Original Depth Research Articles

Conditional Generative Adversarial Network for Monocular Image Depth Map Prediction

Deep map prediction plays a crucial role in comprehending the three-dimensional structure of a scene, which is essential for enabling mobile robots to navigate autonomously and avoid obstacles in complex environments. However, most existing depth estimation algorithms based on deep neural networks rely heavily on specific datasets, resulting in poor resistance to model interference. To address this issue, this paper proposes and implements an optimized monocular image depth estimation algorithm based on conditional generative adversarial networks. The goal is to overcome the limitations of insufficient training data diversity and overly blurred depth estimation contours in current monocular image depth estimation algorithms based on generative adversarial networks. The proposed algorithm employs an enhanced conditional generative adversarial network model with a generator that adopts a network structure similar to UNet and a novel feature upsampling module. The discriminator uses a multi-layer patchGAN conditional discriminator and incorporates the original depth map as input to effectively utilize prior knowledge. The loss function combines the least squares loss function and the L1 loss function. Compared to traditional depth estimation algorithms, the proposed optimization algorithm can effectively restore image contour information and enhance the visualization capability of depth prediction maps. Experimental results demonstrate that our method can expedite the convergence of the model on NYU-V2 and Make3D datasets, and generate predicted depth maps that contain more details and clearer object contours.

Restoration of the original depth distribution from experimental SIMS profile using the depth resolution function in framework of RMR model

In this paper, the problem of depth profiling analysis of nanoscale heterostructures containing doped delta layers and quantum wells using the SIMS method is considered. Based on computer simulation data and previously obtained experimental data, we demonstrated that the RMR model most accurately and completely describes the redistribution of the analyzed element in ultrathin layers that occurs during ion sputtering. A comparative analysis of the surface roughness–ion mixing–recoil implantation (RMR) model with MRI (mixing-roughness-information depth) and UDS (up-and-down slope) models proposed by Hoffman and Dowsett, respectively, was performed. It was shown that the introduction into the MRI model of a parameter describing some layer of constant thickness, in which the components of the analyzed layer and matrix elements are uniformly mixed, is not quite justified. It is concluded that during depth profiling of a monoatomic layer, the center of mass of this layer shifts away from the surface, as predicted by the RMR model, rather than toward the surface, as predicted by the MRI model. It is found that preferential sputtering does not affect the experimental depth distribution of elements obtained by the SIMS method.

Aspect ratio analysis of distinct Paleoproterozoic mafic dyke swarms and related fracture systems in the Eastern Dharwar Craton, India: Implications for emplacement mechanism and depth of origin

Understanding emplacement mechanism and depth of origin of continental mafic dyke swarms is pivotal in resolving outstanding questions regarding magma flow dynamics, plumbing system architecture, and amount of crustal dilation related to large igneous provinces. Paleoproterozoic mafic dyke swarms are often deemed as suitable candidates to establish the crustal evolution of cratonic regions. Here, we present the geometric and statistical analyses of five distinct Paleoproterozoic mafic dyke swarms and associated fracture systems in the Eastern Dharwar Craton (EDC) to constrain their magmatic overpressures and magma chamber depths. The geometric analysis is further validated with field evidence and measurements. It is suggested that mafic dykes of different swarms are formed primarily due to vertical magma injection from deep-seated magma reservoirs, followed by lateral magma flow at shallower depths. This study suggests a direct derivation of magma from deep-seated magma reservoirs, extending from lower crustal depths (∼17 km) to the crust-mantle boundary (∼36 km). It is also suggested that the emplacement of mafic dykes at ca. 2.37–2.36 Ga, ca. 2.26–2.25 Ga, ca. 2.22 Ga, and ca. 2.21 Ga can be traced back to the development of fracture system formed during and subsequent to the Neoarchean accretion event of Eastern and Western Dharwar Cratons (< 2.52 Ga). Therefore, the emplacement systems of the studied mafic dyke swarms have been largely controlled by the regional stress field and large-scale structural architecture of the Dharwar Craton.

Estimation of magma overpressure from partially exposed dykes - A new approach

We present a new method to estimate full length and maximum thickness of dykes from their partial exposures having at least one tip. The method is particularly applicable to dykes which originate as dominantly opening mode fractures. The idealized canonical model for Mode I fracture shows it to open up in the shape of an ellipse. We solve the equation of this ellipse using every possible combination of two points lying on the dyke margin measured from the observed tip to acquire the results. The method has been validated with observations made on felsic dykes found within intrusive porphyritic granitoids of Chotanagpur Granite Gneiss Complex (CGGC), Purulia, India which are completely exposed (showing tips at both ends) or have an exposed centre with at least one tip. The method has also been tested against published data collected from incomplete dyke outcrops found in the caldera walls of Miyake-jima volcano, Japan. Acquired results are found to be in good agreement with the ones estimated through a previously published method. The present method has been successfully employed to calculate the aspect ratios (maximum thickness/total length) of partially exposed mafic dykes emplaced within younger granite of Chitradurga Schist Belt, Western Dharwar Craton, India. We comment on the magma overpressure ranges and depth of origin of these dykes and on the fracture toughness of the host granite.

Inspection-Nerf: Rendering Multi-Type Local Images for Dam Surface Inspection Task Using Climbing Robot and Neural Radiance Field

For the surface defects inspection task, operators need to check the defect in local detail images by specifying the location, which only the global 3D model reconstruction can’t satisfy. We explore how to address multi-type (original image, semantic image, and depth image) local detail image synthesis and environment data storage by introducing the advanced neural radiance field (Nerf) method. We use a wall-climbing robot to collect surface RGB-D images, generate the 3D global model and its bounding box, and make the bounding box correspond to the Nerf implicit bound. After this, we proposed the Inspection-Nerf model to make Nerf more suitable for our near view and big surface scene. Our model use hash to encode 3D position and two separate branches to render semantic and color images. And combine the two branches’ sigma values as density to render depth images. Experiments show that our model can render high-quality multi-type images at testing viewpoints. The average peak signal-to-noise ratio (PSNR) equals 33.99, and the average depth error in a limited range (2.5 m) equals 0.027 m. Only labeled 2% images of 2568 collected images, our model can generate semantic masks for all images with 0.957 average recall. It can also compensate for the difficulty of manual labeling through multi-frame fusion. Our model size is 388 MB and can synthesize original and depth images of trajectory viewpoints within about 200 m2 dam surface range and extra defect semantic masks.

Origin of Late Cretaceous, enclave-bearing granitoids in southern Tibet: Implications for magma recharge and crustal thickening

Exposures of enclave-bearing granitoids can provide rare opportunities to directly evaluate the connection between compositional variability and the depth of origin of arc magmatic rocks. The ∼1000 km long Gangdese batholith is a composite batholith with composition from mafic to felsic; SiO2 ranges from 51 wt% to 70 wt%. New zircon U−Pb dating of the Nyemo plutons, Renbu plutons, and Xigaze plutons in the Gangdese batholith is consistent with their emplacement and crystallization in the Late Cretaceous (ca. 90−85 Ma). Mafic magmatic enclaves (MMEs) in the plutons are characterized by low SiO2 (50.9−56.0 wt%) and Nb/U, Ce/Pb, and Nb/La ratios coupled with enrichment in light rare earth elements and large ion lithophile elements and depletion in high field strength elements. These geochemical features, combined with depleted whole-rock εNd(t) (+4.2 to +4.7) and zircon εHf(t) (+9.0 to +13.8), suggest that they were derived by partial melting of a depleted mantle source associated with subduction-related fluids. The granitoids with high SiO2 (55.6−66.9 wt%) display adakitic geochemical characteristics, such as low Y and Yb contents, and high Sr/Y and La/Yb ratios. Their positive whole-rock εNd(t) (+4.0 to +5.5) and zircon εHf(t) (+6.9 to +14.3) values, as well as enrichment of incompatible elements, indicate that the granitoids were derived from partial melting of the juvenile lower crust. Geochemical modeling suggests that the compositional diversities of MMEs and adakitic granitoids were inherited from heterogeneous sources. This genetic relationship indicates that the underplated basaltic magmas could have supplied sufficient heat to trigger the melting of the thickened crust and thus formation of the enclave-bearing granitoid. In this regard, the origin of arc rocks can mirror the evolution of crustal thickness. Our results reveal that the crust was thickened to ∼50 km during the Late Cretaceous (90−85 Ma) and provide a magmatic record of crustal thickening prior to the Cenozoic Indo-Asia collision.

Numerical Study on the Rebound of Low-Velocity Impact-Induced Indentation in Composite Laminate

Indentation is an effective indication of LVI damage in PMCs. However, indentation can rebound partly with time. Thus, a good understanding of the rebound behavior of the impacted pit is helpful in damage assessment for composites. In this paper, a transverse isotropic viscoelastic model and a viscoelastic cohesive interface model are proposed to represent the viscoelastic properties of ply and the interface between adjacent plies, respectively. In these models, we implement the in-plane 3D Hashin failure criterion to simulate ply level failures and the stress-based quadratic failure criterion and linear softening mixed-mode BK law to simulate cohesive interface failure initiation and propagation, respectively. LVI testing was performed on specimens at different impact energies (30 J, 40 J, and 50 J). Dents induced by impact will eventually rebound due to the viscoelastic behavior of plies and cohesive interfaces. This results in a decrease in depth with time. This indentation and its rebound phenomenon were simulated in ABAQUS by considering viscoelasticity with user-defined material subroutines. The simulation results show good agreement with the experimental observations and are validated accurately in terms of the indentation’s initial depth upon impact and its final rebound with time. From experiments, it was observed that the decrease in the original depth of indentation initially becomes faster with time after impact; then, it slows down with time and eventually stops due to viscoelasticity. While this decrease in the original depth of indentation remains invariable with time in simulation, it has a different rebound path.

Limited Mediterranean sea-level drop during the Messinian salinity crisis inferred from the buried Nile canyon

The extreme Mediterranean sea-level drop during the Messinian salinity crisis has been known for >50 years, but its amplitude and duration remain a challenge. Here we estimate its amplitude by restoring the topography of the Messinian Nile canyon and the vertical position of the Messinian coastline by unloading of post-Messinian sediment and accounting for flexural isostasy and compaction. We estimate the original depth of the geomorphological base level of the Nile River at ~600 m below present sea level, implying a drawdown 2–4 times smaller than previously estimated from the Nile canyon and suggesting that salt precipitated under 1–3 km deep waters. This conclusion is at odds with the nearly-desiccated basin model (>2 km drawdown) dominating the scientific literature for 50 years. Yet, a 600 m drawdown is ca. five times larger than eustatic fluctuations and its impact on the Mediterranean continental margins is incomparable to any glacial sea-level fall.

Analysis and evaluation of different sequencing depths from 5 to 20 million reads in shotgun metagenomic sequencing, with optimal minimum depth being recommended.

Our study was to analyze and evaluate the impact of different shotgun metagenomic sequencing depths from 5 to 20 million in metagenome-wide association studies (MWASs), and to determine the optimal minimum sequencing depth. We included a set of 200 previously published gut microbial shotgun metagenomic sequencing data on obesity (100 obese vs. 100 non-obese). The reads with original sequencing depths>20million were downsized into seven experimental groups with depths from 5 to 20 million (interval 2.5 million). Using both integrated gene cluster (IGC) and metagenomic phylogenetic analysis 2 (MetaPhlAn2), we obtained and analyzed the read matching rates, gene count, species richness and abundance, diversity, and clinical biomarkers of the experimental groups with the original depth as the control group. An additional set of 100 published data from a colorectal cancer (CRC) study was included for validation (50 CRC vs. 50 CRC-free). Our results showed that more genes and species were identified following the increase in sequencing depths. When it reached 15 million or higher, the species richness became more stable with changing rate of 5% or lower, and the species composition more stable with ICC intraclass correlation coefficient (ICC) higher than 0.75. In terms of species abundance, 81% and 97% of species showed significant differences in IGC and MetaPhlAn2 among all groups with p<0.05. Diversity showed significant differences across all groups, with decreasing differences of diversity between the experimental and the control groups following the increase in sequencing depth. The area under a receiver operating characteristic curve, AUC, of the obesity classifier for running the obesity testing samples showed an increasing trend following the increase in sequencing depth (τ = 0.29). The validation results were consistent with the above results. Our study found that the higher the sequencing depth is, the more the microbial information in structure and composition it provides. We also found that when sequencing depth was 15 million or higher, we obtained more stable species compositions and disease classifiers with good performance. Therefore, we recommend 15 million as the optimal minimum sequencing depth for an MWAS.

Heidegger’s Way to “The Last God”

After Being and Time, “the last god” is born ex nihilo in Contributions to Philosophy. This has aroused extensive interest and discussion in the academic world. This paper focuses on the manifestation of “the last god” in Contributions to Philosophy. I will show that Contributions to Philosophy conveys Heidegger’s “deep experience”. This “deep experience” contains several key moments: solitude, stillness, silence and restraint. Solitude is the essential state of philosophers and poets. In solitude, one can enter a still place, which comes from the “stillness of Being”. Silence corresponds to this stillness. Silence has an original depth. These experiences finally point to the grounding attunement of “restraint”, which contains a relationship with powerful things. “The last god” appears in such deep experience, and its mode of manifestation is called “passing by”.

Health-related quality of life predictors in people with chronic wounds

ObjectiveTo assess health-related quality of life and its predictors among people with chronic wounds. Material and methodsA cross-sectional, analytical study was conducted with 85 people with chronic wounds, from July to September 2019, at a university hospital in the state of Paraíba, Brazil. Data were collected using forms and the Cardiff Wound Impact Schedule (CWIS). For data analysis, multiple linear regression was performed. ResultsThe mean quality of life score according to the CWIS was 45.57. The variables gender, marital status, comorbidities, duration of injury and appearance of exudate were negatively associated with the well-being domain. Injury duration, tissue depth, tissue type, and exudate volume were variables negatively associated with physical symptoms and mastery of daily living. Religion, wound origin, duration, lesion size, and tissue depth were negatively associated with the social life domain. ConclusionSociodemographic characteristics and wound-related aspects need to be considered when assessing and caring for patients with chronic wounds to ensure a better quality of life.

Fast hologram calculation method using wavelet transform: WASABI-2

Computer-generated holograms can reconstruct three-dimensional (3D) images using spatial light modulators. In addition, it has several applications, such as virtual and augmented reality devices; however, the hologram calculation is time-consuming. The wavelet shrinkage-based superposition (WASABI) has been proposed to accelerate hologram calculations by compressing point-spread functions with the wavelet transforms but gives rise to the problem of deepening the depth of field of 3D reconstructions. In this study, we proposed a fast calculation method, WASABI-2, to solve this problem by compressing 3D scenes with the wavelet transforms. The proposed method accelerates hologram calculations while maintaining the original depth of field.

Software Choice and Sequencing Coverage Can Impact Plastid Genome Assembly-A Case Study in the Narrow Endemic Calligonum bakuense.

Most plastid genome sequences are assembled from short-read whole-genome sequencing data, yet the impact that sequencing coverage and the choice of assembly software can have on the accuracy of the resulting assemblies is poorly understood. In this study, we test the impact of both factors on plastid genome assembly in the threatened and rare endemic shrub Calligonum bakuense. We aim to characterize the differences across plastid genome assemblies generated by different assembly software tools and levels of sequencing coverage and to determine if these differences are large enough to affect the phylogenetic position inferred for C. bakuense compared to congeners. Four assembly software tools (FastPlast, GetOrganelle, IOGA, and NOVOPlasty) and seven levels of sequencing coverage across the plastid genome (original sequencing depth, 2,000x, 1,000x, 500x, 250x, 100x, and 50x) are compared in our analyses. The resulting assemblies are evaluated with regard to reproducibility, contig number, gene complement, inverted repeat length, and computation time; the impact of sequence differences on phylogenetic reconstruction is assessed. Our results show that software choice can have a considerable impact on the accuracy and reproducibility of plastid genome assembly and that GetOrganelle produces the most consistent assemblies for C. bakuense. Moreover, we demonstrate that a sequencing coverage between 500x and 100x can reduce both the sequence variability across assembly contigs and computation time. When comparing the most reliable plastid genome assemblies of C. bakuense, a sequence difference in only three nucleotide positions is detected, which is less than the difference potentially introduced through software choice.

Model Simulation of Storm Surge in the Northwestern South China Sea Under the Impact of Sea Level Rise: A Case Study of Super Typhoon Rammasun (2014)

Because of global warming, the sea level is expected to continue to rise, possibly having a significant impact on the intensities and spatial distribution characteristics of coastal storm surges. In this study, we took super typhoon Rammasun (2014) as a case study and applied the SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model) to simulate storm surge in the northwestern South China Sea under future sea level rise (SLR) scenarios. To improve the accuracy of storm surge hindcast, we used reconstructed wind field to drive the model in which ERA5 reanalysis data were superposed on the wind field calculated from the Holland parametric cyclone model. The results show that the storm surge hindcast was significantly improved by using this reconstructed wind forcing. 2-D and 3-D model hindcast capabilities were compared; the 3-D model reproduced the storm surge better. The regional sea level projections in 2050, 2100, 2200, and 2300 for RCP 4.5 scenarios (provided by the IPCC AR6 dataset) were superposed on the original water depth as the predicted sea levels, then those depths were used in models of storm surge in the study area under a typhoon identical to Rammasun. Model results demonstrate that storm surge peaks in most sea areas decrease nearly linearly with SLR, especially in regions of high surges.

Effects of sputtering induced artifacts on the determination of diffusion coefficient: Application to Ni/Cu system

The influence of the deformation of the measured depth profile as compared to the originals, on the determination of diffusion coefficient was evaluated in depth profiling. Based on Fick's second law, the original simulation depth profiles were obtained. By application of the mixing-roughness-information depth model, the influences of sputtering induced artifacts on the original depth profiles could be predicted and, as a result, we could investigate the effects of those artifacts on the determination of the diffusion coefficient. Firstly, a numerical simulation was applied to evaluate the effects of those sputtering induced artifacts on the determination of the diffusion coefficient. Subsequently, an experiment was performed to obtain the diffusion coefficient in a Ni–Cu system and the influences of the sputtering induced artifacts on the measured diffusion coefficient were estimated according to the previous simulation results. The simulation results showed that, for roughness less than 10 nm, and mixing length or information depth less than 4 nm, the effects of sputtering induced artifacts on the determination of the diffusion coefficient could be ignored. In addition, Cu(100 nm)/Ni(100 nm)/SiOx/Si(100) thin films were synthesized using electron-beam evaporation and then annealed at different temperatures under vacuum. The samples were characterized by time-of-flight secondary ion mass spectrometry depth profiling. The effects of sputtering induced artifacts on the depth profiles of the Ni/Cu films were very small since the roughness and mixing length are very small. The measured diffusion coefficient agrees well with the results of others.

Present-day infralittoral prograding wedges (IPWs) in Central-Eastern Tyrrhenian Sea: Critical issues and challenges to their use as geomorphological indicators of sea level

A census of 83 Infralittoral Prograding Wedges (IPWs) was carried out in the Central-Eastern Tyrrhenian Sea, to learn more about their morpho-bathymetric variability and test their reliability as environmental indicators of current sea level. With this aim, a database recording for each wedge the main morphometric indices, the effective fetch and the significant height of the storm waves– here used as proxies for sea state forcing to which they are exposed- and the ground elevation in the backshore - here used as a numerical descriptor of coastal morphology and energy of the relief- was realized (Campania Region IPWs Database).The statistical analysis on the entire IPWs dataset explored the relationship between the environmental and morphometric variables while the Principal Component Analysis grouped the variables into two clusters, governed by sea state forcing and energy of relief in the backshore, respectively. The multi-regression analysis highlighted a significant correlation of IPWs depth with effective fetch and extreme significant wave height and a moderate correlation with the ground elevation in the backshore. The outcomes that emerged from the observational law on present-day IPWs were then applied to relict IPWs, currently lying on the continental shelf and at the shelf margin, with the aim of establishing their original depth of formation. This procedure aims to solve the non-trivial issue, namely that concerning the reliability of paleo-IPWs as proxies for past sea levels. Thus, a simplified equation based only on the use of geographical variables is proposed here to roughly establish the original depth (with errors of few metres) of paleo-IPWs, whose geographical exposure is known and the effective fetch computable. Although the applicability of this method suffers from spatial and temporal restrictions, due to the girth of the original dataset, it provides a first analytical procedure for gauging the original depth of formation of paleo-IPWs which, over the last decade, have been increasingly used as environmental indicators of past sea levels. This study highlights the relationship between the depth of these sedimentary coastal bodies and sea storm wave climate at a regional scale and provides clues for the use of their past counterparts as morphological proxies of past sea level stands. Further developments of this study would use a wider dataset so as to extend the observational law on present-day IPWs to a Mediterranean scale and strengthen the applicability of the method to a spatially broader set of paleo-IPWs.

Phototherapeutische Keratektomie bei rezidivierenden Hornhauterosionen verschiedener epithelialer Genese: Einfluss der Ablationstiefe auf Pachymetrie und Refraktion

Phototherapeutic keratectomy (PTK) is an established treatment method for patients suffering from either genetic corneal dystrophy or recurrent corneal erosion (RCE) without underlying basement membrane dystrophy, often caused by trauma. This study aimed to describe the changes in manifest subjective refraction and pachymetry after PTK treatment in patients suffering from epithelial basement membrane dystrophy (EBMD) and traumatic or atraumatic RCE without underlying EBMD. This was aretrospective, single-center study performed at the Department of Ophthalmology of the Ludwig-Maximilians University (Munich). Patient data were retrospective collected using the smart-eye database of the Department of Ophthalmology including diagnostic data from an autorefractometer and from the Pentacam HR. All laser treatments were performed with an ablation depth of 10 μm for EBMD patients and 6 μm for RCE patients without EBMD. Both collectives showed adecrease in pachymetry larger than the calculated ablation depths after afollow-up interval of 126days (95% CI 104-147days). While the EBMD collective receiving an ablation of 10 μm showed adecrease of 25.8 μm (N = 74; 95% CI 21.2-30.3; p < 0.001), the non-EBMD collective receiving an ablation of 6 μm showed a decrease of 12.3 μm (N = 44, 95% CI 7.0-17.7; p < 0.001). Both, total corneal refractive power (TCRP) as well as spherical equivalent (SE) offered no significant change in preoperative and postoperative comparison for the EBMD collective. On the other hand, patients without underlying EBMD showed asignificant myopic decrease in SE of 0.4 dpt (±0.7 dpt SD, p < 0.05). The mean follow-up interval was 126 days (95% CI 104-147 days). PTK treatment offers an effective method for patients suffering from either EBMD dystrophy or RCE syndrome without underlying EBMD. The final ablation based on pachymetry at the apex can be estimated at 2.3 to 2.6 times higher compared to the original ablation depth. The reasons for this are on the one hand the laser ablation itself and the influence of the reactive wound healing of the corneal epithelium.

Grossular Exsolution at Pyrope Dislocation: New Evidence for the Ultradeep Origin of Dabie Orogenic Peridotite

Exsolution and dislocation microstructures are an important basis to decipher the conditions of metamorphic deformation and evolution processes of its host minerals and rocks. The grossular-rich exsolution in pyrope-rich garnet grains of Bixiling orogenic crustal cumulative peridotite, Dabie orogen, China, was studied by electron backscatter diffraction (EBSD), conventional and high-resolution transmission electron microscopy (TEM/HRTEM) and electron-microprobe analysis (EMPA). Our results indicate that the precursor pyrope-rich host grains had undergone plastic deformation and developed numerous dislocation microstructures before the grossular precipitated. When the pressure and/or temperature decreased during the exhumation of subducted slab, the grossular-rich lamellae exsolved and precipitated at the dislocation structures of host and inherited their shapes. EBSD and TEM analyses show that the crystallographic orientation of exsolution is controlled by, and coherent with, the host grain. These exsolution textures and the chemical composition of precursor garnet correspond to a balance pressure–temperature (P–T) condition of &gt;6 GPa and &gt;850 °C based on the previous thermodynamic models, which indicates that the origin depth of the Bixiling garnet peridotite should be more than 200 km.

A New Urban Waterlogging Simulation Method Based on Multi-Factor Correlation

Waterlogging simulation is a key technology for solving urban waterlogging problems. The current waterlogging modeling process is relatively complex and requires high basic data, which is not conducive to rapid modeling and popularization. In this study, we evaluated the correlation between rainfall and waterlogging water using the following factors: terrain, evaporation, infiltration, pipe drainage capacity, and river flood water level. By quantifying the influence value of each factor on rainfall, we established a simplified model for fast calculation of waterlogging depth through input rainfall. Waterlogging data was collected from Guangzhou, China to set up the multi-factor correlation model, and verify the simulation results of the model. After the original rainfall is added/deducted, the added/loss value, the relationship between net rainfall, and maximum water depth is better than that between original rainfall and maximum water depth. Establishing a stable multi-factor correlation model for a waterlogging point requires at least three historical waterlogging event data for parameter calibration by sensitivity analysis. Comparing the simulation of four waterlogging points, the multi-factor correlation model (error = −13%) presented the least error in simulating the maximum water volume, followed by the Mike Urban model (error = −19%), and finally the SWMM model (error = 20%). Furthermore, the multi-factor correlation model and SWMM model required the least calculation time (less than 1 s), followed by the Mike Urban model (About half a minute). By analyzing the waterlogging data of Guangzhou, 42 waterlogging points with modeling conditions were screened out to further validate the multi-factor correlation model. Each waterlogging point was modeled based on the historical field, and the last rainstorm was used for model verification. The mean error of the comparison between the simulated maximum waterlogging and the measured maximum waterlogging was 3%, and the R2 value was 0.718. In summary, the multi-factor correlation model requires fewer basic data, has a simple modeling process and wide applicability, and makes it easy to realize the intelligent parameter adjustment, which is more suitable for the urgent requirements of current urban waterlogging prediction. The model results may prove accurate and provide scientific decision support for the prevention and control of urban waterlogging.

Exhumation and carbonation of the Atlantis Bank core complex constrained by in situ U-Pb dating and Δ47 thermometry of calcite veins, SW Indian Ridge

The Atlantis Bank is a representative example of an oceanic core complex formed on a slow-spreading ridge. It is dominated by olivine gabbros emplaced at ∼12 Ma and exhumed from original depths of more than ∼2500 metres below seafloor (mbsf). In order to investigate the timing of exhumation and low-temperature alteration we investigated twenty-two calcite veins in samples of core recovered from the 809-mbsf Hole U1473A drilled during Expedition 360 of the International Ocean Discovery Program. The calcite veins yielded laser ablation U-Pb and bulk U-Th ages ranging from 10.4±0.3 Ma to 273±5 Ka. They have an average Δ47 formation temperature of 21±4°C and 87Sr/86Sr and rare earth element signatures typical of low-temperature veins dominated by seawater. These data preclude previous cooling models that invoked a 250°C heat pulse related to sill emplacement at ∼9.4 Ma. Instead, the combined Δ47 and U-Pb age data indicate a simple cooling path in which the gabbros were exhumed close to the seafloor and cooled to a mean of 21±4°C by 10.4±0.3 Ma. The timing of the earliest low-temperature veins 1.6±0.7 Myr after accretion is broadly similar to that reported for other oceanic core complexes. However, the 12 Ma age of the Atlantis Bank means it has recorded a longer carbonation history. The vein ages indicate ∼83% of vein growth occurred during a period of 3.1±0.9 Myr between ∼10.4 and ∼7.3 Ma. The Atlantis Bank gabbros are estimated to have a bulk concentration of 0.15±0.04 wt% CO2. Therefore if carbonation and veining occurred proportionally to one another, the initial carbonation rate was ∼400±200 μg/g CO2 per Myr. A single vein with an age of 5.8±0.4 Ma formed between 7.3 and 1 Ma suggesting a virtual hiatus in carbonation. However, resumed vein growth after 0.27-1 Ma is recorded by three samples. The uncertainty in these very young U-Pb ages is substantial, meaning the carbonation rate is only loosely constrained as similar to, or lower than, the initial rate of ∼400 μg/g CO2 per Myr. These data demonstrate that recent carbonation of 12 Ma old ocean crust is significant and probably ongoing. Given that ocean core complexes form on crustal-scale detachments that provide high permeability pathways, and they are bathymetric highs where reactive lithologies can be exposed on the seafloor, oceanic core complexes like the Atlantis Bank could be sites of long-lived alteration on the seafloor.