scholarly journals Radiocarbon and Varve Chronologies of Annually Laminated Lake Sediments of Gościαz Lake, Central Poland

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 940-947 ◽  
Author(s):  
Tomasz Goslar ◽  
Anna Pazdur ◽  
Mieczysław F Pazdur ◽  
Adam Walanus
Keyword(s):  
Water Depth ◽  
Time Scale ◽  
Laminated Sediments ◽  
Varve Thickness ◽  
Varve Chronology ◽  
Continuous Sequence ◽  
The World ◽  
Annually Laminated Sediments ◽  
Annually Laminated Lake Sediments ◽  
Good Agreement

A sequence of annually laminated sediments of the Gościαz Lake spans ca 13,000 yr and is actually the longest known continuous sequence in the world. 14C age measurements were performed on organic and carbonate fractions of bulk samples of laminated sediments from core GO. Accurate measurements of varve thickness performed on the lower part of cores G1 and G2 were used to establish a floating varve chronology covering ca 10,000 yr. Matching of cores GO, G1 and G2 permits comparison of 14C dates with varve chronology. Good agreement of calibrated 14C dates with the varve time scale suggests annual lamination of the sediment. Analysis of periodicities in varve thickness indicates solar 11-and 22-yr cycles, as well as a 200-yr cycle over a good part of the investigated sequence. Results of 14C measurements of carbonate fractions are used to study changes in the water depth of the lake during its history.

scholarly journals A 40,000-Year Varve Chronology from Lake Suigetsu, Japan: Extension of the 14C Calibration Curve

Radiocarbon ◽  
1997 ◽  
Vol 40 (1) ◽  
pp. 505-515 ◽  
Author(s):  
Hiroyuki Kitagawa ◽  
Johannes Van Der Plicht
Keyword(s):  
Tree Ring ◽  
Calibration Curve ◽  
Time Scale ◽  
Mass Spectrometric ◽  
Laminated Sediments ◽  
Varve Chronology ◽  
Total Range ◽  
Dating Method ◽  
Annually Laminated Sediments ◽  
Potential Tool

A sequence of annually laminated sediments is a potential tool for calibrating the radiocarbon time scale beyond the range of the absolute tree-ring calibration (11 ka). We performed accelerator mass spectrometric (AMS) 14C measurements on >250 terrestrial macrofossil samples from a 40,000-yr varve sequence from Lake Suigetsu, Japan. The results yield the first calibration curve for the total range of the 14C dating method.

scholarly journals Solar activity expressed in a modern varve thickness sequence

2019 ◽  
Vol 56 (1) ◽  
pp. 32-46 ◽  
Author(s):  
Gary B. Hughes ◽  
Jordan Adams ◽  
Jaclyn M.H. Cockburn
Keyword(s):  
Solar Activity ◽  
Laminated Sediments ◽  
Varve Thickness ◽  
Ice Cap ◽  
Uv Emission ◽  
Depositional Settings ◽  
Climate Simulations ◽  
Direct Forcing ◽  
Climate Signals ◽  
Annually Laminated Sediments

Annually laminated sediments (varves) form in particular depositional settings, e.g., where seasonal climate produces fluctuations in runoff volume; variations in runoff affect the amount and type of sediment delivered to a catchment. Prior studies confirm that variations in selected varve traits correlate with inter-annual climate signals. In some locations, solar activity also appears to be expressed in varve characteristics, either through a direct effect or indirectly via influence of solar activity on climate. Evidence from proglacial Iceberg Lake, Alaska, indicates that solar activity may have directly contributed to varve deposition. A varve thickness sequence is compared to sunspot observations from 1610–1995 CE. Maunder and Dalton minima are clearly expressed in a varve power spectrogram; varve signal amplification beginning ca. 1950s CE coincides with increasing activity evident in a sunspot spectrogram, features that are only vaguely discernible in the raw time-series plots. Spectral relationships at sunspot periodicities are consistent with direct solar forcing of varve thickness, independent of any effect solar activity might otherwise have on climate. Simulations based on a meltwater model indicate that direct forcing could result from amplified ultraviolet (UV) emission during solar maxima, combined with lower UV albedo of glacial ice. The plausible forcing mechanism bolsters epistemology for concluding a cause–effect relationship: solar variability likely contributed directly to inter-decadal patterns in Iceberg Lake varve thicknesses. The putative effect could be enhanced at higher latitudes, where Earth’s atmosphere absorbs less of the UV energy emitted by the Sun; periods of lowered ozone concentration near the poles would exacerbate the natural abetting UV phenomena, potentially linking human activity to recent and accelerated polar ice cap melting.

Construction and validation of calendar-year time scale for annually laminated sediments – an example from Lake Szurpiły (NE Poland)

GFF ◽  
2013 ◽  
Vol 135 (3-4) ◽  
pp. 248-257 ◽  
Author(s):  
Małgorzata Kinder ◽  
Wojciech Tylmann ◽  
Dirk Enters ◽  
Natalia Piotrowska ◽  
Grzegorz Poręba ◽  
...  
Keyword(s):  
Time Scale ◽  
Laminated Sediments ◽  
Ne Poland ◽  
Annually Laminated Sediments

scholarly journals Age-Depth Model of Lake Soppensee (Switzerland) Based on the High-Resolution 14C Chronology Compared with Varve Chronology

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 1027-1040 ◽  
Author(s):  
Irka Hajdas ◽  
Adam Michczyński
Keyword(s):  
High Resolution ◽  
Late Glacial ◽  
Laminated Sediments ◽  
Depositional Model ◽  
Data Set ◽  
Sedimentary Records ◽  
Varve Chronology ◽  
Good Agreement

An age-depth model for laminated sediments of Lake Soppensee is constructed using radiocarbon ages of macrofossils and a depositional model of the OxCal v 4.1 program with the updated IntCal09 data set. The resulting calendar chronology is compared with the varve chronology that was built for this record in a previous study (Hajdas 1993); there is a very good agreement between the 2 approaches. This illustrates the potential of high-resolution 14C dating for construction of reliable, high-resolution calendar timescales for sedimentary records. Based on the age-depth model of this study, the Vasset/Killian tephra found in sediment of Soppensee dates to a calendar age of 9291–9412 cal BP (2-σ range) while the Lachersee tephra dates to 12,735–12,871 cal BP (2-σ range). Precise dating of the Late Glacial boundaries is possible with this chronology but requires more precise correlation between proxies and records than typically practiced.

Absolute Dating of the Late-Glacial Period in Switzerland Using Annually Laminated Sediments

1991 ◽  
Vol 35 (3-Part1) ◽  
pp. 321-330 ◽  
Author(s):  
André F. Lotter
Keyword(s):  
Late Glacial ◽  
Laminated Sediments ◽  
Glacial Period ◽  
Radiocarbon Age ◽  
Expected Time ◽  
Late Glacial Period ◽  
Varve Chronology ◽  
Central Switzerland ◽  
Annually Laminated Sediments ◽  
Radiocarbon Chronology

AbstractResults of a high-resolution late-glacial AMS 14C chronology from Rotsee, central Switzerland, have given evidence that the atmospheric radiocarbon concentration was not constant between 13,000 and 9500 yr B.P. This resulted in three marked phases of constant radiocarbon age: at 12,700, at 10,000, and at 9500 yr B.P. New results of a late-glacial varve chronology from Soppensee, central Switzerland, suggest that the younger two phases of constant 14C age each had a duration of ca. 400 calendar years. The length of the late-glacial chronozones has been calculated on the basis of these replicate varve counts and a comparison with their estimated duration in radiocarbon years shows that the estimated duration of the chronozones Bölling (ca. 800 calendar yr vs 1000 14C yr) and Younger Dryas (ca. 900 calendar yr vs 1000 14C yr) agree with the expected time span, whereas the estimated duration of the Alleröd chronozone (ca. 400 calendar yr vs 1000 14C yr) is substantially shorter than expected. Furthermore, a tentative comparison of varve ages and 14C ages suggests that the varve chronology is more than 1000 yr offset toward older ages from the radiocarbon chronology during the late-glacial period.

scholarly journals The frequency of Kozai–Lidov disc oscillation driven giant outbursts in Be/X-ray binaries

2019 ◽  
Vol 489 (2) ◽  
pp. 1797-1804 ◽  
Author(s):  
Rebecca G Martin ◽  
Alessia Franchini
Keyword(s):  
Orbital Period ◽  
Time Scale ◽  
Orbital Plane ◽  
Material Flows ◽  
X Ray ◽  
System Parameters ◽  
Be Star ◽  
Chaotic Nature ◽  
X Ray Binaries ◽  
Good Agreement

ABSTRACT Giant outbursts of Be/X-ray binaries may occur when a Be-star disc undergoes strong eccentricity growth due to the Kozai–Lidov (KL) mechanism. The KL effect acts on a disc that is highly inclined to the binary orbital plane provided that the disc aspect ratio is sufficiently small. The eccentric disc overflows its Roche lobe and material flows from the Be star disc over to the companion neutron star causing X-ray activity. With N-body simulations and steady state decretion disc models we explore system parameters for which a disc in the Be/X-ray binary 4U 0115+634 is KL unstable and the resulting time-scale for the oscillations. We find good agreement between predictions of the model and the observed giant outburst time-scale provided that the disc is not completely destroyed by the outburst. This allows the outer disc to be replenished between outbursts and a sufficiently short KL oscillation time-scale. An initially eccentric disc has a shorter KL oscillation time-scale compared to an initially circular orbit disc. We suggest that the chaotic nature of the outbursts is caused by the sensitivity of the mechanism to the distribution of material within the disc. The outbursts continue provided that the Be star supplies material that is sufficiently misaligned to the binary orbital plane. We generalize our results to Be/X-ray binaries with varying orbital period and find that if the Be star disc is flared, it is more likely to be unstable to KL oscillations in a smaller orbital period binary, in agreement with observations.

The First Holocene Varve Chronology for the UK: based on the integration of varve counting, radiocarbon dating and tephrostratigraphy from Diss Mere (UK).

2021 ◽  
Author(s):  
Celia Martin-Puertas ◽  
Amy A. Walsh ◽  
Simon P.E Blockley ◽  
Poppy Harding ◽  
George E. Biddulph ◽  
...  
Keyword(s):  
Laminated Sediments ◽  
Seasonal Patterns ◽  
Sediment Record ◽  
Radiocarbon Dates ◽  
Varve Chronology ◽  
Counting Error ◽  
Tephra Layers ◽  
Core Depth ◽  
The Uk ◽  
Varve Counting

<p>This paper reports the first Holocene varved chronology for the lacustrine sediment record of Diss Mere in the UK. The record of Diss Mere is 15 m long, and shows 4.2 m of finely-laminated sediments, which are present between ca. 9 and 13 m of core depth. The microfacies analysis identified three major seasonal patterns of deposition, which corroborate the annual nature of sedimentation throughout the whole interval. The sediments are diatomaceous organic and carbonate varves with an average thickness of 0.45 mm. A total of 8473 varves were counted with maximum counting error of up to  40 varves by the bottom of the varved sequence. To tie the resulting floating varve chronology to the IntCal 2020 radiocarbon timescale, we used a Bayesian Deposition model (P_Sequencewith outlier detection) on all available chronological data from the core. The data included five radiocarbon dates, two known tephra layers (Glen Garry and OMH-185) with calendar ages based on Bayesian modelling of sequences of radiocarbon ages, and the relative varve counts between dated points. The resulting age-depth model (DISSV-2020) dates the varved sequence between ca. 2100 and 10,300 cal BP and age uncertainties are decadal in scale (95% confidence). </p>

scholarly journals ADDED MASSES OF LARGE TANKERS BERTHING TO DOLPHINS

1976 ◽  
Vol 1 (15) ◽  
pp. 161 ◽  
Author(s):  
Taizo Hayashi ◽  
Masujiro Shirai
Keyword(s):  
Shallow Water ◽  
Froude Number ◽  
Water Depth ◽  
Head Loss ◽  
Theoretical Formula ◽  
Counter Flow ◽  
Added Masses ◽  
Mass Factor ◽  
Large Vessels ◽  
Good Agreement

The added masses of large tankers berthing to dolphins are studied both theoretically and experimentally. The movements of large vessels in shallow water in the directions normal to their planes of symmetry cause counterflows of appreciable velocities under the hulls. The inertia of these counter-flows is shown to have an important effect on the added masses of the vessels. A theoretical formula is derived to determine the mass factor of an ocean vessel in shallow water as a function of the ratio Draught/Water- depth, the Froude number of the vessel and the coefficient of head loss of the counter-flow under the hull. Experiment is made to determine the mass factor. Comparison:, between the theory and the experiment shows a good agreement.

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