Erik Ekdahl

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The Lake Titicaca Drilling Project
Erik Ekdahl Sheri Fritz Paul Baker Geoff Seltzer
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South American Altiplano
During periods of high lake level, outflow
through Lago Huinaimarca via the Rio
Desaguadero. Hydrologically connected to Lago
Poopo, and likely to the Salar de Uyuni, the
largest salt-flat on Earth.
Image taken on 28V2001
http//titicaca.ucsb.edu/chamak_pacha/ docs/lake_s
pace_imagery/images/modis_annotated.jpg
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Drill Core Stratigraphy from Copacabana Bay
From Seltzer et al., 2001
C. Scholz
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Site 2B
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Holocene
Glacial
Transition to Last Interglacial
LT01 2B
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Site 1 Water depth 141 m
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Site 2B
Site 2 Water depth 235 m
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Site 3 Water depth 40 m
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Glacial
Interglacial
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4 Major Glacial and Interstadial Intervals
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Onset of Glaciation 65,000 yr BP
Penultimate Low-stand MIS Stage 5e
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Low stands correlative with global warm periods
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Lake level as precipitation gauge
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Lake Titicaca Inter-annual Precipitation
Variability
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Biogenic silica record, centennial scale
resolution from 20-70 kya.
Percent BSi
Age (yr bp)
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MTM Spectral Analysis of Lake Titicaca Biogenic
Silica Record
Significant peak at 1670 yrs/cycle, with
several higher-frequency peaks above the 99
confidence interval
Power
1370
700
Frequency
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• Millennial-scale fluctuations are major component
  of Lake Titicaca biogenic silica record
• Fluctuations at 1200-1900 yrs describe 21 of
  variance in GRIP 48 of Lake Titicaca biogenic
  silica record

GRIP SSA PC2 and Lake Titicaca BSi
pc 2
BSi
Age (kyr BP)
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Working Conclusions

• Four major glacial and interglacial periods
  evident in record
• Onset of most recent glacial expansion 65,000 yr
  BP
• MIS5e was dry
• Millennial scale variation manifest in Southern
  Hemisphere tropics (cold N.Atl. wet Altiplano)
• Titicaca high (low) stands approximately
  synchronous with global cold (warm) periods