![Page 1: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/1.jpg)
160
LEDENJACI
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Antarktičkaledena kapa
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Grenlandskaledena kapa
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
![Page 2: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/2.jpg)
161
Sniježna granica:
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Snijeg
Zrnati snijeg
Firn
Ledenjački led
Prelazak snijega u ledenjački led zbog zatrpavanja
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Kako se ledenjak može kretati niz padinu i istovremeno na drugom kraju kretati uzbrdo?
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
![Page 3: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/3.jpg)
162
To ovisi o količini ledenjačkog leda kojiuključuje:
1) količinu ledenjačke akumulacije2) količinu ledenjačkog gubitka (ablacije)
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Ledenjačka zaliha
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Slijed povlačenja ledenjačkog šelfa
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
![Page 4: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/4.jpg)
163
Kada je ledenjačka akumulacija veća od ablacije, rezultat je rast
ledenjaka i pridružena ledenjačka erozija.
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Kada je ledenjačka akumulacija manja od ablacije, rezultat je
povlačenje ledenjaka i pridružena ledenjačka depozicija.
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Ledenjaci se kreću plastičnim
tokom i bazalnim klizanjem
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
![Page 5: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/5.jpg)
164
Plastični tok:
Ledenjaci u ledenjačkim dolinama uglavnom se kreću plastičnim tokom
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Bazalno klizanje:
Kontinentalni ledenjaci se kreću uglavnom bazalnim
klizanjem.
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Krivasi:
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
![Page 6: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/6.jpg)
165
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Morska razina ne raste ako se plutajući
led topi
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Morska razina raste ako se led topi na
kopnu
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
![Page 7: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/7.jpg)
166
Led polira ravne površine
Krivasi nastaju kretanjem ledenjaka preko stube (topografija temeljne stijene)
Led odlama dijelove stijene, proizvodeći grubu
površinu
Posljedica je oblik temeljne stijene roche
moutannée
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Prije glacijacije
Za vrijeme glacijacije Nakon glacijacije
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Erozijski oblici reljefa udruženi s glacijacijom doline
• doline oblika U• fjordovi• cirkete• arete• roche moutannées
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
![Page 8: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/8.jpg)
167
Vrste ledenjačkih taloga
• ledenjački drift:• ledenjački til:• eratički blokovi:• isprani talozi:
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Ledenjački drift:
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Taložni oblici udruženi s ledenjakom uključuju:
• ledenjačke morene– vršne morene– morene tla – bočne i središnje morene
• eskere• dramline• jezera u obliku kotla• ravnice ispranih taloga
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
![Page 9: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/9.jpg)
168
Središnjemorene
Bočnemorene
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Ledenjačkitalozi
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Za vrijeme otapanja leda
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
![Page 10: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/10.jpg)
169
Nakon potpunog otapanja
jezero uobliku kotla
dramlin
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Permafrost
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Rasprostiranje glacijacije na sjevernoj hemisferi, temeljeno na distribuciji glacijalnog drifta
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
![Page 11: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/11.jpg)
170
Rasprostiranje i debljina glacijalnog leda i temperature morske površine za tipičan dan u kolovozu, prije 18.000 god., u vrijeme zadnjeg ledenog doba.
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Izotopi kisika u marinskim mikrofosilima obilježavaju brojnaglacijalna i interglacijalna razdoblja
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Periodičnost glacijalnih i interglacijalnihciklusa je objašnjena cikličnim varijacijama Sunčeve energije,
upravljane periodičnim varijacijama:
• orbitalnoj ekscentričnosti• nagnutosti osi• precesiji osi ("vrludanje")
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
![Page 12: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/12.jpg)
171
Orbitalna ekscentričnost
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Nagnutost Zemljine osi
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Precesija
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
![Page 13: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/13.jpg)
172
Sustav oceanskih struja ima važan utjecaj na svjetsku klimu
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Dokazi nekadašnjih ledenih doba
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Gornjopaleozojski glacijalni talozi~350 mil. god.
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
![Page 14: LEDENJACI - rgn.hrrgn.hr/~dpavelic/OG-Web-PDF/OG15 - Ledenjaci.pdf · erozija . ... glacijalna i interglacijalna razdoblja](https://reader038.vdocuments.net/reader038/viewer/2022102822/5a75a60b7f8b9a63638ca1ec/html5/thumbnails/14.jpg)
173
Gornjopaleozojski glacijalni talozi~350 mil. god.
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Gornjoprekambrijski glacijalni talozi~700 mil. god.
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Hipoteza o Zemlji kao sniježnoj kugli:
Postoje dokazi da se gornjoprekambrijska glacijacija pružala sve do ekvatorijalnih područja.
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________