Editing Drumlin (section)

==Morphology==

Drumlins occur in various shapes and sizes,<ref>{{cite journal|title=The planar shape of drumlins|doi=10.1016/j.sedgeo.2010.01.008|volume=232|issue=3–4|pages=119–129|journal=Sedimentary Geology|bibcode=2010SedG..232..119S|year=2010|last1=Spagnolo|first1=Matteo|last2=Clark|first2=Chris D.|last3=Hughes|first3=Anna L.C.|last4=Dunlop|first4=Paul|last5=Stokes|first5=Chris R.}}</ref> including symmetrical (about the long axis), spindle, parabolic forms, and transverse asymmetrical forms. Generally, they are elongated, oval-shaped hills, with a long axis parallel to the orientation of ice flow and with an up-ice (stoss) face that is generally steeper than the down-ice (lee) face.<ref>{{Cite journal|last=Menzies|date=1979|title=A review of the literature on the formation and location of drumlins|journal=Earth-Science Reviews|volume=14|issue=4|pages=315–359|doi=10.1016/0012-8252(79)90093-X|bibcode=1979ESRv...14..315M}}</ref>

Drumlins are typically between {{convert|250 and 1,000|m|ft|abbr=on}} long and between {{convert|120 and 300|m|ft|abbr=on}} wide.<ref name="Clark Hughes Greenwood et al 2009">{{cite journal |last1=Clark |first1=Chris D. |last2=Hughes |first2=Anna L.C. |last3=Greenwood |first3=Sarah L. |last4=Spagnolo |first4=Matteo |last5=Ng |first5=Felix S.L. |title=Size and shape characteristics of drumlins, derived from a large sample, and associated scaling laws |journal=Quaternary Science Reviews |date=April 2009 |volume=28 |issue=7–8 |pages=677–692 |doi=10.1016/j.quascirev.2008.08.035 |bibcode=2009QSRv...28..677C |url=http://nora.nerc.ac.uk/id/eprint/6960/1/Drumlins.pdf }}</ref> Drumlins generally have a length to width ratio of between 1.7 and 4.1<ref name="Clark Hughes Greenwood et al 2009"/> and it has been suggested that this ratio can indicate the velocity of the glacier. That is, since ice flows in laminar flow, the resistance to flow is frictional and depends on area of contact; thus, a more elongated drumlin would indicate a lower velocity and a shorter one would indicate a higher velocity.<ref>{{Cite journal|last=Nye|first=J|date=1952|title=The Mechanics of Glacier Flow|journal=Journal of Glaciology|volume=2|issue=12|page=82|doi=10.1017/S0022143000033967|bibcode=1952JGlac...2...82N|doi-access=free}}</ref>