Active drumlin field revealed at the margin of Múlajökull, Iceland: A surge-type glacier

Abstract

Recent marginal retreat of Múlajökull, a surge-type outlet glacier of Hofsjökull, Iceland, has revealed a drumlin fi eld consisting of more than 50 drumlins. The drumlins are 90-320 m long, 30-105 m wide, 5-10 m in relief, and composed of multiple beds of till deposited by lodgment and bed deformation. The youngest till layer truncates the older units with an erosion surface that parallels the drumlin form. Thus, the drumlins are built up and formed by a combination of subglacial depositional and erosional processes. Field evidence suggests each till bed to be associated with individual recent surges. We consider the fi eld to be active in the sense that the drumlins are shaped by the current glacial regime. The Múlajökull fi eld is the only known active drumlin fi eld, and is therefore a unique analogue to Pleistocene drumlin fi elds.

Manual mapping of drumlins in synthetic landscapes to assess operator effectiveness

“…Drumlins are elongate hills, typically 100 s m long and up to a few 10 s of metres high (Clark, Hughes, Greenwood, Spagnolo, & Ng, 2009;Menzies, 1979;Smith et al, 2007;Spagnolo, Clark, & Hughes, 2012;Wellner, Lowe, Shipp, & Anderson, 2001). They are very likely formed subglacially, parallel to ice flow (Johnson et al, 2010;King, Hindmarsh, & Stokes, 2009;Smith et al, 2007), and, as they can persist in the landscape, they encode information on the location and direction of flow of former ice cover (e.g. Finlayson et al, 2010;Hollingsworth, 1931;Kleman & Borgström, 1996) and perhaps even the nature and velocity of ice flow (e.g.…”

Late Quaternary Terrestrial Processes, Sediments and History: From Glacial to Postglacial Environments

“…Krüger and Thomsen 1984;Fuller and Murray 2002;Kjaer et al 2003;Schomacker et al 2014), although they are commonly scattered and in small numbers. The newest observations at the active drumlin field in the forefield of Múlajökull reveal the large number (110) of drumlins formed during recent surges (Johnson et al 2010;Hilmarsdóttir 2013;Jónsson et al 2014). These drumlins are 70 to 380 m in length, 20 to 180 m in width, and 2 to 10 m in height (Jónsson et al 2014), in such a way resembling the Pleistocene drumlins contrary to very small contemporary drumlins found at other locations in Iceland (Krüger and Thomsen 1984).…”

“…History of Múlajökull surges are known from 1924, four surges occurred since then within interval of 10-20 years. The last surge took place in 1992, when prominent end moraine was created (Johnson et al 2010). The Múlajökull was firstly visited by the first author of this paper on July, 2013, and overall observations of the distribution of glacial landforms were made.…”

A comparative case study of subglacial bedforms in northern Lithuania and south-eastern Iceland

“…Special attention should be paid to the investigations of actively forming subglacial bedforms in West Antarctica (Smith et al 2007;King et al 2009) and the recently exposed active drumlin field of Múlajökull (Iceland) where more than 50 drumlins was identified beyond the glacier's current margin (Johnson et al 2010). These papers provide an insight into the subglacial conditions in which these subglacial bedforms are created.…”

“…In this regard, investigations of subglacial bedforms near modern glaciers in Iceland (Johnson et al 2010, Waller et al 2008, Schomacker et al 2006, Boulton 1987Krüger 1987;), Sweden (Møller 2010), Antarctica (Smith et al 2007;King et al 2009;Rabassa 1987), and Switzerland (van der Meer 1983) are very important. Special attention should be paid to the investigations of actively forming subglacial bedforms in West Antarctica (Smith et al 2007;King et al 2009) and the recently exposed active drumlin field of Múlajökull (Iceland) where more than 50 drumlins was identified beyond the glacier's current margin (Johnson et al 2010).…”