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Important processes:

• Tectonism• Volcanism• Cratering• Climate links

Impact craters Pancake domesShield volcanoes

Class 14: Topography,Tectonics, Volcanism

Magellan Mapping of Venus

SAR image

topography

gravity

Resolution & Topography

Height above mean (km)

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Magellan Gravity Data

Magellan-measured Gravity

milligals

Topography of Venus

Ishtar Ovda/Thetis

Atla Beta

Lavinia

Highlands: Atla

Ozza Mons

Sappas Mons

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Plains: Lavinia

Radar Imaging

flatsurface

forest cropland mountains roughsurface

city

surfacetype

RadarImage

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Example: Radar Image

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Stuff about Radar Images

slopingsurface

flatsurface

roughsurface

Example: Radar Image

Radar Image Properties

Surface

(reflective stuff)

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Plateaus: Ishtar

Maxwell Montes

Plateaus: Thetis

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tectonics: crustal stresses & resulting features (forces) (faults, folds)

Tectonics & Deformation

stresses can push crust together (compression),

building mountains

stresses can pull crustapart (extension) ,

making cracks/valleys

Appalachian Mts. Ceranius Valleys (Mars)

compression extension

Rock Strength

stronger

Brittle and Ductile Deformation

Extension(normal faults)

Transform(strike-slip faults)

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Brittle and Ductile Deformation

50 km

Venus: Folds & Mountain Belts(Earth)Akna Montes

Ishtar

Venus: Faults

Gumby

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Venus: Rifting

25 km

Venus: Volcanoes

Maat Mons

caldera

main volcanic edifice

lava flowsextending away

from edifice

Size & Shape

volatiles releasedinto atmosphere

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Locations

Shield Fields

Volcano Flows