LPSC Notes Part 3

I guess I wrote down more than I thought, so here is more:

• RADAR Lakes/Dark Spot - Lorenz
  • sharp boundaries
  • typically 10-15 km across
  • cardoid or crescent shaped
  • emission is a bit stronger
  • crater lake at circus maximus?
  • Seasonal effects on distribution - more "lakes" in far north
• VIMS topography
  • ridges found through shape-from-shading, a few hundred km - 10 km between ridges
  • possible H2O and NH3 features in bright regions
  • perhaps the bright regions are the theorized ammonia-water cryovolcanic eruptive material
• Photometric studies with VIMS - Nelson
  • I/F values - bright 0.168, bright intermediate 0.138, low 0.07
  • tau may increase values by 20% or more
  • no evidence for large accumulation of flat lying liquids
  • older surface, slow erosion
• VIMS Observations of Titan's surface - Rodriguez
  • Ta hires - 1.8 km/pixel - snail
  • 30 km diameter bright feature w/ two elongated wings extending west
  • 1 pixel much darker than surroundings at center of feature
  • cryovolcanism with caldera at center
  • E-W darker linear feature
  • Tectonic features or flow lines
  • similar to Ganymede's grooved terrain?
  • not pure water ice
    • 2.67 microns/2.75 microns > 1
    • other constituent absorbs at 2.67 microns
• RADAR Mapping - E. Stofan
  • wavelength = 2.17 cm
    spatial resolution 400m-1km
  • swaths 120-450 km
  • incidence angles - Ta=<10-30 deg; T3=15-45 deg
  • volume scattering may be important due to ice, hydrocarbons, ammonia-ice mixtures, tholins
  • units
    • 8 basic units (2-3% of planet)
    • distinctions - radar brightness, planform shape, slope
    • boundaries on T3 obscured by apparent surficial deposits
    • sinuous features
    • Impact craters
      • 2 craters in T3
      • none w/ confidence in Ta
    • Homogenous Unit
      • dominant in Ta (50-60%)
      • less common, brighter in T3 (20%)
    • mottled unit - boundary gradational
    • bright mottled unit (T3) - Xanadu
    • Bright lobate unit
      • cryovolcanic flows
      • lobate
      • sheet-like and digitate
    • Bright lineated unit
      • fan shaped deposits
      • grooved
    • dark mottled unit - smooth, mobilized unit
    • hummocky unit - small, isolated hills, center of circus maximus, end of Ta
• Cryovolcanism as seen by RADAR - Lopez
  • Ganesa Macula
    • channels 91 km in length
    • 23 km depression in middle
    • flow south and east from central pit that runs over edge
  • Large flow
    • 49N, 43W
    • 23,700 km2
    • 100-200 km in length
  • western caldera - 18 km across
  • eastern caldera
    • ~13 km
    • area 1235 km2
    • flow thickness - 200-300 m
  • ammonia-water flow viscocities similar to silicates - consistant with flow thickness
• Channels and Fan-like features
  • between Ganesa and giant flow, resolution jumped from 500-1000 m/pixel
  • channels 1000 meters across
    • drainage not fully developed
    • low order, short lasting drainage present
    • depositional surface ha the same SAR bright return as the channels
    • channels could represent erosional surfaces leading to triangular fan deposits
  • Channels near Circus Maximus
    • rim 430 meters high
    • channels 500m-1km across extend for 100-180 km on a ENE sloping surface
    • fan features
    • accumulation surface
    • lineations/flow lines/cracks?
    • dendritic drainage at crater rim
    • presence of transported materials w/ different radar properties than surrounding surface