pure and applied geophysics最新文献

{"title":"PNN Enhanced Seismic Inversion for Porosity Modeling and Delineating the Potential Heterogeneous Gas Sands via Comparative Inversion Analysis in the Lower Indus Basin","authors":"Urooj Shakir,&nbsp;Aamir Ali,&nbsp;Muyyassar Hussain,&nbsp;Ahmed E. Radwan,&nbsp;Ahmed Abd El Aal","doi":"10.1007/s00024-024-03562-5","DOIUrl":"10.1007/s00024-024-03562-5","url":null,"abstract":"<div><p>Seismic inversion has been in use for the last two decades to measure inverted impedances using an integrated data set approach. This research focuses on the application of multi-attribute seismic inversion and the geostatistical <i>probabilistic neural network</i> (PNN) approach for determining rock properties and litho-fluid classification in the Mehar-Mazarani Field of the Lower Indus Basin (<i>LIB</i>), Pakistan. The study compares five different inversion techniques, including <i>model-based inversion</i> (MBI), <i>colored inversion</i> (CI), <i>linear sparse spike inversion</i> (LSSI), <i>band-limited inversion</i> (BLI), and <i>maximum likelihood sparse spike inversion</i> (MLSSI). The inverted outputs, such as acoustic <i>P-impedance</i> (Zp), <i>density</i> (ρ), <i>porosity</i> (φ), and <i>shale volume</i> (Vsh), were analyzed in Paleocene and Cretaceous geological complex reservoirs to identify gas-bearing zones. The results indicated the existence of gas between 1630 and 1700 <i>ms</i> (ms) and corresponding depth ranges from approximately 3200 m up to 4200 m with varying thickness. Amongst the inversion techniques, MBI demonstrated greater accuracy, with inverted density volumes showing a strong correlation coefficient of 0.98 and the lowest <i>root mean square error</i> (RMSE) and relative error of 0.10 m/s * g/cc. A geostatistical PNN approach was employed to estimate variations in Vsh and φ within the sand reservoir. MBI again yielded more reliable results, with a strong correlation between the measured and inverted attributes. High φ and low Vsh were observed in predetermined low-impedance zones. Overall, MBI is proven to be the most accurate and reliable technique, providing clear identification of the gas occurrence. This research highlights the effectiveness of seismic inversion, particularly the application of MBI, in determining rock properties and identifying gas-bearing zones within the Mehar-Mazarani gas field.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 9","pages":"2801 - 2821"},"PeriodicalIF":1.9,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00024-024-03562-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 Multisynchrosqueezing-Based S-Transform for Time-Frequency Analysis of Seismic Data","authors":"Wei Liu, Zhixing Zhai, Zhou Fang","doi":"10.1007/s00024-024-03566-1","DOIUrl":"https://doi.org/10.1007/s00024-024-03566-1","url":null,"abstract":"<p>Time-frequency analysis (TFA) technique has a powerful capacity to characterize non-stationary signals. In this paper, a highly energy concentrated TFA method, called multisynchrosqueezing-based S-transform (MSSBST), is proposed for the analysis of seismic data. Herein, we combine S-transform (ST) and multisynchrosqueezing framework by making full use of an iterative reassignment procedure to concentrate time-frequency energy in a stepwise manner. Furthermore, we derive a series of formulas about MSSBST and its inverse transform, which means that the MSSBST allows for signal reconstruction from its time-frequency representation (TFR). The numerical analysis shows that the proposed method not only can effectively enhance the time-frequency energy concentration but also can offer better performance in characterizing non-stationary signals compared with the short-time Fourier transform (STFT), ST and synchrosqueezing S-transform (SSST). Field examples further demonstrate its potential in depicting spectral anomalies related to hydrocarbon reservoir, thus, facilitating seismic interpretation.</p>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"4 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Continuous Gravity Observations at Campi Flegrei Caldera: An Accurate Assessment of Tidal and Non-Tidal Signals and Implications for Volcano Monitoring","authors":"U. Riccardi, T. Pivetta, A. Fedele, G. Ricciardi, S. Carlino","doi":"10.1007/s00024-024-03555-4","DOIUrl":"https://doi.org/10.1007/s00024-024-03555-4","url":null,"abstract":"<p>We present the results of nearly one year of gravity recording acquired at the active caldera of Campi Flegrei (CFc). CFc is one of the three active volcanoes in the Neapolitan area (southern Italy) and is currently the most active one. In fact, the CFc is undergoing a period of unrest characterised by slow uplift of the ground, a peculiar phenomenon known worldwide as <i>bradyseism</i>, accompanied by seismicity and intense fumarolic emissions. Due to the increased intensity of the volcano dynamics, a permanent gravity station equipped with a gPhoneX spring gravimeter was installed to enhance the geodetic monitoring programmes. The purpose of the continuous recordings is to complement the time-lapse observations carried out periodically on networks of benchmarks, in order to continuously monitor the short-term gravity signals. We report on the various processing steps and analyses performed to obtain reliable parameters of the Earth's tides, non-tidal corrections and gravity residuals. The various methodologies employed to investigate the instrumental drift are also elucidated in depth, because it may masquerade the elusive gravity changes resulting from mass fluctuations within the volcanic and geothermal systems. Residual gravity signals, retrieved from the recordings, after reduction of body and ocean tides, polynomial drift, atmospheric, tilt and change of the Earth Orientation Parameters (EOP) effects, appear to be uncorrelated with hydrology, while they show a clear correlation with the most energetic earthquakes, that strongly characterise the current bradyseismic crisis. The residual gravity signals display peculiar trends characterized by steps or offsets (up to about 600 nm/s²) and transients in coincidence of the most energetic volcano-tectonic events (Magnitude &gt; 2.5) and seismic swarms. The steps in the gravity residuals are likely to be of instrumental origin, while the amplitudes of the observed transients are not consistent with co-seismic or volcanological phenomena, for which there is no evidence from other monitoring techniques. Unfortunately, the lack of repeated absolute gravity measurements severely limits our ability to attribute the observed gravity variations to geological sources. From the analysis of the gravity records, reliable tidal gravity models have been derived, which will improve the accuracy of volcano monitoring by allowing a precise reduction of tidal effects for both relative and absolute gravity measurements taken in these volcanic areas.</p>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"21 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of Annual and Seasonal Surface Air Temperature Simulations in CMIP6 Models over India","authors":"A. Sabarinath,&nbsp;T. Kesavavarthini,&nbsp;Meera M. Nair,&nbsp;A. Naga Rajesh","doi":"10.1007/s00024-024-03564-3","DOIUrl":"10.1007/s00024-024-03564-3","url":null,"abstract":"<div><p>Surface air temperature (SAT) affects both natural systems and human activities, impacting health, agriculture, energy demand, and so on. To investigate and analyze SAT over the region of interest, it is crucial to choose suitable climate models. The study commenced with the evaluation of 42 Coupled Model Intercomparison Project phase 6 (CMIP6) models’ simulations of SAT over India for annual and all four seasons (summer, southwest monsoon, northeast monsoon, and winter) during the historical period 1985 to 2014 with respect to the gridded SAT datasets obtained from the India Meteorological Department (IMD). Multi Model Mean (MMM) of 42 models was included in the evaluation. The evaluation was performed with various statistical metrics such as root mean squared error (RMSE), mean bias error (MBE), correlation coefficient (R), mean squared error (MAE), Taylor skill score (TSS), Brier skill score (BSS), and Interannual variability skill score (IVSS). By the method of estimating Comprehensive Rating Index (CRI), the top-ranking models were identified to be CMCC-CM2-SR5 for the annual and summer season, MIROC6 for the winter season, ACCESS-ESM-1-5 for the southwest monsoon, and NorESM2-LM for northeast monsoon. The novelty of this study lies in the approach of identifying the best ensemble. For each season, statistical metric-wise top-ranked models were picked to develop the best ensemble. Again, the overall ranking of the models along with the best ensemble for each season is determined by estimating CRI. It was observed that for all seasons, the best ensemble falls within the top 3 models’ category. Future projections of SAT under four shared socio-economic pathways (SSP-2.6, 4.5, 7.0, and 8.5) were also analyzed with the best ensemble obtained for each season. The results convey that, the country will witness, especially during the summer season, there will be a 1.160 °C, 1.288 °C and 2.368 °C rise in the mean SAT between historical (1985–2014) and near future (2021–2040), near and mid future (2041–2060), mid and far future (2081–2100) if the pathway, SSP5-8.5 is followed.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 9","pages":"2949 - 2971"},"PeriodicalIF":1.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine Learning Assisted State-of-the-Art-of Petrographic Classification From Geophysical Logs","authors":"Bappa Mukherjee,&nbsp;Sohan Kar,&nbsp;Kalachand Sain","doi":"10.1007/s00024-024-03563-4","DOIUrl":"10.1007/s00024-024-03563-4","url":null,"abstract":"<div><p>In the E&amp;P industry, accurate lithology classification is an essential task for successful exploration and production. Geophysical logs provide high-resolution petrophysical properties, but core logging is expensive and traditional techniques may not accurately classify lithologies. We demonstrated a comparative analysis of six ML algorithms: k-nearest neighbor (kNN), support vector machine (SVM), decision tree (DT), random forest (RF), extreme gradient boosting (XGBoost) and artificial neural network (ANN) for the prediction of lithologies from geophysical logs. Here we analysed the wireline logs of eight wells associated with the petroliferous Lakadong-Therria formation of the Bhogpara oil field of the Assam-Arakan Basin. This formation contains eight typical lithologies, namely clay stone, sand stone, calcareous sandstone, shale, calcareous shale, carbonaceous shale, coal and limestone. Performance of the ML algorithms were evaluated through accuracy, precision, recall, F1-score and receiver operating characteristic (ROC) curve. During the training and test phases, the computed overall accuracy of the predicted ML modes exceeded 82% and 71%, respectively. The model accuracy hierarchy was ANN &gt; XGBoost &gt; RF &gt; SVM &gt; DT &gt; kNN during training, and ANN/XGBoost &gt; kNN &gt; DT/RF &gt; SVM during testing. This approach allows interpreters to select the most accurate ML model based on training phase performance. This study provided a clear insight towards generating a supplement for litholog sequence and improving the accuracy and efficiency of lithology prediction in a geologically complex petroleum reservoir using pre-received core derived litholog information at few wells.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 9","pages":"2839 - 2871"},"PeriodicalIF":1.9,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seawater Intrusion Mapping Using Geophysical Methods, Piezometry, and Hydrochemical Data Analysis: Application in the Coastal Aquifer of Nador Wadi Plain in Tipaza (Algeria)","authors":"Mohamed Amine Bechkit,&nbsp;Abdelmadjid Boufekane,&nbsp;Gianluigi Busico,&nbsp;Giuseppe Francesco Cesare Lama,&nbsp;Fayçal Chafiheddine Mouhoub,&nbsp;Moussa Aichaoui,&nbsp;Khiereddine Arrache,&nbsp;Seid Bourouis","doi":"10.1007/s00024-024-03565-2","DOIUrl":"10.1007/s00024-024-03565-2","url":null,"abstract":"<div><p>Nowadays the salinization of freshwater resources due to seawater intrusion represent a worldwide issue. Accordingly, this study aims to identify and locate the freshwater-saltwater interface in the downstream part of the Nador wadi plain (Algeria), a coastal area characterized by a semi-arid mediterranean climate using a multi-methodologies approach including geophysical methods, hydrostatics approach, hydrochemical method, and piezometry situation. The investigation was carried out by the electrical survey and refraction seismic methods in the period of April-May 2018. Moreover, the hydrochemical and piezometry methods were used to confirm the results of the geophysical technique. The results of the present study case showed that the seawater intrusion interface is located at 420–1380 m from the shoreline. Additionally, the presence of the bedrock bulge (clay formation) at a distance ranging between 550 and 1050 m from the shoreline, plays the role of the natural hydraulic barrier for the seawater advance. The findings indicate that the identified seawater intrusion interface and the natural hydraulic barrier formed by the bedrock bulge are critical for managing groundwater resources in the Nador wadi plain. This methodology can be applied to other coastal plains worldwide to address the challenges of seawater intrusion and groundwater salinization.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 9","pages":"2823 - 2837"},"PeriodicalIF":1.9,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Algorithmic Analysis Towards Time-Domain Extended Source Waveform Inversion","authors":"Pengliang Yang,&nbsp;Wei Zhou","doi":"10.1007/s00024-024-03556-3","DOIUrl":"10.1007/s00024-024-03556-3","url":null,"abstract":"<div><p>Full waveform inversion (FWI) updates the subsurface model from an initial model by comparing observed and synthetic seismograms. Due to high nonlinearity, FWI is easy to be trapped into local minima. Extended domain FWI, including wavefield reconstruction inversion (WRI) and extended source waveform inversion (ESI) are attractive options to mitigate this issue. This paper makes an in-depth analysis for FWI in the extended domain, identifying key challenges and searching for potential remedies towards practical applications. WRI and ESI are formulated within the same mathematical framework using Lagrangian-based adjoint-state method with a special focus on time-domain formulation using extended sources, while putting connections between classical FWI, WRI and ESI: both WRI and ESI can be viewed as weighted versions of classic FWI. Due to symmetric positive definite Hessian, the conjugate gradient is explored to efficiently solve the normal equation in a matrix free manner, while both time and frequency domain wave equation solvers are feasible. This study finds that the most significant challenge comes from the huge storage demand to store time-domain wavefields through iterations. To resolve this challenge, two possible workaround strategies can be considered, i.e., by extracting sparse frequencial wavefields or by considering time-domain data instead of wavefields for reducing such challenge. We suggest that these options should be explored more intensively for tractable workflows.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 9","pages":"2765 - 2785"},"PeriodicalIF":1.9,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crustal Structure and its Control on Gold Mineralization in Wulong Goldfield, Liaodong Peninsula of China: Constraints from Ambient Noise Tomography with a Short-Period Dense Array","authors":"Tingwei Yang,&nbsp;Tao Xu,&nbsp;Yinshuang Ai,&nbsp;Qingdong Zeng,&nbsp;Jinhui Yang,&nbsp;Laicheng Miao,&nbsp;Fan Zheng,&nbsp;Nanqiao Du","doi":"10.1007/s00024-024-03554-5","DOIUrl":"10.1007/s00024-024-03554-5","url":null,"abstract":"<div><p>During the destruction of the North China Craton in the Mesozoic era, a significant gold mineralization event occurred, leading to the formation of the world-renowned Jiaodong Gold Province. The Liaodong and Jiaodong regions have similar tectonic backgrounds and geological evolution histories. However, the confirmed gold resources in the Liaodong region are only one-tenth of those in Jiaodong. To reveal the controlling factors behind the differences in mineralization between these two regions and explore the deep mineralization prospects in the Liaodong region, we conducted a short-period and high-density array (WSP array) in the Wulong Gold Concentrated Area, the largest goldfield in the Liaodong region. Using data recorded by 334 SmartSolo seismometers for one month, we applied ambient noise tomography to obtain the S-wave velocity structure of the crust down to a depth of 3.5 km beneath the Wulong goldfield. The velocity structure revealed the presence of two sets of low-velocity anomalies trending NNE and NW, respectively, in the shallow crust (shallower than 1.5 km) of the Wulong goldfield, while two high-velocity anomalies were identified at deeper depths (1.5–3.5 km). By combining these findings with the geological characteristics of the Wulong goldfield, it was discovered that the high-velocity anomaly (II) corresponds to the Sanguliu granitic body exposed at the surface, while the high-velocity anomaly (I) could be a concealed intrusive body. The shallow low-velocity anomalies are the result of hydrothermal alteration caused by mineralizing fluids along the NNE- and NW-trending faults. The intersection of these two sets of faults, where the low-velocity anomalies exist, represents the center of the hydrothermal activities. Based on these observations, it is proposed that the area between the Sanguliu granitic body and the concealed intrusive body in the northwest has favorable metallogenic conditions. The intersections of the NNE- and NW-trending faults show the high potential for forming large to super-large altered rock-type gold deposits.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 9","pages":"2973 - 2990"},"PeriodicalIF":1.9,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Omori Epoch: On the 100th Anniversary of the Death of a Famous Japanese Seismologist","authors":"Anatol Guglielmi,&nbsp;Alexey Zavyalov,&nbsp;Oleg Zotov,&nbsp;Boris Klain","doi":"10.1007/s00024-024-03560-7","DOIUrl":"10.1007/s00024-024-03560-7","url":null,"abstract":"<div><p>One hundred years ago, Fusakichi Omori died. Our paper is dedicated to his memory. Omori made an outstanding contribution to the physics of earthquakes. In 1894 he formulated the law of aftershock evolution. Omori’s Law states that after the main shock of an earthquake, the frequency of aftershocks decreases hyperbolically with time. In this paper, we briefly describe one of the directions of modern aftershock research. We present Omori’s law in the form of a differential equation describing the evolution of aftershocks. The evolution equation allows us to solve the inverse problem of the earthquake source “cooling down” after the main shock. The solution of the inverse problem allowed us to reveal the existence of the so-called Omori epoch. It is established that at the end of the Omori epoch something similar to a bifurcation of the source state occurs. A logistic equation supposedly describing the bifurcation phenomenon is proposed.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 9","pages":"2741 - 2752"},"PeriodicalIF":1.9,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Artificial Structures on Grain Size and Characteristics of the 2018 Anak Krakatau Tsunami Deposits","authors":"Septriono Hari Nugroho,&nbsp;Purna Sulastya Putra,&nbsp; Amar,&nbsp;Mohammad Heidarzadeh","doi":"10.1007/s00024-024-03558-1","DOIUrl":"10.1007/s00024-024-03558-1","url":null,"abstract":"<div><p>This paper presents the first detailed analysis of grain size parameters and tsunami deposit of the 2018 Anak Krakatau tsunami, considering artificial structures such as buildings and roads. The deposition of tsunamis on land is extremely complex, involving contributions from both the hydrodynamics of tsunami flow propagation and the characteristics of the tsunami, as well as topographical conditions. In both local and detailed contexts, artificial structures can affect the formation of tsunami deposits. In this study, we focused on the effect of artificial structures on the characteristics of the 2018 Anak Krakatau tsunami deposits. Field observations showed that the remains of dikes, houses and asphalt roads significantly influenced the source, thickness, structure of tsunami deposits and grain size parameters. Tsunami deposits consisting of fine-grained material originated from the sediment on the seafloor. Tsunami deposits were thicker in areas closer to the part of the sea unaffected by artificial structures and exhibited a thinning trend inland. In general, the grain size of tsunami deposits is coarser than that of pre-tsunami deposits. Tsunami deposits predominantly exhibit an upward fining trend. Our study explains the key role of artificial structures in the formation of tsunami deposits and the sediment structure produced in coastal areas. A drastic change in the characteristics of the grain size parameters results from the presence of artificial structures. Overall, the tsunami deposit layers could have been better sorted. Significantly different sortation values were observed at sites located above the asphalt road. Similarly, kurtosis values showed an anomaly. The skewness value was inversely proportional to the average grain size in areas affected by artificial structures.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 10","pages":"2991 - 3003"},"PeriodicalIF":1.9,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}