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

Recent marginal retreat of Mulajokull, a surge-type outlet glacier of Hofsjokull, 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 Mulajokull fi eld is the only known active drumlin fi eld, and is therefore a unique analogue to Pleistocene drumlin fi elds.