Surface Features Overview N vs. S differences Tharsis Plateau Volcanoes Shield Volcanoes Patera Volcanoes Planitia Valles Marineris Outflow Channels Polar Ice Caps Canals? Evidence of Past Water 31

32 North vs. South

Typical N. hemisphere region 33 Typical N. hemisphere region

Typical S. hemisphere region 34 Typical S. hemisphere region

High Elevation Region One ‘continent’: Tharsis, about the size rst.gsfc.nasa.gov One ‘continent’: Tharsis, about the size of Africa. 35

Olympus Mons Alba Patera (Volcanoes) Aligned Shield Volcanoes Valles Marineris 36

Volcanoes on Mars 2 types of volcanoes: shields and pateras. Shield volcanoes are wide and low. What does this tell you about the consistency or ‘viscosity’ of the lava? 37

Mars ‘typical’ volcano. www.bbc.co.uk Mars ‘typical’ volcano. Earth has shield volcanoes, but also has cone-shaped or “strato-volcanoes”, made from thicker, high-viscosity, lava. 38

Runnier basaltic lava, non-explosive eruptions 39

Mt. Kilauea – large caldera

Ascraeus Mons Parvonis Mons Arsia Mons The main shield volcanoes on Mars are Olympus Mons, and the aligned shield volcanoes: Ascraeus Mons Parvonis Mons Arsia Mons 41

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Olympus Mons If one edge were in Lancaster, the opposite edge would be in Chicago! At 15 miles or 80,000 feet, the crater is above Mars’ thin atmosphere. You could stand on Mars’ surface and be in space at the same time! 43

Olympus Mons 27 kilometers above mean datum. Slope is only 2.5o. 3x higher than Mt. Everest 2.6x taller than Mauna Kea (from sea floor base to caldera) Slope is only 2.5o. Surrounded by an escarpment up to 6 km high. Caldera is 85 km x 60 km. 44

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46 Olympus Mons

How did they get so big?

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than shield volcanos. Apollinaris patera The other type of volcano is a patera – a huge crater with almost no slope around it. Larger, but lower, than shield volcanos. Apollinaris patera http://www.the-planet-mars.com/pictures/Apollinaris-Patera-volcano.jpg 49

Alba Patera – almost no slope, huge caldera 50 Alba Patera – almost no slope, huge caldera

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From high to low – the Planitia Hellas Planitia 9 km deep 2100 km across rim is 1.25 km high impact debris thrown out to a distance of 4000 km Argyre Planitia 5 km deep 1800 several deep channels flow into it from surrounding terrain 52

Hellas www.astro.virginia.edu/class/oconnell/astr121/im/global-altim-hel-hem.jpg 53

Light-colored Hellas Planitia 54

Valles Marineris Huge canyon system 4000 km long up to 600 km wide up to 10 km deep (6-7 times deeper than our Grand Canyon) NOT formed by flowing water! (but possibly modified by water) How was it formed? 55

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www.astro.virginia.edu/class/oconnell/astr121/im/ValMar-v-GrCan-TSmith-uwash-enl.jpg 58

How was it formed? qnck.imageg.net 59

rst.gsfc.nasa.gov/Sect19/FHA-01278sub_bw2b.JPG 61

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63 Near the eastern end of the Valles Marineris are huge canyons called “outflow channels”.

Ravi Vallis 64

How did they form? Here on earth, in Washington State, there are similar rugged canyon-lands called the Scablands. 65

The Scablands of Washington State, USA www.uwsp.edu/geo/projects/geoweb/participants/dutch/GeoPhotoVtrips/Scablands www.kidscosmos.org/kid-stuff/mars-trip-graphics/ flood-channel-map-sml.jpg The Scablands of Washington State, USA 66

Catastrophic Flooding Glacial dam across a river in Washington State. Lake Missoula. Pressure of the water broke through the ice, releasing hundreds of cubic miles of water all at once. Scablands carved in just a few weeks. 67