Pub Date : 2025-04-14DOI: 10.1016/j.qsa.2025.100281
Somasundharam Magalingam , Selvakumar Radhakrishnan , Shankar Karuppannan , Edris Alam , Md Kamrul Islam
A reconstruction of paleoflood stages reflects the magnitude and frequency of historic floods. Sediment-filled landforms store centuries-old paleoflood data, allowing examination of past events, though river changes and human activities can obscure these valuable records. Hence, identifying the plausible locale for collecting the sediment core is cumbersome. The present research proposes a methodological approach for precisely identifying the repositories. The Cauvery Delta, the largest sediment deposit on Tamil Nadu's eastern coast, is chosen for the study. The study's methodology is structured into: (1) reconstructing a catalogue of significant flood events using documentary records; (2) mapping fluvial geomorphic landforms using satellite images; (3) spatially correlating the records obtained from documentary sources with landforms, and (4) identifying flood geomorphic landforms (FGL) and demarcating promising prospective locales for future chronological studies. It has been observed that the Cauvery River has experienced recurrent instances of flooding throughout the past 8000 years. The FGL mapped using digitally processed satellite images displayed 17 types of landforms. Subsequently, the FGL are precisely identified by spatially integrating documentary data with landforms. Braided bar, channel bar, lateral bar, channel islands, natural levees, paleochannels, older flood plains, point bars, oxbow lakes, and water bodies are the most promising FGL for paleoflood research.
{"title":"Demarcating paleoflood repositories using documentary evidence and flood geomorphic landforms","authors":"Somasundharam Magalingam , Selvakumar Radhakrishnan , Shankar Karuppannan , Edris Alam , Md Kamrul Islam","doi":"10.1016/j.qsa.2025.100281","DOIUrl":"10.1016/j.qsa.2025.100281","url":null,"abstract":"<div><div>A reconstruction of paleoflood stages reflects the magnitude and frequency of historic floods. Sediment-filled landforms store centuries-old paleoflood data, allowing examination of past events, though river changes and human activities can obscure these valuable records. Hence, identifying the plausible locale for collecting the sediment core is cumbersome. The present research proposes a methodological approach for precisely identifying the repositories. The Cauvery Delta, the largest sediment deposit on Tamil Nadu's eastern coast, is chosen for the study. The study's methodology is structured into: (1) reconstructing a catalogue of significant flood events using documentary records; (2) mapping fluvial geomorphic landforms using satellite images; (3) spatially correlating the records obtained from documentary sources with landforms, and (4) identifying flood geomorphic landforms (FGL) and demarcating promising prospective locales for future chronological studies. It has been observed that the Cauvery River has experienced recurrent instances of flooding throughout the past 8000 years. The FGL mapped using digitally processed satellite images displayed 17 types of landforms. Subsequently, the FGL are precisely identified by spatially integrating documentary data with landforms. Braided bar, channel bar, lateral bar, channel islands, natural levees, paleochannels, older flood plains, point bars, oxbow lakes, and water bodies are the most promising FGL for paleoflood research.</div></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"18 ","pages":"Article 100281"},"PeriodicalIF":2.9,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143825530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-28DOI: 10.1016/j.qsa.2025.100270
Shengxue Lei , Richard Walker , Yanbao Li , Ji Ma , Ben Johnson , Qi Ou , Chia-Hsin Tsai , Changyun Chen , Xijie Feng , Liangxin Xu
On January 23, 1556, a large normal-faulting earthquake struck Huaxian county, in the eastern part of the Weihe Graben, North China. The direct effects of the great shock and the following famine, exposure to coldness, and disease together killed more than 830,000 people, making the Huaxian earthquake the deadliest in history. Estimates of its magnitude vary widely, with intensity data leading to estimates of 8¼ to 8½, whereas geological estimates of slip and fault length suggest a range of 7.5–8.0, but with remaining uncertainty due to the lack of detailed measurements along the entire rupture zone. In this study, we use high-resolution digital elevation models (DEMs) derived from Pléiades stereo satellite imagery to map the surface ruptures and measure the fault scarps associated with the 1556 earthquake. We use the vertical offset measurements and the cumulative offset probability density (COPD) method to constrain the surface slip distribution of the 1556 event and to examine evidence for prior rupture. We find an average vertical displacement of 6.3 ± 0.7 m, consistent with a moment-magnitude (Mw) of 7.3–7.9 that, although large, is much smaller than earlier estimates derived from seismic intensity data. Although the Huaxian earthquake is likely the largest known well-defined normal-faulting event in history, it aligns with the global pattern that normal-faulting earthquakes in continental interiors rarely exceed Mw 8. We suggest that the magnitudes of other large historical earthquakes in North China need to be reexamined by direct fault parameters, rather than by shaking intensity and death toll.
{"title":"Surface ruptures from the 1556 Huaxian earthquake, North China, measured using high-resolution topography: Implications for large magnitude normal-faulting earthquakes in continental interiors","authors":"Shengxue Lei , Richard Walker , Yanbao Li , Ji Ma , Ben Johnson , Qi Ou , Chia-Hsin Tsai , Changyun Chen , Xijie Feng , Liangxin Xu","doi":"10.1016/j.qsa.2025.100270","DOIUrl":"10.1016/j.qsa.2025.100270","url":null,"abstract":"<div><div>On January 23, 1556, a large normal-faulting earthquake struck Huaxian county, in the eastern part of the Weihe Graben, North China. The direct effects of the great shock and the following famine, exposure to coldness, and disease together killed more than 830,000 people, making the Huaxian earthquake the deadliest in history. Estimates of its magnitude vary widely, with intensity data leading to estimates of 8¼ to 8½, whereas geological estimates of slip and fault length suggest a range of 7.5–8.0, but with remaining uncertainty due to the lack of detailed measurements along the entire rupture zone. In this study, we use high-resolution digital elevation models (DEMs) derived from Pléiades stereo satellite imagery to map the surface ruptures and measure the fault scarps associated with the 1556 earthquake. We use the vertical offset measurements and the cumulative offset probability density (COPD) method to constrain the surface slip distribution of the 1556 event and to examine evidence for prior rupture. We find an average vertical displacement of 6.3 ± 0.7 m, consistent with a moment-magnitude (<em>M</em><sub><em>w</em></sub><em>)</em> of 7.3–7.9 that, although large, is much smaller than earlier estimates derived from seismic intensity data. Although the Huaxian earthquake is likely the largest known well-defined normal-faulting event in history, it aligns with the global pattern that normal-faulting earthquakes in continental interiors rarely exceed <em>M</em><sub><em>w</em></sub> 8. We suggest that the magnitudes of other large historical earthquakes in North China need to be reexamined by direct fault parameters, rather than by shaking intensity and death toll.</div></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"18 ","pages":"Article 100270"},"PeriodicalIF":2.9,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-10DOI: 10.1016/j.qsa.2025.100278
Manuel Chevalier , William D. Gosling , Henry Hooghiemstra , Olivier Cartapanis , Brian M. Chase , Stefanie Kaboth-Bahr
This study presents a detailed pollen-based climate reconstruction from Lake Fúquene, Colombia, spanning the past 284,000 years and revealing significant changes in temperature and hydroclimate modes of variability, particularly between glacial periods. Our findings highlight the central role of eccentricity in modulating the influence of high-latitude glacial climate variability on the northern Andes. During periods of high eccentricity (∼70–260 ka), we conclude that the region was shielded from northern high-latitude glacial ice-sheet dynamics by an intensified Walker circulation. After ∼70 ka, a weakening of this zonal circulation allowed high-latitude, millennial-scale glacial climate variability to penetrate deeper into the tropics, influencing the position of the ITCZ and the rainbelt. This shift in climate dynamics led to increased regional millennial-scale climate variability. A detrended correspondence analysis (DCA) on fossil pollen data highlights a contemporaneous compositional shift previously masked by glacial-interglacial vegetation changes. The observed ecological shift coincides temporally with predictions of elevated speciation rates in mechanistic simulations. Combined, these results suggest a long-lasting environmental impact from glacial millennial-scale climate dynamics, supporting the hypothesis that increased environmental dynamism during glacial periods may trigger the speciation pump in the Northern Andes more than glacial inceptions or terminations. These findings underscore the evolving nature of regional climate drivers and their complex interplay with ecology, offering new insights into the role of climate variability in shaping biodiversity in this hotspot.
{"title":"Eccentricity-driven glacial climate variability and its influence on speciation in the tropical Andes","authors":"Manuel Chevalier , William D. Gosling , Henry Hooghiemstra , Olivier Cartapanis , Brian M. Chase , Stefanie Kaboth-Bahr","doi":"10.1016/j.qsa.2025.100278","DOIUrl":"10.1016/j.qsa.2025.100278","url":null,"abstract":"<div><div>This study presents a detailed pollen-based climate reconstruction from Lake Fúquene, Colombia, spanning the past 284,000 years and revealing significant changes in temperature and hydroclimate modes of variability, particularly between glacial periods. Our findings highlight the central role of eccentricity in modulating the influence of high-latitude glacial climate variability on the northern Andes. During periods of high eccentricity (∼70–260 ka), we conclude that the region was shielded from northern high-latitude glacial ice-sheet dynamics by an intensified Walker circulation. After ∼70 ka, a weakening of this zonal circulation allowed high-latitude, millennial-scale glacial climate variability to penetrate deeper into the tropics, influencing the position of the ITCZ and the rainbelt. This shift in climate dynamics led to increased regional millennial-scale climate variability. A detrended correspondence analysis (DCA) on fossil pollen data highlights a contemporaneous compositional shift previously masked by glacial-interglacial vegetation changes. The observed ecological shift coincides temporally with predictions of elevated speciation rates in mechanistic simulations. Combined, these results suggest a long-lasting environmental impact from glacial millennial-scale climate dynamics, supporting the hypothesis that increased environmental dynamism during glacial periods may trigger the speciation pump in the Northern Andes more than glacial inceptions or terminations. These findings underscore the evolving nature of regional climate drivers and their complex interplay with ecology, offering new insights into the role of climate variability in shaping biodiversity in this hotspot.</div></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"18 ","pages":"Article 100278"},"PeriodicalIF":2.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quaternary pollen-geochemical based-studies in Sonoran Desert are poorly documented. Two sedimentary profiles were studied at Félix Gómez, Sonora in the Plains of Sonoran Desert: Paleosols “La Cárcava” (335 cm depth) and “La Morita” (220 cm depth) covers the latest Pleistocene and all Holocene. The results of paleoenvironmental proxy analysis (fossil pollen, geochemical data, and radiocarbon ages), show a variation in Late Pleistocene conditions with high precipitations and low temperatures leading to an open forest vegetation (Pinus sp., Quercus sp. and Poaceae) in the actual desert. From Late Pleistocene to Early Holocene increasing temperature and higher evaporation rates were constated with the establishment of tropical-desert vegetation. Recovering to wetter al cooler conditions appear in early Holocene with a woodland vegetation type-Chaparral (Pinus, Quercus and Pteridophytes). In the middle-late Holocene the hottest conditions were recorded, with mostly herbaceous plants (Asteraceae and Chenopodiaceae). Finally, in the Latest Holocene (last 2500 years) similar conditions to present days were documented (Chenopodiaceae, Asteraceae, Cactaceae and Fabaceae).
{"title":"Late Pleistocene and Holocene paleoenvironments at Plains of Sonoran Desert, based on fossil pollen content and geochemical analysis","authors":"B.A. Valle-Caro , C.I. Ortega-Rosas , T. Gámez , J.R. Vidal-Solano , D.M. Meza-Figueroa","doi":"10.1016/j.qsa.2025.100276","DOIUrl":"10.1016/j.qsa.2025.100276","url":null,"abstract":"<div><div>Quaternary pollen-geochemical based-studies in Sonoran Desert are poorly documented. Two sedimentary profiles were studied at Félix Gómez, Sonora in the Plains of Sonoran Desert: Paleosols “La Cárcava” (335 cm depth) and “La Morita” (220 cm depth) covers the latest Pleistocene and all Holocene. The results of paleoenvironmental proxy analysis (fossil pollen, geochemical data, and radiocarbon ages), show a variation in Late Pleistocene conditions with high precipitations and low temperatures leading to an open forest vegetation (<em>Pinus</em> sp., <em>Quercus</em> sp. and Poaceae) in the actual desert. From Late Pleistocene to Early Holocene increasing temperature and higher evaporation rates were constated with the establishment of tropical-desert vegetation. Recovering to wetter al cooler conditions appear in early Holocene with a woodland vegetation type-Chaparral (<em>Pinus</em>, <em>Quercus</em> and Pteridophytes). In the middle-late Holocene the hottest conditions were recorded, with mostly herbaceous plants (Asteraceae and Chenopodiaceae). Finally, in the Latest Holocene (last 2500 years) similar conditions to present days were documented (Chenopodiaceae, Asteraceae, Cactaceae and Fabaceae).</div></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"18 ","pages":"Article 100276"},"PeriodicalIF":2.9,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ethiopian groundwater assessments are often conducted using field surveys as a basis. Although conventional groundwater exploration methods yield results of varying scale and improved quality, they are typically costly and time-consuming tasks. Utilizing remotely sensed data and geographic information systems (GIS), data may now be efficiently collected, analyzed, and managed across extensive spatial and temporal scales. This study will use timely, affordable remote sensing (RS) data and GIS approaches to map the groundwater potential in the Dabus Sub-Basin in Western Ethiopia. This study examines various geographic parameters, including lithology, slope, rainfall, drainage density, lineament density, soil texture, land use/cover (LULC), and geomorphology. Weight overlay analysis and Multi-Criteria Decision Analysis (MCDA), particularly the analytical hierarchy process (AHP) method, were employed to delineate the groundwater potential zone (GWPZs). Then, using Saatty's (AHP) scale, the weights for each element were allocated based on their relative relevance. The results of the primary components show that lithology has the lowest weight and rainfall, and geomorphology has the highest weights when calculating the prospective groundwater potential zone in the research region. The findings showed that approximately 310.2 km2 (1.5%) had very high groundwater potential, 16216 km2 (77.1%) had high groundwater potential, 4476 km2 (21.3%) had moderate groundwater potential, and 27.77 km2 (0.13%) had low groundwater potential. After employing borehole points and the Receiver Operating Characteristic (ROC) curve method to assess the created groundwater potential zone map, a good correlation of 73.8% was found. Thus, this study demonstrates a reliable way to utilize GIS and remote sensing tools to map and define GWPZs. To make prompt judgments about groundwater management, planners and decision-makers rely heavily on the GWPZ that is produced.
{"title":"Geospatial mapping of groundwater potential zones using multi-criteria decision analysis and GIS fuzzy logic in Dabus Sub-Basin, western Ethiopia","authors":"Dawit Girma Burayu , Shankar Karuppannan , Gemechu Shuniye","doi":"10.1016/j.qsa.2025.100275","DOIUrl":"10.1016/j.qsa.2025.100275","url":null,"abstract":"<div><div>Ethiopian groundwater assessments are often conducted using field surveys as a basis. Although conventional groundwater exploration methods yield results of varying scale and improved quality, they are typically costly and time-consuming tasks. Utilizing remotely sensed data and geographic information systems (GIS), data may now be efficiently collected, analyzed, and managed across extensive spatial and temporal scales. This study will use timely, affordable remote sensing (RS) data and GIS approaches to map the groundwater potential in the Dabus Sub-Basin in Western Ethiopia. This study examines various geographic parameters, including lithology, slope, rainfall, drainage density, lineament density, soil texture, land use/cover (LULC), and geomorphology. Weight overlay analysis and Multi-Criteria Decision Analysis (MCDA), particularly the analytical hierarchy process (AHP) method, were employed to delineate the groundwater potential zone (GWPZs). Then, using Saatty's (AHP) scale, the weights for each element were allocated based on their relative relevance. The results of the primary components show that lithology has the lowest weight and rainfall, and geomorphology has the highest weights when calculating the prospective groundwater potential zone in the research region. The findings showed that approximately 310.2 km<sup>2</sup> (1.5%) had very high groundwater potential, 16216 km<sup>2</sup> (77.1%) had high groundwater potential, 4476 km<sup>2</sup> (21.3%) had moderate groundwater potential, and 27.77 km<sup>2</sup> (0.13%) had low groundwater potential. After employing borehole points and the Receiver Operating Characteristic (ROC) curve method to assess the created groundwater potential zone map, a good correlation of 73.8% was found. Thus, this study demonstrates a reliable way to utilize GIS and remote sensing tools to map and define GWPZs. To make prompt judgments about groundwater management, planners and decision-makers rely heavily on the GWPZ that is produced.</div></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"18 ","pages":"Article 100275"},"PeriodicalIF":2.9,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.qsa.2025.100266
Stefanie Kaboth-Bahr , André Bahr , Patrick Blaser , Antje H.L. Voelker , Jörg Lippold , Marcus Gutjahr , David A. Hodell , James E.T. Channell , Anne de Vernal , Claude Hillaire-Marcel
We present a comprehensive multi-proxy analysis spanning 550,000 years from the outer Labrador Sea region at the Integrated Ocean Drilling Program (IODP) Sites U1302/1303. We combine new benthic foraminiferal stable oxygen (δ18O) and carbon (δ13C) isotope records, with sediment elemental composition and authigenic neodymium isotope measurements, to provide insights into deep-water mass sourcing and changes of the Deep Western Boundary Current (DWBC), which exports North Atlantic Deep Water (NADW) into the wider North Atlantic as part of the lower limb of the Atlantic Meridional Overturning Circulation.
We find that a prominent DWBC likely remained a persistent feature within the Labrador Sea region throughout the past 550 kyr. However, glacial peaks of marine isotope stage (MIS) 14 to MIS 2 were consistently characterized by a weaker or shallower DWBC, while all interglacial periods of MIS 13a to MIS 1, with the exception of MIS 7e, were marked by enhanced DWBC. Additionally, the dominant deep-water masses feeding into the DWBC during these glacial-interglacial periods varied from regional (K-rich sediment, unradiogenic εNd) to more distal sources from the Nordic Seas (Ti-rich sediment, radiogenic εNd). Yet, these changes in deep-water provenance did not consistently correlate with DWBC strength, suggesting that additional factors may have played a significant role in shaping the DWBC strength or core depth throughout the geological past.
{"title":"Reconstruction of deep-water undercurrent variability from the outer Labrador Sea during the past 550,000 years","authors":"Stefanie Kaboth-Bahr , André Bahr , Patrick Blaser , Antje H.L. Voelker , Jörg Lippold , Marcus Gutjahr , David A. Hodell , James E.T. Channell , Anne de Vernal , Claude Hillaire-Marcel","doi":"10.1016/j.qsa.2025.100266","DOIUrl":"10.1016/j.qsa.2025.100266","url":null,"abstract":"<div><div>We present a comprehensive multi-proxy analysis spanning 550,000 years from the outer Labrador Sea region at the Integrated Ocean Drilling Program (IODP) Sites U1302/1303. We combine new benthic foraminiferal stable oxygen (δ<sup>18</sup>O) and carbon (δ<sup>13</sup>C) isotope records, with sediment elemental composition and authigenic neodymium isotope measurements, to provide insights into deep-water mass sourcing and changes of the Deep Western Boundary Current (DWBC), which exports North Atlantic Deep Water (NADW) into the wider North Atlantic as part of the lower limb of the Atlantic Meridional Overturning Circulation.</div><div>We find that a prominent DWBC likely remained a persistent feature within the Labrador Sea region throughout the past 550 kyr. However, glacial peaks of marine isotope stage (MIS) 14 to MIS 2 were consistently characterized by a weaker or shallower DWBC, while all interglacial periods of MIS 13a to MIS 1, with the exception of MIS 7e, were marked by enhanced DWBC. Additionally, the dominant deep-water masses feeding into the DWBC during these glacial-interglacial periods varied from regional (K-rich sediment, unradiogenic εNd) to more distal sources from the Nordic Seas (Ti-rich sediment, radiogenic εNd). Yet, these changes in deep-water provenance did not consistently correlate with DWBC strength, suggesting that additional factors may have played a significant role in shaping the DWBC strength or core depth throughout the geological past.</div></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"17 ","pages":"Article 100266"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.qsa.2025.100271
Dagnachew Daniel Molla , Fitsum Aschnaki Haile , Tarun Kumar Lohani
The 40-spring discharge system (40SDS) in Arba Minch, Ethiopia, is significantly influenced by the complex geomorphology and tectonic activities of the Ethiopian Rift Valley. These springs are the major source of water supply for drinking, domestic use, and tourism, with historical discharge rates between 130 and 250 L per second (l/s). The study aimed to characterize the 40SDS through an integrated approach using litho-structural, hydro-geochemical, and numerical modeling techniques to understand the dynamics and continuing decline rate. The results showed that faults channelize groundwater from the western plateau through the escarpment to the rift floor, discharging into Lakes Abaya and Chamo. Hydro-geochemical analysis identified magnesium (Mg2⁺), calcium (Ca2⁺), and bicarbonate as dominant ions, reflecting interactions with silicate minerals, with concentrations increasing downstream due to water-rock contact. Numerical modeling indicated that the aquifer is highly sensitive to hydraulic conductivity, with 99.8% of groundwater outflow occurring through constant head boundaries. Recharge estimates from WetSpass ranged from 0 to 331.8 mm/year, with an average of 64.7 mm/year. A lag in rainfall-discharge correlation was noted, with a 1-month lag during wet seasons and a 2-month lag during dry seasons, linking recharge to western highland precipitation. Long-term data (1981–2015) indicates a continuous decline in mean annual flow due to reduced recharge and anthropogenic pressures. The springs exhibit a Ca-Na-HCO₃ water type, contrasting with nearby Mg-Na-HCO₃-Cl surface and groundwater. This decline threatens Arba Minch's socioeconomic stability, as these springs are the primary source of water for the community. Effective management strategies are crucial for the sustainable use of this essential resource.
{"title":"Integrated litho-structural, hydro-geochemical, and numerical modeling analysis to characterize the 40 springs discharge system, Arba Minch, Ethiopia","authors":"Dagnachew Daniel Molla , Fitsum Aschnaki Haile , Tarun Kumar Lohani","doi":"10.1016/j.qsa.2025.100271","DOIUrl":"10.1016/j.qsa.2025.100271","url":null,"abstract":"<div><div>The 40-spring discharge system (40SDS) in Arba Minch, Ethiopia, is significantly influenced by the complex geomorphology and tectonic activities of the Ethiopian Rift Valley. These springs are the major source of water supply for drinking, domestic use, and tourism, with historical discharge rates between 130 and 250 L per second (l/s). The study aimed to characterize the 40SDS through an integrated approach using litho-structural, hydro-geochemical, and numerical modeling techniques to understand the dynamics and continuing decline rate. The results showed that faults channelize groundwater from the western plateau through the escarpment to the rift floor, discharging into Lakes Abaya and Chamo. Hydro-geochemical analysis identified magnesium (Mg<sup>2</sup>⁺), calcium (Ca<sup>2</sup>⁺), and bicarbonate as dominant ions, reflecting interactions with silicate minerals, with concentrations increasing downstream due to water-rock contact. Numerical modeling indicated that the aquifer is highly sensitive to hydraulic conductivity, with 99.8% of groundwater outflow occurring through constant head boundaries. Recharge estimates from WetSpass ranged from 0 to 331.8 mm/year, with an average of 64.7 mm/year. A lag in rainfall-discharge correlation was noted, with a 1-month lag during wet seasons and a 2-month lag during dry seasons, linking recharge to western highland precipitation. Long-term data (1981–2015) indicates a continuous decline in mean annual flow due to reduced recharge and anthropogenic pressures. The springs exhibit a Ca-Na-HCO₃ water type, contrasting with nearby Mg-Na-HCO₃-Cl surface and groundwater. This decline threatens Arba Minch's socioeconomic stability, as these springs are the primary source of water for the community. Effective management strategies are crucial for the sustainable use of this essential resource.</div></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"17 ","pages":"Article 100271"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.qsa.2024.100261
Yan Hu , Peng Cheng , Jibao Dong , Haiyan Zhao , Mengyu Zang , Minwen Lan , Xuefeng Lu , Weijian Zhou
Terrestrial mollusks serve as potential radiocarbon materials for dating loess deposits in the late Quaternary. However, the reliability of gastropod shell 14C ages is complicated by two issues: open-system behavior and the limestone problem. Due to lack of assessment on the preservation status of shell fossils and factors affecting old carbon, correction for age anomalies remains an unresolved question. This study investigated two gastropod shells, Cathaicarossimontana and Succinea sp., discovered from a loess section rich in charcoal in the North Kunlun Mountains of Central Asia. By analyzing local climate condition, leaching degree, and mineral composition, we revealed that the open systems have a negligible influence on shell fossils. The values of age anomalies of Cathaicarossimontana and Succinea sp. are respectively 1788 ± 240 years and 492 ± 100 years. Furthermore, we obtained the temporal variation patterns of different carbon sources in shell fossils through a mass balance model analysis. The results indicate that the proportion of carbonate sources ranges from 17.5% to 26.8% in Cathaicarossimontana, while it ranges from 6.0% to 7.8% in Succinea sp., which may result from their size and calcium demand. Succinea sp. is recommended for stratigraphic dating for its minor age anomalies. Our study further demonstrates that snails of the same species absorb a highly consistent proportion of limestone under stable environment. This provides a theoretical basis for correcting age anomalies in fossil shells. The corrected ages of Cathaicarossimontana, based on living specimens, are consistent with reliable charcoal ages. Our findings offer a potential approach to correct the old carbon in snail fossils and facilitate the reliable dating for loess deposits in Central Asia.
{"title":"Radiocarbon age anomalies, potential carbon sources analysis and correction of terrestrial gastropods in a loess sequence from Kunlun Mountains since 3.6 ka","authors":"Yan Hu , Peng Cheng , Jibao Dong , Haiyan Zhao , Mengyu Zang , Minwen Lan , Xuefeng Lu , Weijian Zhou","doi":"10.1016/j.qsa.2024.100261","DOIUrl":"10.1016/j.qsa.2024.100261","url":null,"abstract":"<div><div>Terrestrial mollusks serve as potential radiocarbon materials for dating loess deposits in the late Quaternary. However, the reliability of gastropod shell <sup>14</sup>C ages is complicated by two issues: open-system behavior and the limestone problem. Due to lack of assessment on the preservation status of shell fossils and factors affecting old carbon, correction for age anomalies remains an unresolved question. This study investigated two gastropod shells, <em>Cathaica</em> <em>rossimontana</em> and <em>Succinea</em> sp., discovered from a loess section rich in charcoal in the North Kunlun Mountains of Central Asia. By analyzing local climate condition, leaching degree, and mineral composition, we revealed that the open systems have a negligible influence on shell fossils. The values of age anomalies of <em>Cathaica</em> <em>rossimontana</em> and <em>Succinea</em> sp. are respectively 1788 ± 240 years and 492 ± 100 years. Furthermore, we obtained the temporal variation patterns of different carbon sources in shell fossils through a mass balance model analysis. The results indicate that the proportion of carbonate sources ranges from 17.5% to 26.8% in <em>Cathaica</em> <em>rossimontana</em>, while it ranges from 6.0% to 7.8% in <em>Succinea</em> sp., which may result from their size and calcium demand. <em>Succinea</em> sp. is recommended for stratigraphic dating for its minor age anomalies. Our study further demonstrates that snails of the same species absorb a highly consistent proportion of limestone under stable environment. This provides a theoretical basis for correcting age anomalies in fossil shells. The corrected ages of <em>Cathaica</em> <em>rossimontana</em>, based on living specimens, are consistent with reliable charcoal ages. Our findings offer a potential approach to correct the old carbon in snail fossils and facilitate the reliable dating for loess deposits in Central Asia.</div></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"17 ","pages":"Article 100261"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.qsa.2024.100259
Alexandra L. Norwood , John Rowan , J. Tyler Faith
Across southern Africa, the Pleistocene-Holocene transition was associated with changes in community composition of large mammalian herbivores, which included the extinction and extirpation of numerous grazers. Past research has often linked these changes to the contraction and disappearance of grasslands; however, the relationship between faunal and pollen records spanning this transition has not been systematically analyzed. Here, we investigate changes in fossil ungulate community composition and grass pollen abundance from late Quaternary sites across southern Africa to evaluate the extent to which these communities track paleovegetation change across this interval. Our dataset draws from faunal and pollen records across southern Africa. Results from the comparison of compositional changes in both records suggest a sub-continental-scale decoupling of grass cover and ungulate community composition during the Pleistocene-Holocene transition. Although there is strong evidence for a regional-scale decline in grazers from the Last Glacial-Interglacial Transition to the early Holocene, there is no evidence for regional-scale declines in grassy vegetation. Several potential mechanisms may account for this decoupling of grazers and grass abundance. The possible strengthening of winter rainfall systems during glacial Pleistocene may have played a role by enhancing year-round availability of grasses in the interior and by elevating moisture availability and productivity in the Cape Floristic Region. Alternatively, current paleoecological data allow for the possibility that Pleistocene ‘grazers’ consumed more dicots, such that their decline at the onset of the Holocene reflects dietary niche contraction rather than vegetation change. These findings contribute to a growing body of evidence challenging the link between grass abundance and grazer diversity and complicate our understanding of the drivers of late Quaternary extinctions in southern Africa.
{"title":"Reconciling the environmental implications of late Quaternary faunal and pollen records in southern Africa","authors":"Alexandra L. Norwood , John Rowan , J. Tyler Faith","doi":"10.1016/j.qsa.2024.100259","DOIUrl":"10.1016/j.qsa.2024.100259","url":null,"abstract":"<div><div>Across southern Africa, the Pleistocene-Holocene transition was associated with changes in community composition of large mammalian herbivores, which included the extinction and extirpation of numerous grazers. Past research has often linked these changes to the contraction and disappearance of grasslands; however, the relationship between faunal and pollen records spanning this transition has not been systematically analyzed. Here, we investigate changes in fossil ungulate community composition and grass pollen abundance from late Quaternary sites across southern Africa to evaluate the extent to which these communities track paleovegetation change across this interval. Our dataset draws from faunal and pollen records across southern Africa. Results from the comparison of compositional changes in both records suggest a sub-continental-scale decoupling of grass cover and ungulate community composition during the Pleistocene-Holocene transition. Although there is strong evidence for a regional-scale decline in grazers from the Last Glacial-Interglacial Transition to the early Holocene, there is no evidence for regional-scale declines in grassy vegetation. Several potential mechanisms may account for this decoupling of grazers and grass abundance. The possible strengthening of winter rainfall systems during glacial Pleistocene may have played a role by enhancing year-round availability of grasses in the interior and by elevating moisture availability and productivity in the Cape Floristic Region. Alternatively, current paleoecological data allow for the possibility that Pleistocene ‘grazers’ consumed more dicots, such that their decline at the onset of the Holocene reflects dietary niche contraction rather than vegetation change. These findings contribute to a growing body of evidence challenging the link between grass abundance and grazer diversity and complicate our understanding of the drivers of late Quaternary extinctions in southern Africa.</div></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"17 ","pages":"Article 100259"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.qsa.2025.100268
Manuel Domínguez-Rodrigo , Marina Vegara-Riquelme , Juan Palomeque-González , Blanca Jiménez-García , Gabriel Cifuentes-Alcobendas , Marcos Pizarro-Monzo , Elia Organista , Enrique Baquedano
Bidimensional information of tooth marks and other bone surface modifications (BSM) presents limitations, as highlighted in this study. Here, we establish a methodological comparison on a controlled experimentally-derived set of BSM generated by four different types of carnivores, using geometric morphometric (GMM) and computer vision (CV) methods. We highlight that previous generalizations of high accuracy on tooth marks using GMM are heuristically incomplete, because only a small range of allometrically-conditioned tooth pits have been used. Biased replication and exclusion of the most widely represented forms of non-oval tooth pits from such analyses have compromised the published results and their ensuing generalizations. Here, we document bidimensionally a much wider range of tooth pits, using their outlines (and not a limited set of non-reproducible idem locus semi-landmarks), through Fourier analyses. The resulting tooth mark sets show low accuracy (and resolution) in the classification of tooth marks per carnivore modifying agent. This low resolution is also reproduced when using a semi-landmark approach. In contrast, our study demonstrates that CV approaches, through Deep Learning (DL), using convolutional neural networks (DCNN), and Few-Shot Learning (FSL) models, classify experimental tooth pits with 81% and 79.52% accuracy, respectively, being equally efficient at classification. However, a limitation in CV methods occurs when applied to the fossil record, as BSM undergo dynamic transformations over time. The most impactful processes occur early in taphonomic history, altering the original BSM properties. Consequently, no objective referents exist for marks combining original and subsequent diagenetically or biostratinomically modifying processes. However, in well-preserved contexts, such as the 1.8 Ma tooth marks from some of the Olduvai sites, confidence in interpretations can be high with convergent CV models indicating high agent attribution probability. While GMM shows potential in 3D, its current bidimensional application yields limited discriminant power (<40%). Thus, future research should utilize complete 3D topographical information for more complex GMM and CV analyses, potentially resolving current interpretive challenges. Despite necessary cautions, these new methods offer an unprecedented objective means of classifying BSM to taxon-specific agency with confidence indicators. Continued research should refine these approaches, enhancing the reliability of prehistoric interpretations.
{"title":"Testing the reliability of geometric morphometric and computer vision methods to identify carnivore agency using Bi-Dimensional information","authors":"Manuel Domínguez-Rodrigo , Marina Vegara-Riquelme , Juan Palomeque-González , Blanca Jiménez-García , Gabriel Cifuentes-Alcobendas , Marcos Pizarro-Monzo , Elia Organista , Enrique Baquedano","doi":"10.1016/j.qsa.2025.100268","DOIUrl":"10.1016/j.qsa.2025.100268","url":null,"abstract":"<div><div>Bidimensional information of tooth marks and other bone surface modifications (BSM) presents limitations, as highlighted in this study. Here, we establish a methodological comparison on a controlled experimentally-derived set of BSM generated by four different types of carnivores, using geometric morphometric (GMM) and computer vision (CV) methods. We highlight that previous generalizations of high accuracy on tooth marks using GMM are heuristically incomplete, because only a small range of allometrically-conditioned tooth pits have been used. Biased replication and exclusion of the most widely represented forms of non-oval tooth pits from such analyses have compromised the published results and their ensuing generalizations. Here, we document bidimensionally a much wider range of tooth pits, using their outlines (and not a limited set of non-reproducible <em>idem locus</em> semi-landmarks), through Fourier analyses. The resulting tooth mark sets show low accuracy (and resolution) in the classification of tooth marks per carnivore modifying agent. This low resolution is also reproduced when using a semi-landmark approach. In contrast, our study demonstrates that CV approaches, through Deep Learning (DL), using convolutional neural networks (DCNN), and Few-Shot Learning (FSL) models, classify experimental tooth pits with 81% and 79.52% accuracy, respectively, being equally efficient at classification. However, a limitation in CV methods occurs when applied to the fossil record, as BSM undergo dynamic transformations over time. The most impactful processes occur early in taphonomic history, altering the original BSM properties. Consequently, no objective referents exist for marks combining original and subsequent diagenetically or biostratinomically modifying processes. However, in well-preserved contexts, such as the 1.8 Ma tooth marks from some of the Olduvai sites, confidence in interpretations can be high with convergent CV models indicating high agent attribution probability. While GMM shows potential in 3D, its current bidimensional application yields limited discriminant power (<40%). Thus, future research should utilize complete 3D topographical information for more complex GMM and CV analyses, potentially resolving current interpretive challenges. Despite necessary cautions, these new methods offer an unprecedented objective means of classifying BSM to taxon-specific agency with confidence indicators. Continued research should refine these approaches, enhancing the reliability of prehistoric interpretations.</div></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"17 ","pages":"Article 100268"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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