| SPELEOTHEMS |
Frisia et al. 2003 Grotta di Ernesto, Italy Speleothem Layer Thickness Data
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Frisia, S.;Borsato, A.;Preto, N.;McDermott, F. 2003 Late Holocene annual growth in three Alpine stalagmites records the influence
of solar activity and the North Atlantic Oscillation on winter climate Earth and Planetary Science Letters Vol. 216, Issue
3, pp.411-424, 30 November 2003.
| Data Coverage |
North: 45.98 * South: 45.98 |
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West: 11.66 * East: 11.66 |
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Altitude: 1167 m |
Start Year: 1387 AD
End Year: 2000 AD
Data: Please Cite Data Contributors!
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Summary: Annual growth rates and the ratio of dark to light-colored calcite within
single annual laminae in three contemporaneously deposited Holocene
speleothems from Grotta di Ernesto, an Alpine cave in northern Italy,
respond to changes in surface temperature rather than precipitation.
Based on monitoring of present-day calcite growth, and correlation with
instrumental data for surface climatic conditions, we interpret a higher
ratio of dark to light-colored calcite and the simultaneous thinning of
annual laminae as indicative of colder-than-present winters. Such dark
and thin laminae occur in those parts of the three stalagmites deposited
from AD 1650 to 1713 and from AD 1798 to 1840, as reconstructed through
lamina counting. These periods correspond to the well-known Maunder and
Dalton Minima of solar activity. An 11-yr cyclicity in growth rate,
coupled with reduced calcite deposition during the historic minima of
solar activity, is indicative of a solar influence on lamina thickness.
Spectral analysis of the lamina thickness data also suggests that the
North Atlantic Oscillation variability influenced winter temperatures.
Based on the present-day controls on cave calcite formation, we infer
that high-frequency changes in solar activity modulated the seasonal
duration of soil CO2 production.
More Info on Speleothems |
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Complete XML Record: noaa-cave-5438
(Last Revised: 2007-10-18 )
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