Mars and its landscapes

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Mars and its landscapes

• Global topography and hemispheric differences
• Huge basalt shield volcanoes
• Gigantic rift valleys and canyons
• Gigantic landslides
• Flowing water in the past
• Spontaneous, catastrophic melting of permafrost
• Impact craters with lobate ejecta blankets
• Dust storms and wind-formed features (e.g.,
  dunes)
• Polar regions with ice/dust layers
• Ancient oceans?

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Topography of Mars
Range 20,000 m (20 km)
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Southern Highlands and Northern Plains at the
same scale
S. Highlands many craters, and high.
N. Plains few craters and low.
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Mars and its landscapes

• Global topography and hemispheric differences
• Huge basalt shield volcanoes
• Gigantic rift valleys and canyons
• Gigantic landslides
• Flowing water in the past
• Spontaneous, catastrophic melting of permafrost
• Impact craters with lobate ejecta blankets
• Dust storms and wind-formed features (e.g.,
  dunes)
• Polar regions with ice/dust layers
• Ancient oceans?

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The volcanoes of Mars
Alba
Hecates Tholus
Olympus Mons
Elysium Mons
Ascraeus Mons
Tyrrhena Patera
Pavonis Mons
Hadriaca Patera
Arsia Mons
Apollinaris Patera
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Olympus Mons compared to Hawaiian Islands
640 km (400 miles)
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Olympus Mons basal scarp and water channels
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Same features at Fernandina, Galapagos Islands
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Olympus Mons
Lava flows
Olympus Mons
Hawaii
Mauna Loa, Hawaii
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Mars and its landscapes

• Global topography and hemispheric differences
• Huge basalt shield volcanoes
• Gigantic rift valleys and canyons
• Gigantic landslides
• Flowing water in the past
• Spontaneous, catastrophic melting of permafrost
• Impact craters with lobate ejecta blankets
• Dust storms and wind-formed features (e.g.,
  dunes)
• Polar regions with ice/dust layers
• Ancient oceans?

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Valles Marineris
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Valles Marineris
2500 km long up to 250 km wide up to 8 km deep
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Dark layers in walls may be volcanic ash
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More views of layers within interior of Valles
Marineris
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Mars
Martian geologic features

• Layers of sedimentary and/or volcanic rocks
  (water?)
• Important for climate studies

Colorado
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Mars and its landscapes

• Global topography and hemispheric differences
• Huge basalt shield volcanoes
• Gigantic rift valleys and canyons
• Gigantic landslides
• Flowing water in the past
• Spontaneous, catastrophic melting of permafrost
• Impact craters with lobate ejecta blankets
• Dust storms and wind-formed features (e.g.,
  dunes)
• Polar regions with ice/dust layers
• Ancient oceans?

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Gigantic landslides show that the walls of the
canyons have not always been stable
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Mars and its landscapes

• Global topography and hemispheric differences
• Huge basalt shield volcanoes
• Gigantic rift valleys and canyons
• Gigantic landslides
• Flowing water in the past
• Spontaneous, catastrophic melting of permafrost
• Impact craters with lobate ejecta blankets
• Dust storms and wind-formed features (e.g.,
  dunes)
• Polar regions with ice/dust layers
• Ancient oceans?

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Outflow water channels such as Kasei Vallis
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Kasei Vallis
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Martian geologic features Kasei Vallis
Impact crater eroding out of rock layers in wall
of outflow channel
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Eastern end of Valles Marineris may be source of
much water
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Gullies in walls of impact craters suggest recent
water flow
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Mars and its landscapes

• Global topography and hemispheric differences
• Huge basalt shield volcanoes
• Gigantic rift valleys and canyons
• Gigantic landslides
• Flowing water in the past
• Spontaneous, catastrophic melting of permafrost
• Impact craters with lobate ejecta blankets
• Dust storms and wind-formed features (e.g.,
  dunes)
• Polar regions with ice/dust layers
• Ancient oceans?

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Martian features may be similar to channeled
scablands of Washingtons Columbia River Plateau,
the result of a gigantic flood resulting from the
failure of a glacial dam during the ice age
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Mars Odyssey Gamma Ray detection of water
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Mars and its landscapes

• Global topography and hemispheric differences
• Huge basalt shield volcanoes
• Gigantic rift valleys and canyons
• Gigantic landslides
• Flowing water in the past
• Spontaneous, catastrophic melting of permafrost
• Impact craters with lobate ejecta blankets
• Dust storms and wind-formed features (e.g.,
  dunes)
• Polar regions with ice/dust layers
• Ancient oceans?

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Ejecta ray pattern for the 92 km diameter lunar
crater Copernicus
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Meteorite impact craters on Mars as subsurface
probes
Text book pages 252 - 256
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Many impact craters on Mars have mud-like
ejecta. Suggests water or ice in target at time
of crater formation
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Mars and its landscapes

• Global topography and hemispheric differences
• Huge basalt shield volcanoes
• Gigantic rift valleys and canyons
• Gigantic landslides
• Flowing water in the past
• Spontaneous, catastrophic melting of permafrost
• Impact craters with lobate ejecta blankets
• Dust storms and wind-formed features (e.g.,
  dunes)
• Polar regions with ice/dust layers
• Ancient oceans?

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The great dust storms of Mars during the arrival
of Mariner 9
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The dust veil is beginning to dissipate
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Mars has global (and local) dust storms
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Wind erosion of floor reveals rock layers of
different strength
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Mars
Atmospheric Features
Dunes (wind)
Saudi Arabia
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Mars and its landscapes

• Global topography and hemispheric differences
• Huge basalt shield volcanoes
• Gigantic rift valleys and canyons
• Gigantic landslides
• Flowing water in the past
• Spontaneous, catastrophic melting of permafrost
• Impact craters with lobate ejecta blankets
• Dust storms and wind-formed features (e.g.,
  dunes)
• Polar regions with ice/dust layers
• Ancient oceans?

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Martian polar caps
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Martian polar caps are made of
Water (H2O) ice
Carbon dioxide (CO2) ice
North Pole
South Pole
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Mars and its landscapes

• Global topography and hemispheric differences
• Huge basalt shield volcanoes
• Gigantic rift valleys and canyons
• Gigantic landslides
• Flowing water in the past
• Spontaneous, catastrophic melting of permafrost
• Impact craters with lobate ejecta blankets
• Dust storms and wind-formed features (e.g.,
  dunes)
• Polar regions with ice/dust layers
• Ancient oceans?

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Possible ancient oceans in the north polar
regions of Mars?
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Argyre Basin may once have been flooded with water
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Dried sediments on floor Former shallow seas?
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Mars
Geologic features of Southern Highlands

• Valley networks in Southern Highlands suggest
  small volumes of water for long time periods.
• Rainfall???

Earth
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