scholarly journals Application of Corrected Methods for High-Resolution XRF Core Scanning Elements in Lake Sediments

2020 ◽  
Vol 10 (22) ◽  
pp. 8012
Author(s):  
Xiaonan Zhang ◽  
Hucai Zhang ◽  
Fengqin Chang ◽  
Umar Ashraf ◽  
Wei Peng ◽  
...  
Keyword(s):  
High Resolution ◽  
Water Content ◽  
Lake Sediments ◽  
Lake Sediment ◽  
Sediment Cores ◽  
Xrf Core Scanner ◽  
Calibration Methods ◽  
Xrf Scanning ◽  
The Impact ◽  
Log Ratio

Contemporary studies emphasize theoretical and analytical aspects of monitoring water quality within lacustrine settings. The X-ray fluorescence (XRF) core scanner provides the most rapid, non-destructive high-resolution elemental measurements for unprocessed sediments. However, the analytical precision of measured elemental composition may be offset due to water content and inhomogeneities in the physical properties of the sediment. A range of calibration approaches developed specifically for converting XRF scanning intensities to element fractions has been made available. Here, two lake sediment-cores retrieved from southwest China were used to evaluate the performance of various calibration methods. In particular, the influence of sediment properties on XRF scanning intensities was assessed by redundancy analyses (RDA) and the generalized additive model (GAM). The results demonstrate that for fine-grained sediments, the impact of grain size results in only minor deviations in the XRF scanning intensities. Water content of the lake sediment was shown to be the most important factor influencing the XRF scanning intensities, especially for light elements (e.g., Al to Fe). Significant decreases in XRF scanning intensities may occur when sediment water content is greater than 47%. We recommend testing the element fractions obtained via conventional techniques throughout the core and applying the multivariate log-ratio calibration for high-resolution XRF scanning elements within lake sediments.

Tsunami hazard from lacustrine mass wasting in Lake Tekapo, New Zealand

2018 ◽  
Vol 477 (1) ◽  
pp. 413-426 ◽  
Author(s):  
Joshu J. Mountjoy ◽  
Xiaoming Wang ◽  
Susi Woelz ◽  
Sean Fitzsimons ◽  
Jamie D. Howarth ◽  
...  
Keyword(s):  
High Resolution ◽  
Sediment Cores ◽  
Lake Basin ◽  
Diverse Range ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Tectonically Active ◽  
Tsunami Risk ◽  
Western Shore ◽  
The Impact

AbstractLacustrine-tsunami risk from landslides can be significant yet for most locations globally the hazard remains unquantified. Lake Tekapo, in the tectonically active mountain belt of New Zealand's South Island, has been chosen to develop surveying and modelling techniques to assess the hazard from landslide tsunamis. Lake Tekapo is ideal for this study due to the high sedimentation rates, steep surrounds and the proximity to active faulting that indicate a high landslide potential. The shoreline tourist settlement and hydropower infrastructure mean the impact of any tsunami could be significant. In 2016 a survey was carried out to collect high-resolution (1 m grid) EM2040 multibeam bathymetry, high-resolution seismic reflection data (Boomer and chirp) and 6 m long sediment cores. These data reveal a diverse range of sedimentary processes in response to high sediment input and numerous landslides with varied styles of emplacement. For example, a one-off landslide initiated 40 m above the shoreline with debris deposits that have runout onto the lake floor to 100 m water depth contrasts with the Cass River delta on the western shore that has failed multiple times during the lake-basin infilling history. Landslide-generated tsunami scenarios are used to determine the relative hazard at different regions of the lake to guide development of a probabilistic tsunami model.

scholarly journals Tracking climate signals in varved lake sediments: research strategy and key sites for comprehensive process studies in the Masurian Lakeland

2017 ◽  
Vol 17 (3) ◽  
pp. 159-166 ◽  
Author(s):  
Wojciech Tylmann ◽  
Paulina Głowacka ◽  
Agnieszka Szczerba
Keyword(s):  
High Resolution ◽  
Lake Sediments ◽  
Sediment Cores ◽  
Monitoring Program ◽  
Sediment Traps ◽  
Research Strategy ◽  
Meteorological Conditions ◽  
Lake Basin ◽  
Climate Signals ◽  
Process Studies

AbstractLake sediments are excellent archives of environmental and climate change. Especially important are varved sediments which can provide high-resolution (annual) records of those changes. Process studies including limnological measurements, particle flux monitoring and analyses of sediment structures give an opportunity to explain relationships between meteorological conditions, in-lake processes and varve formation. In our study, three lakes were selected in the Masurian Lakeland: Lake Żabińskie, Łazduny and Rzęśniki. These relatively small and deep lakes contain well preserved biogenic varves. The lakes are influenced by the same meteorological conditions but differ in terms of their catchment size, land use, hydrology, lake basin morphology and trophic status. To explore the relationships between different parameters and preservation/transformation of climate signals in the sediments we started systematic limnological measurements in the water column of these lakes, water sampling for hydrochemical analyses, monitoring of modern sedimentation using sediment traps and analysis of topmost varves from short sediment cores. With this comprehensive and high-resolution monitoring program scheduled for at least four years we are going to verify the potential of varves to track short-term meteorological phenomena in lake sediments.

scholarly journals Radiocarbon Dating of Lake Sediment from Two Karst Lakes in Yugoslavia

Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 495-502 ◽  
Author(s):  
Dušan Srdoč ◽  
Bogomil Obelić ◽  
Nada Horvatinčić ◽  
Ines Krajcar-Bronić ◽  
Elena Marčenko ◽  
...  
Keyword(s):  
Lake Sediments ◽  
Lake Sediment ◽  
Sedimentation Rate ◽  
National Park ◽  
Radiocarbon Dating ◽  
Sediment Cores ◽  
Karst Area ◽  
Seismic Profiles ◽  
Karst Lakes ◽  
Isotopic Studies

Samples of sediment cores from two lakes in the karst area of northwest Yugoslavia were analyzed. Both Lakes Kozjak and Prošće are in the Plitvice National Park, Central Croatia. 14C dating, sedimentologic, seismic, and isotopic studies, and distribution of diatoms are presented.14C dating of lake marl revealed a uniforn sedimentation rate in Lake Prošće as opposed to Lake Kozjak. Both lake sediments belong to the Holocene period. 14C dating of lake sediment is in agreement with seismic profiles, sedimentologic analysis, and diatom frequency measurements both in an undisturbed as well as in a disturbed lake sediment.

Paleolimnology of Two Lakes in the Klutlan Glacier Region, Yukon Territory, Canada

1980 ◽  
Vol 14 (1) ◽  
pp. 149-168 ◽  
Author(s):  
J. Platt Bradbury ◽  
M. C. Whiteside
Keyword(s):  
Lake Sediments ◽  
Lake Sediment ◽  
Surface Sediment ◽  
Second Generation ◽  
Sediment Cores ◽  
Yukon Territory ◽  
Turbid Water ◽  
Baseline Information ◽  
Basin Formation ◽  
Diatom Stratigraphy

AbstractLakes developed on progressively younger end moraines of the Klutlan Glacier were initially assumed to have originated shortly after moraine emplacement and to have persisted to the present. Limnological differences between lakes on old vs young moraines were thought to result from limnological maturation within the lakes and ponds themselves and in response to the development of soils and vegetation on moraine surfaces. This study represents a paleolimnological test of this hypothesis. If true, the first-formed sediments of lakes on old moraines should be comparable to sediments presently forming in lakes on young moraines. Geochemical and paleontological studies of surface sediment to a series of lakes on progressively older moraines provide baseline information for comparing successive levels of lake sediment cores from older moraines. Results indicate that the time of lake initiation seldom reflects moraine age. Even on the oldest moraine (Harris Creek), lake basins are presently forming. Their sediment character more closely relates to the rapidity of basin formation due to melting of buried ice than to age of the lake itself or of the moraine on which it is situated. Vegetation and soil development play an important but secondary role in determining the character of lake sediments; rapid subsidence can convert humic-water lakes surrounded by second-generation spruce forests into turbid-water lakes with unstable, slumping margins. A detailed paleolimnological study of two lakes, one on the unglaciated upland and another in an outwash channel penetrating the oldest moraine, revealed progressive limnologic changes through time, suggesting that their basins were stable for 1200 and 400 yr, respectively. The changes in diatom stratigraphy of these lakes appear to relate to natural limnological changes associated with lake maturation and accumulation of nutrients as well as to changes in the surrounding vegetation and soils.

Alpine lake sediment records of the impact of glaciation and climate change on the biogeochemical cycling of soil nutrients

2006 ◽  
Vol 66 (1) ◽  
pp. 158-166 ◽  
Author(s):  
Gabriel M. Filippelli ◽  
Catherine Souch ◽  
Brian Menounos ◽  
Sara Slater-Atwater ◽  
A.J. Timothy Jull ◽  
...  
Keyword(s):  
Lake Sediment ◽  
Sediment Cores ◽  
Soil Nutrient ◽  
Nutrient Status ◽  
P Fractions ◽  
Cold Event ◽  
Coast Mountains ◽  
Geochemical Fractions ◽  
The North ◽  
The Impact

AbstractLake sediment cores from the Coast Mountains of British Columbia were analyzed using chemical sequential extractions to partition the dominant geochemical fractions of phosphorus (P). The P fractions include mineral P (the original source of bioavailable P), occluded P (bound to soil oxides), and organic P (remains of organic matter). By comparing P fractions of soil and recent lake sediment samples, these fractions are shown to be a valid proxy for landscape-scale nutrient status. Changes in soil development for an alpine watershed (Lower Joffre Lake) are inferred from the P fractions in the basin's outlet lake sediments. Glacially sourced mineral P dominates at the base of the core, but several rapid shifts in P geochemistry are evident in the first ∼3000 yr of the record. The latter indicates an interval of early and rapid soil nutrient maturation from ∼9600 to 8500 cal yr BP and a significant influx of slope-derived material into Lower Joffre Lake. A substantial increase in mineral P occurs at ca. 8200 cal yr BP, consistent with the cold event in the vicinity of the North Atlantic at that time. The more recent record reveals a continual increase in the proportion of mineral P from glacial sources to the lake, indicating a trend toward cooler conditions in the Coast Mountains.

Geomorphology of the lakebed and sediment deposition during the Holocene in Lake Visovac

2021 ◽  
Author(s):  
Nikolina Ilijanić ◽  
Slobodan Miko ◽  
Ozren Hasan ◽  
Dea Brunović ◽  
Martina Šparica Miko ◽  
...  
Keyword(s):  
High Resolution ◽  
Lake Sediment ◽  
National Park ◽  
Lake Level ◽  
Evolutionary Dynamics ◽  
Environmental Changes ◽  
Sediment Cores ◽  
Depositional Environments ◽  
Lake Levels ◽  
The Holocene

<p>Lake Visovac is a tufa barrier lake on the Krka River between Roški slap (60 m asl) and Skradinski buk (46 m absl) waterfalls, included in the Krka national park as primarily unaltered area of exceptional natural value. Paleolimnological research was conceived to address a lake evolution and depositional environments through the geophysical survey and collection of the lake sediment cores. A high-resolution bathymetric map was obtained using a multibeam sonar. The average lake depth varies between 20 and 25 m. Sediment cores were investigated to extract physical properties, sedimentological, mineralogical, geochemical and paleoecological records constrained by the radiocarbon chronology, to understand what was happening to both the landscapes and lakescapes of Lake Visovac during the last 2.000 cal yr.</p><p>Significant findings of the project are geomorphological features on the lake bottom: submerged sinkholes of various sizes (up to 40 m deep); submerged tufa barriers in the area of Kalički kuk (southern part of Lake Visovac) at the depths of 15 and 17 m, followed by a series of buried cascade tufa barriers at the depth of 25 m covered with up to 10 m of Holocene lake sediments; submerged vertical tufa barrier up to 32 m-high near the mouth of Čikola River; submerged landslides, small (river) fan structures characterized by sediment waves. Ground-penetrating-radar (GPR) data have been acquired due to the presence of gas-saturated sediments over a large area of the lake, that limited the use of high-resolution acoustic profiling. A total thickness of sediments is up to 40 m. High resolution paleoenvironmental record through the Late Holocene gives evidence of high sedimentation rates in Lake Visovac, variable soil erosion impact on lake sediment composition and carbonate authigenic sedimentation. Higher organic carbon is observed in the last 50 years due to changes in land cover and reforestation. Pleistocene lake sediment outcrops occur up to 20 m above the present lake levels indicating higher lake levels as a consequence of higher elevation of tuffa barriers. Kalički kuk, which lies up to 20 m above present lake level, is a remnant of these barriers which have been dated to MIS5. Results allow us to interpret the environmental and evolutionary dynamics of Lake Visovac in the following way: lake level more than 20 m higher than today in mid-Pleistocene with significantly larger lake volume in Lake Visovac, with active Kalički kuk and Skradinski buk waterfalls; lower lake-level at the beginning of the Holocene when several small lakes existed in isolated basins in the area of Lake Visovac. The tufa barrier at Skradinski buk started to grow faster than the Kalički kuk barriers and waterfalls resulting in their flooding and submergence during the Holocene. The tufa barrier at Skradinski buk has grown 15 m since then. This study demonstrates the role of geomorphological lakebed characteristics in reshaping our understanding of the environmental changes and the future of Lake Visovac.</p><p>The research was conducted as part of the project funded by the Krka National Park and CSF funded QMAD project (IP-04-2019-8505).</p>

scholarly journals Investigation of Adequate Calibration Methods for X-Ray Fluorescence Core Scanning Element Count Data: A Case Study of a Marine Sediment Piston Core from the Gulf of Alaska

2021 ◽  
Vol 9 (5) ◽  
pp. 540
Author(s):  
Md Nurunnabi Mondal ◽  
Keiji Horikawa ◽  
Osamu Seki ◽  
Katsuya Nejigaki ◽  
Hideki Minami ◽  
...  
Keyword(s):  
High Resolution ◽  
Marine Sediment ◽  
Count Data ◽  
Gulf Of Alaska ◽  
Piston Core ◽  
X Ray ◽  
X Ray Scattering ◽  
Calibration Methods ◽  
Log Ratio ◽  
Ray Scattering

X-ray fluorescence (XRF) core scanner elemental count data are useful for high-resolution paleoceanographic studies. However, because several factors, such as changes in physical core properties, significantly affect element count intensities, the appropriate calibration of the count data is required. Besides, the existing approaches for calibration were not widely employed and require rigorous testing based on sediment variety. In this study, we analyzed high-resolution element intensity (cps) using a wet muddy marine sediment piston core that was collected from the northeast Gulf of Alaska and tested several approaches with ratio and log-ratio methods, and the reliability was evaluated by comparison with the concentrations that were measured by WD-XRF and an elemental analyzer. The results show that the lighter elements (Ti and K) exhibited a significantly weak relationship between raw counts measured by ITRAX and concentrations that were measured by the WD-XRF, indicating that some factors artificially influence ITRAX intensity data. The Cl intensity that is expressed as the water content in marine sediment increased significantly in the upper 202 cm by 42% and the top 25 cm by 73% as compared to the down-core (below 202 cm), which deviates the X-ray scattering and element-counts. The calibration of raw data through coherent/incoherent X-ray scattering ratio (CIR) and additive- and centered-log ratio reduces the offsets. The calibration by CIR performed best for Sr, Fe, Mn, Ti, Ca, K, and Br (0.56 < R2 < 0.91), and the correlation with concentration significantly increased for Ti and K of 100% and 56%, respectively. Therefore, the study suggests that the correction of raw counts through CIR is an effective approach for wet marine sediment when core physical properties have greater variability.

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