Global and Planetary Change最新文献

{"title":"Lake sediment record of eolian activity on the eastern Tibetan Plateau since 15 cal ka BP","authors":"","doi":"10.1016/j.gloplacha.2024.104592","DOIUrl":"10.1016/j.gloplacha.2024.104592","url":null,"abstract":"<div><div>Atmospheric dust has important influences on atmospheric circulation, global biogeochemical cycles, and hydrological processes. However, understanding the history of dust storms on the Tibetan Plateau (TP) remains challenging due to the lack of suitable geological archives. Lakes in dust-influenced regions act as dust repositories, offering the opportunity to trace the history of dust emissions and eolian activity. Here we present a synthesis of eolian activity on the eastern TP covering the past 15,000 years. It is based on records of grain size and <em>n</em>-alkanes from a sediment core from Gahai lake, which we combined with published pollen and other records from the same core, to reconstruct variations in surface runoff and eolian activity in this region. Our results indicate a correlation between vegetation conditions and eolian activity during different periods. Increased eolian activity occurred during the transition from the last deglaciation to the early Holocene, due to suboptimal vegetation conditions. Between 7.5 and 3.5 cal ka BP (ka), higher moisture levels resulted in the dominance of arboreal vegetation, which suppressed eolian activity. However, after 3.5 ka a sustained intensification of eolian activity occurred in the Gahai area, which was linked to decreasing vegetation cover, reduced regional humidity, and growing human impacts, especially in the eastern plateau, in southern Gansu. In recent decades, human interventions have suppressed eolian activity. Additionally, a ∼ 1435-year cyclicity in our record, and other regional records, suggests a link between increased eolian activity on the eastern TP and ice-rafting events in the North Atlantic. Generally, Holocene eolian dynamics were primarily influenced by the regional vegetation and climatic conditions which were controlled by the atmospheric circulation. However, in the late Holocene, climatic shifts and human influences had a synergistic effect which intensified the eolian activity, highlighting the important role of humans on recent dust dynamics in this region.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global carbon cycle disruption during the latest Pliensbachian (Lower Jurassic) evidenced by simultaneous isotopic depletion in marine and terrestrial carbon pools","authors":"","doi":"10.1016/j.gloplacha.2024.104591","DOIUrl":"10.1016/j.gloplacha.2024.104591","url":null,"abstract":"<div><div>The Pliensbachian-Toarcian (Pl-To) boundary was marked by an extinction event in marine organisms, and localised ocean anoxia – resulting in the deposition of black shales. Negative isotopic excursions in bulk organic carbon in many of these black shales, are widely believed to indicate that a global carbon cycle disruption accompanied this extinction event. The Pl-To preceded a period of more intense global carbon cycle disruption that occurred during the Toarcian Oceanic Anoxic Event (T-OAE) by around a million years. It is evident from targeted carbon isotopic analyses of marine and terrestrial organic matter that simultaneous disruptions to the marine and terrestrial carbon cycles occurred during the T-OAE. However, it remains a matter of debate whether the main source of carbon emissions was a climate-sensitive methane reservoir, or volcanic processes. No records of terrestrial carbon cycle disruption exist for the latest Pliensbachian, and so the causal mechanisms behind localised anoxia in this stage of the Lower Jurassic are poorly constrained. We present a record of concomitant isotopic depletion in short and long-chain <em>n</em>-alkanes derived from a thin black shale (the Lower Sulphur Band – LSB) deposited during the latest Pliensbachian (located in Yorkshire, UK). A key argument is that simultaneous isotopic depletions in these different compound classes implies the presence of a brief global hyperthermal event in the latest Pliensbachian, with a timescale too short to have been captured by previous analyses of the Yorkshire section. We discuss the relevance of our data to the stratigraphic record of the Lower Jurassic sediments of Yorkshire, highlighting, in particular, the need for better constraint on the ammonite biostratigraphy of the study section. We further argue that the brief climate disruption that occurred in the latest Pliensbachian made the shallow marine environment vulnerable to the development of more widespread marine anoxia, during the succeeding Toarcian stage.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0921818124002388/pdfft?md5=92040a9887e0bfe8ae09c0b1670bb7c8&pid=1-s2.0-S0921818124002388-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maastrichtian-Cenozoic erosional history of the northern Peruvian Amazonian Andes implications for the Eastern Cordillera evolution (Huallaga Basin, northern Peru)","authors":"","doi":"10.1016/j.gloplacha.2024.104584","DOIUrl":"10.1016/j.gloplacha.2024.104584","url":null,"abstract":"<div><p>Late Cretaceous-Cenozoic Andean mountain building may have experienced various phases of orogenesis in response to variations the dip angle of the subducting slab, distinct magmatic pulses, and shortening rates of the orogen. The timing of the Eastern Cordillera (EC) erosion and the relationship between the Andean orogenesis and the establishing of the transcontinental Amazon River remains unclarified. The erosional history of the Amazon Andes and the timing of these orogenic events may be revealed by the late Cretaceous-Cenozoic sedimentary record of the Amazonian retroarc foreland basin. We investigate the provenance of the Maastrichtian-Cenozoic deposits of the Huallaga Basin based on major and trace elements concentrations, Sm<img>Nd isotopic composition, and U<img>Pb zircon dating. We also refined the Oligocene paleoenvironment and calculated Paleogene sedimentation rates. Our results show that despite the 25 Myr-long sedimentary hiatus, both the Maastrichtian and Eocene units show dominant sourcing from the magmatic arc of the Western Cordillera (WC). Increases in Paleozoic and Famatinian zircon grains and a shift toward more negative ƐNd(0) values, indicate dominant EC sources during the Oligocene to middle Miocene. This change in provenance area is Rupelian in age based on the Maximum Likelihood Age (MLA) of JUA22 (29.70 ± 0.62 Ma), suggesting that the onset of Peruvian EC erosion started at ∼30 Ma. The erosion of the EC was accompanied by an increase in sedimentation rates and the development of a meandering fluvial system. Finally, a substantial decrease in zircon grains derived from the Cretaceous and Cenozoic Andean arcs from late Miocene to Recent sediments suggests no contribution of the WC. In contrast, an increase in Paleozoic magmatic arc zircon grains indicates sources in the EC. We compare our findings to constrain the erosional history of the Amazonian Andes and investigate the relationship between the timing of EC uplift and the onset of the transcontinental Amazon drainage system during the Cenozoic.</p></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mercury enrichments as a paleo-volcanism proxy: Sedimentary bias and a critical analysis across the end-Triassic","authors":"","doi":"10.1016/j.gloplacha.2024.104589","DOIUrl":"10.1016/j.gloplacha.2024.104589","url":null,"abstract":"<div><div>Mercury (Hg) anomalies in sedimentary rocks have been increasingly used in paleoclimatology studies for tracing volcanic signals, as Hg emissions from volcanic activity can cause contemporaneous sedimentary Hg enrichment. However, non-volcanic sedimentary controls on Hg have clear potential to mask these signals. These factors include host phase variability linked to environmentally controlled sourcing and settling changes, and/or variable preservation conditions associated with weathering, oxidation and diagenesis. Such factors can limit the efficacy of Hg as a paleo-volcanism proxy. In this study, sedimentary effects on Hg concentration within a complex depositional system in southwest England (St. Audrie's Bay) across the end-Triassic have been analyzed, together with published data from coeval end-Triassic sections globally – an interval of time coeval with the Central Atlantic Magmatic Province (CAMP). Our statistical analysis of Hg and associated geochemical data highlights significant fluctuations in sedimentary Hg due to relative supply differences in Hg and host phases, as well as the changing types and preservation conditions of host phases. End-Triassic sections globally show a consistent undersupply of Hg relative to organic matter across the end-Triassic mass extinction (ETME). To better assess the magnitude and significance of possible Hg enrichments in sedimentary rocks, we present a statistical method for quantifying Hg anomalies to robustly distinguish Hg variations linked to host phase/depositional changes from paleo-volcanism. Our method supports the existence of transient but asynchronous Hg anomalies linked to volcanism from the CAMP across the end-Triassic in most global sections, albeit not in the St. Audrie's Bay section.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate change driven by LUCC reduced NPP in the Yellow River Basin, China","authors":"","doi":"10.1016/j.gloplacha.2024.104586","DOIUrl":"10.1016/j.gloplacha.2024.104586","url":null,"abstract":"<div><p>Anthropogenic activities and the resulting climate change affect the type, structure, and function of ecosystems. Understanding vegetation dynamics related to anthropogenic activities and climate change is critical to address the terrestrial carbon cycle in the context of global warming. The objective of this study is to quantify the effects of human-induced land use and land cover change (LUCC) and LUCC-induced climate change on terrestrial net primary productivity (NPP) in the Yellow River Basin (YRB) during 2000–2020 using Weather Research and Forecasting (WRF) model and Integrated Biosphere Simulator (IBIS) model through different experimental scenarios. Results indicated that LUCC can cause an increase in NPP of 1.2 ± 0.67 gC m⁻² yr⁻¹ in YRB. The increased precipitation and decreased temperature due to LUCC showed weak negative effect on annual mean NPP in YRB (−0.2 ± 0.74 gC m⁻² yr⁻¹). The coupling of LUCC and LUCC-induced climate change increased annual mean NPP approximately 0.6 ± 0.86 gC m⁻² yr⁻¹. The impacts of LUCC and LUCC-induced climate change and their coupling effects on NPP were greatest in spring, increasing NPP by 5.1 ± 0.51, 3.4 ± 0.41, and 6.1 ± 0.79 gC m⁻² yr⁻¹, respectively. These findings provide important guidance for the sustainable and adaptive management of terrestrial ecosystems in river basin in the context of global change.</p></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatiotemporal variability of leaf critical senescence age across northern lands and its key drivers","authors":"","doi":"10.1016/j.gloplacha.2024.104587","DOIUrl":"10.1016/j.gloplacha.2024.104587","url":null,"abstract":"<div><div>Leaf senescence, a pivotal phenological event, signifies the aging of vegetation canopies and triggers abrupt shifts in various biogeochemical processes. However, the spatiotemporal pattern of leaf senescence age and its primary driving factors across northern lands remains unclear. In this study, we introduced a concept termed leaf critical senescence age (CSA) to characterize the initiation of senescence stage, which quantifies the time span between the onset dates of vegetation growth and senescence. Then, utilizing long-term remote sensing vegetation index data, we investigated the spatiotemporal variations of leaf CSA over northern lands (&gt;30°N). Spatially, leaf CSA displayed extensive variability (ranging from 42 to 263 days), with an average of 146 ± 32 days. Deciduous broadleaf forests exhibited the longest CSA (177 ± 28 days), while shrublands demonstrated the shortest (121 ± 22 days). Temporally, most plant functional types experienced a reversal in leaf CSA trends around 2010, leading to the contrasting trends between 1982–2010 (+0.21 days/year) and 2010–2015 (−2.36 days/year) across northern lands. Further random-forest regression and partial correlation analysis together indicated that temperature was the dominant factor driving spatiotemporal variations in leaf CSA. These findings suggest that climate warming is reshaping the geographical pattern of leaf senescence age, posing great uncertainty to future projections of terrestrial feedback to climate change.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paleoclimate evolution of the Middle Triassic Guanling Formation from South China and its significance for the preservation of the Luoping biota","authors":"","doi":"10.1016/j.gloplacha.2024.104588","DOIUrl":"10.1016/j.gloplacha.2024.104588","url":null,"abstract":"<div><div>The Middle Triassic is regarded as an important period of biotic recovery after the end-Permian mass extinction, of which the Middle Triassic Luoping biota represents a full recovery of marine ecosystem. However, the research on the relationship between biotic recovery and environmental evolution in the Middle Triassic remains poorly understood. To investigate this issue, microfacies analysis and multiple geochemical proxies (Al, Ti, Th, Sc, and ∑REY) of an Anisian (Middle Triassic) succession (the Member II of the Guanling Formation, Leniduo section, South China) yielding the Luoping biota are carried out. Five sedimentary facies are identified through field investigation and microfacies analysis: open platform, restricted platform, tidal flat, shoal and intra-platform depression. According to the changes of multiple geochemical proxies, this section can be divided into five stages. A sudden facies transition from open platform to intra-platform depression, and high contents of Al, Ti, Sc, Th, and ∑REY in stage IV indicate a rapid sea-level rise and detrital input increase, coinciding with the preservation of the Luoping biota. This evidence suggest that enhanced continental weathering caused by global warming, global sea level rise, and frequent regional volcanic activities promoted the death and preservation of the Luoping biota.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Orbital and suborbital climate cycles recorded in terrestrial strata from the late Paleocene-early Eocene in the Subei Basin, East China","authors":"","doi":"10.1016/j.gloplacha.2024.104590","DOIUrl":"10.1016/j.gloplacha.2024.104590","url":null,"abstract":"<div><p>Interannual-to millennial-scale climate cycles have been recognized in ancient sedimentary strata and may be closely associated with solar activity. However, the physical driving mechanisms of such cycles remain a mystery. To better understand the nature and evolution of suborbital cycles in ice-free conditions, we performed a quantitative analysis of high-resolution phosphorus (P), gray-scale values, and iron (Fe) data obtained from a core deposited in a mid-latitude lake (Funing Formation of the Subei Basin) during the Late Paleocene-Early Eocene. Time series analysis reveals evidence for ∼88-yr and ∼ 11-yr solar activity cycles in the gray value data, and ∼ 20-kyr precession cycles, ∼10-kyr half-precession cycles, and ∼ 2-kyr solar activity cycles in the Fe data. The data indicate that paleoclimate changes in the Subei Basin at this time were driven by both orbital and suborbital cycles. Amplitude modulation analysis suggests that ∼20-kyr precession modulated the amplitude of the observed 2-kyr cycles. It is inferred that the Earth's climate is driven not only by eccentricity-modulated precession cycle, but also by precession-modulated millennial cycles.</p></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The expression of the MIS 12 glacial stage in Southeastern Europe and its impact over the Middle Pleistocene hominins in Megalopolis Basin (Greece)","authors":"","doi":"10.1016/j.gloplacha.2024.104585","DOIUrl":"10.1016/j.gloplacha.2024.104585","url":null,"abstract":"<div><p>Southern Europe is hypothesized to have acted as a glacial refugium for hominin populations during the Pleistocene. Of particular importance is South-East Europe, which most likely played a dual role, both as refugium and dispersal corridor, especially during the Middle Pleistocene glaciations, when drastic climatic conditions led to major sea level drops in the Aegean. However, little is known about the palaeoenvironmental conditions at the time of hominin presence in this region, making these hypotheses difficult to test. Here we analyze biomarker data and leaf wax stable isotopic compositions of the MIS 12 Lower Palaeolithic site Marathousa 1 (Megalopolis Basin, Greece) to assess the climatic conditions accompanying the time of hominin presence in the area. Our data indicate a major cooling affecting the north Mediterranean/Aegean domain during this time interval, with lowest temperatures recorded between ∼440–432 ka. The glacial peak is associated with changes in vegetation (i.e., from more forested to more open landscape), reduction of humidity and water availability (i.e., moisture depletion, increased evaporation). Hominins are present at the Marathousa 1 location at the end of this interval (434–432 ka), confirming that the Megalopolis Basin served as a refugium for hunter-gatherer groups during periods of harsh climatic conditions. Additionally, the progressive cooling is associated with an important sedimentary hiatus between ∼465–440 ka reflected in all circum-Mediterranean records (both marine and continental), indicating a regional impact of the MIS 12 glaciation over surface processes.</p></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0921818124002327/pdfft?md5=e8c4c59b5bb228f7480759043185e0f5&pid=1-s2.0-S0921818124002327-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142238294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Change of global land extreme temperature in the future","authors":"","doi":"10.1016/j.gloplacha.2024.104583","DOIUrl":"10.1016/j.gloplacha.2024.104583","url":null,"abstract":"<div><p>Understanding future temperature extremes is pivotal to preparing for and mitigating the impacts of climate change. This study proposed machine learning techniques to develop a multi-model ensemble model for high-resolution projection of global land temperature extremes under different emission scenarios, hence providing enhanced precision over previous climate model projections. By utilizing the NEX-GDDP-CMIP6 dataset with bias adjustment and the Gradient Booster algorithm, we reduced the biases that existed in Global Climate Models. The model significantly reduces the root mean square errors (RMSEs) for both the daily maximum and daily minimum temperature extremes. A future scenario analysis revealed that global temperature extremes would substantially increase under high-emission scenarios, highlighting the urgency for stringent emission reduction commitments. This study also identified regions like Greenland, the Tibetan Plateau, and the regional Arctic Archipelago as potential hotspots of temperature extremes under these scenarios. The multi-model ensemble approach, tuned with machine learning and driven by high-resolution data, contributes to climate science by providing refined insights into future temperature extremes, thereby offering direction to climate change mitigation and adaptation strategies.</p></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142238655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}