Unlike English, in Chinese texts there is no natural separator-like space between words, which makes Chinese word segmentation a difficult information processing problem. At present, geological texts contain a large number of unregistered geological terms, and the existing rule-based methods, machine-learning and deep-learning algorithms still cannot solve the problem of word separation in geology, especially for the large number of unregistered words. In this paper, we explore a dual-corpus, deep learning model-based approach to geological text dictionaries and compare it with the general domain dictionary and single-corpus deep learning model dictionary methods. Our experiments show that the proposed method is significantly better than other methods in open testing, with a precision of 92.56%, recall of 91.44% and F1 of 92.00%. In this paper, the Chinese word segmentation of geological text can identify unregistered geological terms effectively and ensures the recognition rate of common words, which lays the foundation for natural language processing in the domain of geoscience.

Incipient channelization in mountainous landscapes is often associated with the presence of first-order valleys at a regular wavelength under diverse hydroclimatic forcings. Here we provide a formal linear stability analysis of a landscape evolution model in detachment-limited erosion conditions to quantify the impact of the erosion law on the regular valley formation. The linear stability analysis is conducted for the unchannelized hillslope solutions along a long mountain ridge, where the perturbed equations constitute a third-order differential eigenvalue problem. The solutions to the posed eigenvalue problem are obtained by a spectral Galerkin technique with numerical quadrature. Results reveal the dependence of the erosion threshold and the emergent ridge/valley wavelength on the exponents in the power-law scaling coupling fluvial erosion with specific drainage area (m) and local slope (n). As the exponent m increases for a fixed n, the emergent valley spacing expands and the erosion limit for the first channel instability declines. Conversely, the erosion threshold for the first channelization rises with an increase in n at a particular value of m. We also show that predictions of the stability analysis conform with numerical simulations for different degrees of nonlinearity in the erosion mechanism and agree well with topographic data of a natural landscape.

Accurate modeling and simulation of radionuclide migration in clay rocks such as the Opalinus Clay play a key role in the safety assessment of deep geological repositories for nuclear wastes. At the continuum scale, the representative elementary volume (REV) is a fundamental constraint to quantify the effective diffusivity, which is a key parameter in reactive transport (RT) models. Therefore, an accurate estimation of the REV is essential for a meaningful continuum-scale RT simulation in heterogeneous clay rocks. This study presents a comprehensive analysis of the heterogeneities of porosity and effective diffusivity in clay rocks by using the classical sampling theory and pore-scale simulations. First, in this study, the two-dimensional representative elementary area (REA) is correlated with the REV for porosity via a characteristic length. Next, it is shown that the REV for diffusivity is larger than the REV for porosity. Moreover, these two REVs can be correlated using Archie’s law. In such a way, the REV for diffusivity can be determined by the developed correlations through analyzing two-dimensional microstructures, thus significantly reducing the computational cost. Finally, the applicability of our approach for clay rocks is validated by experimental data on the diffusion of tritiated water in the heterogeneous sandy facies of Opalinus Clay. From both the experimental data and the modeling prediction, the REV for diffusivity in the sandy facies of Opalinus Clay is in the order of cubic centimeters. This study provides critical insights into the diffusion in heterogeneous clay rocks towards an enhanced predictability of radionuclide migration.

Worldwide tsunamis generated by atmospheric waves – or planetary meteotsunami waves – are extremely rare events occurring during supervolcano explosions or asteroid impacts. Recently, such waves have been globally recorded after the Hunga volcano eruption (Tonga) but did not pose any serious danger to the coastal communities. However, this study highlights that the mostly ignored destructive potential of planetary meteotsunami waves can be compared to the well-studied tsunami hazards. Through simple numerical experiments we indeed prove that meteotsunami surges above 1.00 m can be generated along more than 7 % of the world coastlines by atmospheric waves either more intense or slower than during the Hunga event. Consequently, the global meteotsunami hazards should now be properly assessed to prepare for the next big volcanic eruption or asteroid impact.

The rapidly enhancing global hydrographic in-situ observations archive is data quality heterogeneous. Different data applications (e.g., climate change science) require a high-performance quality control (QC) system to reliably identify outliers in profile data. This study presents a new automatic QC procedure (CAS-Ocean Data Center quality control system; CODC-QC) for ocean in-situ temperature outliers detection. Unlike many existing QC procedures, no assumption is made of a Gaussian distribution law in CODC-QC as the oceanic variables are typically skewed. Instead, the 0.5% and 99.5% quantiles are used to define the local temperature climatological ranges. Additionally, we constructed local climatological ranges for the vertical temperature gradient which increased the ability of identifying spurious profiles. The performance of CODC-QC was evaluated using two benchmark datasets. Results demonstrated that CODC-QC is effectively in removing spurious data and minimizing the percentage of mistakenly flagged good data. Additionally, the CODC-QC was applied to the global World Ocean Database (WOD) historical temperature profiles and a significant quality-dependent on instrumentation types was found. Finally, as ocean heat content (OHC) is a fundamental indicator of climate change, the impact of different QC systems on OHC estimation is examined. Results based on an existing mapping approach indicate that applying CODC-QC system leads to a 41.7 % (4.9%) difference for linear trend of the global 0-2000m OHC changes within 1955-1990 (1991-2020) compared to the WOD-QC, implying a non-negligible source of error in ocean warming estimate. The new QC procedure could support further improvement of the oceanic climate records and other applications.

This paper describes magnetospheric waves of very long wavelength in thin magnetic filaments. We consider an average magnetospheric configuration with zero ionospheric conductance and calculate waves using two different formulations: classic interchange theory and ideal MHD. Classic interchange theory, which is developed in detail in this paper, is basically analytic and is relatively straightforward to determine computationally, but it can’t offer very high accuracy.The two formalisms agree well for the plasma sheet and also for the inner magnetosphere. The eigenfrequencies range over about a factor of seven, but the formulations generally agree with a root-mean-square difference of the $log_{10}$ of the ratio of the interchange to MHD frequencies to be $\sim 0.054$. The pressure perturbations in the classic interchange theory are assumed constant along each field line, but the MHD computed pressure perturbations along the field line vary in a range $\sim 30 \%$ in the plasma sheet but are larger in the inner magnetosphere. The parallel and perpendicular displacements, which are very different in the plasma sheet and inner magnetosphere, show good qualitative agreement between the two approaches. In the plasma sheet, the perpendicular displacements are strongly concentrated in the equatorial plane, whereas the parallel displacements are spread through most of the plasma sheet away from the equatorial plane; and can be regarded as buoyancy waves. In the inner magnetosphere, the displacements are more sinusoidal and are more like conventional slow modes. The different forms of the waves are best characterized by the flux tube entropy $PV^\gamma$.

The search for life in the universe can inspire students and members of the public alike. Three projects are described which provide an immersive experience with astrobiology. The first is teaching astrobiology to non-science majors in the virtual world Second Life. Second Life can support authentic learning and foster cross-cultural competencies. In the next iteration of the course, students will create simulations of exoplanet landscapes and architectures of exoplanetary systems. The second project is a virtual reality exhibit for education and outreach. It has models of major facilities in astronomy and space science in a virtual space. Users wear Oculus Quest headsets and use game controllers to navigate. Next additions to the VR space will be examples of exoplanet science and fully animated exoplanet systems. The third project is a new version of a multimedia performance piece called StellarScape, combining original electronic music, dance and simulations of star birth. A live dancer interacts with simulations via sensors. The next version is PlanetScape, where back-projected video is a series of realistically rendered exoplanet surfaces. The dancer undertakes a “hero’s journey,” experiencing the altered gravity and physical conditions of alien planets as they try to find their way home.

We present a new 3-D seismic structural model of the eastern Indonesian region and its surroundings from full-waveform inversion (FWI) that exploits seismic data filtered at periods between 15 - 150 s. SASSY21 - a recent 3-D FWI tomographic model of Southeast Asia - is used as a starting model, and our study region is characterized by particularly good data coverage, which facilitates a more refined image. We use the spectral-element solver Salvus to determine the full 3-D wavefield, accounting for the fluid ocean explicitly by solving a coupled system of acoustic and elastic wave equations. This is computationally more expensive but allows seismic waves within the water layer to be simulated, which becomes important for periods ≤ 20 s. We investigate path-dependent effects of surface elevation (topography and bathymetry) and the fluid ocean on synthetic waveforms, and compare our final model to the tomographic result obtained with the frequently used ocean loading approximation. Furthermore, we highlight some of the key features of our final model - SASSIER22 - after 34 L-BFGS iterations, which reveals detailed anomalies down to the mantle transition zone, including a convergent double-subduction zone along the southern segment of the Philippine Trench, which was not evident in the starting model. A more detailed illumination of the slab beneath the North Sulawesi Trench reveals a pronounced positive wavespeed anomaly down to 200 km depth, consistent with the maximum depth of seismicity, and a more diffuse but aseismic positive wavespeed anomaly that continues to the 410 km discontinuity.

In the Katha Range of central Myanmar, lithologic tracers and pressure-temperature-deformation-time data identify Cambro-Ordovician, Indian-affinity Tethyan Himalaya Series (THS), located ~700 km from their easternmost outcrop in S-Tibet and ~450 km from Himalayan rocks in the Eastern Himalayan Syntaxis (EHS). Metamorphism began at ~65 Ma, peaked at ~45 Ma (~510°C, 0.93 GPa), and exhumation/cooling (~25°C/Myr) occurred until ~30 Ma in a subduction-early collision setting. When the Burma microplate—part of the intra-Tethyan Incertus-arc—accreted to SE-Asia, its eastern boundary, the southern continuation of the Indus-Yarlung suture (IYS), was reactivated as the Sagaing fault (SF), which propagated northward into Indian rocks. In the Katha rocks, this strike-slip stage is marked by ~4°C/Myr exhumation/cooling. Restoring the SF system defines a continental collision-oceanic subduction transition junction, where the IYS bifurcates into the SF at the eastern edge of the Burma microplate and the Jurassic ophiolite-Jadeite belt that includes the Incertus suture.

Solar and atmospheric variability influences the ionosphere, causing critical impacts on satellite and ground based infrastructure. Determining the dominant forcing mechanisms for ionosphere variability is important for prediction and mitigation of these threats. However, this is a challenging task due to the complexity of solar-terrestrial coupling processes. At high latitudes, diurnal and semidiurnal variations of temperature and neutral wind velocity can be forced from either below (lower atmosphere waves) or from above (geomagnetic and in-situ solar forcing). We analyse measurements from the incoherent scatter radar (ISR) facility operated by the European Incoherent Scatter Scientific Association (EISCAT). They are complemented by meteor radar data and compared to global circulation models. Experimental and model data both indicate the existence of strong semidiurnal oscillations in a two-band structure at altitudes $\lesssim110$ km and $\gtrsim130$ km, respectively. Analysis of the phase progressions suggests the upper band to be forced \textit{in situ} while the lower band corresponds to upwards propagating tides from lower atmosphere. These results show that the actual transition of tides in the altitude region between 90 and 130 km is more complex than described so far.

Coastal wetlands provide a wide array of ecosystem services, valued at trillions of dollars per year globally. Although accelerating sea level rise (SLR) poses the long-term threat of inundation to coastal areas, wetlands may be sustained in two ways: by positive net surface-elevation change (SEC) from sediment and organic matter buildup and by accommodation, or horizontal migration into refugia—low-lying, undeveloped upland areas that become inundated. Using a simple model together with high-resolution elevation data, we provide, across the contiguous United States, analysis of the local effects of SLR, maximum SEC rates, and coastal development on the long-term resilience of coastal wetlands. We find that protecting current refugia is a critical factor for retaining wetlands under accelerating SLR. If refugia are conserved under an optimistic scenario (a high universal maximum SEC rate of 8mm/yr and low greenhouse gas emissions), wetlands may increase by 25.0% (29.4%−21.5%; 50th, 5th−95th percentiles of SLR) by the end of the century. However, if refugia are developed under a more pessimistic scenario (a low universal maximum SEC rate of 3mm/yr, high greenhouse gas emissions, and projections incorporating high ice-sheet contributions to SLR), wetlands may decrease by -97.0% (-82.3%−-99.9%). These median changes in wetland area could result in an annual gain of ∼$222 billion compared to an annual loss of ∼$732 billion in ecosystem services in the US alone. Focusing on key management options for sustaining wetlands, we highlight areas at risk of losing wetlands and identify the benefits possible from conserving refugia or managing SEC rates.

The damaging effects of climate change and increased ocean temperatures are already visible in marine ecosystems worldwide. Degree heating weeks (DHW) provide a valuable metric for gauging excess sea surface temperature warming and coral bleaching risk. This study produces future DHW projections for the Mesoamerican reef (MAR) using a multi-model climate change ensemble. We show that current marine heat wave conditions linked to coral bleaching will be far exceeded in an average year by mid-century, creating an environment where MAR corals have no opportunity for normal year recovery between extreme years. The dramatic increase in DHW in the MAR indicates strong adaptation interventions need to be developed and implemented as soon as possible to support local communities in adjusting to the effects of a warming climate.

A transition from sugar to flower shallow cumuli occurred under a layer of mineral dust on February 2, 2020, during the multinational ATOMIC and EUREC4A campaign. Lagrangian large eddy simulations following an airmass trajectory along the trade winds are used to explore radiative impacts of the diurnal cycle and mineral dust on the sugar-to-flower (S2F) cloud transition. The large-scale meteorological forcing is derived from the European Center for Medium-Range Weather Forecasts Reanalysis 5th Generation and based on in-situ measurements during the field campaign. A 12-hour delay in the diurnal cycle accelerates the S2F transition, leading to more cloud liquid water and precipitation at night. The aggregated clouds generate more, and stronger cold pools, which alter the original mechanism responsible for the organization. Although there is still mesoscale moisture convergence in the cloud layer, the near-surface divergence associated with cold pools transports the subcloud moisture to the drier surrounding regions. New convection forms along the cold pool edges, resulting in the next generation of flower clouds. The amount of cloud water, rain, and cold pools reduce after sunrise. The modulation of the surface radiative budget by free-tropospheric mineral dust poses a less dramatic effect on the S2F transition. Mineral dust absorbs shortwave radiation during the day, cooling the boundary layer temperature, enabling stronger turbulence, strengthening the mesoscale organization, and enlarging the aggregate areas. At night, the longwave heating effects of the mineral dust and more cloud liquid water warms the boundary layer, reducing the cloud amount and weakening the organization.

I shall define the magnetic field and the equivalence between a body's mass and its electric charge. On this basis, the mass of the Earth's core shall be theoretically calculated, and shall result in a value that corresponds to established findings. The Earth is like a magneto, of which its rotor behaves like an alternator. The inner and outer cores rotate in opposite directions to each other, with the inner core behaving like an inductor and the outer core being induced. Then I shall obtain the electric charge, the force of electric fields and the electric potential at the Earth's surface. Throughout, I shall be applying some theoretical propositions to the concept of Earth's electrical energy. I shall calculate the frequency of alternating electric currents generated by the Earth.

Understanding the distribution of organic material, mineral inclusions, and porosity are critical to properly model the flow of fluids through rock formations in applications ranging from hydraulic fracturing and gas extraction, CO2 sequestration, geothermal power, and aquifer management. Typically, this information is obtained on the pore scale using destructive techniques such as focused ion beam scanning electron microscopy. Neutrons and X-rays provide non-destructive, complementary probes to gain three-dimensional distributions of porosity, minerals, and organic content along with fluid interactions in fractures and pore networks on the core scale. By capturing both neutron and X-ray tomography simultaneously it is possible to capture slowly dynamic or stochastic processes with both imaging modes. To facilitate this, NIST offers a system for simultaneous neutron and X-ray tomography at the Center for Neutron Research. This instrument provides neutron and X-ray beams capable of penetrating through pressure vessels to image the specimen inside at relevant geological conditions at resolutions ranging from 15 micrometers to 100 micrometers. This talk will discuss current efforts at identifying mineral and organic content and fracture and wettability in shales relevant to gas extraction.

River systems represent important drivers of carbon loading, utilization and storage. However, underlying controls of hydrological transport and biological degradation on fluvial dissolved organic carbon (DOC) have yet to be revealed. Here, we explored spatiotemporal variability of DOC concentrations, components and sources, as well as its biodegradability in a headwater tributary of the Yangtze. We found that temporal rainfall stimulated terrestrial inputs and increased terrigenous DOC abundance. Hydrological transport was accompanied by biological generation and utilization of DOC, resulting in reduced labile components and accumulated recalcitrant components from tributaries to the main stem. Biodegradable DOC (BDOC) notably responded to temperature gradients over a 56-day laboratory incubation. Riverine DOC component, molecular weight and source highly predicted its biodegradation. Particularly, partial refractory (ultraviolet humic-like) fractions contributed to biological degradation of DOC, which was incompletely degraded from high-molecular to low-molecular weight compounds. The findings hope to supplement a new understanding of carbon fate under global change.

Local scouring is a bed load transport phenomenon related to different scientific disciplines in Earth-science and hydraulic engineering. However, less attention is given on the enlargement processes of local scour holes at natural instream obstacles like boulders that are exposed to unsteady flow conditions in the course of a flood hydrograph. Experimental investigations in laboratory flumes offer the advantage that hydraulic boundary conditions can be systematically varied. This contribution yields novel experimental data on the impact of submergence ratio, hydrograph skewness, and flow intensity onto local scour holes at boulder-like obstacles and evaluates the effect of discharge chronologies, i.e. subsequent hydrographs in time onto the geometry of local scour holes. In total 48 unscaled flume experiments for subcritical, clear-water and live-bed conditions were performed. Experimental results reveal that (i) local scouring dominantly occurred at the rising limb when flow depth is comparable to the obstacle size so that the obstacle is unsubmerged. (ii) Up to 80% of the scour hole size at the end of experimental runs was reached in only 10% of the experimental runtime while the skewness of the hydrograph is important. The steeper the rising limb the quicker the local scour hole matured. (iii) Local scouring is history dependent and memory effects are present that describe the dependence on antecedent sizes of the scour hole. It is speculated that speculate that local scour holes found at boulders in the field may be used for the interpretation of the minimum duration of the beginning stage of a flood.

The salinity distribution of an estuary depends on the balance between the river outflow, which is seaward, and a dispersive salt flux, which is landward. The dispersive salt flux at a fixed cross-section can be divided into shear dispersion, which is caused by spatial correlations of the cross-sectionally varying velocity and salinity, and the tidal oscillatory salt flux, which results from the tidal correlation between the cross-section averaged, tidally varying components of velocity and salinity. The theoretical moving plane analysis of Dronkers and van de Kreeke (1986) indicates that the oscillatory salt flux is exactly equal to the difference between the “local” shear dispersion at a fixed location and the shear dispersion which occurred elsewhere within a tidal excursion – therefore, they refer to the oscillatory salt flux as “nonlocal” dispersion. We apply their moving plane analysis to a numerical model of a short, tidally dominated estuary and provide the first quantitative confirmation of the theoretical result that the spatiotemporal variability of shear dispersion accounts for the oscillatory salt flux. Shear dispersion is localized in space and time due to the tidal variation of currents and the position of the along-channel salinity distribution with respect to topographic features. We find that dispersion near the mouth contributes strongly to the salt balance, especially under strong river and tidal forcing. Additionally, while vertical shear dispersion produces the majority of dispersive salt flux during neap tide and high flow, lateral mechanisms provide the dominant mode of dispersion during spring tide and low flow.