Mega-scale Glacial Lineations (MSGL)
MSGLs are defined as elongate corrugations in sediment produced beneath an ice sheet, similar to drumlins but much larger in all dimensions.
Characteristics of MSGLs
Typical lengths are 6 to 70 km, widths of 200 to 1300 m and spacings of 300 m to 5 km.
Their large scale requires synoptic images to observe them, as they often appear too fragmented at the scale of aerial photographs or field investigation.
This great length requires fast ice flows for their formation and when found they may indicate the location of former ice streams.
They have been found in Canada, Ireland, Scandinavia and adjacent to the West Antarctic Ice Sheet and beneath it.
Clark, C.D. 1993. Mega-scale glacial lineations and cross-cutting ice flow landforms. Earth Surface Processes and Landforms, 18, 1-29.
King E.C., Hindmarsh R.C.A., Stokes C.R. (2009). Formation of mega-scale glacial lineations observed beneath a West Antarctic ice stream . Nature Geoscience, 2 (8), pp. 585-588