Geen diatitel

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Micromorphology on Mars

• - geometric and dimensionless parameters
• comparison to landforms on Earth
• water-generated landforms

Dr. Maarten Kleinhans m.kleinhans_at_geog.uu.nl www.g
eog.uu.nl/fg/mkleinhans
Universiteit Utrecht Faculty of Geosciences
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Introduction

• Aims - test universality of Earths relations
• - infer morphological processes
• Presentation
• Micromorphology bedforms, bars, channels
• Geometric indices and dimensionless parameters
• Potential settings on Mars

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Bedforms 1m-1km long
wave ripples
current dunes
tidal ridges
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Bars and channels
Example the R. Waimakariri, New Zealand
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Example the R. Allier, France
bars
channel
bedforms
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Example the Amazon leveed turbidity current
channel on the shelf
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Geometry relations

• bedform geometric indices
• steepness height / length process
• asymmetry currents / waves
• three-dimensionality energy

• channel geometry f (bankfull discharge)
• width / depth
• channel sinuosity
• w cQp p 0.53 width
• h cQq q 0.37 depth
• u cQr r 0.10 velocity
• since Q W h u, pqr1 by definition

Ratio discharge-dept.
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Dimensionless numbers

• stream power ? ?u
• Shields number ? ?/(?s-?)gD
• Froude number Fr u/(g h)0.5
• Reynolds number Re for various length scales

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Stream power river planform
? Allier ? Meuse ? Rhine ? Volga
Stream power
(Van den Berg, 1995)
Grain size
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Delta forming...
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....a classical case of river lake
sedimentation....
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with extensive meander formation Individual
channels must have been in equilibrium!
chute cut-offs
flow direction
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We know something about meanders.
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Potential settings on Mars

• not the catastrophic outflow channels (not in
  equilibrium)
• not the tiniest morphology (destroyed, resolution
  of Mars Express HR Stereo Camera limited)
• impact crater lakes?
• outflow channels from incipient channel networks?
• potential continental margins for coastal,
  estuarine and deltaic landforms?

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Approach

• time limited...
• literature review summarising geometric indices
  and non-dimensional relations for various
  landforms
• autumn 2004 ESA Mars Express workshop
• study images and find goldmines...
• extract 3D information from stereo-images using
  conventional DEM extraction software for Remote
  Sensing

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Dutch Philosophy of Geosciences Symposium
Utrecht, the Netherlands, 16 April 2004 (friday)
For geoscientists, philosophers and
students interested in the nature of
geosciences, civil engineering, geology,
meteorology, geography, environmental sciences,
climatology, paleontology, geochemistry,
biogeology, sedimentology, geophysics,
oceanography, water and sediment management
employing scientific knowledge, philosophy of
science, of biology, of physics, of
experimentation and of technology
Information www.geog.uu.nl/fg/philosophy Register
m.kleinhans_at_geog.uu.nl Price 25 EURO
Programme 1000 Opening - Maarten Kleinhans 1030
physical earth scientist Gerbrand Komen1140
interdisciplinary earth scientist Victor
Baker1330 philosopher of physics - Henk de Regt
1420 philosopher of biology Arno Wouters1600
happy hour