Groundwatersapping Origin for the Giant Quebradas of Northern Chile

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Groundwater-sapping Origin for the Giant
Quebradas of Northern Chile

• Gregory D. Hoke, Bryan L. Issacks, Teresa E.
  Jordan, and Jennifer S. Yu
• Presented by Karen R. Carroll

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Research Location
Pica
Atacama Desert
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Digital Elevation Model (DEM) and Climate
Atamaca Desert (age 14 Ma) -Hadley cell
circulation -Peru current -Mountain barrier
(GTOPO30)
(InSAR)
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Groundwater Sapping vs. Dendritic Drainage
Central Yemen (Asia)

• Canyonlands National Park, Utah

http//en.wikipedia.org/wiki/Groundwater_sapping
http//www.lpi.usra.edu/publications/slidesets/geo
logy/sgeo/slide_21.html
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Groundwater Sapping in Basaltat Box Canyon, near
Hagerman, Idaho (Lamb and Detrich, 2004)
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Iceberg Canyon, Utah Escalante River
Tributary, Utah Groundwater Sapping
Overland Flow/Downcutting
Theater-headed terminations
Tapered terminations
Laity and Malin, 1985
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Model of Drainage Extension by Groundwater
Sapping (Laity and Malin, 1985)
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Materials in Stratigraphy of Oxaya Formation
(Oligocene-Miocene) and El Diablo Formation
(mid-upper Miocene)

• Lava flows (andesite)
• Ignimbrites
• Alluvial fans

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Polyphase Landscape Crosscutting Relationships
and Parallel Drainage
InSAR
Landsat
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Morphologies on Western Slope
A Theater-headed termination of sapping valley
with landslide activity B Abandoned sapping
valley with overlying surface drainage, showing
parallel drainage C Sapping valley not
showing parallel drainage
(InSAR and InSAR with Thermal Emission Radiometer
Image)
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Conclusions

• Climate is a factor in Atacama Desert for
  morphologies of canyons
• Slope, ancient direct rainfall, and emerging
  groundwater create parallel channel morphologies
• Uplift of Altiplano is a likely factor in arid
  climate