Volcanism in the Inner Solar System Allan Treiman

Volcanism in the Inner Solar System Allan Treiman Again

Earth’s Volcanos I Shield v Composite / Stratovolcano v Cinder Cone v

Earth’s Volcanos II Caldera Complex ‘Super. Volcano’ v Lava Plateau v Dome v Single Flow v Tuff Ring v And … v

Venus v v v Venus Earth From Sun (AU) 0. 72 1. 0 Mean radius (km) 6052 6371 Mass (1024 kg) 4. 87 5. 98 Surface T (K) 735 295 Gravity (m s-2) 8. 9 9. 8

Venus Surface Landers: Venera & VEGA

Sapas Mons 400 km across, 1. 5 km tall v Slope ~ 0. 5° v Very long flows v What kind of volcano? ? v

Maat Mons v JPL Press Image 20 x Vertical Exaggeration v v Unexaggerated … What kind of volcano?

Pancake Domes v v Single Flows, Steep sides Height 1/2 - 1 km. v v What kind of volcano? What kind of lava?

Pancake Domes v v Rhyolite? Or merely cold, crystal -rich basalt? v v What kind of volcano? What kind of lava?

? Low cones in flat lava plains v A few km diam. (5 km for inset) v What type of lava? v What kind of volcano? v

Mars

Olympus Mons 640 x 840 km across v 21 km tall v Avg slope 5° v What kind of volcano? v What kind of lava? v

Lava Flows on O. M. 1 <-- - - 3 km - - -->

Lava Flows on O. M. 2 <-- - - 3 km - - -->

On Syrtis Major, a Shield Volcano � Small Hill v Steep Slope, ~30° v Surrounded by thin lava flows v What is it? v

On Syrtis Major, a Shield Volcano � v Broken Cinder Cone?

Hadriaca Patera 50 km

~ 25 km Sinuous Pit Chain South margin, Hadriaca Patera. v What could this be? v What type of lava? v

Moon 1/3 diam of Earth v 1/6 gravity v Dark, low, mare plains. v

Mare Plains

Channels

Domes v v Gruithuisen domes 20 km across, 1. 2 km tall. Avg ~7° slope; steepest ~20°. Are these volcanic? If so, what are they most like on Earth?

Mercury Tons of Craters v Some Flat Plains v Only ~ 1/3 imaged v Messenger spacecraft on its way to orbit! v

Craters and Plains v Crater Rims Partly buried 500 km v Large crater, flat fill 500 km