The Clay-Varve Based Swedish Time Scale and Its Relation to the Late Weichselian Radiocarbon Chronology

1992 ◽  
pp. 25-44 ◽  
Author(s):  
Svante Björck ◽  
Ingemar Cato ◽  
Lars Brunnberg ◽  
Bo Strömberg
Keyword(s):  
Time Scale ◽  
Late Weichselian ◽  
Radiocarbon Chronology

14C AMS measurements from the Late Weichselian part of the Swedish Time Scale

1995 ◽  
Vol 27 ◽  
pp. 11-18 ◽  
Author(s):  
Svante Björck ◽  
Barbara Wohlfarth ◽  
Göran Possnert
Keyword(s):  
Time Scale ◽  
Late Weichselian

scholarly journals The Swedish Time Scale: A Potential Calibration Tool for the Radiocarbon Time Scale During the Late Weichselian

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 347-359 ◽  
Author(s):  
Barbara Wohlfarth ◽  
Svante Björck ◽  
Göran Possnert
Keyword(s):  
Time Scale ◽  
East Coast ◽  
Short Term ◽  
Data Set ◽  
Varve Chronology ◽  
Data Points ◽  
The Difference ◽  
Late Weichselian ◽  
Calibration Program ◽  
Calibration Tool

The Swedish Time Scale (STS) is a ca. 13,300-yr-long varve chronology that has been established for the Swedish east coast from >1000 overlapping clay-varve diagrams. We describe the present state of the STS and illustrate the application of this worldwide unique varve chronology for AMS radiocarbon measurements. The results are compared to other 14C-dated calendar-year chronologies: dendrochronology, laminated lake sediments and U/Th. Our data set agrees with the oldest part of the dendrochronological calibration curve, and with AMS 14C-dated lake lamination data and U/Th on corals down to ca. 12 ka calendar years bp. Further back in time, the AMS-dated part of the STS partly compares well with lake lamination chronologies and shows that the difference between 14C and calendar years decreases rapidly between 12,600 and 12,800 calendar years bp. Such a development seems to contrast with U/Th measurements on corals. We suggest that the cause for the divergence among three supposed calendar-year chronologies lies in the fact that the data points on the marine 14C-U/Th curve are more widely spaced in time than the tightly grouped set of terrestrial AMS 14C dates, and thus are not able to reflect short-term changes in atmospheric 14C. Therefore, we argue that the use of the pre-Holocene part of the calibration program is premature and inadvisable.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

The E-ring: interactions with plasma and implications for its evolution

1984 ◽  
Vol 75 ◽  
pp. 599-602
Author(s):  
T.V. Johnson ◽  
G.E. Morfill ◽  
E. Grun
Keyword(s):  
Time Scale ◽  
Particle Density ◽  
High Energy ◽  
Particle Removal ◽  
Density Region ◽  
Drag Forces ◽  
Orbit Evolution ◽  
History Of ◽  
Ring Particle ◽  
Ring Material

A number of lines of evidence suggest that the particles making up the E-ring are small, on the order of a few microns or less in size (Terrile and Tokunaga, 1980, BAAS; Pang et al., 1982 Saturn meeting; Tucson, AZ). This suggests that a variety of electromagnetic and plasma affects may be important in considering the history of such particles. We have shown (Morfill et al., 1982, J. Geophys. Res., in press) that plasma drags forces from the corotating plasma will rapidly evolve E-ring particle orbits to increasing distance from Saturn until a point is reached where radiation drag forces acting to decrease orbital radius balance this outward acceleration. This occurs at approximately Rhea's orbit, although the exact value is subject to many uncertainties. The time scale for plasma drag to move particles from Enceladus' orbit to the outer E-ring is ~104yr. A variety of effects also act to remove particles, primarily sputtering by both high energy charged particles (Cheng et al., 1982, J. Geophys. Res., in press) and corotating plasma (Morfill et al., 1982). The time scale for sputtering away one micron particles is also short, 102 - 10 yrs. Thus the detailed particle density profile in the E-ring is set by a competition between orbit evolution and particle removal. The high density region near Enceladus' orbit may result from the sputtering yeild of corotating ions being less than unity at this radius (e.g. Eviatar et al., 1982, Saturn meeting). In any case, an active source of E-ring material is required if the feature is not very ephemeral - Enceladus itself, with its geologically recent surface, appears still to be the best candidate for the ultimate source of E-ring material.

The Late Weichselian sea level history of the Kullen Peninsula in northwest Skåne, southern Sweden

Boreas ◽  
2001 ◽  
Vol 30 (2) ◽  
pp. 115-130
Author(s):  
Per Sandgren, Ian Snowball
Keyword(s):  
Sea Level ◽  
Southern Sweden ◽  
History Of ◽  
Late Weichselian

The long-term instability of the new generation hydrogen masers

2020 ◽  
pp. 35-38
Author(s):  
S.I. Donchenko ◽  
I.Y. Blinov ◽  
I.B. Norets ◽  
Y.F. Smirnov ◽  
A.A. Belyaev ◽  
...  
Keyword(s):  
Time Scale ◽  
Frequency Difference ◽  
Clock Frequency ◽  
Quantum Frequency ◽  
Frequency Standards ◽  
Quantum Frequency Standards ◽  
New Generation ◽  
Atomic Time

The latest changes in the algorithm for the formation of the international atomic time scale TAI are reported in terms of estimating the weights of the clocks involved in the formation of TAI. Studies of the characteristics of the long-term instability of new-generation hydrogen masers based on processing the results of the clock frequency difference with respect to TAI are performed. It has been confirmed that at present, new-generation hydrogen masers show significantly less long-term instability in comparison with quantum frequency standards ofsimilar and other types.

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