scholarly journals Chronology of Lake El'gygytgyn sediments – a combined magnetostratigraphic, palaeoclimatic and orbital tuning study based on multi-parameter analyses

2013 ◽  
Vol 9 (6) ◽  
pp. 2413-2432 ◽  
Author(s):  
N. R. Nowaczyk ◽  
E. M. Haltia ◽  
D. Ulbricht ◽  
V. Wennrich ◽  
M. A. Sauerbrey ◽  
...  
Keyword(s):  
Global Climate ◽  
Far East ◽  
Climatic Conditions ◽  
Sedimentation Rates ◽  
Scientific Drilling ◽  
Lake El’Gygytgyn ◽  
Age Model ◽  
Orbital Tuning ◽  
Lake Floor ◽  
The Impact

Abstract. A 318-metre-long sedimentary profile drilled by the International Continental Scientific Drilling Program (ICDP) at Site 5011-1 in Lake El'gygytgyn, Far East Russian Arctic, has been analysed for its sedimentologic response to global climate modes by chronostratigraphic methods. The 12 km wide lake is sited off-centre in an 18 km large crater that was created by the impact of a meteorite 3.58 Ma ago. Since then sediments have been continuously deposited. For establishing their chronology, major reversals of the earth's magnetic field provided initial tie points for the age model, confirming that the impact occurred in the earliest geomagnetic Gauss chron. Various stratigraphic parameters, reflecting redox conditions at the lake floor and climatic conditions in the catchment were tuned synchronously to Northern Hemisphere insolation variations and the marine oxygen isotope stack, respectively. Thus, a robust age model comprising more than 600 tie points could be defined. It could be shown that deposition of sediments in Lake El'gygytgyn occurred in concert with global climatic cycles. The upper ~160 m of sediments represent the past 3.3 Ma, equivalent to sedimentation rates of 4 to 5 cm ka−1, whereas the lower 160 m represent just the first 0.3 Ma after the impact, equivalent to sedimentation rates in the order of 45 cm ka−1. This study also provides orbitally tuned ages for a total of 8 tephras deposited in Lake El'gygytgyn.

scholarly journals Chronology of Lake El'gygytgyn sediments

2013 ◽  
Vol 9 (3) ◽  
pp. 3061-3102 ◽  
Author(s):  
N. R. Nowaczyk ◽  
E. M. Haltia ◽  
D. Ulbricht ◽  
V. Wennrich ◽  
M. A. Sauerbrey ◽  
...  
Keyword(s):  
Global Climate ◽  
Far East ◽  
Climatic Conditions ◽  
Sedimentation Rates ◽  
Scientific Drilling ◽  
The Past ◽  
Lake El’Gygytgyn ◽  
Age Model ◽  
Lake Floor ◽  
The Impact

Abstract. A 318 m long sedimentary profile drilled by the International Continental Scientific Drilling Program (ICDP) at Site 5011-1 in Lake El'gygytgyn, Far East Russian Arctic, has been analysed for its sedimentologic response to global climate modes by chrono-stratigraphic methods. The 12 km wide lake is sited in an 18 km large crater that was created by the impact of a meteorite 3.58 Ma ago. Since then sediments have been continuously deposited. For establishing their chronology, major reversals of the Earth's magnetic field provided initial tie points for the age model, confirming that the impact occurred in the earliest Gauss chron. Various stratigraphic parameters, reflecting redox conditions at the lake floor and climatic conditions in the catchment were tuned synchronously to Northern Hemisphere insolation variations and the marine oxygen isotope stack, respectively. Thus, a robust age model comprising more than 600 tie points could be defined. It could be shown that deposition of sediments in Lake El'gygytgyn occurred in concert with global climatic cycles. The upper ~160 m of sediments represent the past 3.3 Ma, equivalent to sedimentation rates of 4 to 5 cm ka−1, whereas the lower 160 m represent just the first 0.3 Ma after the impact, equivalent to sedimentation rates in the order of 45 cm ka−1.

scholarly journals Petrophysical characterization of the lacustrine sediment succession drilled in Lake El'gygytgyn, Far East Russian Arctic

2013 ◽  
Vol 9 (1) ◽  
pp. 351-391 ◽  
Author(s):  
A. C. Gebhardt ◽  
A. Francke ◽  
J. Kück ◽  
M. Sauerbrey ◽  
F. Niessen ◽  
...  
Keyword(s):  
Mass Movement ◽  
Far East ◽  
Lacustrine Sediments ◽  
Lacustrine Sediment ◽  
Organic Carbon Content ◽  
Meteorite Impact ◽  
Seismic Profiles ◽  
Scientific Drilling ◽  
Lake El’Gygytgyn ◽  
Lake Floor

Abstract. Seismic profiles of Far East Russian Lake El'gygytgyn which was formed by a meteorite impact some 3.6 million years ago show a stratified sediment succession that can be separated into Subunits Ia and Ib at approximately 167 m below lake floor (= ∼ 3.17 Ma). The former is well-stratified, while the latter is acoustically more massive. The sediments are intercalated with frequent mass movement deposits mainly in the proximal parts, while the distal part is almost free of such deposits at least in the upper part. In spring 2009, a long core drilled in the lake center within the framework of the International Continental Scientific Drilling Program (ICDP) penetrated the entire lacustrine sediment succession down to ~ 320 m below lake floor and about 200 m further into the meteorite-impact related bedrock. Downhole logging data down to 390 m below lake floor show that the bedrock and the lacustrine part of the core differ largely in their petrophysical characteristics. The contact between the bedrock and the lacustrine sediments is not abrupt, but rather transitional with a mixture of impact-altered bedrock clasts in a lacustrine matrix with varying percentages. Physical and chemical proxies measured on the cores can be used to divide the lacustrine part into five different clusters. These can be plotted in a redox-condition vs. input type diagram with total organic carbon content and magnetic susceptibility values indicating anoxic or oxic conditions and with the Si/Ti ratio representing more clastic or more biogenic input. Plotting the clusters in this diagram allows identifying clusters that represent glacial phases (Cluster I), super interglacials (Cluster II), and interglacial phases (Clusters III and IV).

scholarly journals Petrophysical characterization of the lacustrine sediment succession drilled in Lake El'gygytgyn, Far East Russian Arctic

2013 ◽  
Vol 9 (4) ◽  
pp. 1933-1947 ◽  
Author(s):  
A. C. Gebhardt ◽  
A. Francke ◽  
J. Kück ◽  
M. Sauerbrey ◽  
F. Niessen ◽  
...  
Keyword(s):  
Mass Movement ◽  
Far East ◽  
Lacustrine Sediments ◽  
Distal Region ◽  
Lacustrine Sediment ◽  
Organic Carbon Content ◽  
Meteorite Impact ◽  
Scientific Drilling ◽  
Lake El’Gygytgyn ◽  
Lake Floor

Abstract. Seismic profiles of Far East Russian Lake El'gygytgyn, formed by a meteorite impact some 3.6 million years ago, show a stratified sediment succession that can be separated into subunits Ia and Ib at approximately 167 m below lake floor (=~3.17 Ma). The upper (Ia) is well-stratified, while the lower is acoustically more massive and discontinuous. The sediments are intercalated with frequent mass movement deposits mainly in the proximal areas, while the distal region is almost free of such deposits at least in the upper part. In spring 2009, a long core drilled in the lake center within the framework of the International Continental Scientific Drilling Program (ICDP) penetrated the entire lacustrine sediment succession down to ~320 m below lake floor and about 200 m farther into the meteorite-impact-related bedrock. Downhole logging data down to 390 m below lake floor show that the bedrock and the lacustrine part differ significantly in their petrophysical characteristics. The contact between the bedrock and the lacustrine sediments is not abrupt, but rather transitional with a variable mixture of impact-altered bedrock clasts in a lacustrine matrix. Physical and chemical proxies measured on the cores can be used to divide the lacustrine part into five different statistical clusters. These can be plotted in a redox-condition vs. input-type diagram, with total organic carbon content and magnetic susceptibility values indicating anoxic or oxic conditions and with the Si / Ti ratio representing more clastic or more biogenic input. Plotting the clusters in this diagram allows identifying clusters that represent glacial phases (cluster I), super interglacials (cluster II), and interglacial phases (clusters III and IV).

scholarly journals Phenotypic plasticity of stomatal and photosynthetic features of four Picea species in two contrasting common gardens

AoB Plants ◽  
2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Ming Hao Wang ◽  
Jing Ru Wang ◽  
Xiao Wei Zhang ◽  
Ai Ping Zhang ◽  
Shan Sun ◽  
...  
Keyword(s):  
Climate Change ◽  
Phenotypic Plasticity ◽  
Global Climate ◽  
Physiological Activity ◽  
Climatic Conditions ◽  
Leaf Mass Per Area ◽  
Picea Crassifolia ◽  
Common Gardens ◽  
Picea Species ◽  
The Impact

Abstract Global climate change is expected to affect mountain ecosystems significantly. Phenotypic plasticity, the ability of any genotype to produce a variety of phenotypes under different environmental conditions, is critical in determining the ability of species to acclimate to current climatic changes. Here, to simulate the impact of climate change, we compared the physiology of species of the genus Picea from different provenances and climatic conditions and quantified their phenotypic plasticity index (PPI) in two contrasting common gardens (dry vs. wet), and then considered phenotypic plastic effects on their future adaptation. The mean PPI of the photosynthetic features studied was higher than that of the stomatal features. Species grown in the arid and humid common gardens were differentiated: the stomatal length (SL) and width (SW) on the adaxial surface, the transpiration rate (Tr) and leaf mass per area (LMA) were more highly correlated with rainfall than other traits. There were no significant relationships between the observed plasticity and the species’ original habitat, except in P. crassifolia (from an arid habitat) and P. asperata (from a humid habitat). Picea crassifolia exhibited enhanced instantaneous efficiency of water use (PPI = 0.52) and the ratio of photosynthesis to respiration (PPI = 0.10) remained constant; this species was, therefore, considered to the one best able to acclimate when faced with the effects of climate change. The other three species exhibited reduced physiological activity when exposed to water limitation. These findings indicate how climate change affects the potential roles of plasticity in determining plant physiology, and provide a basis for future reforestation efforts in China.

Breeding strategies in a changing climate and implications for biodiversity

1992 ◽  
Vol 68 (4) ◽  
pp. 472-475 ◽  
Author(s):  
D. P. Fowler ◽  
J. A. Loo-Dinkins
Keyword(s):  
Climate Models ◽  
Global Climate ◽  
Forest Tree ◽  
Climatic Conditions ◽  
Rate Of Change ◽  
Global Climate Models ◽  
Weather Patterns ◽  
Short Rotation ◽  
The Impact ◽  
Time Of Harvest

Most global climate models predict a rapid increase in temperature over the next few decades as a result of elevated levels of carbon dioxide and other greenhouse gases. Although the resolution of the existing models is not sufficient to predict specific weather patterns for the Maritimes region, the predicted rate of change is such that forest tree populations will be unable to adapt fully to future conditions. If conventional rotation lengths are planned, presently adapted seedlings will be poorly adapted to the new conditions by the time of harvest. A three-pronged approach is proposed to mitigate the impact of climate change in the Maritimes: development of short rotation clonal forestry, testing and breeding for stability of genotypes over a range of climatic conditions, and collection, storage, and testing of native and non-native materials of potential value.

scholarly journals Multivariate statistic and time series analyses of grain-size data in quaternary sediments of Lake El'gygytgyn, NE Russia

2013 ◽  
Vol 9 (6) ◽  
pp. 2459-2470 ◽  
Author(s):  
A. Francke ◽  
V. Wennrich ◽  
M. Sauerbrey ◽  
O. Juschus ◽  
M. Melles ◽  
...  
Keyword(s):  
Time Series ◽  
Grain Size ◽  
Far East ◽  
Principal Component ◽  
Sediment Supply ◽  
Multivariate Statistic ◽  
Lake El’Gygytgyn ◽  
Lake Center ◽  
The Impact ◽  
Size Data

Abstract. Lake El'gygytgyn, located in the Far East Russian Arctic, was formed by a meteorite impact about 3.58 Ma ago. In 2009, the International Continental Scientific Drilling Program (ICDP) at Lake El'gygytgyn obtained a continuous sediment sequence of the lacustrine deposits and the upper part of the impact breccia. Here, we present grain-size data of the past 2.6 Ma. General downcore grain-size variations yield coarser sediments during warm periods and finer ones during cold periods. According to principal component analysis (PCA), the climate-dependent variations in grain-size distributions mainly occur in the coarse silt and very fine silt fraction. During interglacial periods, accumulation of coarser material in the lake center is caused by redistribution of clastic material by a wind-induced current pattern during the ice-free period. Sediment supply to the lake is triggered by the thickness of the active layer in the catchment and the availability of water as a transport medium. During glacial periods, sedimentation at Lake El'gygytgyn is hampered by the occurrence of a perennial ice cover, with sedimentation being restricted to seasonal moats and vertical conduits through the ice. Thus, the summer temperature predominantly triggers transport of coarse material into the lake center. Time series analysis that was carried out to gain insight into the frequency of the grain-size data showed variations predominately on 98.5, 40.6, and 22.9 kyr oscillations, which correspond to Milankovitch's eccentricity, obliquity and precession bands. Variations in the relative power of these three oscillation bands during the Quaternary suggest that sedimentation processes at Lake El'gygytgyn are dominated by environmental variations caused by global glacial–interglacial variations (eccentricity, obliquity), and local insolation forcing and/or latitudinal teleconnections (precession), respectively.

scholarly journals Biomarker Proxy Records of Arctic Climate Change During the Mid-Pleistocene Transition from Lake El’gygytgyn (Far East Russia)

2021 ◽  
Author(s):  
Kurt R. Lindberg ◽  
William C. Daniels ◽  
Isla S. Castañeda ◽  
Julie Brigham-Grette
Keyword(s):  
Global Climate ◽  
Far East ◽  
Warm Season ◽  
The Arctic ◽  
Geochemical Data ◽  
Temperature Record ◽  
Higher Plant ◽  
Temperature Variations ◽  
Lake El’Gygytgyn ◽  
East Russia

Abstract. The Mid-Pleistocene Transition (MPT) is a widely recognized global climate shift occurring between approximately 1,250 to 700 ka. At this time, Earth's climate underwent a major transition from dominant 40 kyr glacial-interglacial cycles to quasi-100 kyr cycles. The cause of the MPT remains a puzzling aspect of Pleistocene climate. Presently, there are few, if any, continuous MPT records from the Arctic yet understanding the role and response of the high latitudes to the MPT is required to better evaluate the causes of this climatic shift. Here, we present new continental biomarker records of temperature and vegetation spanning 1,142 to 752 ka from Lake El'gygytgyn (Far East Russia). We reconstruct warm-season temperature variations across the MPT based on branched glycerol dialkyl glycerol tetraethers (brGDGTs) using the MBTʹ5ME proxy. The new Arctic temperature record does not display an overall cooling trend during the MPT but does exhibit strong glacial-interglacial cyclicity. Spectral analysis demonstrates persistent obliquity and precession pacing over the study interval and reveals substantial sub-orbital temperature variations at ~900 kyr during the first “skipped” interglacial. Interestingly, Marine Isotope Stage (MIS) 31, which is widely recognized as a particularly warm interglacial, does not exhibit exceptional warmth at Lake El'gygytgyn. Instead, we find that MIS 29, 27 and 21 were as warm or warmer than MIS 31. In particular, MIS 21 (~870 to 820 ka) stands out as an especially warm and long interglacial in the continental Arctic while MIS 25 is a notably cold interglacial. Throughout the MPT, Lake El'gygytgyn pollen data exhibits a long-term drying trend, with a shift to an increasingly open landscape noted after around 900 ka (Zhao et al., 2018), which is also reflected in our higher plant leaf wax (n-alkane) distributions. Although the mechanisms driving the MPT remain a matter of debate, our new climate records from the continental Arctic exhibit some similarities to changes noted around the North Pacific region. Overall, the new organic geochemical data from Lake El'gygytgyn contribute to expanding our knowledge of the high-latitude response to the MPT.

scholarly journals Evaluation of the influence of climate change on the productivity of millet in the central part of Ukraine

2018 ◽  
pp. 35-41
Author(s):  
N. V. Danilova
Keyword(s):  
Climate Change ◽  
Global Climate ◽  
Perennial Grass ◽  
Arable Land ◽  
Precipitation Amount ◽  
Early Spring ◽  
Climatic Conditions ◽  
Eating Quality ◽  
Winter Crops ◽  
The Impact

Climate change is a change of climatic conditions in the global atmosphere and on the Earth in general (or within its individual zones or territories) caused directly or indirectly due by the human activity on the planet, which are overlaid on the natural climatic variations (fluctuations) and ob-served during comparable periods of time.    Both the climate of Ukraine and the global climate are changing, but warming within our terri-tory progresses even faster than in other regions of the Northern Hemisphere. Ukraine in general and southern regions in particular are becoming increasingly vulnerable to climate change – droughts, extremely high temperatures, inefficient precipitation, reduced irrigated area cause of precipitation amount and regime, severer and more long-lasting droughts, reduced water availability. The majority of arable land in Ukraine are located in zones of unstable and insufficient humidity, it is quite possible that for plant growing, especially for growing winter crops and early spring crops, climate change will rather have a positive effect than negative one. Among the main types of cereals millet is the most common one. It is valuable for its groats, which is known by its high eating quality. Millet as a fast-growing crop having a certain agrotechnical importance: it is used as a backup crop for re-sowing dead winter crops and is suitable for stubble and post-harvest sowing, it also can be used as a cover culture for perennial grass. Millet is one of the most drought-resistant and heat-resistant crops. It is able to withstand heat injuries which is very important in arid areas and during dry years, when other grain crops have reduced yield. Millet suffers less from pests and diseases than other crops. The task was to evaluate the agro-climatic conditions of millet crops formation in the central part of Ukraine under conditions of climate change. The study of the impact of climate change on the formation of millet productivity for different time intervals was performed by comparing the data of the RCP scenario and the average long-term climatic and agro-climatic parameters. The in-fluence of agroclimatic conditions on the dynamics of increase of agroecological yield of different levels is also assessed.

Promising Areas for Ensuring Food Security in the Region (on the example of the Far East)

2020 ◽  
pp. 35-39
Author(s):  
M.S. Oborin ◽  
Keyword(s):  
Food Security ◽  
Agricultural Production ◽  
Agricultural Development ◽  
Positive Impact ◽  
Rapid Development ◽  
Import Substitution ◽  
Far East ◽  
Federal District ◽  
Climatic Conditions ◽  
The Impact

In the current political and economic situation in the Russian Federation, due to the need for rapid development of import substitution in the food sector, agriculture has become one of the priority sectors of the Russian economy. In the context of sanctions restrictions, food security as an essential component of the country’s national security depends entirely on the level of agricultural development. The problems and features of agricultural production development in regions with difficult natural and climatic conditions are relevant, since additional investments and the introduction of innovative technologies that reduce the impact of negative factors are required there. The article discusses the trends and prospects of ensuring food security of the Far Eastern Federal District. This direction includes the physical availability of food for the population of all subjects of the district, the necessary volumes and quality of food, its positive impact on the health of the population. Indicators of agricultural production in the district and its features in the regions are considered. The main problem of regions with unfavorable climatic conditions remains insufficient production of various types of products. The necessary directions for improving food security are systematic state support and strategic cooperation with neighboring regions at the inter-sectoral and inter-municipal levels.

scholarly journals Biogeochemical variability during the past 3.6 million years recorded by FTIR spectroscopy in the sediment record of Lake El'gygytgyn, Far East Russian Arctic

2014 ◽  
Vol 10 (1) ◽  
pp. 209-220 ◽  
Author(s):  
C. Meyer-Jacob ◽  
H. Vogel ◽  
A. C. Gebhardt ◽  
V. Wennrich ◽  
M. Melles ◽  
...  
Keyword(s):  
Far East ◽  
Climatic Conditions ◽  
Russian Arctic ◽  
Accumulation Rates ◽  
Sediment Record ◽  
High Accumulation ◽  
Late Pliocene ◽  
The Past ◽  
Lake El’Gygytgyn ◽  
Middle Pliocene

Abstract. A number of studies have shown that Fourier transform infrared spectroscopy (FTIRS) can be applied to quantitatively assess lacustrine sediment constituents. In this study, we developed calibration models based on FTIRS for the quantitative determination of biogenic silica (BSi; n = 420; gradient: 0.9–56.5%), total organic carbon (TOC; n = 309; gradient: 0–2.9%), and total inorganic carbon (TIC; n= 152; gradient: 0–0.4%) in a 318 m-long sediment record with a basal age of 3.6 million years from Lake El'gygytgyn, Far East Russian Arctic. The developed partial least squares (PLS) regression models yield high cross-validated (CV) R2CV = 0.86–0.91 and low root mean square error of cross-validation (RMSECV) (3.1–7.0% of the gradient for the different properties). By applying these models to 6771 samples from the entire sediment record, we obtained detailed insight into bioproductivity variations in Lake El'gygytgyn throughout the middle to late Pliocene and Quaternary. High accumulation rates of BSi indicate a productivity maximum during the middle Pliocene (3.6–3.3 Ma), followed by gradually decreasing rates during the late Pliocene and Quaternary. The average BSi accumulation during the middle Pliocene was ~3 times higher than maximum accumulation rates during the past 1.5 million years. The indicated progressive deterioration of environmental and climatic conditions in the Siberian Arctic starting at ca. 3.3 Ma is consistent with the first occurrence of glacial periods and the finally complete establishment of glacial–interglacial cycles during the Quaternary.

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