An investigation of the deforllling layer/debris-rich basalice continuulll, illustrated frolll three Alaskan glaciers
DepaTtmml oJ G'eogra/Ay, Universil)l Il / SOlllham/JIOn, SOlllha m/JlolI S0 9 5NH, t 'ng/and ABSTRACT. Three small Alaska n g laciers with different bed eonditio ns \\'ere studied: E xit Glacier h ad a thin d efo rming layer a nd produced subg lacia l a nd prog lacia l glaciotectonic...
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Format: | Text |
Language: | English |
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Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.430.842 http://www.igsoc.org/journal/41/139/igs_journal_vol41_issue139_pg619-633.pdf |
Summary: | DepaTtmml oJ G'eogra/Ay, Universil)l Il / SOlllham/JIOn, SOlllha m/JlolI S0 9 5NH, t 'ng/and ABSTRACT. Three small Alaska n g laciers with different bed eonditio ns \\'ere studied: E xit Glacier h ad a thin d efo rming layer a nd produced subg lacia l a nd prog lacia l glaciotectonic la nd forms; Childs Glacier a lso had a thin d efo rming lavcr hut the upper pa n was frozen to the ice; t-.la tanuska Glacier had no d e fo rming layer but h a d subglacia l d ebri s-rich ice. Since it has been shown th a t sedime nt at the base can account for the m aj o rity of ice movem ent, it is suggcsted th a t th ere is a d eforming bed /d e bris- ri ch continuum \\'hereby simila r processes occur througho ut th e d ifferent subg lacia l environme l1ls. These include: sim il ar longitudina l deforma ti o n pa tterns (compression a t the m a rg in, ex tension a nd simple shear up-glacier); simila r ve rtical defo rma ti on pa lLerns, in crease in d eform a tion (a nd ra b ri c strength) upwa rds th rough the seque nce (leading to the a ttenua ti o n o f stratifi ed ice in to d ispersed ice); and simila r a nd interrela ted in corpo ra ti on processes. The major diffe re nces we re th a t the processes occurred at a much faste r ra te within th e d eforming layer and that probably onh ' th e d efo rming layer \·\·i11 be recorded in the geological recorcl. |
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