bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural Evolution of Lorestan salient in North Zagros Mountain Belt, Iran
Authors: Pang Jun Wei , Hu Jyr-Ching
Published: March 2020

Zagros foreland basin is the most important oil-gas foreland basin in the world. At least 60 oil and gas fields have been found. Therefore, research in this area will enrich the petroleum geological information of the foreland basin as an important basis for oil and gas exploration. First, we conduct 2D restoration of Lorestan salient in North Zagros Mountain Belt with 2DMove to test the rationality of the equilibrium profile and understand the structural evolution of the Lorestan salient. Base on the 2D restoration, faults evolved in the ways of in-sequence and out-of-sequence, many faults have breached the cover layer from basement then produced anticline, in the earlier stage of deformation. Anaran anticline and Kabir Kuh anticline caused by the thrusts that displacement along the thrust are 5769 m and 11496 m, respectively. The Vardalan, Dareh Baneh and Naft Anticline also produced by the basement thrust later, this result suggest that surface topography and anticline are highly associated with basement thrust. Second, using the Move2017-Surface to establish the 3D structural model to observe the lateral variation of the strata, some strata have lateral variation, the Mishan formation is absent in the NW but gradually appear to the SE and the Triassic carbonates thickness decreases from almost 1000 m in the southwest to 200 m in the northeast. This reduction in thickness may associated with late Triassic normal faulting and erosion. Third, we project the earthquake on the cross section to understanding the relation between earthquake distribution and tectonic patterns. Based on the analysis of seismicity and geological profiles, earthquake focal mechanisms are mostly reverse faulting with NW–SE strikes and the distribution is over whole horizontal Zagros belt but concentrated in depth of 5~16 km. In addition, larger magnitude earthquakes mainly distribute in southwest Lorestan, it implies that it is the main regime of active tectonics.
Indentation tectonics of the Zhongtiaoshan Block in the Trans-North China Orogen
Authors: Cui Jiawei
Published: March 2020

The North China (NCC) is one of the oldest cratons in the world. The tectonic evolution processes of the NCC have been debated for decades (Zhao and Zhai, 2013; Zhao, 2007; Zhao et al., 2002, 2003, 2005, 2009; Zhai et al., 2005; Zhai and Santosh, 2011; Wilde et al., 2002, 2005; Kroner et al., 2005; Kusky et al., 2001, 2007; Kusky and Li, 2003; Faure et al., 2007; Trap et al., 2012; Hu et al., 2013; Zhao et al.,2019). The controversy focuses on the time of the formation of the NCC is in the late Paleoproterozoic or the late Archean. The key point of the controversy is that there are serious disagreement about the nature and implications of the late Paleoproterozoic orogen in the NCC. Some researchers thought the NCC underwent compression in 1.85 Ga according to previous researchers (Zhai et al., 2005; Zhai and Santosh, 2011; Zhao et al., 2019). Some researchers even thought that the NCC was finally formed resulted from the collision of the east block and the west block (Kusky et al., 2001, 2007; Kusky and Li, 2003; Trap et al., 2012; Zhao et al., 2002a, 2003a, 2005, 2009;). Recently, we found that NE-NEE trending extensional ductile shear zones developed in the Paleoproterozoic granitic gneiss (2.4Ga) in the northern margin of the Zhongtiaoshan, the middle part of the NCC. The ductile shear zone was unconformity covered by the Changcheng System and the deformation ages according to the 40Ar/39Ar dating results is 1.92 Ga, which indicate that the deformation time was in the late Paleoproterozoic. Therefore, We propose that that the NCC was in the post-collision extension environment or lateral and vertical extrusion of blocks might have happened after the orogeny in late Paleoproterozioc.
Exploring future wave climate changes from directional spectra: Implications for coastal impacts
Authors: Lobeto Hector , Menendez Melisa , Alvarez Moises , Mazzaretto Ottavio
Published: March 2020

Climate change may alter wave climate along most of world’s coasts (Morin et al., 2019). This could have implications on coastal impacts such as flooding and erosion (Wong et al., 2014). Traditional approaches to assess coastal impacts due to wind waves rely on, among other variables, the bulk sea-state parameters (e.g. significant wave height, peak period, mean wave direction). In this work, we analyse projected changes in wave climate considering the full directional spectra, particularly focusing on the added information this approach could offer. The analysed wave database consists of directional spectra and sea-state parameters at several coastal locations worldwide and in the western Mediterranean basin. Multi-model ensemble wave climate projections are obtained using WaveWatchIII model forced with surface wind fields and ice marine coverage outputs from several global and regional climate models (CMIP5 and CORDEX projects, respectively). Hourly spectra are stored with a discretization of 32 frequencies and 24 directions.

Results for sea-state parameters are coherent with previous studies about global wave climate changes (Camus et al., 2017; Collins et al., 2019), showing a wave height increase in the Southern Ocean and tropical eastern Pacific and a decrease in the North Atlantic and Mediterranean Sea. Nevertheless, the spectral analysis of wave climate changes provides new insights about the wave climate change signal. Thus, while projected changes of sea-state parameters provide an averaged information (both in magnitude and sign), the use of the full directional spectra makes it possible to study the projected change of each individual wave system. Also, this approach helps to note displacements of wave energy to higher or lower periods at each direction, which is especially relevant due to the important role that wave period and direction plays in coastal impacts such as dune erosion (Van Gent, 2008). The main conclusions reached in this study are the expected general increase of wave height in swells generated in the Southern Hemisphere that can travel north beyond the equator, and the decrease of wave systems generated in the Northern Hemisphere.

Finally, a comparison between the results from a coastal erosion assessment using estimated changes of sea-state parameters and climate change information from spectral wave data is shown.
Image recognition of microplastic particles in marine sediments – planned activities
Authors: Junttila Juho , Aagaard Sørensen Steffen , Haugland Johansen Thomas , Wing Gabrielsen Geir
Published: March 2020

Information about the distribution microplastics is crucial in marine environmental research. At present, plastic pollution is an environmental threat to the oceans and more than 90 % of microplastic particles are assumed to be deposited in the sediments on the ocean floor. An efficient way of identifying microplastic particles in marine sediments would result in improved understanding of microplastic distribution, inception, accumulation areas, and impact on marine ecosystems. Today, manual classification of microplastic particles using a microscope is time consuming. The goal of this study is to identify microplastic particles in marine sediment samples with the help of image recognition and machine learning. The possibility of using artificial microplastic particles will also be tested as a means of constructing comprehensive training sets. Existing algorithms already have been successful in classification of microfossils, which could be further developed for recognition of microplastic particles. Furthermore, hyperspectral analysis will be tested to determine the origin of the microplastic particles. Our overall goal is to train classifiers that in the future successfully can recognize different plastic objects in marine sediment samples and thereby replace the time-consuming manual classification task. Comparison between human based and machine based identifications for a large number of data sets will be made to test these classifiers.
The impact of the Pliensbachian-Toarcian crisis on belemnite diversity and size distribution
Authors: De Baets Kenneth , Rita Patrícia , Duarte Luís Vítor , Neige Pascal , Piñuela Laura , García-Ramos José Carlos , Weis Robert
Published: March 2020

The Pliensbachian–Toarcian transition has been considered a major bottleneck in the early evolution of belemnites, probably related to major palaeoenvironmental and climatic changes during the Early Toarcian. Previous research has focused on the study of belemnites from higher, temperate latitudes, while high-resolution studies on diversity and size of subtropical belemnite assemblages in the northwest Tethys are comparatively rare. The lack of high-resolution (ammonoid subzone) abundance data on diversity and size distributions of belemnite assemblages does not allow separating changes during the Pliensbachian–Toarcian boundary event from those during the Toarcian anoxic event. Sample standardized diversity analyses on new data from Iberian sections suggest the Pliensbachian–Toarcian corresponds to a slight decrease in diversity and an adult size decrease within dominant species. Cluster and non-metric multidimensional scaling analyses, however, indicate that the largest changes in diversity and palaeogeographic distribution of belemnite assemblages occurred during the Toarcian oceanic anoxic event (TOAE) rather than the Pliensbachian–Toarcian boundary. In southern basins like the Lusitanian Basin and Riff Mountains, belemnites even disappear entirely during the TOAE. More generally, the TOAE corresponds with an increase in body size of belemnite assemblages driven by species turnover. The lack of widespread anoxia in southern basins of the northwest Tethys indicates that direct impact of warming or increased pCO2 triggered by volcanism as well as indirect effects on nutrient availability and productivity might have played an important role during both crises.
Identifying Antarctic Ice Sheet Tipping Points
Authors: Reed Bradley , Green Mattias , Gudmundsson Hilmar , Jenkins Adrian
Published: March 2020

Warmer atmospheric and oceanic temperatures have led to a six-fold increase in mass loss from Antarctica in the last four decades. It is difficult to predict how the ice sheet will respond to future warming because it is subject to positive feedback mechanisms, which could lead to destabilisation. Observational and modelling work has shown that ice streams in West Antarctica may be undergoing unstable and possibly irreversible retreat due to increased basal melting beneath their ice shelves. Being able to identify and predict stability thresholds in ice streams draining the Antarctic Ice Sheet could help establish early warning indicators of near-future abrupt changes in sea level. 
 
Here, we use the shallow-ice flow model Úa to investigate the stability of an idealised ice stream from the third Marine Ice Sheet Model Intercomparison Project (MISMIP+). Initial results show that a gradual variation in ice viscosity, which corresponds to a change in temperature, causes the ice stream to undergo hysteresis across an overdeepened bed. This hysteresis means there are two tipping points, one for an advance phase and one for a retreat phase, both of which lie off the retrograde sloping bedrock. Beyond these tipping points, changes in ice stream grounding line position are unstable and irreversible. This behaviour is also apparent in wider ice streams although there is a change to the onset of instability and the location of tipping points. Further studies will investigate the additional effects of basal melting on these tipping points.
Are locked-in or living deltas more at risk?
Authors: Santos Maria J. , Reader Martin O. , Dekker Stefan C.
Published: March 2020

Delta systems are growingly at risk from ongoing global changes, sediment dynamics, and face many pressures from both upstream land use change and downstream sea level rise. Historically, deltas have been key locations for human occupation, and currently hold over 340 million inhabitants globally. This continuing pressure and risks have led deltas to become locked-in, likely losing their ability to provide ecosystem services and resilience to global change. To assess whether global deltas ranging from living to locked-in have lost their resilience to changes, we (i) used historical HYDE data to reconstruct the development of population and land use in 48 major deltas over the last 310 years, (ii) determine whether deltas are in locked in states, and (iii) assess whether locked-in deltas are more at risk due to relative sea level rise (RSLR), hazards, anthropogenic condition, investment deficit, and provision of nature contributions to people. 46% of the analyzed deltas are living deltas (22 out of 48), i.e. yet to be locked-in. Of the locked-in deltas (26 out of 48), 21% (n=10) emerge due to engineered natural infrastructure as the development of cropland and irrigation and 33% (n=16) are locked-in due to institutional infrastructure, such as no development of population or agricultural land uses.  We find that average risk index is higher for locked-in deltas due to natural infrastructure changes (higher hazard and anthropogenic risks for cropland development and higher investment deficit risk for irrigation development). Surprisingly, the most at risk deltas to future RSLR are the ones locked-in due to institutional changes and living deltas. Many locked-in deltas may be even more at risk when considering their current ability to supply regulating and material ecosystem services/nature contributions to people. Our results suggest that locked-in deltas might be more at risk from current pressures, due to a reduction in the functioning of the natural processes that govern deltas, while deltas locked-in due to social and institutional infrastructure will be more at risk in the future. Further work is necessary to understand whether these trends can be reversed.
Earthquake swarms in West Bohemia-Vogtland and South-West Iceland: are they of similar nature?
Authors: Horálek Josef , Jakoubková Hana , Doubravová Jana , Bachura Martin
Published: March 2020

Earthquake swarms occurred worldwide in diverse geological units, however, their origin is still unclear. West Bohemia-Vogtland represents one of the most active intraplate earthquake-swarm areas in Europe, South-West Iceland is characterized by intense interplate earthquake swarms. Both these areas exhibit high activity of crustal fluids.

We investigated earthquake swarms from W-Bohemia and from different areas in SW-Iceland: the Hengill volcanic complex, Ölfus transition zone (the edge of the SISZ), and Reykjanes Peninsula, from the perspective of their magnitude-time development, seismic moment release with time, the magnitude-frequency distribution and distribution of the inter-event times, and the space and time distribution of the foci. The aim was to determine the swarm characteristics that are dependent or vice-versa independent on the tectonic environment, and also the characteristics which should help us to distinguish more precisely earthquake swarms from mainshock-aftershock sequences.

We found that the frequency-magnitude (b-values) and inter-event-time distributions are similar for both areas, while total seismic moment release and its rate are much larger for the SW Icelandic activities compared to the W-Bohemia ones. One dominant short-term swarm phase with one or a few dominant events in which significant part of M0tot released, is typical of the SW Icelandic swarms, whereas the W-Bohemia swarms are characterised by stepwise seismic moment release, which is manifested by several swarm phases. MFDs of the SW-Iceland swarms indicate significantly lower a-value (number of ML > 0 evens), particularly of those on the Reykjanes Peninsula, compared to W-Bohemia swarms; it is due to the fact that considerable amount of M0tot released in quasi-mainshocks and the rest in aftershocks; lower a-value was also found for the W-Bohemian mainshock-aftershock sequence in 2014. The W-Bohemian swarms took place in a bounded focal zone consisting of several fault segments but the SW-Icelandic swarms correspond well to tectonic structures along the Mid Atlantic Ridge. We conclude that most of the W-Bohemia earthquake swarms were series of subswarms with one or more embedded mainshock-aftershock sequences, while the SW-Icelandic swarms (particularly those on the Reykjanes Peninsula appear to be a transition between earthquake swarm and mainshock-aftershock sequence. The W-Bohemia and SW-Iceland focal zones are characterized by complex system of short, differently oriented faults/fault segments; interestingly, the W-Bohemia and some SW-Icelandic focal zones exhibit coexistence of faults susceptible to earthquake swarms and differently oriented faults predisposed to common earthquakes (mainshock-aftershocks).
The contribution of phyllospheric microbes on nitrous oxide fluxes of Norway spruce
Authors: Martikainen Inga , Putkinen Anuliina , Pumpanen Jukka , Pihlatie Mari , Siljanen Henri
Published: March 2020

Current atmospheric models show that we still lack the knowledge of all possible sinks of nitrous oxide (N2O). One potential, yet not studied sink could be the phyllospheric microbiota of trees. We studied Norway spruce (Picea abies) branches collected from three locations in Finland; from southern (Helsinki), central (Kuopio) and from northern (Kittilä) parts of the country. In our study, we differentiated the functioning and diversity of microbes living on the plant surfaces (epiphytic) and inside the plant (endophytic). Our preliminary data from incubation experiment suggest that the epiphytic microbes of spruce branches from central and southern parts of Finland have the potential to reduce N2O although the variation within sites was notable. We isolated microbial clones from both epiphytic and endophytic samples and amplified their nitrous oxide reductase enzyme coding gene, nosZ. N2O consumption potential study of clones in oxic and anoxic circumstances showed that N2O reduction on phyllosphere has a microbial origin.  We are going to determine the original microbial population of spruce phyllospheric samples with targeted metagenomic sequencing of nitrogen cycling genes and with nosZ amplicon sequencing. As a conclusion, phyllospheric N2O consuming microbes can potentially cause sink for atmospheric and internally produced N2O in trees.
The molecular composition of dissolved organic matter (DOM) and its effects on the greenhouse gas production in pristine subarctic rivers
Authors: Saarela Taija , Jäntti Helena , Ohashi Mizue , Ide Jun’ichiro , Berninger Frank , Ojala Anne , Pumpanen Jukka
Published: March 2020

Controls on the degradation of dissolved organic matter (DOM) in freshwaters play a major role in the global carbon cycle. Under the changing climate, the aquatic systems are exposed to increasing terrestrial OM load due to changes in precipitation and air temperature. However, little is known about how the source and composition of this DOM influence its microbial processing in receiving waters.

In this study, we aimed to determine the composition of riverine DOM at a molecular level to gain a more comprehensive understanding on how the quality and quantity of DOM reflect its microbial degradability. Our objectives were to determine how the DOM decay patterns differ between brown-water and clearwater river and how these further regulate the potential greenhouse gas production (carbon dioxide, CO2 and methane, CH4) in these waters.

We collected water samples during two sampling occasions (June and October 2018) from two pristine subarctic rivers in Finnish Lapland and conducted 21-day incubation studies to follow the changes in the concentration and molecular composition of DOM, as well as the changes in the CO2 and CH4 concentrations. The molecular characterization of DOM was carried out using electrospray ionization (ESI) coupled to high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS).

Both rivers acted as a source of CO2 and CH4. Our preliminary results show that river water surrounded by peatlands contained a higher number of compounds such as condensed aromatic structures and lignin-like molecules, which led to slower decomposition rates compared to DOM in clearwater river. Overall, the decomposition of DOM was higher during spring flow than during fall due to recently released fresh DOM in the water.
Differential microbial colonization on microplastic in the Mediterranean Sea coastal zone
Authors: Vaksmaa Annika , Knittel Katrin , Abdala Asbun Alejandro , Goudriaan Maaike , Ellrott Andreas , Witte Harry , Niemann Helge
Published: March 2020

Ocean plastic debris poses a large threat to the marine environment. Millions of tons of plastic end up in the ocean each year and the Mediterranean Sea is one of the most plastic polluted sea. Ocean plastic particles are typically covered with microbial biofilms, but it remains unclear if different polymer types are colonized by different communities. Knowledge in this aspect strengthens our understanding if microbes purely use plastic debris as attachment surface or if they may even contribute to the degradation of plastic. To gain a better understanding of the composition and structure of biofilms on micro plastic particles (MP) in the Mediterranean Sea, we analyzed microbial community covering floating MP in a bay/marina (Marina di Campo) on the island of Elba. MPs were collected with a plankton net (mesh size 50µm), fixed for fluorescence microscopy and stored for subsequent DNA extraction, and identification of the polymer with Raman spectroscopy. The particles were mainly comprised of polyethylene (PE), polypropylene (PP) and polystyrene (PS) and were often brittle and with cracks (PE, PP) and showed visual signs of biofouling (PE, PP, PS). Fluorescence in situ hybridization and imaging by high resolution confocal laser scanning microscopy of single MPs revealed high densities of colonization by microbes. 16S rRNA gene amplicon sequencing (Illumina Miseq) revealed higher abundance of archaeal sequences on PS (up to 29% of the reads) in comparison to PE or PP (up to 3% of the reads).  The bacterial community in the biofilms on each of the three plastic types consisted mainly of the orders Flavobacteriales, Rickettsiales, Alteromonadales, Cytophagales, Rhodobacterales and Oceanospirillales. Furthermore, we found significant difference in the community composition of biofilms on PE compared to PP and PS but not between PP and PS. The indicator species on PE were Calditrichales, detected at 10 times higher sequence abundance on PE than on PP and PS, as well as several uncultured orders. This study sheds light on preferential microbial attachment and biofilm formation on microplastic particles, yet it remains to be revealed, whether and which of these may contribute to plastic degradation.
Testing direct dating of Alpine faults by luminescence and ESR
Authors: Tsukamoto Sumiko , Tanner David , Brandes Christian , von Hagke Christoph
Published: March 2020

For a better understanding of the recent exhumation history of the Alps and the distribution of palaeo- and recent earthquakes within the orogen, it is important to elucidate the Quaternary activity of major faults. In this study, we test the applicability of luminescence and electron spin resonance (ESR) dating, which have ultralow closure temperatures, to directly date fault gouge of the Simplon Fault. A dark grey to black, fine-grained fault gouge was sampled near Visp, Switzerland, from an outcrop that exposes rocks that formed at ductile/brittle conditions. Quartz and feldspar grains were extracted from the sample; quartz grains were used for ESR dating, whereas feldspar grains were used for infrared stimulated luminescence (IRSL) dating.

The IRSL measurements reveal that the natural post-IR IRSL signal, stimulated at 225°C (pIRIR225) was in saturation. The pIRIR225 signal had an extremely low saturation dose, with a characteristic saturation dose (D0) of ~90 Gy. The natural IRSL signal at 50°C (IR50) is about 80 % of the laboratory saturation, so that this signal is presumably in the field saturation. The IR50 also showed a small D0 of ~250 Gy. Although these D0 values are unexpectedly small, the IRSL signals can be used to calculate the minimum age of the last seismic movement of the fault.

Both natural and laboratory-irradiated ESR spectra did not contain detectable Ti centre. Therefore, only the Al centre was used for ESR dating. The natural Al centre from the fault was not in saturation, with a preliminary equivalent dose value of ~1500 Gy. Since the last seismogenic movement most likely only partially reset the Al centre, the ESR age can be regarded as the maximum age of the last event.  We show that by combining luminescence and ESR dating, it is possible to narrow down the age range of the last seismic activity on the fault.
Polished slickensides preserved in the Obir Caves (Austria) close to the Periadriatic Fault System
Authors: Koppensteiner Stefanie , Bauer Harald , Plan Lukas , Grasemann Bernhard
Published: March 2020

We studied polished slickensides, which are perfectly preserved in the Obir Caves (Northern Karavanke Mountains, Austria) situated in the Middle Triassic Wetterstein limestone of the Hochobir massif. The investigated area is located close to the seismogenic ESE-trending Periadriatic Fault System, which is the border between the Eastern and Southern Alps. The polished slickensides observed on a block between two major left-lateral NE-SW trending slickensides record a range of polishing from none to highly-reflective fault surfaces. A classification of the different polishing grades of the fault surfaces inside the cave compared with their spatial orientation shows that there is no relationship between the degree of polishing and fault orientation. Associated cataclastically deformed brittle fault zones and partly polished slickensides at the cave entrance and on the Eastern slope of the Hochobir massif where the fault zone localizes in shattered dolomitic rocks, show similar kinematics and spatial orientation to the faults inside the Obir Caves.

Thin section analysis identified the smooth fault mirror surfaces as principal slip surfaces. Cataclastic grains are truncated along the principal slip surfaces and along secondary Riedel faults. Five different stages of cataclastic deformation can be distinguished: I) Undeformed carbonate host rock. II) Isolated fractures in the host rock with injected ultracataclastic material. III) Dilation cataclasites containing jigsaw breccia. IV) Ultracataclasite with angular-to-rounded host rock fragments and jigsaw breccia. V) Ultracataclasite with isolated clasts and truncated grains close to the mirror surfaces.

The microstructures including polished slickensides, injected cataclasites and truncated grains along principal slip surfaces as well as the geological position close to the seismogenic Periadriatic Fault System suggest that the investigated fault surfaces in the Obir Caves formed during seismic slip.
Regional Impacts of Offshore Windfarming on the Hydro- and Ecosystem Dynamics in the North Sea
Authors: Christiansen Nils , Daewel Ute , Schrum Corinna , Carpenter Jeff , Djath Bughsin , Schulz-Stellenfleth Johannes
Published: March 2020

The production of renewable offshore wind energy in the North Sea increases rapidly, including development in ecologically significant regions. Recent studies identified implications like large-scale wind wake effects and mixing of the water column induced by wind turbines foundations. Depending on atmospheric stability, wind wakes imply changes in momentum flux and increased turbulence up to 70 km downstream, affecting the local conditions (e.g. wind speed, cloud development) near offshore wind farms. Atmospheric wake effects likely translate to the sea-surface boundary layer and hence influence vertical transport in the surface mixing layer. Changes in ocean stratification raise concerns about substantial consequences for local hydrodynamic and biogeochemical processes as well as for the marine ecosystem.
Using newly developed wind wake parametrisations together with the unstructured-grid model SCHISM and the biogeochemistry model ECOSMO, this study addresses windfarming impacts in the North Sea for future offshore wind farm scenarios. We focus on wind wake implications on ocean dynamics as well as on changes in tidal mixing fronts near the Dogger Bank and potential ecological consequences. At this, we create important knowledge on how the cross-scale wind farm impacts can be modelled suitably on the system scale.
Sedimentary Cyclicity in the Upper Paleocene- Eocene Successions of the Haymana Basin (Ankara, Turkey): Responses of Fossils to Cyclicity
Authors: Bengül Nilya
Published: March 2020

The Haymana Basin in central Anatolia (Turkey) formed during the closure of the Neo-Tethys on Late Cretaceous to Middle Eocene as a forearc accretionary wedge. Late Paleocene to Middle Eocene aged units in this basin are exposed near Çayraz Village, Haymana. The Çayraz Formation is the youngest unit of the Haymana Basin, and it is represented by packages of nummulitic banks, and the intercalation of calcareous mudstones. The aim of this study is to investigate the sedimentary cyclicity and depositional sequences in the Upper Paleocene- Eocene successions of the Haymana Basin. To be able to achieve this objective, a stratigraphic section has been measured through this succession. In this study, detailed microfacies analyses of the shallow-water carbonate successions indicate a ramp type depositional model of the carbonate rocks. The facies composed of Alveolina sp., Orbitolites sp., and  Miliolids that indicate low energy depositional environment . After that depositional environment to  the shoal; the facies composed of Nummulites spp., Assilina spp. occur and increase their abundance towards high-energy environments. Absence of the Alveolina sp., Orbitolites sp., and Miliolids. occur in accordance with that. The facies composed of Nummulites spp., Assilina spp. become associated with Discocyclina sp. towards to open sea on the ramp, and the shallow open marine part is represented by the shale with the association of planktonic foraminifera. Lateral relationships of the facies from proximal (inner ramp) to the distal (mid ramp) part of the ramp are investigated by using the knowledge of paleoecology preferences of the fossils, lithologic data of the rocks and biological aspects of the fossils.  The fossil associations and their indicator environments can be used in vertical changes of the facies as in the lateral relationships of the facies. It has potential to derive cyclic relationships of the stratigraphic sequence. Therefore, based on the detailed microfacies analysis and change in the distribution of the fossil associations in the stacking pattern of the sequence, a composite depositional model has been suggested. At this part of the research newly acquired question is that the driven factor of these cyclic relationships of the sequence, whether it occurred by the control of the eustatic sea- level or the interplay between tectonics and the eustacy as the dominating factor in the sequence formation.

 

Keywords: Large Benthic Foraminifera, Nummulites spp., Assilina spp., Haymana Basin, Çayraz Formation
Comparing Wind Patterns at Menderes Area in Aegean Region, Turkey using different datasets at higher resolutions using Regional Climate Modeling RegCM4
Authors: Collu Kamil , Kurnaz M. Levent
Published: March 2020

In this study, it is aimed to compare wind patterns at Menderes area in Aegean Region in Turkey using HadGEM2 dataset from Hadley Center, United Kingdom and MPI-ESM-MR dataset from Max Planck Institute, Germany. These datasets are downscaled to high resolutions at 10km, 5km and 1km for two different RCP scenarios RCP 4.5 and RCP 8.5 and for different time periods 1970-1999, 2020-2049 and 2070-2099 using Regional Climate Modeling RegCM4.5 and above of the Abdus Salam International Centre for Theoretical Physics (ICTP) to see the changes of the wind patterns at Menderes area in Aegean Regiion in Turkey due to climate change.
Evaluation of multi-component ensemble simulation of PM2.5 in the Pearl River Delta region
Authors: Wu Qian , Tang Xiao , Kong Lei , Lu Miaomiao , Wang Zifa
Published: March 2020

Sulfate, nitrate, ammonium, organic carbon and black carbon are the key components of PM2.5, but their simulations are still facing high uncertainty. Exploring the sources of such uncertainty is important for the modeling of PM2.5 and the understanding of atmospheric chemical processes. This study aims to evaluate and investigate the modeling uncertainty of these aerosols over Pearl River Delta (PRD) region based on Monte Carlo simulations of a Nested Air Quality Prediction Modeling System (NAQPMS) during 2015. Emission inventory as one of the most important uncertainty sources are perturbed according to their uncertainties to derive 50 ensemble simulations of NAQPMS with 15km horizontal resolution. The surface observations of sulfate, nitrate, ammonium, OC and BC from 10 sites in PRD region for one year are used to evaluation the performance of the ensemble mean estimation of the simulations. The results suggested that the ensemble mean could well reproduce the spatial and temporal variations of nitrate, ammonium, OC and BC with the correlation coefficients above 0.74 and their mean bias less than 2μg·m-3 . However, the model has poor skills in the sulfate modeling with the correlation coefficients 0.26 and remarkable underestimation in winter. Further analysis for such modeling uncertainties suggested that the uncertainties in emissions can explain most of modeling uncertainties for BC and OC. However, the biases in sulfate and ammonium modeling especially during the wintertime are probably caused by the uncertainty in heterogeneous reaction modeling. The above results provide an overall assessment of the uncertainty in inorganic aerosol modeling over PRD region and can serve a basis for its simulation improvement.
Reshuffling of Nutrients in the Southern Ocean
Authors: Frenger Ivy , Cerovecki Ivana , Mazloff Matthew
Published: March 2020

Deep waters upwell in the Southern Ocean, replete with nutrients. Some of these nutrients enter lighter mode and intermediate waters (MIW), fueling upper ocean productivity in the otherwise nutrient depleted (sub)tropical waters. However some of the upwelled nutrients are retained in the Southern Ocean or leak into denser bottom waters (AABW), making them unavailable for upper ocean productivity. Despite its fundamental importance for the global ocean productivity, this “reshuffling” of nutrients between Southern Ocean water masses, and its driving forces and temporal variability, have not been quantified to date.

We analyze the globally major limiting macronutrient, nitrate (NO3), using the results of a data-assimilating coupled ocean-sea-ice and biogeochemistry model, the Biogeochemical Southern Ocean State Estimate (B-SOSE), for the years 2008 – 2017. Using a water mass framework, applied to five day averaged SOSE output south of 30oS, we quantify the processes controlling NO3 inventories and fluxes. The water mass framework enables us to assess the relative importance of physical processes (such as surface buoyancy fluxes and diapycnal mixing) and biogeochemical processes (such as productivity and remineralization) in driving the transfer of NO3 from upwelling deep waters (CDW) to MIW and AABW, and its interannual variability.

Our results show that two thirds of the NO3 supplied to MIW occurs through lightening, or transforming, of CDW waters during the course of the overturning circulation. The other third of the NO3 supplied to MIW occurs through upward mixing of NO3 from NO3-enriched CDW. This means that physical processes determine the mean MIW NO3 content. Biology does not have a net effect on MIW NO3: while biological uptake draws down the MIW concentration of  NO3 near the surface, remineralization of organic matter compensates for this MIW loss below the surface. Also, we find that the productivity in the subtropical waters south of 30oS is fed through both, the canonical upward mixing of NO3 through the thermocline, and through the near surface supply from MIW. Thus, again, water mass transformation is playing a large role in nutrient distributions. 

In ongoing work, we assess the drivers of variability of the reshuffling of NO3 between water masses and their potential sensitivity to climate change.
Discharge estimation and monitoring extreme events by satellite altimetry
Authors: Belloni Rossella , Camici Stefania , Tarpanelli Angelica
Published: March 2020

In view of recent dramatic floods and drought events, the detection of trends in the frequency and magnitude of long time series of flood data is of scientific interest and practical importance. It is essential in many fields, from climate change impact assessment to water resources management, from flood forecasting to drought monitoring, for the planning of future water resources and flood protection systems. 
To detect long-term changes in river discharge a dense, in space and time, network of monitoring stations is required. However, ground hydro-meteorological monitoring networks are often missing or inadequate in many parts of the world and the global supply of the available river discharge data is often restricted, preventing to identify trends over large areas.  
The most direct method of deriving such information on a global scale involves satellite earth observation. Over the last two decades, the growing availability of satellite sensors, and the results so far obtained in the estimation of river discharge from the monitoring of the water level through satellite radar altimetry has fostered the interest on this subject.  
Therefore, in the attempt to overcome the lack of long continuous observed time series, in this study satellite altimetry water level data are used to set-up a consistent, continuous and up-to-date daily discharge dataset for different sites across the world. Satellite-derived water levels provided by publicly available datasets (Podaac, Dahiti, River& Lake, Hydroweb and Theia) are used along with available ground observed river discharges to estimate rating curves. Once validated, the rating curves are used to fill and extrapolate discharge data over the whole period of altimetry water level observations. The advantage of using water level observations provided by the various datasets allowed to obtain discharge time series with improved spatio-temporal coverages and resolutions, enabling to extend the study on a global scale and to efficiently perform the analysis even for small to medium-sized basins.  
Long continuous discharge time series so obtained are used to perform a global trend analysis on extreme flood and drought events. Specifically, annual maximum discharge and peak-over threshold values are extracted from the simulated daily discharge time series, as proxy variables of independent flood events. For flood and drought events, a trend analysis is carried out to identify changes in the frequency and magnitude of extreme events through the Mann-Kendall (M-K) test and a linear regression model between time and the flood magnitude.  
The analysis has permitted to identify areas of the world prone to floods and drought, so that appropriate actions for disaster risk mitigation and continuous improvement in disaster preparedness, response, and recovery practices can be adopted. 
Longshore variation in coastal foredune growth on a megatidal beach from UAV measurements
Authors: Fairley Iain , Horrillo-Caraballo Jose , Mendzil Anouska , Blow Georgie , Miller Henry , Masters Ian , Karunarathna Harshinie , Reeve Dominic
Published: March 2020

Coastal dunes are both a vital natural coastal defence and a key ecological habitat; therefore, understanding their evolution is important to inform coastal management. Megatidal environments are the world largest tidal ranges and hence provide a unique endmember of the tidal range continuum. A study site at Crymlyn Burrows, Swansea Bay, UK is monitored here; the area was originally of applied interest due to its identification as a key receptor of the Swansea Bay Tidal Lagoon project. The study site comprises of 2km of dune frontage bounded to the west by hard sea defences and to the east by the River Neath estuary. The intertidal is characterized by a shallow slope and crescentic intertidal bars. Mean spring tidal range at the nearby Mumbles tide gauge is 8.46m; mean wave heights at a wave buoy offshore of the site (depth 9m LAT) are 0.66m and storm wave heights exceed 3m; predominant wind direction is in an alongshore – onshore direction.

A Sensefly Ebee-RTK drone with a Sony RGB camera has been used to map the dune system and the mid to upper intertidal beach on a monthly – bimonthly frequency since October 2018. Initial post-processing was conducted in the Sensefly Emotion3 software; Pix4D was then used to generate a point cloud from the georeferenced images. RTK-GPS surveyed ground control points distributed over the study area were used to improve the accuracy of the solution. Point clouds were cleaned to remove noise using Cloud Compare, an open source point cloud editor, before being interpolated onto a gridded surface. Comparison of the gridded surface against RTK-GPS surveyed points gave a vertical mean absolute error (MAE) of 0.05m over the beach area. Comparison in the dune area is more complex since the raw point cloud includes the vegetation and hence over-estimates height compared to the bare earth. Based on the raw point cloud, MAE over the dune area was 0.22m; however, when vegetation points were removed using artificial neural network based colour discrimination, the MAE was 0.05m.

Longshore variation in dune evolution is clearly evident. At the eastern and western ends of the dune system, dune progradation can be observed whereas in the central portion the frontal dune is cliffed and the dune foot position is static or eroding landward. Pressure transducers have been deployed in a longshore array at the neap high tide level to assess variation in wave energy reaching the upper intertidal over the study area.

This presentation will explore whether this variation in behavior is due to longshore variation in wave energy (erosion potential), variation in sediment availability (accretion potential) or the persistence of antecedent morphology.
Seismoacoustic research of lakes bottom sediments of the eastern part of the Republic of Bashkortostan (Russia).
Authors: Krylov Pavel , Nurgaliev Danis
Published: March 2020

Seismoacoustic survey is a necessary and important method for studying a water area, both from the point of view of studying the structure of bottom sediments bedding, and choosing the optimal point for selecting core columns. In the process of sedimentation, the bottom sediments of modern lakes react very sensitively to climate changes due to changes in the nature and rate of incoming terrigenous material, changes in the lake level and its area, and changes in its bio productivity. Large lakes are investigated using large ships and installations; however, the study of small water areas is rare for a number of reasons. Nevertheless, new detailed results of the regional climate changes can be obtained in such lakes. In 2019, it was conducted detailed seismic investigations of 6 lakes in the eastern part of the Republic of Bashkortostan (Russia) using the “Boomer” seismic complex. For field work we used an inflatable boat and an environmentally friendly electric motor. All lakes are relatively close to each other. However, different structure of bottom sediments bedding on seismic sections was obtained in all lakes. For example, in Lake Sabakty, a layered thickness of bottom sediments of up to 6 m was observed. In some places there are gas-saturated sediments. A slight uplift is observed in these areas, probably related to the “swelling” of bottom sediments as the gas concentration in the sediments increases. In Lake Bannoye, on seismic section observed a bedding structure on a slope of greater thickness (more than 8m) than in the deepest plane part (thickness 2m). 8 cores were selected in these 2 lakes for laboratory investigations. In the remaining 4 lakes, bottom sediments with lower thickness, with the presence of gas-saturation, or sediments were not detected. This work was funded by the Russian Science Foundation under grant № 18-17-00251.
The Impact of Extratropical Cyclones on the Greenland Ice Sheet
Authors: Maffezzoni Luca , Edwards Laura , Matthews Tom
Published: March 2020

The Greenland Ice Sheet (GrIS) stores enough freshwater to raise global sea level by more than 7 m, so its response to climate variability and change is of considerable societal significance. In this context, extratropical cyclones are known to impact the surface mass budget (SMB) via their influence on precipitation and the surface energy budget (SEB). However, there has so far been limited research on these pathways. We address this by expanding process-based knowledge of cyclones and their influence on the GrIS. Using a 58-year integration of the Model Atmospherique Regional (MAR) along with a cyclones`dataset covering the Northern Hemisphere for the same period, we show the mean standardized anomalies of SMB and SEB over the GrIS when cyclones are in close proximity. Overall, our results, show a positive contribution of extratropical cyclones to the SMB during warm and cold seasons alike, especially via snowfall. In both winter and summer, cyclones enhance the downwelling longwave radiative flux due to higher temperatures and increased humidity. In summer an increase (decrease) of long-wave downward and relative humidity (sensible heat flux and temperature) is observed. In winter the impact on these surface energy variables is similar, apart for temperature which have an opposite sign. Overall, cyclones suppress melt and run-off, especially in the ablation zone and peripherals areas of the Ice Sheet during the warm season. Results from this study will contribute to better understanding of how the GrIS may respond in terms of SMB and SEB to changes in the North Atlantic storm tracks under global warming scenarios.