Living Reference Work Entry

Encyclopedia of Planetary Landforms

pp 1-6

Date: Latest Version

Esker

  • Jarmo KorteniemiAffiliated withEarth and Space Physics, Department of Physics, University of Oulu Email author 
  • , Hazen A. J. RussellAffiliated withGeological Survey of Canada
  • , David R. SharpeAffiliated withGeological Survey of Canada
  • , Robert D. StorrarAffiliated withSchool of Geography, Queen Mary University of London

Definition

Straight-to-sinuous ridge composed of sand/gravel, deposited in a confined glacial meltwater drainage channel.

Category

A type of straight-to-sinuous ridge (Linear ridge types (various origins)).

Proposed origin of some of the inverted channels and sinuous ridges on Mars.

Description

Winding, steep sided, narrow, sharp- to broad-crested ridges of cross-stratified and massive sand, gravel, and boulders. May be mistaken for other slightly sinuous or Linear ridge types (various origins). In planform, eskers can be sinuous, anastomosing, and/or discontinuous. Isolated, closed depressions (kettles), commonly water filled, may flank or be part of broader esker ridges.

Esker Patterns

Eskers may occur in isolation or form networks that branch upflow in either subparallel or dendritic patterns (Brennand 2000) with up to fourth-order tributaries (Shilts et al. 1987). Esker systems may be composed of (in increasing order of scale) anastomosing eskers, short sub-parallel esker systems, and long ...

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