Ngesikhathi esifanayo, amanzi ngakolunye uhlangothi loMhlaba nawo ashanelwa, abangele elinye igagasi eliphakeme. Lapho amanzi ebohla, kuba namagagasi aphansi.
Ama-tides ukushintshashintsha okuvamile ezingeni lolwandle, okubangelwa amandla adonsela phansi eLanga neNyanga ahlobene noMhlaba. Leli qiniso lidala ukufuduka kwezindimbane zamanzi emhlabeni wonke, njengoba zithonywa izindikimba zasezulwini eziseduze kwethu. Ukudonsa kweNyanga amandla adonsela phansi cishe izikhathi ezi-2-3 kuneLanga, njengoba iNyanga iseduze kakhulu noMhlaba.
Ukwakheka kwamagagasi kwenzeka ekujuleni kolwandle, okwenza umthelela wawo usabalale ngaphandle futhi uthinte ugu emhlabeni wonke, okuholela ekuwohlokeni nokugeleza kolwandle. Ulwandle lunamanzi amaningi anyakazayo ngenxa yamandla adonsela phansi.
Ukuhamba kwamanzi ebheke ogwini kwaziwa ngokuthi "ukugeleza", kuyilapho amanzi ebuyela olwandle ngenxa yamandla adonsela phansi eLanga futhi ikakhulukazi iNyanga ibizwa ngokuthi "ebb". Lo mjikelezo oqhubekayo wokuhamba kwamanzi udala lokho esikubiza ngokuthi amagagasi, okuwukuphuma nokuphuma kwamanzi okuqhubekayo ogwini. Lo mjikelezo udala amagagasi aphezulu amabili kanye namagagasi amabili aphansi ngosuku, okubangela ukugeleza kwamanzi okubili ukuya ngasogwini kanye nama-ebbs amabili amanzi abheke olwandle. Ekugcineni, ukwehla nokugeleza kwamanzi kungamandla aqhuba amagagasi.
Newton, amagagasi nenyanga
Amagalelo ka-Isaac Newton kwezesayensi aqashelwa kabanzi, nomsebenzi wakhe ophathelene namandla adonsela phansi kanye nesayensi yolwandle uthakazelisa ngokukhethekile. Izinkolelo-mbono zikaNewton zamandla adonsela phansi azigcinanga nje ngokuba isisekelo se-physics yesimanje, kodwa futhi zasisiza ukuba siqonde izinsimbi zesimiso sonozungezilanga kanye nokuhamba komkhathi. Izifundo zakhe kwisayensi ye-tidal, ehlola ukuxhumana okuyinkimbinkimbi phakathi kweNyanga nolwandle loMhlaba, kuholele ekuqondeni okusha ngokuziphatha kwamagagasi namaphethini awo. Umsebenzi kaNewton useyingxenye eyisisekelo yolwazi lwesayensi kuze kube namuhla.
Incazelo yamagagasi itholakala ezimisweni ezimiswe imithetho kaNewton. Umthetho wokudonselana kwamandla adonsela phansi phakathi koMhlaba, iLanga neNyanga ngokuyinhloko usekelwe emandleni adonsela phansi. U-Newton ubeke ukuthi ukukhangana phakathi kwezinto ezimbili kuhambisana nesisindo sazo futhi kuhambisana ngokuphambene nesikwele sebanga eliphakathi kwazo.
Ukukubeka ngenye indlela, ukukhangana kwamandla adonsela phansi phakathi kwezinto ezimbili kunamandla lapho uquqaba lwazo lulukhulu nalapho ziseduze. Indlela yeNyanga ezungeze uMhlaba i-elliptical, njengoba nje umjikelezo wethu ozungeza iLanga nawo u-elliptical. Ngokuqondene neNyanga, uhlangothi loMhlaba olubheke kuyo luba namandla adonsela phansi anamandla ngenxa yokuba seduze kwesathelayithi.
Lokhu kubangela ukuthi amanzi amaningi adonselwe kuwo, abangele amagagasi aphezulu. Ngokuphambene, uhlangothi oluphambene luba namandla adonsela phansi abuthaka ngenxa yamandla amaphakathi omhlaba ahlobene neNyanga, okuholela ekutheni kube namandla aphansi aphezulu.
Uma usebenzisa ifomula ka-Newton, kubalulekile ukuqaphela ukuthi ibanga lidlala indima enkulu kunesisindo ekubaleni amandla adonsela phansi phakathi kwemizimba emibili. Ngenxa yalokho, amandla akhangayo asetshenziswa yiNyanga makhulu ngokuphindwe izikhathi ezi-2 kuya kwezingu-3 kunalawo eLanga, naphezu kobukhulu bayo bamuva. Ngakho-ke, amagagasi enyanga akhombisa izinga elikhulu lamandla uma kuqhathaniswa namaza elanga.
High tide futhi low tide
Ukwenzeka kwamagagasi aphezulu naphansi kuyinto yemvelo eyenzeka ngenxa yokudonsela phansi kwenyanga nelanga olwandle olwandle. Phakathi namagagasi aphezulu, izinga lamanzi lisezingeni eliphezulu kakhulu, kuyilapho phakathi namagagasi aphansi, lisezingeni eliphansi kakhulu. Le iphethini I-cyclical futhi ivela kabili ngosuku, cishe amahora ayisithupha phakathi kwegagasi ngalinye eliphakeme neliphansi. Iyingxenye ebalulekile yemvelo yasogwini futhi idlala indima ebalulekile ekulawuleni impilo yasolwandle kanye nokuguguleka kogu.
Iphuzu eliphakeme kakhulu olwandle elifinyelela kulo laziwa ngokuthi ama-high tide. Lokhu kwenzeka kabili ngosuku, ngesikhawu samahora angu-12 nemizuzu engu-25 phakathi kokubonakala ngakunye. Amagagasi aphansi, noma indawo ephansi kakhulu olwandle olufinyelela kuyo, nawo ayenzeka kabili ngosuku, ngesikhathi esifanayo namagagasi aphezulu. Ubude besikhathi se-half-tide, okuyibanga lesikhathi phakathi kwamagagasi aphezulu namaza aphansi, Kungamahora ayisi-6, imizuzu eyi-12 nemizuzwana engama-30. Ngenxa yalokho, igagasi liyashintsha nsuku zonke cishe imizuzu engama-50.
Izikole ze-Surf zisekelwe indawo eyireferensi ehlala cishe imizuzu engama-45-50 ukuze usethe izikhathi zakho zezifundo zama-surf zosuku olulandelayo. Le ndlela isetshenziswa ngoba ibhishi ngalinye linendawo ekahle yokuntweza emanzini. Abatshuzi kufanele baqaphele lapho igagasi eliphezulu lenzeka futhi lapho "i-ebb" yamanzi iqala, njengoba amandla olwandle angabadonsa emanzini ajulile. Ngakho-ke, kunconywa ukucwilisa phakathi kwamagagasi aphansi. Ngokunjalo, i-low tide iyisikhathi esifanele sokuba abadobi abaningi bayodoba, ikakhulukazi ngezikhathi zamagagasi entwasahlobo.
Ngithemba ukuthi ngalolu lwazi ungafunda kabanzi mayelana namagagasi nenyanga.