Earth and Space Science最新文献

{"title":"In-Depth Evaluation of Inversion of Coastal Tsunami Waveforms Utilizing Tsunami Source Constrained by Offshore Tsunami Waveforms From a Wide, Dense Observation Network: Application to the 2016 Mw 6.9 Off-Fukushima Earthquake, Japan","authors":"Hiroaki Tsushima,&nbsp;Yutaka Hayashi,&nbsp;Takeyasu Yamamoto","doi":"10.1029/2024EA004043","DOIUrl":"10.1029/2024EA004043","url":null,"abstract":"<p>The tsunami generated by the 2016 <i>M</i>_w 6.9 off-Fukushima earthquake, Japan, was recorded by offshore pressure gauges on a wide, dense ocean-bottom cable network, called S-net, as well as by offshore GPS buoys, coastal wave gauges and coastal tide gauges. In this work, source of the tsunami was inverted from the offshore tsunami waveforms and coastal tsunami waveforms independently, using the Green's functions based on linear long-wave theory. We found that inversion of the offshore waveforms returned robust results, more accurate and better resolved than those obtained from the coastal waveforms. Furthermore, nonlinear long-wave simulation using the offshore-data-inverted tsunami source, accurately reproduced the leading waves recorded at offshore and coastal stations. These results also demonstrated that tsunami nonlinearities are non-negligible, which is the main reason, together with weak constraints from the coastal waveforms, for the relative inaccuracy of the results of inversion from the coastal waveforms. This inaccuracy can be reduced by rearranging the conditions of inversion. Our analysis demonstrated that offshore tsunami waveforms from a wide, dense network are beneficial to deeply evaluate and improve inversion of coastal tsunami waveforms.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 8","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA004043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep Argo Improves the Accuracy and Resolution of Ocean Bathymetry","authors":"N. V. Zilberman,&nbsp;M. Scanderbeg,&nbsp;K. Balem,&nbsp;T. Schmitt,&nbsp;P. Weatherall,&nbsp;V. Thierry,&nbsp;E. Van Wijk,&nbsp;D. Sandwell","doi":"10.1029/2025EA004304","DOIUrl":"10.1029/2025EA004304","url":null,"abstract":"<p>Ocean bathymetry plays an instrumental role in stirring ocean circulation and ocean mixing, shaping the transport of ocean heat, freshwater, oxygen, and carbon, influencing the propagation of tides and tsunamis, and controlling the dispersion of sediments, nutrients, and planktonic species. The dearth of direct ocean bathymetry measurements from shipboard echo sounders covering only 26% of the ocean floor calls for supplemental data. Satellites can provide bathymetry estimates in poorly-sampled regions, but intrinsic limitations of satellite measurements limit their ability to resolve features at horizontal scale &lt;6 km (1/2 wavelength). Here, profile pressure and float descent rate from Deep Argo floats of the Deep Arvor and Deep SOLO float models were used to infer ∼14,000 ocean bathymetry measurements between 2014 and 2024. Our analysis indicates high consistency, 0.98 and 0.97 correlation coefficient, and small rms difference, 88 and 96 m, between multibeam sounding at 1,500–6,000 m depth and bathymetry measurements from Deep SOLO and Deep Arvor models respectively. The stronger agreement between Deep Argo-derived depths and multibeam data compared to altimetry is consistent with lower spatial uncertainties (&lt;1.5 km for &gt;77% of data coverage) and higher vertical accuracy of the Deep Argo data set (3.9–4.2 m at 4,000–6,000 m depth). The inclusion of the Deep Argo bathymetry in the general bathymetric chart of the ocean shows 50–200 m range improvement in the accuracy of altimetrically derived predicted depths.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 8","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025EA004304","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Robust Edge Detection for Structural Mapping Beneath the Aristarchus Plateau on the Moon Using Gravity Data","authors":"Hanbing Ai,&nbsp;Qian Huang,&nbsp;Yunus Levent Ekinci,&nbsp;Ahmad Alvandi,&nbsp;Satya Narayan","doi":"10.1029/2025EA004379","DOIUrl":"10.1029/2025EA004379","url":null,"abstract":"<p>Accurately detecting the edges of subsurface geological structures from potential field anomalies remains a fundamental challenge. We applied the HTHG (Hyperbolic tangent function with horizontal and vertical derivatives of Total Horizontal Derivative) method to enhance subtle details in lunar gravity anomalies, focusing on the Aristarchus region and its surroundings. Initial assessments were conducted on synthetic noise-free and noisy gravity data sets and compared against eleven representative edge detectors. In the noise-free data case, HTHG demonstrated superior performance over other detectors in terms of accuracy, resolution, sharpness, and amplitude balancing. However, similar to other approaches, its directional derivative calculations are highly susceptible to noise amplification. To address this challenge, we implemented various noise reduction techniques, including the <i>β</i>-VDR and MNLM methods. Notably, we also presented different methods for estimating the tuning parameters of the involved noise attenuation methods. HTHG, in conjunction with MNLM, demonstrated the most superior performance. We subsequently applied the HTHG operator to lunar gravity anomalies from the Aristarchus region. Our results were compared with the outputs of 2D inversion employing a mixed-weighted function, a correlation imaging algorithm, and 3D inversion enhanced by spectral analysis. Our findings indicate that the Aristarchus crater hosts a low-density subsurface mass. The outcomes of this study confirm the robust performance of the HTHG method in addressing edge detection challenges and underscore the necessity of integrating various methods, including edge detection, noise suppression, fast imaging, and inversion, to guarantee the interpretation reliability and advance our understanding about the internal architecture of the Moon.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 8","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025EA004379","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SWOT Reveals Fine-Scale Balanced Motions Driving Near-Surface Currents and Dispersion in the Antarctic Circumpolar Current","authors":"Y.-T. Tranchant,&nbsp;B. Legresy,&nbsp;A. Foppert,&nbsp;B. Pena-Molino,&nbsp;H. Phillips","doi":"10.1029/2025EA004248","DOIUrl":"10.1029/2025EA004248","url":null,"abstract":"<p>The Antarctic Circumpolar Current (ACC) is a hotspot for the generation of small-scale motions that have a key role in cross-frontal exchanges. We present the first analysis of surface currents in the ACC derived from high-resolution sea surface height (SSH) fields provided by the new Surface Water and Ocean Topography (SWOT) satellite. To mitigate the impact of noise and unbalanced SSH, we introduce a two-dimensional fitting kernel method for deriving geostrophic and cyclogeostrophic velocities at different lengthscales. These velocity estimates are evaluated against the low-pass filtered component (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>&gt;</mo>\u0000 </mrow>\u0000 <annotation> ${ &gt;} $</annotation>\u0000 </semantics></math>1 day) of trajectories from 21 surface drifters that passed through the ACC meander. The SSH is found to be balanced and appropriate for inferring surface velocities at scales as small as 10 km, with an 18 km length scale identified as a trade-off between suppressing residual unbalanced waves and preserving finer-scale balanced signals in SWOT denoised SSH. At this scale, the geostrophic approximation becomes inaccurate, and higher-order terms in the momentum balance contribute up to 20% of the observed drifter velocities. Finally, distance-averaged pair statistics calculated from drifter pairs and virtual particles reveal that SWOT accurately captures dispersion properties over the 10–200 km range, providing observational evidence of the dominant role of balanced motions in particle dispersion within this range. By capturing balanced dynamics with unprecedented accuracy, SWOT SSH offers new opportunities to understand the impact of small scales on tracer exchange in the ACC and the Southern Ocean more broadly.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 8","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025EA004248","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144811200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Innovative Tool for Measuring Sunlight Propagation Through Different Snowpacks","authors":"Luca Teruzzi,&nbsp;Andrea Spolaor,&nbsp;David Cappelletti,&nbsp;Claudio Artoni,&nbsp;Marco A. C. Potenza","doi":"10.1029/2025EA004337","DOIUrl":"10.1029/2025EA004337","url":null,"abstract":"<p>Sunlight penetration in the snowpack plays a fundamental role in many environmental processes, ranging from local energy balance to snow microbiology and can potentially contribute to climate change. In addition, many photochemical reactions typically occur in the snowpack driven by solar radiation. Although a few measurements have been attempted in the past decades, light penetration through the snowpack is currently almost only modeled numerically, frequently using severe assumptions. The lack of experimental data and dedicated studies leave a remarkable scientific gap in snow research. In this paper, we propose a novel custom-made sensor to assess sunlight propagation through the snowpack in three different spectral bands with high spatial resolution (3 mm). The probe has been designed to be very compact and lightweight and therefore easily transportable. Measurements were performed across multiple sites with different altitudes and geographic exposure, illumination conditions and snowpack characteristics. We report how the snowpack physical properties have a significant impact on the characteristic sunlight penetration length, ranging from 37.4 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>±</mo>\u0000 </mrow>\u0000 <annotation> $pm $</annotation>\u0000 </semantics></math> 0.1 mm up to 75.2 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>±</mo>\u0000 </mrow>\u0000 <annotation> $pm $</annotation>\u0000 </semantics></math> 0.4 mm in the green spectral range (550 nm central wavelength, 90 nm FWHM) varying with environmental conditions. Data are compared to numerical simulations from the “Snow, Ice and Aerosol Radiative” (SNICAR) code. This approach provides important constraints to model the snowpack characteristics, deriving values for snowpack density and average snow grain size that are very consistent with field observations. In addition, this also allows us to extrapolate the radiative information to the UV range (300 nm). UV fluxes exhibit slopes that are systematically smaller than the green ones by about 25<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>%</mi>\u0000 </mrow>\u0000 <annotation> $%$</annotation>\u0000 </semantics></math>, consistently with the fact that UV radiation penetrates deeper than visible light. Nevertheless, in some cases the comparison between our measurements and model runs suggests complex light penetration dependent on the snowpack peculiar characteristics that SNICAR simulations cannot capture. We believe that our tight experimental approach will strongly contribute to a better understanding of the radiative transfer process inside the snow, as well as to a quantitative description of all those processes that occur in the uppermost layers of the snowpack.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 8","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025EA004337","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144811255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Study on Inferring Daytime Variations of \u0000 \u0000 \u0000 \u0000 XCO\u0000 2\u0000 \u0000 \u0000 ${text{XCO}}_{2}$\u0000 From Current and Future Space-Based Missions","authors":"Calla Marchetti,&nbsp;Jonathan Hobbs,&nbsp;Peter Somkuti,&nbsp;Joshua L. Laughner","doi":"10.1029/2024EA003947","DOIUrl":"10.1029/2024EA003947","url":null,"abstract":"&lt;p&gt;Net ecosystem exchange (NEE) measures the net transfer of carbon between terrestrial ecosystems and the atmosphere, and is an important quantity for understanding land-atmosphere feedbacks and constraining the land carbon sink. Atmospheric inverse models and biophysical models provide regional and global net ecosystem exchange (NEE) estimates, but validation of these models is limited by the sparsity of flux towers. NEE can also be calculated from the change in &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;XCO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{XCO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; over the course of a day. &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;XCO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{XCO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; is observed by the Orbiting Carbon Observatory 2 and 3 (OCO-2 and -3) satellites, which working together have the potential to observe locations between &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;∼&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${sim} $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;52°S and 52°N twice a day but at a sparse temporal frequency. Here, we investigate the possibility of using machine learning (ML) to extrapolate the variation in &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;XCO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{XCO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; over daytime hours, which could be in turn be used to derive NEE. We find that the current temporal sampling from OCO-2 and -3 is not ideal for this purpose, and our ML approach is not able to reliably infer either the daily patterns of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;XCO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{XCO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; or the difference of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;XCO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{XCO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; across solar noon. A thrice-daily observation pattern, such as co","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 8","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003947","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145135323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinematic Representations of Viscoelastic Postseismic Deformation","authors":"John P. Loveless,&nbsp;Brendan J. Meade","doi":"10.1029/2025EA004460","DOIUrl":"10.1029/2025EA004460","url":null,"abstract":"<p>Following large earthquakes, viscoelastic stress relaxation may contribute to postseismic deformation observed at Earth's surface. Mechanical representations of viscoelastic deformation require a constitutive relationship for the lower crust/upper mantle material where stresses are diffused and, for non-linear rheologies, knowledge of absolute stress level. Here, we describe a kinematic approach to representing geodetically observed postseismic motions that does not require an assumed viscoelastic rheology. The core idea is to use observed surface motions to constrain time-dependent displacement boundary conditions applied at the base of the elastic upper crust by viscoelastic motions in the lower crust/upper mantle, approximating these displacements as slip on a set of dislocation elements. Using three-dimensional forward models of viscoelastically modulated postseismic deformation in a thrust fault setting, we show how this approach can accurately represent surface motions and recover predicted displacements at the base of the elastic layer. Applied to the 1999 Chi-Chi (Taiwan) earthquake, this kinematic approach can reproduce geodetically observed displacements and estimates of the partitioning between correlated postseismic deformation mechanisms. Specifically, we simultaneously estimate afterslip on the earthquake source fault that is similar to previous estimates, along with slip on dislocations at the base of the elastic layer that mimic predictions from viscous stress dissipation models in which viscosity is inferred to vary three-dimensionally. A use case for the dislocation approach to modeling viscoelastic deformation is the estimation of spatiotemporally variable fault slip processes, including across sequential interseismic phases of the earthquake cycle, without assuming a lower crust/upper mantle rheology.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 8","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025EA004460","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145135343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Situ Geometric Validation of SWOT Satellite Observations in Bass Strait, Australia","authors":"Andrea Hay,&nbsp;Christopher Watson,&nbsp;Benoît Legresy,&nbsp;Matt King,&nbsp;Boye Zhou,&nbsp;Jack Beardsley,&nbsp;Alejandro Bohé","doi":"10.1029/2025EA004326","DOIUrl":"10.1029/2025EA004326","url":null,"abstract":"<p>Here we validate the Surface Water and Ocean Topography (SWOT) satellite mission sea surface height (SSH) products using an array of nine GNSS buoys at the long-term altimetry validation facility in Bass Strait. As a groundbreaking swath altimetry mission, the opportunities presented by SWOT are vast, but extensive and geographically diverse validation of data is required to ensure these new data are robustly understood and fit for purpose. The Bass Strait site provides a complementary validation target in a coastal shelf sea environment, with heritage back to the launch of TOPEX/Poseidon. We demonstrate the GNSS buoys can provide reliable SSH estimates with a differential-SSH uncertainty of ∼5 mm. Over the shortest separation distances within our array of 10 km, we find an upper bound for the KaRIn SSH noise of 7.0 mm from the standard SWOT product with 2 km pixel size, and an upper bound of 13.0 mm from the unsmoothed product with 250 m pixels. Errors increase with larger separation distances, which we can partially attribute to errors in the present set of product geophysical corrections. The relative magnitude of these errors compared to instrument noise highlights that care must be taken when interpreting SWOT SSH and SSH anomaly fields. Finally, we find an absolute height bias of KaRIn SSH of −10.3 mm (standard deviation of 33 mm) and an RMSE of significant wave heights of 0.22 m, further demonstrating the outstanding performance of the KaRIn instrument over the challenging coastal environment of Bass Strait.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 8","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025EA004326","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145135326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectroscopic Investigation of Synthetic Martian Analog Mineral Mixtures Relevant to Gale and Jezero Craters Exploration","authors":"E. Bruschini,&nbsp;M. Ferrari,&nbsp;A. Pisello,&nbsp;S. De Angelis,&nbsp;J. Brossier,&nbsp;M. C. De Sanctis,&nbsp;F. Altieri","doi":"10.1029/2025EA004386","DOIUrl":"10.1029/2025EA004386","url":null,"abstract":"<p>We produced several mineral mixtures and measured their reflectance in the VNIR range (350–2,500 nm) with the aim of reproducing the spectral features observed by the rovers Perseverance and Curiosity in the Jezero and Gale Crater respectively. We chose two specific case-study spectra of the rovers namely the Bellegarde #5 abrasion patch in Jezero and the Voyageurs target drill in Gale. After selecting a number of mineral components representative of the two sites we first produced several binary (two components) mixtures and measured their reflectance. The binary mixtures are characterized by systematic variations of mineral proportions and were used to assess specific aspects of the relationships between spectral properties and mineralogical composition of mineral mixtures. Based on the results from the binary mixtures we then produced multicomponent (4, 5 or 6 components) mixtures through an iterative approach in which the spectrum of each produced mixture is compared with a target spectrum and its mineralogical composition is adjusted to match the target spectrum as closely as possible. The retrieved mineral composition of the final mixtures was eventually used to infer the conditions of formation of the investigated target emphasizing how the mineralogical composition of a laboratory mixture can give insights into the environmental conditions experienced by the target rock.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 8","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025EA004386","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145135324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applying SOM Cluster Analysis With Iterative Refinement to Infer Lithology Units in Eastern Victoria, Australia","authors":"Limin Xu,&nbsp;Eleanor C. R. Green,&nbsp;Mark A. McLean,&nbsp;Leonardo Feltrin","doi":"10.1029/2024EA003999","DOIUrl":"10.1029/2024EA003999","url":null,"abstract":"<p>This study presents a semi-supervised machine learning method for predicting the occurrence of specific surface lithologies over a 330 km × 115 km area in Victoria, Australia. The study area is a geologically complex region within the Lachlan Fold Belt, characterized by orogenic events and surface lithologies that include deep-marine sedimentary turbidites, granitic intrusions, volcanic formations and metamorphic complexes. The approach used a modified Self-Organizing Map algorithm that was enhanced by an iterative multi-step clustering process that used geophysical surveys (magnetic, radiometric, and gravity) with varying signal enhancements as inputs. The clustering results were refined through validation with a lithological database, allowing the algorithm to associate clusters of characteristics in the geophysical survey data with lithological categories. The lithological database comprised both natural rock samples, and synthetic samples derived from published geological maps in order to compensate for severe spatial heterogeneity in the locations of natural samples. It divided the observed and synthetic samples into 11 manually chosen categories that were expected to show distinctive fingerprints in the geophysical survey data: psammitic sedimentary, pelitic sedimentary, chert (quartz-dominant) sedimentary, felsic intrusive, intermediate/mafic/ultramafic intrusive, felsic volcanic, intermediate/mafic/ultramafic volcanic, and regional metamorphic units. Within this simplified set of lithological categories, the output of the algorithm agreed well with a published geological map. The algorithm's performance demonstrates potential for broader applications to spatial lithological prediction, provided that the target rock types are characterized within existing global databases of rock samples and geophysical observations.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 8","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003999","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145135322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}