D. Attolini, Francesco Ciani, Mariangela Guido, C. Montanari
This research focuses on the recent pollen image of several vegetation types in NW Italy. In 201 arboreal, shrubby, and herbaceous plant populations, pollen samples were taken from moss polsters, and the corresponding vegetation was recorded using the phytosociological method. Since studies on recent pollen rain in the Mediterranean mountains and coast are rare, this research aims to provide new data and tools to better interpret fossil pollen spectra. Pollen analysis provided data for the comparison between surface spectra and vegetation. Davis indices, fidelity, dispersion, and the relation with vegetation data were calculated for each taxon, and PCA was carried out. Most vegetation types are identifiable through the taxa dominating the pollen spectra, as frequently happens in woodlands (e.g., beech woods, chestnut woods, etc.). Characterizing shrubland and certain tree-dominated vegetation types (e.g., Larix forests) through pollen data is more complex. In this regard, Davis indices are particularly useful for identifying pollen/plant association, over- and underrepresentation of pollen, and taxa indicating vegetation types. Pollen threshold values were calculated which allow the assessment of the local presence of a plant. Overall, the achieved results partially confirm those of previous research carried out in the region, greatly expanding the comparisons between several different plant communities and the database in view of future sharing through the EMPD.
{"title":"Assessment of Pollen Representation in NW Italy (Liguria and Piedmont)","authors":"D. Attolini, Francesco Ciani, Mariangela Guido, C. Montanari","doi":"10.3390/quat6020036","DOIUrl":"https://doi.org/10.3390/quat6020036","url":null,"abstract":"This research focuses on the recent pollen image of several vegetation types in NW Italy. In 201 arboreal, shrubby, and herbaceous plant populations, pollen samples were taken from moss polsters, and the corresponding vegetation was recorded using the phytosociological method. Since studies on recent pollen rain in the Mediterranean mountains and coast are rare, this research aims to provide new data and tools to better interpret fossil pollen spectra. Pollen analysis provided data for the comparison between surface spectra and vegetation. Davis indices, fidelity, dispersion, and the relation with vegetation data were calculated for each taxon, and PCA was carried out. Most vegetation types are identifiable through the taxa dominating the pollen spectra, as frequently happens in woodlands (e.g., beech woods, chestnut woods, etc.). Characterizing shrubland and certain tree-dominated vegetation types (e.g., Larix forests) through pollen data is more complex. In this regard, Davis indices are particularly useful for identifying pollen/plant association, over- and underrepresentation of pollen, and taxa indicating vegetation types. Pollen threshold values were calculated which allow the assessment of the local presence of a plant. Overall, the achieved results partially confirm those of previous research carried out in the region, greatly expanding the comparisons between several different plant communities and the database in view of future sharing through the EMPD.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42110488","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}
Tamás Bartyik, P. Urdea, T. Kiss, Alexandru Hegyi, G. Sipos
Fluvial terrace formation is a complex process governed by the interplay of climatic and tectonic forcings. From a climatic perspective, an incision is usually related to climatic transitions, while valley aggradation is attributed to glacial periods. We have reconstructed the formation of Late Pleistocene fluvial terraces along the middle, mountainous section of a temperate zone river (Mureş/Maros) in order to identify the roles of different climatic periods and potential vertical displacement in terrace development. Investigations were based on two profiles representing two different terrace levels. The profiles were subjected to sedimentological and detailed geochronological analyses using optically stimulated luminescence (OSL). The results indicated that the investigated terraces represent different incision events coinciding with climatic transition periods. However, a joint MIS 3 valley aggradation period can be identified at both of them. Thus, the relatively mild but highly variable climate of the MIS 3 facilitated sediment mobilization from upland catchments. On the other hand, there is no evidence of aggradation under the cold and stable climate of MIS 2. However, the tectonic setting favours incision at the site. Based on our results, we concluded that the timing of the main events was controlled primarily by climatic forcing. The terrace formation model recognised might also be applied at other rivers in the region.
{"title":"The Role of Past Climatic Variability in Fluvial Terrace Formation, a Case Study from River Mureş (Maros), Romania","authors":"Tamás Bartyik, P. Urdea, T. Kiss, Alexandru Hegyi, G. Sipos","doi":"10.3390/quat6020035","DOIUrl":"https://doi.org/10.3390/quat6020035","url":null,"abstract":"Fluvial terrace formation is a complex process governed by the interplay of climatic and tectonic forcings. From a climatic perspective, an incision is usually related to climatic transitions, while valley aggradation is attributed to glacial periods. We have reconstructed the formation of Late Pleistocene fluvial terraces along the middle, mountainous section of a temperate zone river (Mureş/Maros) in order to identify the roles of different climatic periods and potential vertical displacement in terrace development. Investigations were based on two profiles representing two different terrace levels. The profiles were subjected to sedimentological and detailed geochronological analyses using optically stimulated luminescence (OSL). The results indicated that the investigated terraces represent different incision events coinciding with climatic transition periods. However, a joint MIS 3 valley aggradation period can be identified at both of them. Thus, the relatively mild but highly variable climate of the MIS 3 facilitated sediment mobilization from upland catchments. On the other hand, there is no evidence of aggradation under the cold and stable climate of MIS 2. However, the tectonic setting favours incision at the site. Based on our results, we concluded that the timing of the main events was controlled primarily by climatic forcing. The terrace formation model recognised might also be applied at other rivers in the region.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48207608","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}
Jessica Zappa, N. Degasperi, M. Bassetti, A. Florenzano, P. Torri, Gabriel Servera-Vives, A. Mercuri, R. Micheli
This paper presents palynological data obtained from a trench excavated at the Neolithic pile-dwelling archaeological site of Palù di Livenza (northeastern Italy). The site is in a wetland located in a tectonic basin at the foot of the Cansiglio plateau, crossed by the Livenza river. Environmental conditions have made this wetland a suitable area for settlements since prehistoric times. Thanks to the peaty sediments that characterise the area, archaeological materials and botanical remains have been exceptionally well preserved. Their study has shed light on a Neolithic pile-dwelling settlement that developed in various phases between c. 6350 and 5600 cal BP (c. 4400 and 3650 BC), and has also allowed for a detailed environmental reconstruction of the surrounding environment. A vertical sequence of 20 samples was analysed to study pollen, non-pollen palynomorphs and microcharcoals. An age-depth model was performed based on three radiocarbon dates. The palynological analysis provided insight into the response of vegetation to environmental changes caused by both climatic fluctuations and human pressure. In this sense, it was possible to highlight differences in vegetation cover, some fires, the use of woody resources, the spread of cereal fields, as well as the presence of other cultivated plants and plant processing by the people within the village.
{"title":"Plants, Fire and Landscape at the Prehistoric Pile-Dwelling Village of Palù di Livenza (PaluON1), UNESCO Site in the Italian Alps","authors":"Jessica Zappa, N. Degasperi, M. Bassetti, A. Florenzano, P. Torri, Gabriel Servera-Vives, A. Mercuri, R. Micheli","doi":"10.3390/quat6020034","DOIUrl":"https://doi.org/10.3390/quat6020034","url":null,"abstract":"This paper presents palynological data obtained from a trench excavated at the Neolithic pile-dwelling archaeological site of Palù di Livenza (northeastern Italy). The site is in a wetland located in a tectonic basin at the foot of the Cansiglio plateau, crossed by the Livenza river. Environmental conditions have made this wetland a suitable area for settlements since prehistoric times. Thanks to the peaty sediments that characterise the area, archaeological materials and botanical remains have been exceptionally well preserved. Their study has shed light on a Neolithic pile-dwelling settlement that developed in various phases between c. 6350 and 5600 cal BP (c. 4400 and 3650 BC), and has also allowed for a detailed environmental reconstruction of the surrounding environment. A vertical sequence of 20 samples was analysed to study pollen, non-pollen palynomorphs and microcharcoals. An age-depth model was performed based on three radiocarbon dates. The palynological analysis provided insight into the response of vegetation to environmental changes caused by both climatic fluctuations and human pressure. In this sense, it was possible to highlight differences in vegetation cover, some fires, the use of woody resources, the spread of cereal fields, as well as the presence of other cultivated plants and plant processing by the people within the village.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42222717","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}
James Hill, S. Black, A. Araujo-Murakami, R. Boot, R. Brienen, T. Feldpausch, John Leigue, Samaria Murakami, A. Monteagudo, G. Pardo, M. Peña-Claros, O. Phillips, M. Toledo, V. Vos, P. Zuidema, F. Mayle
Phytolith analysis is a well-established archaeobotanical tool, having provided important insights into pre-Columbian crop cultivation and domestication across Amazonia through the Holocene. Yet, its use as a palaeoecological tool is in its infancy in Amazonia and its effectiveness for reconstructing pre-Columbian land-use beyond archaeological sites (i.e., ‘off-site’) has so far received little critical attention. This paper examines both new and previously published soil phytolith data from SW Amazonia to assess the robustness of this proxy for reconstructing pre-Columbian land-use. We conducted the study via off-site soil pits radiating 7.5 km beyond a geoglyph in Acre state, Brazil, and 50 km beyond a ring-ditch in northern Bolivia, spanning the expected gradients in historical land-use intensity. We found that the spatio-temporal patterns in palm phytolith data across our soil-pit transects support the hypothesis that pre-Columbian peoples enriched their forests with palms over several millennia, although phytoliths are limited in their ability to capture small-scale crop cultivation and deforestation. Despite these drawbacks, we conclude that off-site soil phytolith analysis can provide novel insights into pre-Columbian land use, provided it is effectively integrated with other land-use (e.g., charcoal) and archaeological data.
{"title":"An Assessment of Soil Phytolith Analysis as a Palaeoecological Tool for Identifying Pre-Columbian Land Use in Amazonian Rainforests","authors":"James Hill, S. Black, A. Araujo-Murakami, R. Boot, R. Brienen, T. Feldpausch, John Leigue, Samaria Murakami, A. Monteagudo, G. Pardo, M. Peña-Claros, O. Phillips, M. Toledo, V. Vos, P. Zuidema, F. Mayle","doi":"10.3390/quat6020033","DOIUrl":"https://doi.org/10.3390/quat6020033","url":null,"abstract":"Phytolith analysis is a well-established archaeobotanical tool, having provided important insights into pre-Columbian crop cultivation and domestication across Amazonia through the Holocene. Yet, its use as a palaeoecological tool is in its infancy in Amazonia and its effectiveness for reconstructing pre-Columbian land-use beyond archaeological sites (i.e., ‘off-site’) has so far received little critical attention. This paper examines both new and previously published soil phytolith data from SW Amazonia to assess the robustness of this proxy for reconstructing pre-Columbian land-use. We conducted the study via off-site soil pits radiating 7.5 km beyond a geoglyph in Acre state, Brazil, and 50 km beyond a ring-ditch in northern Bolivia, spanning the expected gradients in historical land-use intensity. We found that the spatio-temporal patterns in palm phytolith data across our soil-pit transects support the hypothesis that pre-Columbian peoples enriched their forests with palms over several millennia, although phytoliths are limited in their ability to capture small-scale crop cultivation and deforestation. Despite these drawbacks, we conclude that off-site soil phytolith analysis can provide novel insights into pre-Columbian land use, provided it is effectively integrated with other land-use (e.g., charcoal) and archaeological data.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41510163","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}
The Late Holocene fossil pollen records from the Zemu glacier, located in Yabuk, North Sikkim, in the eastern Himalayas, effectively generated quantitative climate reconstructions based on the transfer function model. The transfer function model was developed by establishing a modern pollen–climate calibration set from the temperate alpine belt of North Sikkim. A redundancy analysis was carried out to detect the pattern of variation of climatic variables in the modern pollen datasets. The mean annual precipitation (MAP) and mean temperature of the warming month (MTWA) had the strongest influence on the composition of the modern pollen samples among the climatic variables considered in the analysis. Proxy data in the form of fossil pollen records were analyzed for reconstructing past climate based upon the relationships between modern pollen vegetation assemblages and climatic patterns. Transfer functions for MAP and MTWA were developed with the partial least squares (PLS) approach, and model performance was assessed using leave-one-out cross-validation. The validated model was used to reconstruct MAP and MTWA for the last 2992 cal years BP (1042 BC) in North Sikkim. The variability observed in the reconstructions was analyzed for past global climatic events. It was further compared with the available regional and hemispheric proxy-based climate reconstructions. The reconstructions captured comparable Medieval Warm Period (MWP) and Little Ice Age (LIA)-like events from the Zemu glacier region. The fossil pollen data and climate reconstructions were further compared with the mineral magnetism data of the subsurface sediment profile.
{"title":"Revisit the Medieval Warm Period and Little Ice Age in Proxy Records from Zemu Glacier Sediments, Eastern Himalaya: Vegetation and Climate Reconstruction","authors":"Nivedita Mehrotra, N. Basavaiah, Santosh K. Shah","doi":"10.3390/quat6020032","DOIUrl":"https://doi.org/10.3390/quat6020032","url":null,"abstract":"The Late Holocene fossil pollen records from the Zemu glacier, located in Yabuk, North Sikkim, in the eastern Himalayas, effectively generated quantitative climate reconstructions based on the transfer function model. The transfer function model was developed by establishing a modern pollen–climate calibration set from the temperate alpine belt of North Sikkim. A redundancy analysis was carried out to detect the pattern of variation of climatic variables in the modern pollen datasets. The mean annual precipitation (MAP) and mean temperature of the warming month (MTWA) had the strongest influence on the composition of the modern pollen samples among the climatic variables considered in the analysis. Proxy data in the form of fossil pollen records were analyzed for reconstructing past climate based upon the relationships between modern pollen vegetation assemblages and climatic patterns. Transfer functions for MAP and MTWA were developed with the partial least squares (PLS) approach, and model performance was assessed using leave-one-out cross-validation. The validated model was used to reconstruct MAP and MTWA for the last 2992 cal years BP (1042 BC) in North Sikkim. The variability observed in the reconstructions was analyzed for past global climatic events. It was further compared with the available regional and hemispheric proxy-based climate reconstructions. The reconstructions captured comparable Medieval Warm Period (MWP) and Little Ice Age (LIA)-like events from the Zemu glacier region. The fossil pollen data and climate reconstructions were further compared with the mineral magnetism data of the subsurface sediment profile.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46458685","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}
While the North American mylodont sloth, Parmylodon harlani, has been identified in multiple localities in Mexico, most of these records are from the southern part of the country. Consequently, there is a large geographic gap between its distribution in Mexico and the more northern records of the species in the United States. The recovery of the remains of multiple individuals of Paramylodon harlani, as part of a late Pleistocene fauna in San Clemente de Térapa, Sonora, Mexico, partially fills this geographic gap and provides a broader understanding of the differences in the species’ ecology over a wide latitudinal range. A comparison of the paleoecology of the Térapa site with other sites with P. harlani in the fauna to the south and north provides valuable information on how regional topography and different plant communities impact the sloth’s distribution and underlying causes for its extinction.
{"title":"Late Pleistocene Paramylodon harlani (Xenarthra, Mylodontidae) from Térapa, Sonora, Mexico","authors":"H. Gregory McDonald, J. Mead, Sandra L. Swift","doi":"10.3390/quat6020031","DOIUrl":"https://doi.org/10.3390/quat6020031","url":null,"abstract":"While the North American mylodont sloth, Parmylodon harlani, has been identified in multiple localities in Mexico, most of these records are from the southern part of the country. Consequently, there is a large geographic gap between its distribution in Mexico and the more northern records of the species in the United States. The recovery of the remains of multiple individuals of Paramylodon harlani, as part of a late Pleistocene fauna in San Clemente de Térapa, Sonora, Mexico, partially fills this geographic gap and provides a broader understanding of the differences in the species’ ecology over a wide latitudinal range. A comparison of the paleoecology of the Térapa site with other sites with P. harlani in the fauna to the south and north provides valuable information on how regional topography and different plant communities impact the sloth’s distribution and underlying causes for its extinction.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42661803","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}
Aikaterini Kafetzidou, E. Fatourou, K. Panagiotopoulos, F. Marret, K. Kouli
The Gulf of Corinth is a semi-isolated basin in central Greece interrupting the Pindus Mountain Range, which nowadays is a biodiversity hotspot. Considering its key location, deep drilling was carried out within the International Ocean Discovery Program (IODP; Expedition 381: Corinth Active Rift Development) aiming to improve our understanding of climatic and environmental evolution in the region. Here, we present a new long pollen record from a Mediterranean setting in the southernmost tip of the Balkan Peninsula recording the vegetation succession within the Quaternary. The Corinth pollen record shows no major shifts in arboreal pollen between glacial and interglacial intervals, while Mediterranean and mesophilous taxa remain abundant throughout the study interval. During interglacials, the most frequent reconstructed biomes are cool mixed evergreen needleleaf (CMIX) and deciduous broadleaf forests (DBWB), while graminoid with forb (GRAM) and xerophytic shrubs (XSHB) dominate within glacials. Our findings support the hypothesis that the study area was a significant refugium, providing suitable habitats for Mediterranean, mesophilous and montane trees during successive Quaternary climate cycles.
{"title":"Vegetation Composition in a Typical Mediterranean Setting (Gulf of Corinth, Greece) during Successive Quaternary Climatic Cycles","authors":"Aikaterini Kafetzidou, E. Fatourou, K. Panagiotopoulos, F. Marret, K. Kouli","doi":"10.3390/quat6020030","DOIUrl":"https://doi.org/10.3390/quat6020030","url":null,"abstract":"The Gulf of Corinth is a semi-isolated basin in central Greece interrupting the Pindus Mountain Range, which nowadays is a biodiversity hotspot. Considering its key location, deep drilling was carried out within the International Ocean Discovery Program (IODP; Expedition 381: Corinth Active Rift Development) aiming to improve our understanding of climatic and environmental evolution in the region. Here, we present a new long pollen record from a Mediterranean setting in the southernmost tip of the Balkan Peninsula recording the vegetation succession within the Quaternary. The Corinth pollen record shows no major shifts in arboreal pollen between glacial and interglacial intervals, while Mediterranean and mesophilous taxa remain abundant throughout the study interval. During interglacials, the most frequent reconstructed biomes are cool mixed evergreen needleleaf (CMIX) and deciduous broadleaf forests (DBWB), while graminoid with forb (GRAM) and xerophytic shrubs (XSHB) dominate within glacials. Our findings support the hypothesis that the study area was a significant refugium, providing suitable habitats for Mediterranean, mesophilous and montane trees during successive Quaternary climate cycles.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41775396","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}
Buried river valleys from the Neogene–Quaternary time are widespread throughout the Middle Volga region of the Russian Plain. They have been studied for a long period, since the 1940s, with the last major generalizations dating back to the 1980s. This paper presents new results based on GIS mapping using materials from the state geological study of the region in 1960–1970, 1984–1996 and 2000–2002. On the whole, the pattern of the buried valley network is close to the modern valley network of the region. During the Quaternary, the right-sided displacement of the valley incisions prevailed. The incisions of modern river valleys are located above the Neogene (pre-Akchagyl) incisions almost throughout the entire territory. The vertical displacement amplitude ranges from 30 to 200 m. The morphometric characteristics of the paleovalleys (the depth and width of the incisions, as well as the gradients of the bottoms of the paleovalleys) exceeded modern ones. The maximum values were typical for the middle Paleo-Volga valley: the width of the valley reached 10 km, the incision depth was −201.4 m below sea level and the bottom gradient was 0.9–5.0 m/km. The most important factor that influenced the position of paleovalleys and their morphological appearance was fluctuations in the level of the Caspian paleowaterbody. According to this study, the development of paleovalleys began in the Miocene and ended in the Early Quaternary. The alluvial–lacustrine type of sedimentation was predominant. The results of this work contribute to the study of the paleogeography of the Cenozoic of the southeast of the Russian Plain.
{"title":"Buried River Valleys of the Neogene and Early Quaternary in the Middle Volga Region, European Russia","authors":"Elena V. Petrova, A. Gusarov, A. Beylich","doi":"10.3390/quat6020029","DOIUrl":"https://doi.org/10.3390/quat6020029","url":null,"abstract":"Buried river valleys from the Neogene–Quaternary time are widespread throughout the Middle Volga region of the Russian Plain. They have been studied for a long period, since the 1940s, with the last major generalizations dating back to the 1980s. This paper presents new results based on GIS mapping using materials from the state geological study of the region in 1960–1970, 1984–1996 and 2000–2002. On the whole, the pattern of the buried valley network is close to the modern valley network of the region. During the Quaternary, the right-sided displacement of the valley incisions prevailed. The incisions of modern river valleys are located above the Neogene (pre-Akchagyl) incisions almost throughout the entire territory. The vertical displacement amplitude ranges from 30 to 200 m. The morphometric characteristics of the paleovalleys (the depth and width of the incisions, as well as the gradients of the bottoms of the paleovalleys) exceeded modern ones. The maximum values were typical for the middle Paleo-Volga valley: the width of the valley reached 10 km, the incision depth was −201.4 m below sea level and the bottom gradient was 0.9–5.0 m/km. The most important factor that influenced the position of paleovalleys and their morphological appearance was fluctuations in the level of the Caspian paleowaterbody. According to this study, the development of paleovalleys began in the Miocene and ended in the Early Quaternary. The alluvial–lacustrine type of sedimentation was predominant. The results of this work contribute to the study of the paleogeography of the Cenozoic of the southeast of the Russian Plain.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49003180","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}
Earthquake precursors are the indicators that appear before an earthquake. The release of radon gas, ionospheric disturbances, anomalous animal behavior, and so on are examples of seismic and aseismic events. Ionospheric perturbations can be proved to be a reliable method in earthquake prediction. The GNSS data detect changes in the ionosphere through the time lag of the transmitted GPS signals recorded at the Earth-based receivers. A negative TEC anomaly is caused by the stress released from the rocks before the earthquake, which elevates positive ions or p-holes in the atmosphere and decreases the ions in the ionosphere. A positive TEC anomaly follows this because of the increase in ions in the ionosphere. The ionospheric disruption in the Himalayan region is examined before five random earthquakes. For this, data from 15 separate GNSS stations are investigated using IONOLAB-TEC. A promising total electron content (TEC) data estimate with a temporal resolution of 30 s was analyzed. The results of the TEC data analysis depict the anomaly a month before the five earthquakes, followed by the later perturbation in the earthquake preparation zone. TEC anomalies are enhanced more by the uniform spatial distribution of GNSS stations in the epicentral region than by randomly distributed stations. The results of IONOLAB-TEC and the widely used GPS-TEC software were compared. Owing to its temporal resolution, IONOLAB-TEC has edge over the GPS-TEC software in that it can identify even the slightest negative anomalies before an earthquake.
{"title":"Analysis of GNSS Data for Earthquake Precursor Studies Using IONOLAB-TEC in the Himalayan Region","authors":"S. Joshi, S. Kannaujiya, Utkarsh Joshi","doi":"10.3390/quat6020027","DOIUrl":"https://doi.org/10.3390/quat6020027","url":null,"abstract":"Earthquake precursors are the indicators that appear before an earthquake. The release of radon gas, ionospheric disturbances, anomalous animal behavior, and so on are examples of seismic and aseismic events. Ionospheric perturbations can be proved to be a reliable method in earthquake prediction. The GNSS data detect changes in the ionosphere through the time lag of the transmitted GPS signals recorded at the Earth-based receivers. A negative TEC anomaly is caused by the stress released from the rocks before the earthquake, which elevates positive ions or p-holes in the atmosphere and decreases the ions in the ionosphere. A positive TEC anomaly follows this because of the increase in ions in the ionosphere. The ionospheric disruption in the Himalayan region is examined before five random earthquakes. For this, data from 15 separate GNSS stations are investigated using IONOLAB-TEC. A promising total electron content (TEC) data estimate with a temporal resolution of 30 s was analyzed. The results of the TEC data analysis depict the anomaly a month before the five earthquakes, followed by the later perturbation in the earthquake preparation zone. TEC anomalies are enhanced more by the uniform spatial distribution of GNSS stations in the epicentral region than by randomly distributed stations. The results of IONOLAB-TEC and the widely used GPS-TEC software were compared. Owing to its temporal resolution, IONOLAB-TEC has edge over the GPS-TEC software in that it can identify even the slightest negative anomalies before an earthquake.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48321358","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}
Ravneet Kaur, R. K. Tiwari, R. Maini, Sartajvir Singh
Crop yield prediction is one of the crucial components of agriculture that plays an important role in the decision-making process for sustainable agriculture. Remote sensing provides the most efficient and cost-effective solution for the measurement of important agricultural parameters such as soil moisture level, but retrieval of the soil moisture contents from coarse resolution datasets, especially microwave datasets, remains a challenging task. In the present work, a machine learning-based framework is proposed to generate the enhanced resolution soil moisture products, i.e., classified maps and change maps, using an optical-based moderate resolution imaging spectroradiometer (MODIS) and microwave-based scatterometer satellite (SCATSAT-1) datasets. In the proposed framework, nearest-neighbor-based image fusion (NNIF), artificial neural networks (ANN), and post-classification-based change detection (PCCD) have been integrated to generate thematic and change maps. To confirm the effectiveness of the proposed framework, random forest post-classification-based change detection (RFPCD) has also been implemented, and it is concluded that the proposed framework achieved better results (88.67–91.80%) as compared to the RFPCD (86.80–87.80%) in the computation of change maps with σ°-HH. This study is important in terms of crop yield prediction analysis via the delivery of enhanced-resolution soil moisture products under all weather conditions.
{"title":"A Framework for Crop Yield Estimation and Change Detection Using Image Fusion of Microwave and Optical Satellite Dataset","authors":"Ravneet Kaur, R. K. Tiwari, R. Maini, Sartajvir Singh","doi":"10.3390/quat6020028","DOIUrl":"https://doi.org/10.3390/quat6020028","url":null,"abstract":"Crop yield prediction is one of the crucial components of agriculture that plays an important role in the decision-making process for sustainable agriculture. Remote sensing provides the most efficient and cost-effective solution for the measurement of important agricultural parameters such as soil moisture level, but retrieval of the soil moisture contents from coarse resolution datasets, especially microwave datasets, remains a challenging task. In the present work, a machine learning-based framework is proposed to generate the enhanced resolution soil moisture products, i.e., classified maps and change maps, using an optical-based moderate resolution imaging spectroradiometer (MODIS) and microwave-based scatterometer satellite (SCATSAT-1) datasets. In the proposed framework, nearest-neighbor-based image fusion (NNIF), artificial neural networks (ANN), and post-classification-based change detection (PCCD) have been integrated to generate thematic and change maps. To confirm the effectiveness of the proposed framework, random forest post-classification-based change detection (RFPCD) has also been implemented, and it is concluded that the proposed framework achieved better results (88.67–91.80%) as compared to the RFPCD (86.80–87.80%) in the computation of change maps with σ°-HH. This study is important in terms of crop yield prediction analysis via the delivery of enhanced-resolution soil moisture products under all weather conditions.","PeriodicalId":54131,"journal":{"name":"Quaternary","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41707282","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}
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