scholarly journals Radiocarbon Analysis of Tree Rings from a 15.5-Cal kyr BP Pyroclastically Buried Forest: A Pilot Study

Radiocarbon ◽  
2007 ◽  
Vol 49 (2) ◽  
pp. 1123-1132 ◽  
Author(s):  
Kazuho Horiuchi ◽  
Shinya Sonoda ◽  
Hiroyuki Matsuzaki ◽  
Motonari Ohyama
Keyword(s):  
Solar Activity ◽  
Tree Rings ◽  
Weighted Average ◽  
Activity Change ◽  
Last Glacial Period ◽  
Standard Curve ◽  
Regional Impacts ◽  
Interval Tree ◽  
Honshu Island ◽  
The Last Glacial

We have determined the radiocarbon ages for 40-yr-interval tree rings in 2 fossil trees of the Towada Hachinohe buried forest, northeastern Honshu Island, Japan. The 14C ages range from 13.0 to 13.3 kyr BP (about 15.5 cal kyr BP). The weighted average of the 14C age of the outermost 5 rings is 13,133 ± 33 BP, which can be calibrated to 15,363–15,679 cal BP by using the IntCal04 standard curve (Reimer et al. 2004). The estimated δ14C values range between 265 and 300% and show approximately sinusoidal fluctuation of an indicated ∼200-yr cycle, perhaps reflecting contemporary solar activity change. Comparison between the tree 14C profile and the Cariaco Basin 14C record provides further information on the accurate date of the Towada Hachinohe buried forest and the eruption that produced it. 14C analysis of tree rings from the buried forest may contribute to the construction of a better 14C calibration curve and the elucidation of solar activity change during the last glacial period, as well as possible global and regional impacts of the huge eruption from Towada Volcano.

scholarly journals The Influence of Orbital Forcing on 10Be Deposition in Greenland Over the Glacial Period

2021 ◽  
Vol 9 ◽  
Author(s):  
Anna Sturevik-Storm ◽  
Minjie Zheng ◽  
Ala Aldahan ◽  
Göran Possnert ◽  
Raimund Muscheler
Keyword(s):  
Solar Activity ◽  
Magnetic Field Intensity ◽  
Ice Cores ◽  
Glacial Period ◽  
Orbital Forcing ◽  
Last Glacial Period ◽  
Cosmogenic Isotope ◽  
Precession Cycle ◽  
Cosmogenic Radionuclide ◽  
The Last Glacial

Understanding the transport and deposition of the cosmogenic isotope 10Be is vital for the application of the isotope data to infer past changes of solar activity, to reconstruct past Earth’s magnetic field intensity and climate change. Here, we use data of the cosmogenic isotope 10Be from the Greenland ice cores, namely the NEEM and GRIP ice cores, to identify factors controlling its distribution. After removing the effects of the geomagnetic field on the cosmogenic radionuclide production rate, the results expose imprints of the 20–22 ka precession cycle on the Greenland 10Be records of the last glacial period. This finding can further improve the understanding of 10Be variability in ice sheets and has the prospect of providing better reconstructions of geomagnetic and solar activity based on cosmogenic radionuclide records.

scholarly journals Post-depositional manganese mobilization during the last glacial period in sediments of the eastern Clarion-Clipperton Zone, Pacific Ocean

2020 ◽  
Vol 532 ◽  
pp. 116012 ◽  
Author(s):  
Jessica B. Volz ◽  
Bo Liu ◽  
Male Köster ◽  
Susann Henkel ◽  
Andrea Koschinsky ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
The Last Glacial

scholarly journals <i>δ</i><sup>13</sup>C decreases in the upper western South Atlantic during Heinrich Stadials 3 and 2

2017 ◽  
Vol 13 (4) ◽  
pp. 345-358 ◽  
Author(s):  
Marília C. Campos ◽  
Cristiano M. Chiessi ◽  
Ines Voigt ◽  
Alberto R. Piola ◽  
Henning Kuhnert ◽  
...  
Keyword(s):  
Climate Change ◽  
South Atlantic ◽  
Meridional Overturning Circulation ◽  
Glacial Period ◽  
Last Deglaciation ◽  
Last Glacial Period ◽  
Last Glacial ◽  
Change Events ◽  
The Last Glacial ◽  
Millennial Scale

Abstract. Abrupt millennial-scale climate change events of the last deglaciation (i.e. Heinrich Stadial 1 and the Younger Dryas) were accompanied by marked increases in atmospheric CO2 (CO2atm) and decreases in its stable carbon isotopic ratios (δ13C), i.e. δ13CO2atm, presumably due to outgassing from the ocean. However, information on the preceding Heinrich Stadials during the last glacial period is scarce. Here we present δ13C records from two species of planktonic foraminifera from the western South Atlantic that reveal major decreases (up to 1 ‰) during Heinrich Stadials 3 and 2. These δ13C decreases are most likely related to millennial-scale periods of weakening of the Atlantic meridional overturning circulation and the consequent increase (decrease) in CO2atm (δ13CO2atm). We hypothesise two mechanisms that could account for the decreases observed in our records, namely strengthening of Southern Ocean deep-water ventilation and weakening of the biological pump. Additionally, we suggest that air–sea gas exchange could have contributed to the observed δ13C decreases. Together with other lines of evidence, our data are consistent with the hypothesis that the CO2 added to the atmosphere during abrupt millennial-scale climate change events of the last glacial period also originated in the ocean and reached the atmosphere by outgassing. The temporal evolution of δ13C during Heinrich Stadials 3 and 2 in our records is characterized by two relative minima separated by a relative maximum. This w structure is also found in North Atlantic and South American records, further suggesting that such a structure is a pervasive feature of Heinrich Stadial 2 and, possibly, also Heinrich Stadial 3.

Global population divergence of the sea star Hippasteria phrygiana corresponds to the onset of the last glacial period of the Pleistocene

2013 ◽  
Vol 160 (5) ◽  
pp. 1285-1296 ◽  
Author(s):  
D. W. Foltz ◽  
S. D. Fatland ◽  
M. Eléaume ◽  
K. Markello ◽  
K. L. Howell ◽  
...  
Keyword(s):  
Population Divergence ◽  
Glacial Period ◽  
Sea Star ◽  
Last Glacial Period ◽  
Last Glacial ◽  
Global Population ◽  
The Last Glacial

scholarly journals South Pole glacial climate reconstruction from multi-borehole laser particulate stratigraphy

2013 ◽  
Vol 59 (218) ◽  
pp. 1117-1128 ◽  
Author(s):  
Keyword(s):  
Particle Physics ◽  
Volcanic Ash ◽  
Ice Core ◽  
Hot Water ◽  
Radiometric Dating ◽  
South Pole ◽  
Last Glacial Period ◽  
Annual Layer ◽  
Paleoclimate Records ◽  
The Last Glacial

AbstractThe IceCube Neutrino Observatory and its prototype, AMANDA, were built in South Pole ice, using powerful hot-water drills to cleanly bore >100 holes to depths up to 2500 m. The construction of these particle physics detectors provided a unique opportunity to examine the deep ice sheet using a variety of novel techniques. We made high-resolution particulate profiles with a laser dust logger in eight of the boreholes during detector commissioning between 2004 and 2010. The South Pole laser logs are among the most clearly resolved measurements of Antarctic dust strata during the last glacial period and can be used to reconstruct paleoclimate records in exceptional detail. Here we use manual and algorithmic matching to synthesize our South Pole measurements with ice-core and logging data from Dome C, East Antarctica. We derive impurity concentration, precision chronology, annual-layer thickness, local spatial variability, and identify several widespread volcanic ash depositions useful for dating. We also examine the interval around ∼74 ka recently isolated with radiometric dating to bracket the Toba (Sumatra) supereruption.

scholarly journals Deep Ocean storage of heat and CO2 in the Fram Strait, Arctic Ocean during the last glacial period

2021 ◽  
Author(s):  
Mohamed M. Ezat ◽  
Tine L. Rasmussen ◽  
Mathis P. Hain ◽  
Mervyn Greaves ◽  
James W B Rae ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Deep Ocean ◽  
Fram Strait ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
The Last Glacial
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