scholarly journals Review of Fang et al 14C-DOC ice core dating study

2020 ◽  
Author(s):  
Anonymous
Keyword(s):  
Ice Core ◽  
Ice Core Dating

Progress on absolute dating of ice cores with Argon isotopes

2021 ◽  
Author(s):  
Anais Orsi ◽  
Ilaria Crotti ◽  
Roxanne Jacob ◽  
Amaelle Landais ◽  
Elise Fourré
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Significant Advance ◽  
Large Sample Size ◽  
Argon Isotopes ◽  
Absolute Dating ◽  
Dating Method ◽  
A New Technique ◽  
Ice Core Dating ◽  
Key Parameter

<p>In the search for very old ice, finding the age of the ice is a key parameter necessary for its interpretation. Most ice core dating method are based on chronological markers that require the ice to be in stratigraphic order. However, the oldest ice is likely to be found at the bottom of ice sheets, where the stratigraphy is disturbed, or in ablation areas, where the classical methods cannot be used. Absolute dating techniques have recently been developed to provide new constraints on the age of old ice, but their development in the context of ice cores is limited by the large sample size required. Here, we discuss the analytical performances of a new technique for 40Ar dating, which allows us to provide a reliable age with 80g of ice rather than 800g, as previously published. We present an application to the dating of the bottom of the TALDICE and Dome C ice cores. This method represents a significant advance for its application to the very precious ice at the bottom of ice cores.</p>

scholarly journals Himalayan ice-core dating with snow algae

2000 ◽  
Vol 46 (153) ◽  
pp. 335-340 ◽  
Author(s):  
Yoshitaka Yoshimura ◽  
Shiro Kohshima ◽  
Nozomu Takeuchi ◽  
Katsumoto Seko ◽  
Koji Fujita
Keyword(s):  
Vertical Profile ◽  
Algal Biomass ◽  
Ice Core ◽  
Algal Growth ◽  
Ice Cores ◽  
Late Summer ◽  
Layer Formation ◽  
Snow Algae ◽  
Potential Use ◽  
Ice Core Dating

AbstractSnow algae in shallow ice cores (7 m long) from Yala Glacier in the Langtang region of Nepal were examined for potential use in ice-core dating. Ice-core samples taken at 5350 m a.s.l. in 1994 contained more than seven species of snow algae. In a vertical profile of the algal biomass, 11 distinct algal layers were observed. Seasonal observation in 1996 at the coring site indicated most algal growth occurred from late spring to late summer. Pit observation in 1991, 1992 and 1994 indicated that algal layer formation takes place annually. δ18O, chemical ions (Na+, Cl−, SO42− and NO3−) and microparticles failed to show any clear seasonal variation, particularly at depths exceeding 2 m, possibly due to heavy meltwater percolation. Snow algae in ice cores would thus appear to be accurate boundary markers of annual layers and should prove useful for ice-core dating in Himalayan-type glaciers.

scholarly journals Ice-Core Dating of the Pleistocene/Holocene Boundary Applied to a Calibration of the 14C Time Scale

Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 284-291 ◽  
Author(s):  
Claus U Hammer ◽  
Henrik B Clausen ◽  
Henrik Tauber
Keyword(s):  
Seasonal Variations ◽  
Time Scale ◽  
Ice Core ◽  
Late Glacial ◽  
Dust Content ◽  
Error Limit ◽  
A Value ◽  
C Value ◽  
Estimated Error ◽  
Ice Core Dating

Seasonal variations in 18O content, in acidity, and in dust content have been used to count annual layers in the Dye 3 deep ice core back to the Late Glacial. In this way the Pleistocene/Holocene boundary has been absolutely dated to 8770 BC with an estimated error limit of ± 150 years. If compared to the conventional 14C age of the same boundary a value of Δ14C = 53 ± 13‰ is obtained. This Δ14C value suggests that 14C levels during the Late Glacial were not substantially higher than during the Postglacial.

scholarly journals Ice-core dating and chemistry by direct-current electrical conductivity

1992 ◽  
Vol 38 (130) ◽  
pp. 325-332 ◽  
Author(s):  
Kenorick Taylor ◽  
Richard Alley ◽  
Joe Fiacco ◽  
Pieter Grootes ◽  
Gregg Lamorey ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Ice Core ◽  
Low Frequency ◽  
Ice Cores ◽  
Quantitative Comparison ◽  
Quantitative Interpretation ◽  
Conductivity Measurements ◽  
Temperature Variations ◽  
The Core ◽  
Ice Core Dating

AbstractAlthough quantitative interpretation of the low-frequency electrical conductivity of ice cores from central Greenland is complicated by temperature variations of the measured core, annual layers can be recognized in sections of the core that are not impacted by non-seasonal features. Ambiguities in counting of annual layers can be minimized by comparing the electrical conductivity measurements to measurements of dust concentration and visual stratigraphy. A non-linear relationship between applied voltage and the current measured across two electrodes complicates the quantitative comparison of measurements made with different equipment, but does not affect the overall shape of the observed features.

scholarly journals Development of a model for ice core dating based on grain elongation

Polar Science ◽  
2011 ◽  
Vol 5 (3) ◽  
pp. 319-326 ◽  
Author(s):  
C.L. Di Prinzio ◽  
O.B. Nasello
Keyword(s):  
Ice Core ◽  
Ice Core Dating

scholarly journals Radar stratigraphy connecting Lake Vostok and Dome C, East Antarctica, constrains the EPICA/DMC ice core time scale

2013 ◽  
Vol 7 (1) ◽  
pp. 321-342 ◽  
Author(s):  
M. G. P. Cavitte ◽  
D. D. Blankenship ◽  
D. A. Young ◽  
M. J. Siegert ◽  
E. Le Meur
Keyword(s):  
Ice Core ◽  
Airborne Radar ◽  
Glacial Cycle ◽  
Glacial Cycles ◽  
Last Glacial ◽  
Lake Vostok ◽  
The Last Glacial Maximum ◽  
Radar Technique ◽  
Ice Core Dating ◽  
The Last Glacial

Abstract. New airborne radar sounding surveys at 60 MHz are used to trace internal layering between the Vostok and EPICA Dome C ice core sites. Eleven layers, spanning two glacial cycles from the last glacial maximum back to the MIS 7c interglacial, are used to correlate the two ice core chronologies. Independent of palaeoclimate signals, radar sounding enables correlation of the timescales, with a radar depth uncertainty equivalent to hundreds of years, which is small relative to the ice core dating uncertainties of thousands of years. Along the radar transects, horizons belonging to the last glacial cycle are impacted by aeolian stratigraphic reworking that increases radar technique uncertainty for this interval. However, older layers are used to propagate the higher resolution Vostok ages to the lower resolution Dome C ice core using the Suwa and Bender (2008) Vostok O2 / N2 chronology to give a recalibration of the Parrenin et al. (2007) EPICA EDC3 timescale between 1597 m and 2216 m depth (126 ka to 247 ka age interval).

scholarly journals Implementation of counted layers for coherent ice core chronology

2015 ◽  
Vol 11 (6) ◽  
pp. 959-978 ◽  
Author(s):  
B. Lemieux-Dudon ◽  
L. Bazin ◽  
A. Landais ◽  
H. Toyé Mahamadou Kele ◽  
M. Guillevic ◽  
...  
Keyword(s):  
Bayesian Approach ◽  
Ice Core ◽  
Ice Cores ◽  
Global Error ◽  
A Posteriori ◽  
Sensitivity Tests ◽  
New Type ◽  
Ice Core Dating

Abstract. A recent coherent chronology has been built for four Antarctic ice cores and the NorthGRIP (NGRIP) Greenland ice core (Antarctic Ice Core Chronology 2012, AICC2012) using a Bayesian approach for ice core dating (Datice). When building the AICC2012 chronology, and in order to prevent any confusion with official ice core chronology, the AICC2012 chronology for NGRIP was forced to fit exactly the GICC05 chronology based on layer counting. However, such a strong tuning did not satisfy the hypothesis of independence of background parameters and observations for the NGRIP core, as required by Datice. We present here the implementation in Datice of a new type of markers that is better suited for constraints deduced from layer counting: the duration constraints. Estimating the global error on chronology due to such markers is not straightforward and implies some assumption on the correlation between individual counting errors for each interval of duration. We validate this new methodological implementation by conducting twin experiments and a posteriori diagnostics on the NGRIP ice core. Several sensitivity tests on marker sampling and correlation between counting errors were performed to provide some guidelines when using such a method for future dating experiments. Finally, using these markers for NGRIP in a five-core dating exercise with Datice leads to new chronologies that do not differ by more than 410 years from AICC2012 for Antarctic ice cores and 150 years from GICC05 for NGRIP over the last 60 000 years.

scholarly journals Exploitation of chemical profiles by conjugate variable analysis: application to the dating of a tropical ice core (Nevado Illimani, Bolivia)

2013 ◽  
Vol 9 (3) ◽  
pp. 3399-3447
Author(s):  
M. Gay ◽  
M. De Angelis ◽  
J.-L. Lacoume
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Ion Concentration ◽  
Depth Profiles ◽  
Conjugate Variable ◽  
Chemical Profiles ◽  
Analysis Application ◽  
The Relationship ◽  
Concentration Depth Profiles ◽  
Ice Core Dating

Abstract. Ice core dating is a key parameter for the interpretation of the ice archives. However, the relationship between ice depth and age can generally not be easily established and requires to combine a large number of investigations and/or modeling effort. This paper presents a new approach of ice core dating based on conjugate variable (depth and spatial frequency) analysis of chemical profiles. The relationship between the depth of a given ice layer and the date it was deposited is determined using ion concentration depth profiles obtained along a one hundred-meters deep ice core recovered in the summit area of the Nevado Illimani (6350 m a.s.l.), located in the Eastern Bolivian Andes (16°37' S, 67°46' W). The results of Fourier conjugate analysis and wavelet tranforms are first compared. Both methods are applied to nitrate concentration depth profile. The resulting chronologies are checked by comparison with the multi-proxy year-by-year dating published by de Angelis et al. (2003) and with volcanic tie points, demonstrating the efficiency of Fourier conjugate analysis when tracking the natural variability of chemical proxies. The Fourier conjugate analysis is then applied to concentration depth profiles of seven other ions thus providing information on the suitability of each of them for dating studies of tropical Andean ice cores.

scholarly journals Optimisation of glaciological parameters for ice core chronology by implementing counted layers between identified depth levels

2014 ◽  
Vol 10 (4) ◽  
pp. 3585-3616 ◽  
Author(s):  
L. Bazin ◽  
B. Lemieux-Dudon ◽  
A. Landais ◽  
M. Guillevic ◽  
P. Kindler ◽  
...  
Keyword(s):  
Bayesian Approach ◽  
Accumulation Rate ◽  
Ice Core ◽  
Ice Cores ◽  
Age Difference ◽  
Sensitivity Tests ◽  
New Type ◽  
Lock In ◽  
Ice Core Dating

Abstract. A~recent coherent chronology has been built for 4 Antarctic ice cores and the NorthGRIP (NGRIP) Greenland ice core (Antarctic Ice Core Chronology 2012, AICC2012) using a bayesian approach for ice core dating (Datice). When building the AICC2012 chronology, and in order to prevent any confusion with official ice cores chronology, it has been imposed that the AICC2012 chronology for NGRIP should respect exactly the GICC05 chronology based on layer counting. However, such a strong tuning did not satisfy the hypothesis of independence of background parameters and observations for the NGRIP core as required by Datice. We present here the implementation in Datice of a new type of markers that is better suited to constraints deduced from layer counting: the markers of age-difference. Using this type of markers for NGRIP in a 5 cores dating exercise with Datice, we have performed several sensitivity tests and show that the new ice core chronologies obtained with these new markers do not differ by more than 400 years from AICC2012 for Antarctic ice cores and by more than 130 years from GICC05 for NGRIP over the last 60 000 years. With this new parameterization, the accumulation rate and lock-in depth associated with NGRIP are more coherent with independent estimates than those obtained in AICC2012. While these new chronologies should not be used yet as new ice core chronologies, the improved methodology presented here should be considered in the next coherent ice core dating exercise.

Sign in / Sign up

Export Citation Format

Share Document