The Nikopol manganese deposit is one of the world’s largest deposits among the sedimentary manganese deposits. The Nikopol Oligocene basin is located between the Azov crystalline massif and the Ukrainian shield. Nikopol Ore horizon is traced in a thickness varying from several cm to 4.5 m and a single stratum from the west to the eastwards to about 250 km and separated to three different units; carbonate, mixed carbonate-oxide, and oxide ore. The oxide ores can contain the concretion or earthy masses bigger than 25 cm, sometimes with remnants of carbonate or carbonate-oxide textures. The manganese oxide-hydroxide ores were analyzed for major oxides, trace and rare earth elements (REE) using ICP-MS. The PAAS-normalized REE patterns of the Nikopol manganese oxide ores have similar trends and show MREE and HREEs enrichments. The Ce/Ce* values of manganese oxide-hydroxide ores collected from the study area vary from 0.88 to 1.43, indicating that ore-forming rocks were primarily marine chemical or biogenic deposit. The Eu/ Eu* anomalies of the manganese oxide-hydroxide ores are close to 1. The Y concentrations vary from 9,1 to 47,1 ppm and show negative Y anomalies. Both geochemical and Pb isotope data indicate that the Nikopol manganese oxide-hydroxide ores formed rapidly within oxic/suboxic seawater as reflected by Ce anomalies close to 1 in low-oxygen fugacity in source of the hydrothermal fluids, volcanogenic input or hydrothermal contributions to seawater. Also, our results point out that the metal was transported from both a hydrothermal source in deeper water and terrestrial sources.

We explore the hypothesis that b-value act as stress meter which varies inversely with differential stress and decreases until it reached the depth of brittle-ductile transition. Correlation of seismogenic asperity and brittle-ductile contact (BDC) with b-value is of special interest. Lowest b- and Dc-values coincides with transition depth and interpreted as seismogenic asperities. Moderate ruptures (ML≥5.0) nucleate in vicinity of transition zone where stress concentration is highest. We illustrate behavior of mid-crustal detachment and dependence of topographic elevation above Mid-Crustal Ramp (MCR). The depth 10-15 km is marked as MCR which coincides with fluids, seismogenic asperity and shows seismic clustering. The composite trend in abrupt escalation of b-value is observed at depth ≈12 km and ≈7 km for Garhwal and Kumaun region respectively. These depth ranges is demarcated as BDC which coincides with proposed MCR and exhibiting as an alarming asperity zone (12-15 km) for future great earthquake in Garhwal-Himalaya.

Nighttime airglow images observed at the low-latitude site of São João do Cariri (7.4S, 36.5W) showed the presence of a medium-scale atmospheric gravity wave (AGW) associated with the 21 August 2017 total solar eclipse. The AGW had a horizontal wavelength of ~1,618 km, observed period of ~152 min and propagation direction of ~200 clockwise from the north. The spectral characteristics of this wave are in good agreement with theoretical predictions for waves generated by eclipses. Additionally, the wave was reverse ray-traced and the results show its path crossing the Moon’s shadow of the total solar eclipse in the tropical North Atlantic ocean at stratospheric altitudes. Investigation about potential driving sources for this wave indicate that the total solar eclipse as the most likely candidate. The optical measurements were part of an observational campaign carried out to detect the impact of the August 21 eclipse in the atmosphere at low latitudes.

Ocean swell plays an important role in the transport of energy across the ocean, yet its evolution is still not well understood. In the late 1960s, the nonlinear Schr{\”o}dinger (NLS) equation was derived as a model for the propagation of ocean swell over large distances. More recently, a number of dissipative generalizations of the NLS equation based on a simple dissipation assumption have been proposed. These models have been shown to accurately model wave evolution in the laboratory setting, but their validity in modeling ocean swell has not previously been examined. We study the efficacy of the NLS equation and four of its generalizations in modeling the evolution of swell in the ocean. The dissipative generalizations perform significantly better than conservative models and are overall reasonable models for swell amplitudes, indicating dissipation is an important physical effect in ocean swell evolution. The nonlinear models did not out-perform their linearizations, indicating linear models may be sufficient in modeling ocean swell evolution.

We describe a new method to analyze the properties of plasma waves, and apply it to observations made upstream from Mars by the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. The slow measurement cadence of most charged particle instrumentation has limited the application of analysis techniques based on correlations between particle and magnetic field measurements. We show that we can extend the frequency range of applicability for these techniques, for a subset of waves that remain coherent over multiple wave periods, by sub-sampling velocity distribution function measurements and binning them by the wave phase. This technique enables the computation of correlations and transport ratios for plasma waves previously inaccessible to this technique at Mars. By computing the cross helicity, we find that most identified waves propagate upstream in the plasma frame. This supports the conclusions of previous studies, but enables a clearer determination of the intrinsic wave mode and characteristics. The intrinsic properties of observed waves with frequencies close to the proton cyclotron frequency have little spatial variability, but do have large temporal variations, likely due to seasonal changes in the hydrogen exosphere. In contrast, the predominant characteristics of waves at higher frequencies have less temporal variability, but more spatial variability. We find several indications of the presence of multiple wave modes in the lower frequency wave observations, with unusual wave properties observed for propagation parallel to the magnetic field and for background magnetic fields nearly perpendicular to the solar wind flow.

The simplified anthropogenic aerosol optical properties and an associated Twomey effect provided by CMIP6 (i.e., MACv2-SP) were used in the Grid-point Atmospheric Model of IAP LASG (GAMIL). With the benefit of MACv2-SP, instantaneous radiative forcing (RF) from aerosol-radiation interactions (RFari) and aerosol-cloud interactions (RFaci) can be calculated by double radiation calls in one present-day (PD) simulation. The RFaci determined by this straightforward method is the exact Twomey effect, which previously was impossible to separate from its subsequent rapid adjustments using the default GAMIL model with physically based aerosol-cloud interactions. The RFaci is very robust, with a global average of −0.10 W m. The RFari can be calculated by different methods. The all-sky RFari with and without natural aerosol influence (i.e., different methods) is estimated at −0.21 and −0.33 W m, respectively. This suggests that the natural aerosol burden might substantially impact the estimate of RFari. Furthermore, the RFari determined by the difference between two simulations is more sensitive to model internal year-to-year variability compared with the RFari determined from one PD simulation. The RFaci efficiency usually enhances with increasing cloud cover, whereas the RFari efficiency becomes weaker under cloudy conditions. As a result, the seasonal variability of the global average RFaci is stronger than that of RFari. From 1975 to 2000, both RFari and RFaci show a clear response to the spatial changes in anthropogenic aerosols, and the global average RF (RFari + RFaci) is enhanced by ~6%, even with a slight decrease in the global average anthropogenic aerosols.

As a key global climate and dust archive, the nature of Chinese loess deposition remains debated. We investigate chronostratigraphic variability of eolian deposits in upwind regions of the modern Chinese Loess Plateau (CLP) and reconstruct dust dynamics that potentially affects loess deposition downwind. The strata consist of alternating layers of typical loess, well-sorted sand, and sandy loess, with obvious unconformities occurring at the transitions from loess to sand. We suggest that pre-existing typical loess was eroded by wind, providing homogeneous dust for loess on the CLP. The interbedded well-sorted sand and loess suggest that proximal deserts have greatly expanded and contracted repeatedly, strongly affecting dust emission and transport and thus leading to significant changes in dust accumulation rates on the CLP. Our results suggest active dust processes in upwind regions of the CLP have major implications for using loess sequences to deduce climate and dust changes.

Recent understandings regarding \textit{tresinos} in laboratory experiments and geophysical observations represents a new paradigm for Earth’s energy generation as well as a new direction toward developing \textit{tresino}-generated power reactors.

The Neutral Gas and Ion Mass Spectrometer of the Mars Atmosphere and Volatile Evolution provides a large data set to explore the ion composition and structure of the Martian ionosphere. Here the dayside measurements are used to investigate the minor ion density profiles with distinctive peaks above 150 km, revealing a systematic trend of decreasing peak altitude with increasing ion mass. We specifically focus on a subset of species including O$^+$, N$_2^+$/CO$^+$, C$^+$, N$^+$, He$^+$, and O$^{++}$, all of which are mainly produced via direct photoionization of parent neutrals. Our analysis reveals weak or no variation with solar zenith angle (SZA) in both peak density and altitude, which is an expected result because these ion peaks are located within the optically thin regions subject to the same level of solar irradiance independent of SZA. In contrast, the solar cycle variations of peak density and altitude increase considerably with increasing solar activity, as a result of enhanced photoionization frequency and atmospheric expansion at high solar activities. He$^+$ serves as an exception in that its peak density increases towards large SZA and meanwhile shows no systematic variation with solar activity. The thermospheric He distribution on Mars should play an important role in determining these observed variations. Finally, the peak altitudes for all species are elevated by at least several km within the weakly magnetized regions, possibly attributable to the suppression of vertical diffusion by preferentially horizontal magnetic fields in these regions.

It is generally assumed that seismic activity at volcanoes is closely connected to degassing processes. Intuitively, one would therefore expect a good correlation between degassing rates and seismic amplitude. However, both examples and counterexamples of such a correlation exist. In this study on Villarrica volcano (Chile), we pursued a different approach to relate gas flux and volcanic seismicity using 3 months of SO$_2$ flux rate measurements and 12 days of seismic recordings from early 2012. We analyzed the statistical distributions of interevent times between transient seismic waveforms commonly associated with explosions and between peaks in the degassing time series. Both event types showed a periodic recurrence with a mode of 20-25 s and around 1 h for transients and degassing, respectively. The normalized interevent times were fitted by almost identical log-normal distributions. Given the actually very different time scales, this similarity potentially indicates a scale-invariant phenomenon. We could reproduce these empirical findings by modelling the occurrence of transients as a renewal process from which the degassing events were derived recursively with increasing probability since the previous degassing event. In this model, the seismic transients could be either produced by degassing processes within the conduit or by gas release at the lava lake surface while the longer intervals of the degassing events may be explained by accumulation of gas either in the magma column or in the juvenile gas plume. Additionally, we analyzed volcano-tectonic events, which behaved very differently from the transients. They showed the clustered occurrence of tectonic earthquakes.

Convergence between the Eurasian and the African plates in the West Anatolian-Aegean region results in a trench retreat due to slab roll-back and tearing of the subducted African lithosphere. The upper plate response of this process gave way to back-arc extension in the region. In this context, we have conducted a very rigorous AMS study on the Neogene units in SW Anatolia to unravel the style and amounts of deformation. For this purpose, from 83 sites in 11 structurally homogeneous domains, 1680 paleomagnetic samples were analyzed. Obtained results are used to determine principal strain directions to unravel overall deformation styles and amounts in the region. The results have shown that AMS is related to the tectonic deformation, which facilitated that the AMS directions correspond to cumulative principal strains. Maximum susceptibility is parallel to the major extension (k), minimum susceptibility (k) corresponds to compaction after deposition, almost always normal to the bedding plane. The intermediate axis (k) found to be parallel to a second extension direction that the region has been under the control of multi-directional extension during Neogene. Two mean anisotropy directions are identified. These are Oligocene-Middle Miocene NW-SE, and Late Miocene-Pliocene NE-SW directed extension. The mean anisotropy directions are generally parallel or perpendicular to the general strikes of the normal faults. The results have shown that the deformation in the region resembles to differentially stretched rubber sheet under the influence of SW directed extension exerted by the southwards retreating Eastern Mediterranean subduction system.

Climate warming has accelerated thawing of frozen soil in the northern permafrost, supplying dissolved organic carbon (DOC) to streams and rivers with uncertain fate. Although recent incubation experiments have established that permafrost derived DOC is labile, field evidence is rare and ambiguous, with the linkage to surface – groundwater interaction poorly illustrated. Here, we quantify and characterize DOC for eight types of water sampled from a small (25km), alpine (elevation 2960 to 4820 m a.s.l) watershed with variably degraded permafrost in the Qinghai-Tibetan Plateau (QTP) in July and September of 2012, 2013 and 2018. Spatially variable dissolved organic carbon (DOC) concentrations with high percentages of protein-like fluorophores (48± 41%, n=91), attributable to frozen soil based on tracers, are detected throughout the watershed. Increasing DDOC (loss of DOC) in subsurface waters corresponds to decreasing proportion of protein-like fluorophores and SUVA. Assuming microbial processing of subsurface DOC and using previously established DOC biodegradation kinetics, the mean transit time of groundwater is estimated to be ~ 7 and 25 days based on changes in DDOC of 32% and 74% for July and September, respectively. In addition to providing field evidence for prevalence of labile DOC derived from permafrost in surface and subsurface waters of the QTP, the study establishes that very young groundwater participates in alpine hillslope hydrological and biogeochemical processes. Mass balance of DOC input and export fluxes shows a loss of nearly half of the carbon, indicating that hillslopes are hotspots for DOC processing, with subsurface environment playing a key role.

The artificial impoundment of water behind dams causes global mean sea level (GMSL) to fall as reservoirs fill, but also generates a local rise in sea level due to the increased mass in the reservoir and the crustal deformation this mass induces. To estimate spatiotemporal fluctuations in sea level due to water impoundment, we use a historical data set that includes 6,329 reservoirs completed between 1900 and 2011, as well as projections of 3,565 reservoirs that are expected to be completed by 2040. The GMSL change associated with the historical data (–0.2 mm yr-1 from 1900 – 2011) is consistent with previous studies, but the temporal and spatial resolution allows for local studies that were not previously possible, revealing that some locations experience a sea level rise of as much as 40 mm over less than a decade. Future construction of reservoirs through ~2040 is projected to cause a GMSL fall whose rate is comparable to that of the last century (–0.3 mm yr-1), but with a geographic distribution that will be distinct from the last century, including a rise in sea level in more coastal areas. The analysis of expected construction shows that significant impoundment near coastal communities in the coming decades could enhance the flooding risk already heightened by global sea level rise.

The One Health concept provides a framework to examine the linkages between human, animal, plant, environmental, and ecosystem health. This framework can be represented as a multi-dimensional matrix tool that can be used to examine and address complex GeoHealth challenges. This matrix tool facilitates comprehensive, systems-based thinking and can include up to four dimensions depending upon users' needs. This presentation will briefly review the One Health matrix tool and apply it, as an example, to examine the global impact of human and animal fecal wastes. Applying the tool reveals linkages between food-borne illnesses, food insecurity, antimicrobial resistance, and climate change. Understanding these linkages is necessary for developing effective and equitable public policies that are needed to achieve many of the United Nations' Sustainable Development Goals.

The important task of tracking seismic activity requires both sensitive detection and accurate earthquake location. Approximate earthquake locations can be estimated promptly and automatically; however, accurate locations depend on precise seismic phase picking, which is a laborious and time-consuming task. We adapted a deep neural network (DNN) phase picker trained on local seismic data to meso-scale hydraulic fracturing experiments. We designed a novel workflow, transfer-learning aided double-difference tomography, to overcome the three orders of magnitude difference in both spatial and temporal scales between our data and data used to train the original DNN. Only 3,500 seismograms (0.45% of the original DNN data) were needed to re-train the original DNN model successfully. The phase picks obtained with transfer-learned model are at least as accurate as the analyst’s, and lead to improved event locations. Moreover, the effort required for picking once the DNN is trained is a small fraction of the analyst’s.

Receiver density is key to being able to detect and characterise seismic events at the noise level. This is particularly important in urban environments where high cultural noise levels can obscure seismic event signals at a single station. Here we catalogue the seismicity and describe the basic data features of a dense nodal array that was deployed in the city state of Singapore for a 1 month period in 2019. We utilise array methods to detect and characterise seismic events, the first based on waveform similarity (Li et al 2018) and the second (presented here) on spectral energy. Distant earthquakes are easily detected using the waveform similarity method, but local events are more difficult to detect in this way. We therefore develop a spectrogram stacking approach that highlights the location of anomalous coherent spectral energy. Overall, we identify 76 distant earthquakes and 35 local events. Out of the local events, 22 are determined to be from blasting works, while 13 remain from an origin that we cannot yet determine. We also find that lightning produces a plentiful supply of natural seismic sources through the conversion of acoustic waves propagating through the atmosphere (thunder), to seismic waves. We record hundreds of thunder quakes with a high signal to noise ratio and over a wide frequency range. We suggest that a tropical region such as Singapore has high potential to further advance thunder-quake studies.

By interacting with radiation, aerosols perturb the Earth’s energy budget and thus the global precipitation amount. It was previously shown that aerosols lead to a reduction in the global-mean precipitation amount. We have further demonstrated in aqua-planet simulations that the local response to absorbing aerosols differs between the tropics and the extra-tropics. In this study we incorporate an energy budget perspective to further examine the latitudinal dependence of the effect of aerosol-radiation interaction on precipitation in idealized global simulations. We demonstrate that the transition between a positive local precipitation response in the tropics and a negative local precipitation response in the extra-tropics occurs at relatively low latitudes (~10), indicating a transition between the deep-tropics (in which the Coriolis force is low, hence direct thermally-driven circulation, and associated divergence/convergence of energy/moisture, can form as a result of the diabatic-heating) and their surroundings. In addition, we gradually increase the level of complexity of the simulations and demonstrate that, in the case of absorbing aerosols, the effect of land is to counteract some of the response both inside and outside the deep-tropics due to the reduction in surface latent-heat flux that opposes the diabatic-heating. The effect of scattering aerosols is also examined and demonstrate a decrease in precipitation over land in both the tropics and extra-tropics and no effect over the ocean. Finally, we examine these results in a more realistic set-up and demonstrate that although the physical mechanisms still operate, they are unlikely to be significant enough to be discerned from natural-variability.

The two seminal studies on westward intensification, carried out by Stommel and Munk over 70 years ago, are revisited to elucidate the role of the domain aspect ratio (i.e.~meridional to zonal extents of the basin) in determining the width and speed of a western boundary current (WBC). We examine the general mathematical properties of the two models by transforming them to differential problems that contain only two parameters — the domain aspect ratio and the non-dimensional damping (viscous) coefficient. Simple proxies of width and speed (and hence the transport that equals their product) of the WBC are derived from analytical solutions of the non-dimensional vorticity equations in the relevant region of the (damping, aspect ratio) parameter space. These analytically determined proxies are then benchmarked against numerical simulations of the corresponding time-dependent equations. In both models, the three proxies vary as a power law in the domain aspect ratio and in particular, the non-dimensional transport varies linearly with the domain aspect ratio.