scholarly journals A high-resolution late Holocene lake isotope record from Turkey and links to North Atlantic and monsoon climate

Geology ◽  
2006 ◽  
Vol 34 (5) ◽  
pp. 361 ◽  
Author(s):  
Matthew D. Jones ◽  
C. Neil Roberts ◽  
Melanie J. Leng ◽  
Murat Türkeş
Keyword(s):  
High Resolution ◽  
North Atlantic ◽  
Late Holocene ◽  
Monsoon Climate ◽  
Isotope Record

Late Holocene glacier and climate reconstruction from proglacial records in Vatnsdalur, northern Iceland.

2020 ◽  
Author(s):  
Konstantin Nebel ◽  
Timothy Lane ◽  
Kathryn Adamson ◽  
Iestyn Barr ◽  
Willem van der Bilt ◽  
...  
Keyword(s):  
High Resolution ◽  
Environmental Change ◽  
North Atlantic ◽  
Late Holocene ◽  
Sediment Cores ◽  
Arctic Region ◽  
Arctic Climate ◽  
The Arctic ◽  
Air Masses ◽  
Proglacial Lake

<p>The Arctic region is experiencing surface air temperature increase of twice the global average. To better understand Holocene Arctic climate variability, there is the need for continuous, high-resolution palaeoclimate archives. Sediment cores from proglacial lakes can provide such climate archives, and have the potential to record past environmental change in detail.       </p><p>Vatnsdalur, a valley in northern Iceland, hosts small, climatically sensitive cirque glaciers that became independent from the Iceland Ice Sheet after its retreat following the Last Glacial Maximum (c. 15 ka BP). Importantly, this region is located at the confluence of warm water and air masses from the south and cold polar water and air masses from the north, making it highly sensitive to North Atlantic and Arctic climate change. However, at present the region is highly understudied, lacking any high-resolution climate reconstructions.           </p><p>To address this, we combine geomorphological mapping with the first high-resolution analysis of proglacial lake sediments, to thoroughly examine northern Iceland Late Holocene environmental change.</p><p>Field mapping supplemented by high-resolution drone data was used to characterise catchment geomorphology, including seven Holocene moraines. A sediment core (SKD-P1-18) from proglacial lake Skeiðsvatn, Vatnsdalur, was analysed for sedimentological (dry bulk density, loss-on-ignition, grain size), geophysical (magnetic susceptibility) and geochemical (X-ray fluorescence core scan, 2 mm resolution) parameters.             <br>We identify three main sedimentary facies from these analyses, indicating variations in glacial input and catchment environmental conditions. Radiocarbon dating of lake macrofossils, supplemented by tephrochronology, provides a chronological framework. Catchment point samples, also analysed using the above analytical techniques, were used for sediment fingerprinting to disentangle non-glacial from glacial end-members.</p><p>Our results indicate the disappearance and reformation of small, climatically sensitive cirque glaciers in Vatnsdalur during the Holocene. We interpret the data to show an abrupt return to a glaciated catchment. Our results fill a geographical gap of high-resolution proglacial sediment studies in the Arctic-North Atlantic region.</p>

scholarly journals Late Holocene climate changes in the Altai Region based on a first high‐resolution biomarker isotope record from Lake Khar Nuur

2021 ◽  
Author(s):  
Marcel Bliedtner ◽  
Julian Struck ◽  
Paul Strobel ◽  
Gary Salazar ◽  
Sönke Szidat ◽  
...  
Keyword(s):  
High Resolution ◽  
Late Holocene ◽  
Climate Changes ◽  
Holocene Climate ◽  
Altai Region ◽  
Isotope Record

scholarly journals Maastrichtian carbon isotope stratigraphy and cyclostratigraphy of the Newfoundland Margin (Site U1403, IODP Leg 342)

2016 ◽  
Author(s):  
Oliver Friedrich ◽  
Sietske J. Batenburg ◽  
Kazuyoshi Moriya ◽  
Silke Voigt ◽  
Cécile Cournède ◽  
...  
Keyword(s):  
High Resolution ◽  
Carbon Cycle ◽  
Carbon Isotope ◽  
North Atlantic ◽  
Climatic Variability ◽  
Stable Carbon Isotope ◽  
The North ◽  
Depositional Processes ◽  
Isotope Record ◽  
The North Atlantic

Abstract. Earth’s climate during the Maastrichtian (latest Cretaceous) was punctuated by brief warming and cooling episodes, accompanied by perturbations of the global carbon cycle. Superimposed on a long-term cooling trend, the middle Maastrichtian is characterized by deep-sea warming and relatively high values of stable carbon-isotope ratios, followed by strong climatic variability towards the end of the Cretaceous. A lack of knowledge on the timing of climatic change inhibits our understanding of underlying causal mechanisms. We present an integrated stratigraphy from Site U1403, providing an expanded deep ocean record from the North Atlantic (IODP Expedition 342, Newfoundland Margin). Distinct sedimentary cyclicity suggests that orbital forcing played a major role on depositional processes, which is confirmed by statistical analyses of high resolution elemental data obtained by X-ray fluorescence (XRF) scanning. Astronomical calibration reveals that the investigated interval encompasses seven 405-kyr cycles (Ma4051 to Ma4057) and spans 2.8 Myr directly preceding the Cretaceous/Paleocene (K/Pg) boundary. A high-resolution carbon-isotope record from bulk carbonates allows to identify global trends in the late Maastrichtian carbon cycle. Low-amplitude variations (up to 0.4 ‰), typical for open ocean settings, are compared to the hemipelagic Zumaia section (N-Spain), with a well-established independent cyclostratigraphic framework. Whereas the pre-K/Pg oscillations and the negative values of the Mid-Maastrichtian Event (MME) can be readily discerned in both records, patterns diverge around 67.5 Ma, with Site U1403 more reliably reflecting global climate change. Our new carbon isotope record and the established cyclostratigraphy from Site U1403 may serve as a future reference for detailed studies of late Maastrichtian events in the North Atlantic.

scholarly journals Decadal Variability in a Central Greenland High-Resolution Deuterium Isotope Record and Its Relationship to the Frequency of Daily Atmospheric Circulation Patterns from the North Atlantic Region

2010 ◽  
Vol 23 (17) ◽  
pp. 4608-4618 ◽  
Author(s):  
Norel Rimbu ◽  
Gerrit Lohmann
Keyword(s):  
High Resolution ◽  
North Atlantic ◽  
Decadal Variability ◽  
North Atlantic Region ◽  
Atlantic Region ◽  
Atmospheric Circulation Patterns ◽  
The North ◽  
Circulation Patterns ◽  
Isotope Record ◽  
The North Atlantic

Abstract The variability of an annual resolution deuterium time series from central Greenland is investigated in connection with the variability in the frequency of daily atmospheric circulation patterns in the North Atlantic region. Statistical analysis reveals that a large part of the decadal variability of the deuterium isotope record is related to decadal variability in the frequency of several identified daily circulation patterns. The study shows that these circulation patterns induce variations in the deuterium record by altering where isotopic fractionation occurs, mainly during the passage of the associated air masses over continental areas. The study identifies three significant periodic components in the deuterium isotope record at ∼12, ∼20, and ∼30 yr. It also shows that the ∼20-yr signal in the deuterium isotope record is related to the variability in the frequency of a winter circulation type. An analysis of six oxygen isotope records from central Greenland reveals decadal variations similar to the deuterium isotope record. The authors argue that high-resolution stable isotope records from Greenland ice cores can be used to obtain information about the frequency of certain daily circulation patterns during past periods.

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