Journal of South American Earth Sciences最新文献

{"title":"Mapping discontinuities of Popocatépetl volcano, Mexico, using seismic noise autocorrelations","authors":"Leonarda I. Esquivel-Mendiola ,&nbsp;Arturo Iglesias ,&nbsp;Martin Schimmel","doi":"10.1016/j.jsames.2025.105728","DOIUrl":"10.1016/j.jsames.2025.105728","url":null,"abstract":"<div><div>Popocatépetl is one of the most studied volcanoes in Mexico. Seismic tomography has been a useful tool for obtaining subsurface images and velocity models of the volcano using volcano-tectonic seismicity and ambient noise records. As part of the passive seismic studies, mapping seismic discontinuities is used to complement the seismic tomography studies and detect large impedance variations. In this study, we mapped seismic discontinuities using autocorrelations of seismic ambient noise recorded over 20, 30, and 100 days at 24 broadband seismic stations. The two-way travel times of positive and negative reflections were manually identified using bandpass-filtered strategies. Our observations are compared to a previously reported velocity model and revealed three clusters of reflections categorized by their polarity and depth. The shallow negative polarity cluster is located between 0 and 2 km above sea level (a.s.l.) and correlates with the boundary between older volcanic structures—such as Tlamacas, Ventorrillo, and Nexpayantla—and deeper consolidated materials, including paleo-volcanic flows that follow the regional topographic trend. The positive polarity cluster is located between 0 and 4 km b.s.l. and is associated with a previously mapped low-velocity zone related to limestone and metamorphic basement. The deep negative polarity cluster, situated between 4 and 8 km b.s.l., approximately delimits the upper boundary of a high-velocity zone, indicating a significant velocity increase. We interpreted this as dense magmatic material at depth, potentially with low gas content and confined by lithostatic pressure, which may have favored its accumulation at this depth. Therefore, our observations reinforce the presence of significant seismic anomalies previously reported.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"167 ","pages":"Article 105728"},"PeriodicalIF":1.5,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144926737","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":"Landscapes and landsystems: Rock glaciers in the mountain slope domain of South America","authors":"W. Brian Whalley ,&nbsp;Cedomir Marangunic","doi":"10.1016/j.jsames.2025.105759","DOIUrl":"10.1016/j.jsames.2025.105759","url":null,"abstract":"<div><div>Satellite imagery provides a basis for detailed geomorphological mapping using a landsystem approach for the study of mountain environment landscapes in the Andes. The optical precision now available in repeated Google Earth imagery shows that weathering of rock free-faces supplies debris to glacier systems of various sizes, from snow-patches to cirque and valley glaciers and rock glaciers. The debris supplied to glacier ice bodies gives a variety of landscape features in accord with the relative fluxes of debris and ice. Identification of features and mapping transects provide a means of implementing detailed landsystem analysis in remote mountain areas with field checking in glacigenic systems. Decimal latitude-longitude, [dLL], provides a robust way to identify and record features of interest. In the Andes, no evidence can be found for considering rock glaciers as permafrost-related features, they are best viewed as part of a debris-glacier-debris-covered-glacier to rock glacier continuum. Google Earth images show that the, sometimes complex, nature of rock glacier surfaces can be explained by debris accumulation on active glacier ice systems. Meltwater surface pools, developing over time, have formed in the surfaces of debris-covered glaciers and expose glacier ice cores. This is confirmed by field investigations. Rock glaciers develop in areas outside any high latitude permafrost presence being, clear from rock glacier and moraine systems down valley. The presence of rock glaciers as indicators of mountain permafrost is also falsified by the high geothermal heat flow in many high mountain areas of the Andes. These findings can, with precise geolocation, be brought together in the “Digital Earth” where geo-referenced locations can be viewed in Google Earth as part of information surfaces.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"167 ","pages":"Article 105759"},"PeriodicalIF":1.5,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049965","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":"Fluid substitution and elastic characterization in carbonate rocks of the Barreiras/Pirabas Formation: An integrated approach using XRD and Digital Image Analysis","authors":"Karolina A. Correia ,&nbsp;José J.S. de Figueiredo ,&nbsp;José Frank V. Gonçalvez ,&nbsp;Angela da S. Montalvão ,&nbsp;Cláudio R. dos S. Lucas","doi":"10.1016/j.jsames.2025.105741","DOIUrl":"10.1016/j.jsames.2025.105741","url":null,"abstract":"<div><div>This study investigates fluid substitution in mixed carbonate and siliciclastic rocks, with a focus on the Pirabas/Barreiras Formation in northeastern Pará, located on the Equatorial Margin of Brazil. To evaluate the elastic response of these rocks under fluid saturation, we applied Gassmann and Biot models using an integrated data that includes ultrasonic measurements, X-ray diffraction (XRD), and Digital Image Analysis (DIA). Dry and saturated velocities, porosity, and mineral composition were used as input parameters, and tortuosity derived from image analysis was included in the Biot model. Our results show that the Gassmann and Biot models correlate positively with laboratory measurements, indicating their effectiveness in predicting elastic properties, especially P-wave velocity. Gassmann and Biot models were implemented independently using both empirical parameters and image- and mineralogy-based inputs. The results showed that the integration of XRD and digital image data improved the prediction of bulk modulus and P-wave velocity, reducing the absolute error from 4.47% to 0.32% and from 1.36% to 0.51%, respectively, in the case of the Gassmann model. Despite improvements, S-wave velocity remained more sensitive to pore structure and signal attenuation, which limited its predictive accuracy.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"166 ","pages":"Article 105741"},"PeriodicalIF":1.5,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907007","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":"Exploring best-fit parameters for propagation modeling of shallow landslides, using Flow-R","authors":"Johnnatan Palacio ,&nbsp;Edier Aristizábal ,&nbsp;Martin Mergili ,&nbsp;Oscar Echeverrí","doi":"10.1016/j.jsames.2025.105739","DOIUrl":"10.1016/j.jsames.2025.105739","url":null,"abstract":"<div><div>Approximately one-fifth of the Earth’s surface is exposed to natural hazards – including landslides – yet most studies focus on susceptibility mapping rather than propagation dynamics. Losses from landslides occur predominantly during the post-failure propagation of the failed mass, when runout accelerates, deforms internally, and often evolves into rapid debris flows. This research analyses data from the 31 March 2017 Clustered Shallow Landslide (CSL) event in Mocoa (Colombia) using the empirical Flow-R model. This model combines terrain attributes, flow-direction algorithms, and frictional laws to simulate runout based on travel-distance angle, velocity, and a spreading exponent. Calibration against validation metrics yields optimal parameters: a minimum travel-distance angle of 15°, a maximum velocity of <span><math><mrow><mn>10</mn><mspace></mspace><msup><mrow><mi>ms</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span>, and exponent values <span><math><mrow><mi>x</mi><mo>=</mo><mn>2</mn></mrow></math></span> and 4. We also establish a 25% impact-probability threshold for hazard zoning. These findings advance our understanding of CSL propagation dynamics in steep tropical environments and provide practical parameter guidelines for risk management and land-use planning.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"166 ","pages":"Article 105739"},"PeriodicalIF":1.5,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922027","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":"Corrigendum to ‘Water reservoirs in open coal pits: A useful resource for NE of Mexico?’ [J. S. Am. Earth Sci. 165 (2025) 105731 pages 1–15]","authors":"Ramón Yosvanis Batista Cruz ,&nbsp;Felipe de Jesús López Saucedo ,&nbsp;Frida Mariana Muzquiz Esquivel ,&nbsp;José Alberto Batista Rodríguez ,&nbsp;Yuri Almaguer Carmenates ,&nbsp;Yalina Montecelos Zamora ,&nbsp;Alberto Hernández Rosales ,&nbsp;Luis Eutiquio Canales Gutiérrez","doi":"10.1016/j.jsames.2025.105758","DOIUrl":"10.1016/j.jsames.2025.105758","url":null,"abstract":"","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"166 ","pages":"Article 105758"},"PeriodicalIF":1.5,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049073","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":"Productive and physiological response of Pereskia grandifolia Haw. irrigation deficit with grey and brackish water in the Brazilian Semiarid Region","authors":"Nerissa Carolina Amosse Cumbana ,&nbsp;Genival Barros Junior ,&nbsp;Eduardo Soares de Souza ,&nbsp;Ailton Alves de Carvalho ,&nbsp;José Raliuson Inácio Silva ,&nbsp;Cintya da Silva Fausto ,&nbsp;Emílio Gabriel Freire dos Santos","doi":"10.1016/j.jsames.2025.105738","DOIUrl":"10.1016/j.jsames.2025.105738","url":null,"abstract":"<div><div>Water scarcity in semiarid regions, such as in Brazil, is intensified by irregular rainfall and prolonged droughts, compromising agricultural production. The use of alternative water sources, such as treated greywater and saline water, has emerged as a strategy to reduce pressure on water resources. However, these practices require careful management to avoid adverse effects on the soil. In this context, adapted crops such as Ora-Pro-Nóbis (<em>Pereskia grandifolia</em> Haw.), which is tolerant to poor soils, water deficit, and salinity, represent a sustainable option for the Brazilian Semiarid. Given this scenario, the present study aimed to evaluate the vegetative and physiological responses of Ora-Pro-Nóbis irrigated with deficit irrigation levels using saline water from greywater and well water in the Brazilian Semiarid. The variable assessed included plant growth, stomatal conductance, biomass accumulation and soil salinity. Plants irrigated with filtered greywater produced higher shoot biomass (up to 380 g) compared to saline water (maximum 292 g) and exhibited improved stem diameter and flowering at intermediate soil moisture levels (60 %–80 % of available water). Despite similar salinity levels in both water sources (1.6 dS m⁻¹), irrigation led to significant soil salinization (EC &gt; 5.5 dS m⁻¹), highlighting the need for leaching and appropriate drainage. Ora-Pro-nóbis demonstrated strong tolerance to both water and salt stress, reinforcing its potential for sustainable cultivation in Semiarid environments using alternative water sources. Although the use of wastewater represents a sustainable strategy for agriculture in the Semiarid region, Ora-Pro-Nobis is still considered a restricted-use crop for irrigation with wastewater due to the risk of microbiological contamination of its leaves and flowers. Nonetheless, the promising results with wastewater irrigation indicate its potential for sustainable production systems.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"166 ","pages":"Article 105738"},"PeriodicalIF":1.5,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144917651","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":"Paleomagnetic constraints on the origin of Patagonia","authors":"Augusto Rapalini ,&nbsp;Carmen Martinez Dopico ,&nbsp;Mónica López de Luchi ,&nbsp;Paul Antonio ,&nbsp;Pablo Franceschinis","doi":"10.1016/j.jsames.2025.105757","DOIUrl":"10.1016/j.jsames.2025.105757","url":null,"abstract":"<div><div>After four decades of investigations and disputes, whether Patagonia is an autochthonous or an allochthonous block to Gondwana and if collided against this megacontinent margin at some time during the Paleozoic or Early Mesozoic is still a matter of controversy. Since the early 1990′s paleomagnetic studies have been carried out on Paleozoic rocks exposed mainly in the North Patagonian Massif (NPM) to test these opposite models. However, progress has been slow due to paucity of exposures of suitable rocks. Seven paleomagnetic poles with ages ranging from the Late Ordovician to the Late Permian –Early Triassic have been published. Some of them do not fulfill several of the accepted reliability criteria, while others appear more robust. A comparison of these pole positions with the reference apparent polar wander path for Gondwana in the Paleozoic suggests that the NPM was at paleolatitudes compatible with those corresponding to SW Gondwana since the Late Ordovician. This can be taken as evidence in favor of an autochthonous or para-autochthonous origin of NPM with respect to Gondwana. The latter is however favored due to compelling evidence of a major orogenic event between NPM and Gondwana in Permo-Triassic times that led to the Gondwanides orogen, the development of the huge syn-orogenic Hesperides Basin and a widespread regional remagnetization that affected many geological units in the Rio de la Plata craton. Furthermore, available paleomagnetic poles suggest a rigid-body counter-clockwise rotation of NPM (and the whole of Patagonia?) during final accretion to the SW Gondwana margin. Prior to the Late Ordovician there is no paleomagnetic control on the paleoposition of Patagonia.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"166 ","pages":"Article 105757"},"PeriodicalIF":1.5,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144891909","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":"Neural networks-based ‘first-response’ detection of volcano-tectonic seismic events in poorly monitored active volcanoes: the case of Pico de Orizaba (Citlaltépetl), Mexico","authors":"Ulices Que-Salinas ,&nbsp;Rafael Torres-Orozco ,&nbsp;Katrin Sieron ,&nbsp;Sergio F. Juárez-Cerrillo ,&nbsp;Francisco Córdoba-Montiel","doi":"10.1016/j.jsames.2025.105756","DOIUrl":"10.1016/j.jsames.2025.105756","url":null,"abstract":"<div><div>Volcano-tectonic events (VTs) detection is crucial for real-time volcano monitoring, yet many relatively quiet volcanoes remain poorly instrumented, limiting the detection effectiveness. Pico de Orizaba (Mexico) exemplifies such a challenge, as its sparse seismic network has hindered comprehensive monitoring efforts for three decades. This study applies artificial and convolutional neural networks (ANN and CNN) to improve VTs detection at Pico, demonstrating how ANN/CNN-based tools can compensate for limited instrumental coverage and human resources. Using Pico's six-years (2019–2024) seismic waveforms datasets (raw, 5–15 Hz band-pass filtered, and spectrograms), powered by one-year data (2018) from the neighboring erupting Popocatépetl volcano, we trained and validated the ANN/CNN to classify VTs. The results indicate that both models successfully identified subtle waveform features indicative of VTs. The CNN-based classifiers offered 95–99 % accuracy, 97–100 % recall, and 93–98 % specificity with a F1-score of 0.95–0.99 in a setting where VTs are often obscured by high noise levels and data sparsity. Moreover, our results have proved possible to employ data from an erupting volcano to accurately (92–95 %) identify VTs from a contrastingly quiet volcano. Future efforts will focus on expanding training datasets, and refining model adaptability across different volcanic settings and multiple seismic sources. The deployment of ANN/CNN techniques at Pico represents a significant step toward improving VTs detection in under-monitored volcanic regions, ultimately contributing to more effective hazard assessment strategies.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"166 ","pages":"Article 105756"},"PeriodicalIF":1.5,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144891921","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":"Abelisauroids from equatorial Brazil: New records from the Açu Formation (Cenomanian), Potiguar Basin, Northeast Brazil","authors":"M.P.S. Rocha ,&nbsp;T. Aureliano ,&nbsp;B. Holgado ,&nbsp;C.L.de A. Santos ,&nbsp;A.M. Ghilardi","doi":"10.1016/j.jsames.2025.105755","DOIUrl":"10.1016/j.jsames.2025.105755","url":null,"abstract":"<div><div>Despite the growing number of discoveries in South America, the theropod fossil record from equatorial Gondwana remains fragmentary, limiting our understanding of mid-Cretaceous faunal composition and biogeographic patterns. Here, we report a set of isolated theropod teeth from the Açu Formation (Cenomanian), Potiguar Basin, Northeast Brazil, and analyze them using an integrative framework that combines morphometrics and cladistic analysis. Three well-preserved specimens were taxonomically assigned to Abelisauridae and a likely Noasauridae, with the latter representing the first formal record of this group in the Potiguar Basin. While the phylogenetic analysis placed one tooth within Noasauridae and two within Abelisauridae, the morphometric analysis did not recover the noasaurid specimen within the expected morphospace for this clade, suggesting possible convergent dental morphologies or undersampling bias. We further present a reconstructed trophic web for the Açu Formation paleoecosystem, and compare its theropod assemblage to those of coeval mid-Cretaceous formations in Brazil and North Africa. The results reveal faunal affinities at both regional and intercontinental scales with other Cenomanian deposits, reinforcing the Cenomanian age of the Açu Formation. Furthermore, it underscores the role of this formation as a key area for understanding one of the final episodes of biotic interchange prior to the establishment of the South Atlantic as a biogeographic barrier.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"166 ","pages":"Article 105755"},"PeriodicalIF":1.5,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144878470","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":"Corrigendum to ‘Groundmass glass silica polymorphs distribution associated with the welding rank classification assignment in La Escalera rhyolitic ignimbrite, Michoacán, México’ [J. S. Am. Earth Sci. Volume 153 (2025), 105354]","authors":"Juan Daniel Pérez-Orozco ,&nbsp;Antonio Pola ,&nbsp;Marina Vega González ,&nbsp;Hugo Sereno ,&nbsp;Amador Castro-Colin ,&nbsp;Elizabeth Rivera-Calderón ,&nbsp;Angélica Saraí Campos Granados","doi":"10.1016/j.jsames.2025.105744","DOIUrl":"10.1016/j.jsames.2025.105744","url":null,"abstract":"","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"166 ","pages":"Article 105744"},"PeriodicalIF":1.5,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048997","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}