Malin and Edgett, 2000 (Mars) Costard et al., 2002 (Greenland) Gullies on Mars and Earth.

Malin and Edgett, 2000 (Mars) Costard et al., 2002 (Greenland)

Gullies on Mars and Earth

PSP_002932_1445

Mangold: ‘Debris flows’• Some Levees (argues they are visible in

Fig. 1 & 2).• Cyclical sinuosity: Argues for ‘wet’• Nature of terminal deposits is not a

discriminating factor (wet v dry). Terminal slope may help discriminate if flow properties and inertia are correctly modeled.

5-m high flow, Jiangjia Gully, China (location referenced to by Coussot)

Repeat Time in this channel is roughly 9-10 events/yr. (Chen et al., 2005, Environmental Geology, 48, 771-777.

Image USGS/K. Scott, June 24, 1990

Stock and Dietrich, GSA Bulletin, 118, 1125-1148, 2006.

Discussion Points

• What are discriminating factors for recognizing debris flows?

• Flow magnitude/discharge in gullies?

• Are ‘typical’ flow characteristics inferred from images:

– debris flows, hyperconcentrated flows, or something more quiescent? [two-phase vs one-phase…]

– What is the formative flow conditions on gullied slopes? Is there a spectrum of behaviors?

– Mechanics of sediment incorporation…