Posters virtual: Mon, 4 May, 14:00–18:00 | vPoster spot 1a
The stability of critical infrastructure in Northwest Bulgaria (Western Moesian Platform) could be compromised by ground instability within Neogene sediments that cover the region. This is evidenced by the collapse of the I-1 national road near Dimovo town in 2006, which involved vertical displacements of 3–4 meters. The purpose of this study is to identify the underlying geological drivers of this failure and to evaluate the specific hazard in the area resulting from the interaction between the sediments and the local environmental conditions. We hypothesize that the instability is not merely a result of conventional failure mechanisms but is governed by an anomalous mineralogical composition, specifically by the presence of aragonite and gypsum layers, which could create a dual hazard.
To elucidate geological drivers, we employed a methodology that integrates field mapping and sampling with laboratory analyses. Samples from the Neogene sediments in the area of 2006 damage underwent mineralogical analyses using X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) to determine phase composition and morphology. These analyses were coupled with X-ray fluorescence (XRF) for chemical profiling and standard geotechnical testing to determine grain size distribution, Atterberg limits, and Activity index according to Skempton’s classification.
The analysis reveals a heterogeneous sediment succession with the presence of inorganic clays with high plasticity. The XRD and SEM results identified a mineralogical anomaly where the high concentrations of metastable, acicular aragonite coexist with active swelling phyllosilicates (smectite/illite). Furthermore, various amounts of gypsum were detected in some of the samples, indicating an evaporitic paleoenvironment. Geotechnically, these materials exhibit extreme reactivity. Liquid limits range from 34.85% to 67.88%, and plasticity indices reach up to 47.39%. The Activity index peaks at 2.00, categorizing the sediments as "highly active" and prone to volume change driven by moisture variations.
The study concludes that ground failure is a direct consequence of a synergistic hydro-chemo-mechanical mechanism driven by the sediments' mineralogy. The specific aragonite fabric allows rapid water infiltration, triggering the hydration of smectites that could lead to loss of shear strength. Simultaneously, gypsum dissolution could create secondary porosity, reduce effective stress, and release sulfate ions, which could pose a potential chemical hazard to concrete foundations through sulfate attack. Furthermore, the high silt content facilitates internal erosion and possible piping through fracture networks, which could explain the sudden loss of support and large vertical displacements observed in the 2006 case. These findings imply that standard geotechnical data alone are insufficient for risk assessment in this region. Effective mitigation strategies must integrate mineralogical analysis to address both the physical swelling and the chemical durability risks.
Acknowledgements: This research was funded by the European Union-NextGenerationEU, through the National Recovery and Resilience Plan of the Republic of Bulgaria, Project No BG-RRP-2.004-0008-C01.
How to cite: Dotseva, Z., Vangelov, D., and Stanimirova, T.: Mineralogical Drivers of Ground Failure in Neogene Sediments: a Case Study from Northwest Bulgaria, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10911, https://doi.org/10.5194/egusphere-egu26-10911, 2026.
In the Chundi–Malakonda–Ayyavaripalle region of the Nellore Schist Belt, part of the Dharwar Craton, six north-south (N–S) trending, elongated Banded Magnetite Quartzite (BMQ) bands have been identified. These bands are exposed within meta-rhyolite and quartzite formations and are associated with biotite–muscovite schist. The BMQs vary in width from 20 to 40 meters and extend in length from 1.5 to 4.5 kilometres. High-resolution aeromagnetic surveys with a terrain clearance of 80 meters have revealed significant magnetic anomalies over the study area (source: https://geodataindia.gov.in). These anomalies range from –3,900 to +5,000 nanoteslas (nT), indicating a high concentration of magnetic minerals within the exposed BMQs, designated as Bands 1 to 6. In addition to these exposed bands, a concealed, parallel, N–S trending BMQ band has been identified through detailed analysis of aeromagnetic data. 2D and 3D Interpretation of the magnetic anomalies suggests that meta-rhyolites exist up to an average depth of 250 m from the surface and might be associated with BIF bands at depth. This depth extent highlights the substantial vertical continuity of the magnetite-rich formations in the region. The integration of geological mapping and aeromagnetic data provides a comprehensive understanding of subsurface geology, highlighting the potential for significant mineralization within the Nellore Schist Belt.
How to cite: Dharavathu, S., Kosuri, S. K., Vappangi, P. K., and Kumar, P.: Unveiling concealed Banded Magnetite Quartzites (BMQs) through high-resolution aeromagnetic surveys: New insights from the Nellore Schist belt of Eastern Dharwar Craton, India, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2063, https://doi.org/10.5194/egusphere-egu26-2063, 2026.
The Iberian Pyrite Belt (IPB) hosts one of the largest concentrations of massive sulfide deposits in Europe, yet its lithosphere architecture remains incompletely understood. In this study, we employ magnetotelluric (MT) impedance tensor data to investigate the dimensionality and structural characteristics of the IPB crust. The analysis combines two complementary approaches: WAL invariants, computed from the MT impedance tensor using the Waldim code (Martí et al., 2013), which are scalar, rotation invariant quantities providing a robust, frequency dependent measure of three-dimensionality and highlighting anisotropic features in the conductivity distribution; and the Phase Tensor, following the methodology of Caldwell et al. (2004), which offers distortion free insights into the orientation and geometry of regional conductive structures. Integrating these methods enables a systematic dimensional analysis of the impedance tensor, revealing lateral heterogeneities, preferred orientations of conductive features, and depth dependent variations in lithospheric responses.
The results demonstrate that WAL invariants and Phase Tensor analysis together allow the separation of near surface distortions from deeper geoelectric structures, providing a robust framework for characterizing the lithospheric architecture of the IPB. This study highlights the enhanced resolution and robustness achieved by complementing the tensor based analysis of MT data with invariant derived quantities that provide rotationally independent measures of three-dimensionality and anisotropy.
Consequently, this dimensional and structural assessment constitutes a critical prerequisite for subsequent MT data inversion, as it provides essential constraints on model dimensionality, structural orientation, and the treatment of near surface distortion. By supporting the choice between 2D and 3D inversion strategies, the proposed framework enhances the stability of the inversion process, increases the reliability of the conductivity distributions, and ensures greater geological consistency of the resulting models.
Acknowledgment
This work is supported by FCT, I.P./MCTES through national funds (PIDDAC): LA/P/0068/2020, https://doi.org/10.54499/LA/P/0068/2020,UID/50019/2025, https://doi.org/10.54499/UID/PRR/50019/2025, UID/PRR2/50019/2025
References
Caldwell, T.G., Bibby, H.M. and Brown, C. (2004). The magnetotelluric phase tensor. Geophysical Journal International, 158: 457-469. https://doi.org/10.1111/j.1365-246X.2004.02281.x
Castro, C., Hering, P., Junge, A. (2020). FFMT: a MATLAB-based toolbox for Magnetotellurics (MT). 10.13140/RG.2.2.12465.92007.
F. E. M. Lilley. (1998). Magnetotelluric tensor decomposition; Part, Theory for a basic procedure. Geophysics; 63 (6): 1885–1897. doi: https://doi.org/10.1190/1.1444481.
Martí, A., Queralt, P., Ledo, J., Farquharson, C. (2010). Dimensionality imprint of electrical anisotropy in magnetotelluric responses, Physics of the Earth and Planetary Interiors, Volume 182, Issues 3–4, 2010, Pages 139-151, ISSN 0031-9201. https://doi.org/10.1016/j.pepi.2010.07.007.
Martí, A., Queralt, P., Ledo, J. (2013). WALDIM: A code for the dimensionality analysis of magnetotelluric data using the rotational invariants of the magnetotelluric tensor. Computers & Geosciences. 2295-2303. 10.1016/j.cageo.2009.03.004
Miensopust, M. P. (2017). Application of 3-D electromagnetic inversion in practice: Challenges, pitfalls and solution approaches. Surveys in Geophysics, 38(5), 869–933. https://doi.org/10.1007/s10712-017-9435-1.
Vozoff, K. (1991). The magnetotelluric method: Electromagnetic methods. In M. N. Nabighian (Ed.), Applied Geophysics (pp. 641–712).
Kelbert, A., Meqbel, N., Egbert, G. D., & Tandon, K. (2014). ModEM: A modular system for inversion of electromagnetic geophysical data. Computers & Geosciences, 66, 40–53. https://doi.org/10.1016/j.cageo.2014.01.010.
How to cite: Baltazar-Soares, P., Martinéz-Moreno, F. J., Gonzaléz-Castillo, L., Galindo-Zaldívar, J., Monteiro Santos, F., Mateus, A., and Matias, L.: Dimensionality Analysis of the Iberian Pyrite Belt Lithosphere derived from the Magnetotelluric Impedance Tensor., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21147, https://doi.org/10.5194/egusphere-egu26-21147, 2026.
The source of compressional Pc3 magnetic pulsations has been considered to be the plasma process in the solar wind or in the magnetosphere. However, we found some strong inland earthquakes that occur on the dayside also excite Pc3s. The Lamb waves generated by the January 2022 Tongan undersea volcanic eruption are also believed to have excited large amplitude and short period compressional Pc3 geomagnetic pulsations in the dayside plasmasphere (Iyemori et al., 2025). Increases in power spectral density (PSD) in the Pc3 frequency band were observed 10-30 minutes after the origin time of large inland earthquakes (M>6.5) during the daytime (10-14 LT). During these large earthquakes, seismic waves with period of 10-30 seconds propagate far away (even more than several thousand km), causing slight fluctuations in the orientation of magnetometer sensors, resulting in apparent Pc3-like fluctuations. To avoid such sensor tremor effect, we analyzed the total force of magnetic field, or analyzed comparing with seismometer data. We also used the Swarm satellite observation. The PSD of Pc3s caused by earthquakes or by Lamb wave show many spectral peaks having interval of 3-5 mHz, and this is similar with the characteristic reported by, for example, Samson et al. (1995) for normal, i.e., solar wind origin Pc3s. In this paper, we will also show the commonality between the Pc3s caused by earthquakes or Lamb waves and those originated from the solar wind and discuss what the commonality means.
How to cite: Iyemori, T., Aoyama, T., and Yokoyama, Y.: Pc3 geomagnetic pulsations excited by earthquakes and their commonality with solar wind-originated Pc3, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8566, https://doi.org/10.5194/egusphere-egu26-8566, 2026.
The Swarm Data Fusion (SwarmDF) toolbox is designed as an easy-to-use Python module for analysing the local electrodynamics of the high-latitude ionosphere by combining measurements from ESA’s Swarm satellites with additional ionospheric and thermospheric datasets. Given a Swarm satellite ID, a regional grid, and a time interval, the toolbox automatically retrieves and combines available observations from SuperDARN, SuperMAG, Iridium/AMPERE, and Swarm electromagnetic field measurements. SwarmDF uses the local mapping of polar ionospheric electrodynamics (Lompe) technique to reconstruct two-dimensional maps of key electrodynamic parameters in the vicinity of the Swarm satellite tracks. To assess and quantify reconstruction performance, SwarmDF integrates the LompeOSSE Python module, which generates controlled synthetic electrodynamics datasets based on Gamera simulations and enables systematic comparisons with the toolbox outputs under different data availability and configuration scenarios. Featuring a user-friendly graphical interface, SwarmDF simplifies data handling and model setup for high-latitude ionospheric electrodynamic studies using Swarm observations.
How to cite: Decotte, M., Laundal, K. M., and Kebede, F. T.: SwarmDF: A toolbox for analysing high-latitude ionospheric electrodynamics, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-18706, https://doi.org/10.5194/egusphere-egu26-18706, 2026.
Within the comprehensive framework of the Sun–Earth system, plasma environments exhibit an exceptionally wide range of physical conditions. These encompass the ultra-high-temperature, high-pressure, and high-density liquid metallic outer core of Earth, which generates the geomagnetic field through the geodynamo process; the tenuous, partially ionized ionosphere; and the magnetosphere, which provides essential shielding against energetic cosmic and solar radiation while exerting substantial influence on human technological systems, most notably microwave communication infrastructure. In addition, transient ultra-high-temperature plasmas generated by solar flares and coronal mass ejections (CMEs) represent the primary drivers of disturbed space electromagnetic environments, as they propagate through interplanetary space and subsequently interact with Earth's magnetosphere.Although prior research has extensively employed the first-principles quantum Monte Carlo method coupled with the lattice Boltzmann approach (FPQM-LBM) to address various theoretical and computational aspects of plasma behavior in this context, no existing modeling framework has successfully integrated — within a single consistent methodology — the extreme conditions of the Earth's outer core plasma, the low-density ionospheric plasma, the magnetospheric plasma, and the highly energetic, transient flare/CME plasmas. As a result, a unified and comprehensive understanding of particle transport mechanisms and internal structural properties across the full spectrum of plasma regimes in the Sun–Earth system remains elusive.The present study aims to address this critical gap by developing novel theoretical frameworks and advanced computational methodologies for elucidating the particle migration mechanisms and structural characteristics of space electromagnetic plasmas throughout the panoramic Sun–Earth system. To this end, we will enhance the first-principles quantum Monte Carlo–lattice Boltzmann method (FPQM-LBM) to establish robust techniques capable of modeling particle transport under the complex electromagnetic conditions prevailing in space environments. The improved FPQM-LBM framework will be systematically applied to simulate particle dynamics across the aforementioned plasma regimes — namely, the ultra-high-temperature/pressure/density outer core plasma, the low-density ionosphere, the magnetosphere, and transient flare/CME plasmas — with particular emphasis on ionic characteristics, microstructural evolution, fine-scale particle transport processes, internal structural transformations, and the response of plasma properties to external electromagnetic perturbations. The anticipated results are expected to furnish a solid theoretical foundation and valuable predictive capabilities for advancing solar–terrestrial space physics and enhancing electromagnetic monitoring and forecasting in space weather research.
How to cite: Zhu, B.: Theoretical Foundations and Methodological Developments in the Study of Particle Transport Mechanisms and Microstructural Evolution Employing the Hybrid Quantum Monte Carlo–Boltzmann Transport Model, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3254, https://doi.org/10.5194/egusphere-egu26-3254, 2026.
During intense solar atmospheric activity—such as major solar flares and geomagnetic storms—magnetic energy is converted into plasma kinetic and thermal energy through three-dimensional turbulent magnetic reconnection within large-scale, extended current sheets. This process releases enormous amounts of stored energy, often accompanied by the rapid ejection of high-energy particles into interplanetary space. These high-energy particles include electrons, protons, helium nuclei, and heavier ions, forming a complex multi-component, multi-abundance, and multi-isotopic population. Their energies span from ~100 keV to ~100 MeV and even into the GeV range, making them a primary driver of space weather hazards. Understanding the sources and acceleration mechanisms of these particles remains one of the most critical challenges in space weather research. Previous studies have shown that high-energy particle acceleration is highly complex, involving multiple species, a variety of mechanisms, and interactions across scales. It remains an open and challenging problem in solar and plasma physics. This paper provides a systematic review and forward-looking perspective on recent advances in high-energy particle acceleration during the fine-scale evolution of large-scale current sheets. The discussion is organized around three key pillars: theory, observations, and numerical simulations. First, we summarize the turbulence-fractal model as it applies to typical solar atmospheric events. We focus on acceleration mechanisms in turbulent magnetic reconnection within large spatiotemporal current sheets, with particular emphasis on: Turbulent (second-order) Fermi acceleration, Turbulent shock acceleration, and Turbulent wave-particle resonant acceleration. These mechanisms operate synergistically in the turbulent environment generated by reconnection, enabling efficient energy transfer to particles. Second, we review recent progress in coupling macroscopic (hydrodynamic and magnetohydrodynamic) dynamics to microscopic kinetic processes in high-energy particle acceleration. This includes multi-scale modeling of turbulence, reconnection, and particle transport. Finally, we outline promising future research directions, including improved multi-spacecraft observations, higher-resolution simulations that incorporate kinetic effects, and integrated models that bridge MHD turbulence and particle-in-cell approaches. We also highlight several urgent unresolved issues, such as the relative contributions of different mechanisms across energy regimes, the role of fractal structures in particle trapping and escape, and the origin of observed abundance enhancements in heavy ions. This review synthesizes recent theoretical, observational, and computational developments to provide a comprehensive framework for understanding high-energy particle acceleration in large-scale turbulent current sheets, with implications for solar flares, space weather forecasting, and broader astrophysical plasma processes.
How to cite: Zhu, B.: Research Progress on SEPs on the Fine Structures of the Large Temporal-spatial Current Sheets in Solar Flares/CMEs, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6969, https://doi.org/10.5194/egusphere-egu26-6969, 2026.
Space weather can affect the operation of high voltage AC transformers in power grids by applying an offset DC current during periods of heightened geomagnetic activity. Modelling GIC requires knowledge of magnetic field variation, the response of the local subsurface geoelectric field (related to conductivity) and a representation of the connections between transformers and various resistance parameters of the power network. Presently, in Britain, the largest uncertainty in this chain applies to the resistance parameters of the network, as these values come from open-source data which are known to have many approximations.
Recent work with a transmission network operator in the UK has provided us with an improved dataset of resistance parameters of transformers, power lines and substation grounding. The grounding resistance at electrical substations has not been known before and so historically was set at 0.5 Ω in our models. The new dataset of 110 sites around central Scotland reveals substation grounding resistance varies from 0.04 Ω to 11.7 Ω with a mean of 0.54 Ω but a median of 0.2 Ω. Combined with line and transformer resistance information, we have created an improved representation of the power grid in Scotland.
Using GIC measurements from three sites (Torness, Strathaven and Neilston) for the largest geomagnetic storms in the past 25 years (October 2003, September 2017 and May 2024), we are able to validate the new model, demonstrating its improved accuracy.
The new model demonstrates that our previous assumptions of grounding resistance were too high but our estimate of line resistance was too low, thus balancing out the overall GIC magnitude on average. However, in detail, some locations show large differences in GIC compared to the original model. This highlights the importance of using accurate resistance information to correctly capture GIC.
How to cite: Beggan, C., Richardson, G., and Lawrence, E.: Improving GIC modelling and validation with high-quality information on power network parameters, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5611, https://doi.org/10.5194/egusphere-egu26-5611, 2026.
The Earth's magnetic field is divided into internal and external sources, with the internal field including the main magnetic field, the crustal magnetic field, and the induced magnetic field. Among these, the main magnetic field accounts for approximately 95% of the Earth's total magnetic field. Data from paleomagnetic records in rocks, various geomagnetic observatories, and satellites indicate that the main magnetic field exhibits westward drift, polarity reversals, intensity decay, and brief geomagnetic excursions at the core-mantle boundary. To explain these phenomena, several models have been proposed in previous studies. The prevailing view is that the outer core is composed of liquid metal, and the Earth's main magnetic field is generated by the turbulent fluid motion of this liquid metal, influenced primarily by factors such as its composition and properties, thermal convection, Lorentz force, and Coriolis force. Considering the strong Coulomb forces between electrons and ions, previous research has usually treated the electrons and ions in the outer core's metallic fluid as a unified component, greatly simplifying the study and achieving satisfactory results. However, existing studies have not taken into account the differences in motion between ions and electrons under the dynamics of the outer core, the resulting spatial distribution differences of electrons and ions in the outer core, or the impact of these differential distributions on the Earth's main magnetic field. In view of this, This paper studies the effect of the factors generating outer core dynamics on the distribution of electrons and ions in the outer core. It examines the distribution of electrons and ions in the outer core space under equilibrium conditions and estimates their contribution to Earth's main magnetic field. Then, by changing parameter conditions (such as temperature gradients) and adding convective terms (non-equilibrium state), the calculations are redone. These results are used to explain changes in Earth's magnetic field.
How to cite: Wang, S., Li, Y., Zhu, B., Zhao, Y., Wang, Q., and Liu, H.: The influence of the heterogeneity (stratification) of the outer core fluid on the variation of the geomagnetic field, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9301, https://doi.org/10.5194/egusphere-egu26-9301, 2026.
Lago del Desierto (49°02′S, 72°51′W) is located in a climatically sensitive sector near the Southern Patagonian Ice Field (Argentina). Three sediment cores collected from two sites in the lake were analyzed using a multi-proxy approach to reconstruct past environmental variability (Kastner et al., 2010). Numerous turbidites were identified in the sedimentological record. After excluding these event layers, a new age–depth model was developed for the first 3 sections of the core DES05-3 (289 cm), and paleosecular variations (PSV) were reconstructed for the interval between ~1000 and 3500 cal. BP.
Standard paleomagnetic measurements (alternating-field demagnetization) were performed on 125 samples from the same core. In addition, rock-magnetic measurements, including Anhysteretic Remanent Magnetization (ARM, 100 mT peak AF, 0.05 mT DC field), Isothermal Remanent Magnetization (IRM, acquisition up to 1.5 T and backfield curves), hysteresis loops and thermomagnetic analyses, were applied to extract complementary paleoenvironmental information from the sediment cores.
Rock-magnetic measurements indicate that the magnetic mineralogy is dominated by a low-coercivity component (magnetite-type), accompanied by a secondary high-coercivity fraction (hematite/goethite-type). This downcore distribution mirrors the paleoenvironmental shift described by Kastner et al. (2010): the lower part of the sequence shows an enhanced contribution of high-coercivity Fe oxides, consistent with more stable and chemically weathered catchment conditions. In contrast, the upper part shows an increasing dominance of detrital magnetite, indicating strengthened minerogenic supply and enhanced erosion, matching the onset of warmer conditions and glacier retreat during the Medieval Climate Anomaly as inferred from geochemical and lithological proxies. This agreement between magnetic and non-magnetic sediment parameters suggests coherent changes in the provenience of the sediment and in catchment dynamics over the last millennia. As expected from the catchment instability and the numerous turbidites in the upper part of the sequence, this interval could not be used for PSV reconstruction due to its discontinuous directional record. In contrast, samples from the lower part (~1000–3500 cal. BP) provided a continuous sequence suitable for paleosecular variation analysis. Although samples from this unit were not completely demagnetized at 100 mT, due to the presence of a high-coercivity component, magnetization directions consistently decayed toward the origin with high precision. Characteristic remanent magnetization (ChRM) directions were determined using principal component analysis, with maximum angular deviation (MAD) values below 2.5° for all non-turbidite samples. The resulting PSV record compares well with geomagnetic field models and other Patagonian paleomagnetic reconstructions. Inclination values range from −40° to −70°, displaying coherent directional variability over the last ~3500 years.
References:
Kastner, S., Enters, D., Ohlendorf, C., Haberzettl, T., Kuhn, G., Lücke, A., Mayr, C., Reyss, J.-L., Wastegård, S., & Zolitschka, B. (2010). Reconstructing 2000 years of hydrological variation derived from laminated proglacial sediments of Lago del Desierto at the eastern margin of the South Patagonian Ice Field, Argentina. Global and Planetary Change, 72(3), 201-214. https://doi.org/10.1016/j.gloplacha.2010.04.007
How to cite: Achaga, R. V., Gogorza, C. S. G., Irurzun, M. A., Ohlendorf, C., Haberzettl, T., and Zolitschka, B.: A Late Holocene Paleomagnetic Record from Lago del Desierto, Southern Patagonia (Argentina), EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8141, https://doi.org/10.5194/egusphere-egu26-8141, 2026.
Continental sedimentary sequences of alternating loess and palaeosol horizons preserve detailed records of past global climate changes during the Pleistocene. Obtaining deeper and genuine knowledge on the history of past climates using proxy data depends on interdisciplinary approaches, novel techniques and thinking “out-of-the-box”. The LOEs-CLIMBE team members gather around this concept and present here the first pilot magnetic data from the Kolobar loess-palaeosol section in NE Bulgaria. The 25 m thick section is exposed in an active quarry and was sampled at 2-cm-resolution, covering the Holocene soil, seven palaeosol units and loess horizons L1 to L7 of varying thicknesses. New high resolution magnetic susceptibility data, delineates palaeosol horizons with high values of mass specific magnetic susceptibility except the special case of fourth palaeosol S4, showing no magnetic enhancement as compared to the underlying thin loess. Such depletion of pedogenic magnetic enhancement in paleosol units from the Lower Danube area is rarely reported. This phenomenon will be further examined by detailed magnetic and colorimetric methods. The strongest pedogenic magnetic signal is observed in the three youngest palaeosol units S1, S2 and S3, tentatively related to the interglacial stages MIS 5, MIS 7 and MIS 9. The weakest magnetic susceptibility is typical for the younger part of the loess unit L2, punctuated by the signal of a tephra layer, which is a widespread chronostratigraphic marker in the region. This research is carried out and financed within the framework of the second Swiss Contribution MAPS, LOEs-CLIMBE project № IZ11Z0_230102.
How to cite: Jordanova, D., Georgieva – Ishlyamska, B., Veres, D., Baykal, Y., Robu, M., Jordanova, N., Hambach, U., Ishlyamski, D., Dimov, D., Trott, A., and Wiesenberg, G.: High-resolution magnetic record of environmental changes during Middle – Late Pleistocene from a loess-palaeosol sequence in NE Bulgaria – pilot data from the LOEs-CLIMBE project, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8852, https://doi.org/10.5194/egusphere-egu26-8852, 2026.
Three centuries ago, auroral emissions could be observed over the Korean sector, where the West Pacific Anomaly (WPA) coexisted with the South Atlantic Anomaly (SAA). To investigate this phenomenon, the present study builds upon our recent numerical simulations of the inner proton radiation belt [Girgis et al., JSWSC (2021), Girgis et al., SW (2023,2024)], in which we examined the effects of space weather on the near-Earth particle environment. Here, we extend our modeling framework to explore the historical distribution and state of the radiation environment. A key aspect of this research is the incorporation of a geomagnetic field configuration representative of the year 1650, and the comparison of the resulting particle environment with that derived from contemporary magnetic field models. The primary objective is to model the near-Earth particle environment in a manner that enables future coupling with atmospheric models, while also accounting for the influence of external space weather conditions. A comprehensive understanding of both the present-day and historical particle dynamics in the near-Earth environment is essential for predicting radiation conditions relevant to low Earth orbit (LEO) missions and for assessing the potential impact on Earth’s atmosphere.
How to cite: Girgis, K., Arthus Schanner, M., Panovska, S., and Yoshikawa, A.: Effects of the Historical Geomagnetic Field on Earth's Energetic Particle Environment: Magnetic Anomalies and Auroral Regions , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14934, https://doi.org/10.5194/egusphere-egu26-14934, 2026.
As recent hydrocarbon discoveries rekindle exploration activities in the Black Sea Basin (BSB), efforts to understand the geodynamic processes that led to the formation and evolution of the basin have started to play a significant role in understanding the structural trends formed during rifting. The debate on whether the basin rifted open as one east-west oriented basin, or as two separate basins named the Eastern and Western Black Sea Basins, has been discussed in numerous models. Evidence for the two-basin hypothesis focuses on the basin's semi-parallel ridge and depression architecture, which trends NW-SE in the east and W-E in the west. Conversely, the single-basin model is supported by the correspondence between the regional structure and geodynamic rifting models, specifically those involving an asymmetrical rift pivoting on an eastern hinge caused by slab roll-back of the subducting plate located in the south of the basin.
To address existing tectonic uncertainties, we established a new structural framework for the BSB by reinterpreting 24 long-offset 2D seismic lines. These structural constraints enabled the development of two 2D computational models, allowing us to simulate the distinct kinematic evolution of the basin's western and eastern sections. Our 2D sectioned models show that rift velocities vary significantly in the east-west direction. This contradicts previous analog models showing that the formation of the BSB was related to a simple asymmetrical rift with constantly increasing velocities towards the west from a hinge point located at the eastern margin of the basin. The complex velocity changes throughout the rift axis suggest an uneven movement throughout the subduction zone that drives the back-arc rift. Ultimately, proposing a new complex kinematic history during the evolution of the rift and alternating rift velocities throughout the rift axis, provide a better understanding of the timing of all tectonic events and the final ridge depression geometry observed throughout the BSB.
How to cite: Kaykun, A. and Pysklywec, R.: A New Approach to Rift Kinematics During the Formation of the Black Sea Basin, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9303, https://doi.org/10.5194/egusphere-egu26-9303, 2026.
