Drainage basins and channel incision on Mars

Abstract

Measurements acquired by the Mars Orbiter Laser Altimeter on board the Mars Global Surveyor indicate that large drainage systems on Mars have geomorphic characteristics inconsistent with prolonged erosion by surface runoff. We find the topography has not evolved to an expected equilibrium terrain form, even in areas where runoff incision has been previously interpreted. By analogy with terrestrial examples, groundwater sapping may have played an important role in the incision. Longitudinally flat floor segments may provide a direct indication of lithologic layers in the bedrock, altering subsurface hydrology. However, it is unlikely that floor levels are entirely due to inherited structures due to their planar cross-cutting relations. These conclusions are based on previously unavailable observations, including extensive piece-wise linear longitudinal profiles, frequent knickpoints, hanging valleys, and small basin concavity exponents.

Interior channels in Martian valley networks: Discharge and runoff production

“…1) (Milton, 1973;Masursky et al, 1977;Irwin and Howard, 2002), ubiquitous Noachian impact craters in the equatorial highlands that appear degraded by fluvial processes (Craddock et al, 1997;Forsberg-Taylor et al, 2004), and the need for recharge to support the erosion of valley network volumes (Howard, 1988;Goldspiel and Squyres, 1991;Grant, 2000;Gulick, 2001;Craddock and Howard, 2002). Martian valley networks are immature if formed by runoff, with numerous enclosed drainage basins, headcuts, or knickpoints along their longitudinal profiles (Baker and Partridge, 1986;Aharonson et al, 2002;Irwin and Howard, 2002), and relatively sparse tributary development on intervalley surfaces (Carr, 1996;Malin and Carr, 1999).…”

An Assessment of the Influences of Surface and Subsurface Water Level Dynamics in the Development of Gullies in Anambra State, Southeastern Nigeria

“…This observation is in conformity with the conceptual model ( Figure 5) and the GD-HH relationship (Figure 6). Although the erosive powers of both processes are threshold dependent, seepage erosion has the capability of creating gullies with different dimensions (Lobkovsky et al 2004) and has been suggested to be the dominant process that created the widespread erosion features observed on the surface of Mars (Baker 1990;Aharonson et al 2002).…”

Groundwater Controls and Processes

“…Despite the difficulties in groundtruthing these images and identifying evidence for the operation of seepage erosion processes, not to mention the dangers of circular argument, many Martian valleys were suggested to have formed by groundwater 'sapping' by analogy with terrestrial valley networks (e.g. Pieri, Malin and Laity, 1980;Higgins, 1982;Tanaka et al, 1998;Goldspiel and Squyres, 2000;Gulick, 2001;Aharonson et al, 2002;Grant and Parker, 2002;Luo, 2002;Harrison and Grimm, 2005;Stepinski and Stepinski, 2005;Howard, 2005, 2008). The use of terrestrial analogues to explain the origin of Martian valleys highlights one of the major problems of many studies of the role of exfiltrating water in valley development, namely that seepage erosion is often invoked purely on the basis of morphological and morphometric properties rather than by direct observation of processes (cf.…”

“…(e) Experimental drainage networks Baker (1990), Gomez and Mullen (1992), Howard (1988), Howard and McLane (1988), Kochel, Howard and McLane (1985), Kochel and Piper (1986), Sakura, Mochizuki and Kawasaki, (1987) (f) Extra-terrestrial valley networks Mars Baker and Kochel (1979), Carr (1980), Baker (1982Baker ( , 1983Baker ( , 1985Baker ( , 1990, Baker et al (1992), Belderson (1983), Craddock and Maxwell (1993), El-Baz (1982), Gulick and Baker (1990), Higgins (1982Higgins ( , 1983Higgins ( , 1984, Howard, Kochel and Holt (1988), Kochel, Howard and McLane (1985), Kochel and Piper (1986), Malin, (1980), Mars Channel Working Group (1983), Milton (1973), Pieri (1980), Pieri, Malin and Laity (1980), Sharp (1973), Sharp and Malin (1985), Stiller (1983), Tanaka and Chapman (1992), Tanaka et al (1998), Carr and Malin (2000), Goldspiel and Squyres (2000), Gulick (2001), Aharonson et al (2002), Grant and Parker (2002), Luo (2002), Harrison and Grimm (2005), Stepinski and Stepinski (2005) and Howard (2005, 2008) …”