Broadscale evaluation of the sedimentary Hg proxy for volcanism – insights from data compilation

2021 ◽  
Author(s):  
Joost Frieling ◽  
Isabel Fendley ◽  
Tamsin Mather
Keyword(s):  
Environmental Factors ◽  
Volcanic Activity ◽  
Sediment Chemistry ◽  
High Temporal Resolution ◽  
Gaseous Emissions ◽  
Mass Extinctions ◽  
Volcanic Emissions ◽  
Deep Time ◽  
The Past ◽  
Data Compilation

<p>Over the past few years, mercury (Hg) concentrations in (predominantly) marine sediments have gained widespread attention as a far-field, high-temporal resolution proxy for deep-time enhanced volcanic activity. The primary focus of these Hg studies has been a range of events in the past 500 million years; mostly larger and smaller mass extinctions and periods of high-amplitude climate change. As a result, sedimentary Hg data reinforced the notion many of these events are indeed coeval with and hypothesized causally connected to large igneous provinces (LIPs). </p><p>However, relatively poor constraints on long-term dispersal of emissions through the marine and terrestrial biosphere, accumulation and preservation mechanisms of Hg pose difficulties for its use as a qualitative proxy for enhanced volcanic emissions. As a result, using sedimentary Hg for detailed modeling of Hg cycling or past gaseous emissions of magmatic volatiles, e.g. carbon and sulfur, and by extension environmental impact, remains speculative.</p><p>The use of Hg normalization to common Hg-binding sedimentary components such as organic carbon (TOC), Fe or Al provides a basic means of comparing relative Hg loading within a sedimentary sequence. Yet, normalizing Hg to these major sedimentary components relies on simple linear relations and this approach often leaves substantial variance. While the high Hg concentrations have usually been ascribed to variability in volcanic activity, there are likely other factors that may invoke changes in the Hg concentrations in sediments, or mask Hg emitted by volcanism such as amount or type and flux of organic matter being deposited in basins and oxygenation of water and local sediments.</p><p>To evaluate potential confounding factors, we compiled published Hg, TOC and bulk and trace element data, modern and deep-time events, periods with and without known anomalous volcanic activity and cover a range of depositional settings. We find that the depositional setting, as inferred from lithology and bulk sediment chemistry exerts a major control on the overall concentrations of Hg. Differences in Hg loading between time-correlative deposits persist after normalization to major sedimentary components, likely as a result of a complex interplay between various spatial and environmental factors. Our data compilation further allows us to explore the potential of establishing a range for background Hg values and variability through different periods of geological deep-time. Collectively, such constraints can aid the understanding of changes induced by environmental factors or volcanic emissions and inform Hg-cycling models.</p>

Personal and environmental factors contributing to parenting stress among employed and nonemployed women

1993 ◽  
Vol 7 (2) ◽  
pp. 107-118 ◽  
Author(s):  
Deborah Kirby Forgays ◽  
Donald G. Forgays
Keyword(s):  
Environmental Factors ◽  
Parenting Stress ◽  
Employment Status ◽  
Somatic Complaints ◽  
Infants And Toddlers ◽  
Household Chores ◽  
The Past ◽  
Self Confidence ◽  
Additional Role

Over the past 20 years, significantly more women have returned to the workforce after the birth of their child. Despite gains made by the second women's movement and attendant socio‐political changes, women continue to bear the major parenting responsibilities in addition to household chores. Does this additional role of workforce member result in a more highly stressed mother? This study recruited 120 mothers of infants and toddlers from a range of occupations who provided information on their adjustment to parenting as well as individual difference factors such as maternal self‐confidence, somatic complaints, and Type A behaviour. The results suggest that the level of parenting stress is not related to employment status alone. However, the factors contributing to reported parenting stress do vary by employment status. These results highlight the need to examine the interaction of personal and environmental dimensions when studying this complex area.

Ecology of cultivable yeasts in pristine forests in northern Patagonia (Argentina) influenced by different environmental factors

2014 ◽  
Vol 60 (6) ◽  
pp. 371-382 ◽  
Author(s):  
María Cecilia Mestre ◽  
Sonia Fontenla ◽  
Carlos A. Rosa
Keyword(s):  
Environmental Factors ◽  
Volcanic Activity ◽  
Forest Site ◽  
Nothofagus Pumilio ◽  
Species Accumulation Curves ◽  
Environmental Characteristics ◽  
Factors Affecting ◽  
Complex Interactions ◽  
Forest Sites ◽  
Nothofagus Antarctica

Environmental factors influencing the occurrence and community structure of soil yeasts in forests are not well studied. There are few studies dedicated to Southern Hemisphere soil yeasts populations and even fewer focused on temperate forests influenced by volcanic activity. The present work aimed to study the ecology of soil yeast communities from pristine forests influenced by different environmental factors (precipitation, physicochemical properties of soil, tree species, soil region, and season). The survey was performed in 4 northern Patagonian forests: 2 dominated by Nothofagus pumilio and 2 by Nothofagus antarctica. Yeast communities were described with ecological indices and species accumulation curves, and their association with environmental characteristics was assessed using multivariate analysis. Each forest site showed a particular arrangement of species as a result of environmental characteristics, such as dominant plant species, nutrient availability, and climatic characteristics. Cryptococcus podzolicus was most frequently isolated in nutrient-rich soils, Trichosporon porosum dominated cold mountain forests with low nutrient and water availability in soil, and capsulated yeasts such as Cryptococcus phenolicus dominated forest sites with low precipitation. The present work suggests that environmental factors affecting yeast communities may not be the current soil characteristics but the result of complex interactions of factors including natural disturbances like volcanic activity.

scholarly journals VARDA (VArved sediments DAtabase) – providing and connecting proxy data from annually laminated lake sediments

2020 ◽  
Author(s):  
Arne Ramisch ◽  
Alexander Brauser ◽  
Mario Dorn ◽  
Cecile Blanchet ◽  
Brian Brademann ◽  
...  
Keyword(s):  
High Resolution ◽  
Lake Sediments ◽  
Climate Models ◽  
Detailed Comparison ◽  
High Temporal Resolution ◽  
Proxy Data ◽  
Varved Sediments ◽  
Proxy Records ◽  
Data Compilation ◽  
Varved Lake Sediments

Abstract. Varved lake sediments provide long climatic records with high temporal resolution and low associated age uncertainty. Robust and detailed comparison of well-dated and annually laminated sediment records is crucial for reconstructing abrupt and regionally time-transgressive changes as well as validation of spatial and temporal trajectories of past climatic changes. The VARved sediments DAtabase (VARDA) presented here is the first data compilation for varve chronologies and associated palaeoclimatic proxy records. The current version 1.0 allows detailed comparison of published varve records from 95 lakes. VARDA is freely accessible and was created to assess outputs from climate models with high-resolution terrestrial palaeoclimatic proxies. VARDA additionally provides a technical environment that enables to explore the database of varved lake sediments using a connected data-model and can generate a state-of-the-art graphic representation of multi-site comparison. This allows to reassess existing chronologies and tephra events to synchronize and compare even distant varved lake records. Furthermore, the present version of VARDA permits to explore varve thickness data. In this paper, we report in detail on the data mining and compilation strategies for the identification of varved lakes and assimilation of high-resolution chronologies as well as the technical infrastructure of the database. Additional paleoclimate proxy data will be provided in forthcoming updates. The VARDA graph-database and user interface can be accessed online at https://varve.gfz-potsdam.de, all datasets of version 1.0 are available at http://doi.org/10.5880/GFZ.4.3.2019.003 (Ramisch et al., 2019).

scholarly journals Temps et récit : un défi pour l'écriture de l'histoire. À propos d'une lecture ricœurienne de Landscape and Memory de Simon Schama

2017 ◽  
Vol 8 (1) ◽  
pp. 54-66
Author(s):  
Josef Řídký
Keyword(s):  
Paul Ricoeur ◽  
Historical Consciousness ◽  
The Other ◽  
Work Time ◽  
Deep Time ◽  
Historical Discourse ◽  
The Past ◽  
Paul Ricœur ◽  
The One

During the past fifty years, a dispute over the nature of historical discourse has taken place with the narrativist approach, arguing for the dominance of narration in history, on the one hand, and professional historians defending historiography's will to tell the truth, on the other. Paul Ricoeur entered the discussion with his work Time and Narrative where he offered an inventive response. According to him, both narration and scientific explication are essential to historical discourse. To support his statement, he introduces terms such as ‘a third time,‘ ‘a quasi-narration’ or ‘a historical consciousness.’ Thus, he shifts attention from narration to time. These terms can prove their usefulness when interpreting historical works. In the rest of the article, we aim to carry out such an interpretation on the example of Landscape and Memory by Simon Schama. In a Ricœurian perspective, Schama's book reveals its deep time significance.

scholarly journals A 90,000-year record of Afromontane forest responses to climate change

Science ◽  
2019 ◽  
Vol 363 (6423) ◽  
pp. 177-181 ◽  
Author(s):  
Anne-Marie Lézine ◽  
Kenji Izumi ◽  
Masa Kageyama ◽  
Gaston Achoundong
Keyword(s):  
Climate Changes ◽  
High Temporal Resolution ◽  
Pollen Data ◽  
Glacial Cycles ◽  
Tropical Mountains ◽  
The Past ◽  
Afromontane Forest ◽  
Afromontane Forests ◽  
Lowland Forests ◽  
African Highlands

Pollen records from African highlands are scarce; hence, the paleoecology of the Afromontane forest and its responses to glacial cycles are poorly known. Lake Bambili (Cameroon) provides a record of vegetation changes in the tropical mountains of Africa over the past 90,000 years, with high temporal resolution. Pollen data and biome reconstructions show a diverging response of forests to climate changes; the upper tree line was extremely unstable, shifting substantially in response to glacial-interglacial climate alternation, whereas the transition between the montane and lowland forests remained remarkably stable. Such ecological instability may have had a critical influence on species richness in the Afromontane forests.

scholarly journals How the past impacts the future: modelling the performance of evolutionarily distinct mammals through time

2019 ◽  
Vol 374 (1788) ◽  
pp. 20190210 ◽  
Author(s):  
D. J. Bennett ◽  
M. D. Sutton ◽  
S. T. Turvey
Keyword(s):  
Fossil Record ◽  
Distinct Species ◽  
Performance Impact ◽  
Deep Time ◽  
The Past ◽  
Living Fossils ◽  
Measuring Change ◽  
Molecular Phylogenetic ◽  
Time Changes ◽  
The One

How does past evolutionary performance impact future evolutionary performance? This is an important question not just for macroevolutionary biologists who wish to chart the phenomena that describe deep-time changes in biodiversity but also for conservation biologists, as evolutionarily distinct species—which may be deemed ‘low-performing’ in our current era—are increasingly the focus of conservation efforts. Contrasting hypotheses exist to account for the history and future of evolutionarily distinct species: on the one hand, they may be relicts of large radiations, potentially ‘doomed’ to extinction; or they may be slow-evolving, ‘living fossils’, likely neither to speciate nor go extinct; or they may be seeds of future radiations. Here, we attempt to test these hypotheses in Mammalia by combining a molecular phylogenetic supertree with fossil record occurrences and measuring change in evolutionary distinctness (ED) at different time slices. With these time slices, we modelled future ED as a function of past ED. We find that past evolutionary performance does indeed have an impact on future evolutionary performance: the most evolutionarily isolated clades tend to become more evolutionarily distinct with time, indicating that low-performing clades tend to remain low-performing throughout their evolutionary history. This article is part of a discussion meeting issue ‘The past is a foreign country: how much can the fossil record actually inform conservation?’

scholarly journals Mapping Paleohydrologic Features in the Arid Areas of Saudi Arabia Using Remote-Sensing Data

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 417 ◽  
Author(s):  
Mohamed Abdelkareem ◽  
Fathy Abdalla ◽  
Samar Y. Mohamed ◽  
Farouk El-Baz
Keyword(s):  
Remote Sensing ◽  
Saudi Arabia ◽  
Volcanic Activity ◽  
Remote Sensing Data ◽  
Landsat 8 ◽  
Optical Remote Sensing ◽  
Alos Palsar ◽  
Sensing Data ◽  
The Past ◽  
Aeolian Deposits

At present, the Arabian Peninsula is one of the driest regions on Earth; however, this area experienced heavy rainfall in the past thousand years. During this period, catchments received substantial amounts of surface water and sustained vast networks of streams and paleolakes, which are currently inactive. The Advanced Land Observing Satellite (ALOS) Phased Array Type L-band Synthetic Aperture Radar (PALSAR) data reveal paleohydrologic features buried under shallow aeolian deposits in many areas of the ad-Dawasir, Sahba, Rimah/Batin, and as-Sirhan wadis. Optical remote-sensing data support that the middle of the trans-peninsula Wadi Rimah/Batin, which extends for ~1200 km from the Arabian Shield to Kuwait and covers ~200,000 km2, is dammed by linear sand dunes formed by changes in climate conditions. Integrating Landsat 8 Operational Land Imager (OLI), Geo-Eye, Shuttle Radar Topography Mission (SRTM) digital elevation model, and ALOS/PALSAR data allowed for the characterization of paleodrainage reversals and diversions shaped by structural and volcanic activity. Evidence of streams abruptly shifting from one catchment to another is preserved in Wadi ad-Dawasir along the fault trace. Volcanic activity in the past few thousand years in northern Saudi Arabia has also changed the slope of the land and reversed drainage systems. Relics of earlier drainage directions are well maintained as paleoslopes and wide upstream patterns. This study found that paleohydrologic activity in Saudi Arabia is impacted by changes in climate and by structural and volcanic activity, resulting in changes to stream direction and activity. Overall, the integration of radar and optical remote-sensing data is significant for deciphering past hydrologic activity and for predicting potential water resource areas.

scholarly journals Why COVID-19 Transmission Is More Efficient and Aggressive Than Viral Transmission in Previous Coronavirus Epidemics?

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1312 ◽  
Author(s):  
Fatma Elrashdy ◽  
Elrashdy M. Redwan ◽  
Vladimir N. Uversky
Keyword(s):  
Middle East ◽  
Environmental Factors ◽  
Severe Acute Respiratory Syndrome ◽  
Human Population ◽  
Viral Transmission ◽  
Host Factors ◽  
The Past ◽  
Viral Structure ◽  
The World ◽  
Human Host Factors

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing a pandemic of coronavirus disease 2019 (COVID-19). The worldwide transmission of COVID-19 from human to human is spreading like wildfire, affecting almost every country in the world. In the past 100 years, the globe did not face a microbial pandemic similar in scale to COVID-19. Taken together, both previous outbreaks of other members of the coronavirus family (severe acute respiratory syndrome (SARS-CoV) and middle east respiratory syndrome (MERS-CoV)) did not produce even 1% of the global harm already inflicted by COVID-19. There are also four other CoVs capable of infecting humans (HCoVs), which circulate continuously in the human population, but their phenotypes are generally mild, and these HCoVs received relatively little attention. These dramatic differences between infection with HCoVs, SARS-CoV, MERS-CoV, and SARS-CoV-2 raise many questions, such as: Why is COVID-19 transmitted so quickly? Is it due to some specific features of the viral structure? Are there some specific human (host) factors? Are there some environmental factors? The aim of this review is to collect and concisely summarize the possible and logical answers to these questions.

Impossible to Disprove Yet Impossible to Believe: the Unforgiving Epistemology of Deep-Time Oral Tradition

2009 ◽  
Vol 36 ◽  
pp. 127-234 ◽  
Author(s):  
David Henige
Keyword(s):  
American Indian ◽  
Carrying Capacity ◽  
Oral Tradition ◽  
Prima Facie ◽  
Oral Traditions ◽  
Historical Events ◽  
Deep Time ◽  
The Past ◽  
State Of Affairs

This is not a real old time myth but it is what they say now, and it must have been like that.This man from Ulimang was highly skilled in the art of warfare—like Eisenhower.A Tahitian businessman who provides ‘Polynesian’ entertainment for tourists in Hawaii with a young Marquesan man whom he took to Samoa to be tattooed by their artistsfollowing designs recorded by early European visitors.… as for oral Traditions, what certainty can there be in them? What foundation of truth can be laid upon the breath of man? How do we see the reports vary, of those things which our eyes have seen done? How do they multiply in their passage, and either grow, or die upon hazards?Writing about American Indian reactions to their discovery of large fossil remains, Adrienne Mayor observes in passing that “[f]olklore scholars now generally accept that oral traditions about historical events endure for about a thousand years, although some oral myths about geological and astronomical events can be reliably dated to about seven thousand years.” Mayor's chosen task is to demonstrate that American Indian legends suggest that they rightly regarded fossils as the remains of long extinct megafauna populations. In aid of this, Mayor accepts these arguments in her own work. While this claim might seem extravagantprima facie, and while most folklorists would disown Mayor's claim, she is not without support from the work of a relatively small, but not uninfluential (and possibly growing), cadre of anthropologists, mythographers, geologists, and historians, whose efforts on behalf of deep-time oral tradition I address here.Some interesting—even intriguing—things have been happening recently in discussions of the carrying capacity of oral tradition—its long-term historicity, in particular.À laMayor, the thrust of this is to credit tradition with being able to preserve “intact” various pieces of information for as long as tens of thousands of years. To the historian interested in the reality of the past in oral societies, this state of affairs is challenging, perplexing, and no doubt to some, highly promising. If, for instance, it can be demonstrated that certain information in oral data is thousands of years old and at the same time an accurate recollection, then reservations about much later (say, several centuries old) orally transmitted information might need to be reassessed, and with such rethinking would come new ways to approach great swaths of the past.

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