Eskers are sinuous ridges composed of glacifluvial sand and gravel. They are deposited in channels with ice walls in subglacial, englacial and supraglacial positions. Eskers have been observed widely in deglaciated terrain and are varied in their planform. Many are single continuous ridges, whereas others are complex anastomosing systems and some are successive subaqueous fans deposited at retreating tidewater glacier margins (Benn & Evans 2010). Eskers are usually orientated approximately in the direction of past glacier flow. When basal water flows under pressure in full conduits, the hydraulic gradient and direction of water flow are controlled primarily by ice-surface slope, with bed topography of secondary importance (Shreve 1985). In such cases, eskers typically record the former flow of channelized and pressurized water both up- and downslope.
Description
Sinuous sedimentary ridges, orientated generally parallel to fjord long-axes, have been observed on swath-bathymetric images from several Spitsbergen fjords (Ottesen et al. 2008). In Rindersbukta, innermost van Mijenfjorden, and van Keulenfjorden in central Spitsbergen, the fjord floors have been exposed by glacier retreat over the past century or so (Ottesen et al. 2008). Sinuous sedimentary ridges occur within …
INDIVIDUALS
Log in using your username and password
Purchase access
LIBRARY USERS
Log in through your institution
Eskers formed at the beds of modern surge-type tidewater glaciers in Spitsbergen
