Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2024.104680
Yan-Xia Xue , Yao Wu , Chao-Jun Chen , Jun-Yun Li , Hai Cheng , Chuan-Chou Shen , Jian Zhang , Ting-Yong Li
There are still a series of controversies about the variation patterns and spatial differences of the Asian summer monsoon (ASM) during the Heinrich Stadials (HSs). Using stalagmite δ18O records from Yangkou Cave, Southwest China, this study revealed the climate dynamics of 6 weak ASM events corresponding to Heinrich events since the last glacial period. During the Asian Heinrich Stadial (AHS) 1–6, the ASM intensity in northern China responded rapidly to climate change in the North Atlantic, whereas the response in southern China was gradual. Ocean-atmosphere interactions under the bipolar “see-saw” mechanism dominated the ASM dynamics during the HSs. The ASM strengthening in the south of the Asian monsoon region was earlier and more gradual than in the north during the termination of the AHS, implying that the Southern Hemisphere high latitudes and tropical oceans played a critical role in the termination of millennial-scale abrupt climatic events. According to our observations, variations in moisture transport distances resulted in spatial differences in amplitude of stalagmite δ18O during the AHSs, implying that δ18O can reflect the hydrological imprint of variation in the ASM circulation.
{"title":"Evolution of the Asian summer monsoon during the Heinrich events 1–6","authors":"Yan-Xia Xue , Yao Wu , Chao-Jun Chen , Jun-Yun Li , Hai Cheng , Chuan-Chou Shen , Jian Zhang , Ting-Yong Li","doi":"10.1016/j.gloplacha.2024.104680","DOIUrl":"10.1016/j.gloplacha.2024.104680","url":null,"abstract":"<div><div>There are still a series of controversies about the variation patterns and spatial differences of the Asian summer monsoon (ASM) during the Heinrich Stadials (HSs). Using stalagmite δ<sup>18</sup>O records from Yangkou Cave, Southwest China, this study revealed the climate dynamics of 6 weak ASM events corresponding to Heinrich events since the last glacial period. During the Asian Heinrich Stadial (AHS) 1–6, the ASM intensity in northern China responded rapidly to climate change in the North Atlantic, whereas the response in southern China was gradual. Ocean-atmosphere interactions under the bipolar “see-saw” mechanism dominated the ASM dynamics during the HSs. The ASM strengthening in the south of the Asian monsoon region was earlier and more gradual than in the north during the termination of the AHS, implying that the Southern Hemisphere high latitudes and tropical oceans played a critical role in the termination of millennial-scale abrupt climatic events. According to our observations, variations in moisture transport distances resulted in spatial differences in amplitude of stalagmite δ<sup>18</sup>O during the AHSs, implying that δ<sup>18</sup>O can reflect the hydrological imprint of variation in the ASM circulation.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104680"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142884633","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2025.104696
Jiahao Han , Shibo Fang , Xiaomao Lin , Zhanhao Zhang , Man Li , Yanru Yu , Wen Zhuo , Xinyu Wang
Increased atmospheric water vapor pressure due to the warming climate has led to more frequent and extreme precipitation events, which has resulted in incalculable losses. The hydrothermal circulation suggests that extreme daytime and nighttime precipitation patterns can have many distinct consequences,ranging from changes in various scale hydrological cycles to social security concerns. However, the spatio-temporal patterns of daytime and nighttime precipitation events remain underexplored, lacking quantitative analysis. Therefore, our study analyzed daily precipitation data (including 24-h, daytime, and nighttime) from 1981 to 2022 across China to investigate extreme precipitation patterns at a half-day scale (daytime and nighttime). Fourteen monthly extreme indices associated with atmospheric circulations and sea surface temperatures were examined to clarify precipitation distribution patterns using random forest and optimal fingerprinting techniques. The main findings are: (1) A clear upward trend was found in cumulative precipitation, intensifying the frequency of extreme precipitation events. Notably, the increase in both accumulated 24-h precipitation and the rate of nighttime precipitation exceeded the rate of daytime precipitation between 1981 and 2022. This trend became more pronounced as precipitation events became more extreme. (2) Most regions in China exhibited an increasing trend in both cumulative precipitation days and total precipitation, particularly in the North China Plain, although the Yunnan-Guizhou Plateau saw significant decreases in both variables. (3) Extreme precipitation events were primarily driven by changes in the different types of the Subtropical High (Western Pacific, South China Sea, and Northern Hemisphere Subtropical High), along with the typhoons southeast of the Hu Huanyong line. These findings enhance the understanding of hydrothermal exchange processes and extreme precipitation, providing a useful basis for climate change adaptations in China.
{"title":"Half-day (daytime and nighttime) precipitation extremes in China: Changes and attribution from 1981 to 2022","authors":"Jiahao Han , Shibo Fang , Xiaomao Lin , Zhanhao Zhang , Man Li , Yanru Yu , Wen Zhuo , Xinyu Wang","doi":"10.1016/j.gloplacha.2025.104696","DOIUrl":"10.1016/j.gloplacha.2025.104696","url":null,"abstract":"<div><div>Increased atmospheric water vapor pressure due to the warming climate has led to more frequent and extreme precipitation events, which has resulted in incalculable losses. The hydrothermal circulation suggests that extreme daytime and nighttime precipitation patterns can have many distinct consequences,ranging from changes in various scale hydrological cycles to social security concerns. However, the spatio-temporal patterns of daytime and nighttime precipitation events remain underexplored, lacking quantitative analysis. Therefore, our study analyzed daily precipitation data (including 24-h, daytime, and nighttime) from 1981 to 2022 across China to investigate extreme precipitation patterns at a half-day scale (daytime and nighttime). Fourteen monthly extreme indices associated with atmospheric circulations and sea surface temperatures were examined to clarify precipitation distribution patterns using random forest and optimal fingerprinting techniques. The main findings are: (1) A clear upward trend was found in cumulative precipitation, intensifying the frequency of extreme precipitation events. Notably, the increase in both accumulated 24-h precipitation and the rate of nighttime precipitation exceeded the rate of daytime precipitation between 1981 and 2022. This trend became more pronounced as precipitation events became more extreme. (2) Most regions in China exhibited an increasing trend in both cumulative precipitation days and total precipitation, particularly in the North China Plain, although the Yunnan-Guizhou Plateau saw significant decreases in both variables. (3) Extreme precipitation events were primarily driven by changes in the different types of the Subtropical High (Western Pacific, South China Sea, and Northern Hemisphere Subtropical High), along with the typhoons southeast of the Hu Huanyong line. These findings enhance the understanding of hydrothermal exchange processes and extreme precipitation, providing a useful basis for climate change adaptations in China.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104696"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142935463","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2025.104729
Minghui Li , Qiu Tan , Guangjie Luo , Chaojun Li , Chen Ran , Sirui Zhang , Lian Xiong , Jingjing Liao , Chaochao Du , Zilin Li , Yingying Xue , Mingkang Long , Qing Luo , Xiaoqian Shen , Shu Yang , Xiaoyun Zhang , Yuanhuan Xie , Xiaoyong Bai
Seismic peak ground acceleration (PGA) is a key indicator to characterize the strength of seismic effects, which affects the rate of chemical weathering of carbonate rocks and the ability to capture CO2. However, the response mechanism and process of Carbonate rock weathering Carbon Sink (CCS) to PGA are not clear. To this end, this paper clarifies the spatial and temporal patterns of CCS in China and reveals their response to PGA based on PGA, climate, lithology and other datas, combined with methods such as the random forest model and maximal potential dissolution model. The results showed that the CCS Flux(CCSF) was 5.32 t C km−2 yr−1 and the Full CCS (FCCS) was 1346 × 104 t C yr−1, which was influenced by PGA, with the flux being the largest at 0.05 g PGA (5.38 t C km−2 yr−1), mainly in the south-western part of the country where hydrothermal conditions are favourable. Meanwhile, the response of CCS to PGA was affected by latitude and altitude divergence. CCS at the same latitude showed a fluctuating downward trend with the enhancement of PGA. Two trends of CCS and PGA at the same altitude appeared, one was that CCS increased with the enhancement of PGA when the altitude was less than 2500 m as well as 4500–6500 m, and the other was that CCS decreased with the enhancement of PGA when the altitude was 2500–4500 m. At the same PGA, CCS decreased with increasing latitude and elevation, respectively. This may be due to the fact that higher altitude and latitude are associated with lower temperatures, which affects the rate of chemical weathering of carbonate rocks, and hence CCS. The aim of this paper is to understand the response relationship between CCS and PGA, which helps to reveal how geologic activities affect the carbon cycle. The results of the study bridge the gap between tectonic geology and CCS systematic research to a certain extent, and promote the integration of the disciplines. This is of great significance for assessing the potential impact of natural disasters such as earthquakes on carbon sinks.
地震峰值地面加速度（PGA）是表征地震效应强度的一个关键指标，它影响着碳酸盐岩的化学风化速度和捕获二氧化碳的能力。然而，碳酸盐岩风化碳汇（CCS）对 PGA 的响应机制和过程尚不清楚。为此，本文基于PGA、气候、岩性等数据，结合随机森林模型和最大潜在溶解度模型等方法，阐明了中国碳酸盐岩风化碳汇的时空格局，并揭示了其对PGA的响应。结果表明，CCS通量（CCSF）为5.32 t C km-2 yr-1，全CCS（FCCS）为1346×104 t C yr-1，受PGA影响较大，其中0.05 g PGA时通量最大（5.38 t C km-2 yr-1），主要分布在热液条件较好的西南地区。同时，碳捕获量对 PGA 的响应受纬度和海拔差异的影响。同一纬度的 CCS 随 PGA 的增加呈波动下降趋势。同一海拔高度下的 CCS 与 PGA 呈两种变化趋势，一种是当海拔低于 2500 米和 4500-6500 米时，CCS 随 PGA 的增加而增加；另一种是当海拔在 2500-4500 米时，CCS 随 PGA 的增加而减少。这可能是由于海拔和纬度越高，温度越低，从而影响碳酸盐岩的化学风化速度，进而影响碳酸盐含量。本文旨在了解 CCS 与 PGA 之间的响应关系，这有助于揭示地质活动如何影响碳循环。研究结果在一定程度上弥补了构造地质学与CCS系统研究之间的空白，促进了学科融合。这对于评估地震等自然灾害对碳汇的潜在影响具有重要意义。
{"title":"Response of carbonate rock weathering carbon sink to seismic peak ground acceleration in China","authors":"Minghui Li , Qiu Tan , Guangjie Luo , Chaojun Li , Chen Ran , Sirui Zhang , Lian Xiong , Jingjing Liao , Chaochao Du , Zilin Li , Yingying Xue , Mingkang Long , Qing Luo , Xiaoqian Shen , Shu Yang , Xiaoyun Zhang , Yuanhuan Xie , Xiaoyong Bai","doi":"10.1016/j.gloplacha.2025.104729","DOIUrl":"10.1016/j.gloplacha.2025.104729","url":null,"abstract":"<div><div>Seismic peak ground acceleration (PGA) is a key indicator to characterize the strength of seismic effects, which affects the rate of chemical weathering of carbonate rocks and the ability to capture CO<sub>2</sub>. However, the response mechanism and process of Carbonate rock weathering Carbon Sink (CCS) to PGA are not clear. To this end, this paper clarifies the spatial and temporal patterns of CCS in China and reveals their response to PGA based on PGA, climate, lithology and other datas, combined with methods such as the random forest model and maximal potential dissolution model. The results showed that the CCS Flux(CCSF) was 5.32 t C km<sup>−2</sup> yr<sup>−1</sup> and the Full CCS (FCCS) was 1346 × 10<sup>4</sup> t C yr<sup>−1</sup>, which was influenced by PGA, with the flux being the largest at 0.05 g PGA (5.38 t C km<sup>−2</sup> yr<sup>−1</sup>), mainly in the south-western part of the country where hydrothermal conditions are favourable. Meanwhile, the response of CCS to PGA was affected by latitude and altitude divergence. CCS at the same latitude showed a fluctuating downward trend with the enhancement of PGA. Two trends of CCS and PGA at the same altitude appeared, one was that CCS increased with the enhancement of PGA when the altitude was less than 2500 m as well as 4500–6500 m, and the other was that CCS decreased with the enhancement of PGA when the altitude was 2500–4500 m. At the same PGA, CCS decreased with increasing latitude and elevation, respectively. This may be due to the fact that higher altitude and latitude are associated with lower temperatures, which affects the rate of chemical weathering of carbonate rocks, and hence CCS. The aim of this paper is to understand the response relationship between CCS and PGA, which helps to reveal how geologic activities affect the carbon cycle. The results of the study bridge the gap between tectonic geology and CCS systematic research to a certain extent, and promote the integration of the disciplines. This is of great significance for assessing the potential impact of natural disasters such as earthquakes on carbon sinks.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"246 ","pages":"Article 104729"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143124537","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2024.104668
Zheng Gong , Iona Baillie , Lyle L. Nelson , Stacey H. Gerasimov , Catherine Rose , Emily F. Smith
The Nama Group in southern Namibia captures one of the best-preserved records of the last ∼10 million years of the Ediacaran Period, recording pivotal changes to Earth's biosphere and oceans. Within the Nama Group, the lower Schwarzrand Subgroup preserves early complex bilaterian trace fossils, but uncertainties surrounding the ages of their first occurrences hinder global correlation and the understanding of the rates at which critical biological changes occurred. This study presents magnetic susceptibility cyclostratigraphy of a recently acquired drill core that covers the Nudaus Formation and Nasep Member within the lower Schwarzrand Subgroup. Spectral analysis reveals a hierarchy of orbital cycles that could be responsible for the repeating depositional sequences at various length scales in the Schwarzrand Subgroup. Matching the wavelengths of the orbital cycles to their expected periodicities, we established sedimentation rates throughout the stratigraphy. Utilizing available UPb ages from correlative outcrop sections and the sedimentation rates from cyclostratigraphy, we refine the age-depth model for the lower Schwarzrand Subgroup. Our new age-depth model places tighter temporal constraints on the first appearances of complex trace fossils, thus constraining the earliest major radiation of bilaterian metazoans and contributing to a better-calibrated chronostratigraphy of the terminal Ediacaran Period.
{"title":"Magnetic susceptibility cyclostratigraphy of the lower Schwarzrand Subgroup in southern Namibia refines temporal calibration of late Ediacaran bilaterian radiation","authors":"Zheng Gong , Iona Baillie , Lyle L. Nelson , Stacey H. Gerasimov , Catherine Rose , Emily F. Smith","doi":"10.1016/j.gloplacha.2024.104668","DOIUrl":"10.1016/j.gloplacha.2024.104668","url":null,"abstract":"<div><div>The Nama Group in southern Namibia captures one of the best-preserved records of the last ∼10 million years of the Ediacaran Period, recording pivotal changes to Earth's biosphere and oceans. Within the Nama Group, the lower Schwarzrand Subgroup preserves early complex bilaterian trace fossils, but uncertainties surrounding the ages of their first occurrences hinder global correlation and the understanding of the rates at which critical biological changes occurred. This study presents magnetic susceptibility cyclostratigraphy of a recently acquired drill core that covers the Nudaus Formation and Nasep Member within the lower Schwarzrand Subgroup. Spectral analysis reveals a hierarchy of orbital cycles that could be responsible for the repeating depositional sequences at various length scales in the Schwarzrand Subgroup. Matching the wavelengths of the orbital cycles to their expected periodicities, we established sedimentation rates throughout the stratigraphy. Utilizing available U<img>Pb ages from correlative outcrop sections and the sedimentation rates from cyclostratigraphy, we refine the age-depth model for the lower Schwarzrand Subgroup. Our new age-depth model places tighter temporal constraints on the first appearances of complex trace fossils, thus constraining the earliest major radiation of bilaterian metazoans and contributing to a better-calibrated chronostratigraphy of the terminal Ediacaran Period.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104668"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797879","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2024.104661
Haipeng Wang , Jianhui Chen , Yuanhao Sun , Ruijin Chen , Nasetay Aydenbek , Jianbao Liu
Inland Asia is a major global source of dust and the dust transport from this region has global implications. However, the processes and forcing mechanisms of dust activity in inland Asia during the Holocene are still debated due to the lack of high-quality records with accurate dating, unambiguous dust signals, and a high resolution. Here we present a well-dated record of dust activity based on the Ti content of the sediments of Shuanghu Lake, in the southern Altai Mountains, with a ∼ 15-yr-resolution and covering the entire Holocene. This record shows a gradual decrease in dust intensity during ∼11.7–6 thousand years ago (ka), followed by a persistent increase since ∼6 ka. Frequent dust events are also evident, lasting hundreds of years, and are superimposed on the millennial-scale trend, corresponding to the nine North Atlantic Bond events. We propose that the millennial-scale trend of dust activity was primarily influenced by variations in the mid-latitude Westerlies, while the dust events on the centennial scale were driven primarily by a strengthened East Asian winter monsoon. Overall, this study provides a reliable, high-resolution record of Holocene dust activity in inland Asia, and it updates the previous view that dust activity in this region was solely controlled by the mid-latitude Westerlies or the Siberian High. Our findings contribute to an improved understanding of global dust transport with implications for predicting future dust activity in this region.
{"title":"Holocene dust activity in inland Asia driven by both the mid-latitude Westerlies and the East Asian winter monsoon","authors":"Haipeng Wang , Jianhui Chen , Yuanhao Sun , Ruijin Chen , Nasetay Aydenbek , Jianbao Liu","doi":"10.1016/j.gloplacha.2024.104661","DOIUrl":"10.1016/j.gloplacha.2024.104661","url":null,"abstract":"<div><div>Inland Asia is a major global source of dust and the dust transport from this region has global implications. However, the processes and forcing mechanisms of dust activity in inland Asia during the Holocene are still debated due to the lack of high-quality records with accurate dating, unambiguous dust signals, and a high resolution. Here we present a well-dated record of dust activity based on the Ti content of the sediments of Shuanghu Lake, in the southern Altai Mountains, with a ∼ 15-yr-resolution and covering the entire Holocene. This record shows a gradual decrease in dust intensity during ∼11.7–6 thousand years ago (ka), followed by a persistent increase since ∼6 ka. Frequent dust events are also evident, lasting hundreds of years, and are superimposed on the millennial-scale trend, corresponding to the nine North Atlantic Bond events. We propose that the millennial-scale trend of dust activity was primarily influenced by variations in the mid-latitude Westerlies, while the dust events on the centennial scale were driven primarily by a strengthened East Asian winter monsoon. Overall, this study provides a reliable, high-resolution record of Holocene dust activity in inland Asia, and it updates the previous view that dust activity in this region was solely controlled by the mid-latitude Westerlies or the Siberian High. Our findings contribute to an improved understanding of global dust transport with implications for predicting future dust activity in this region.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104661"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797881","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2024.104676
Yi Zhong , Yuxing Liu , Xiaojing Du , Xiaoxu Shi , Xing Xu , Zhengyao Lu , Stefanie Kaboth-Bahr , Mark J. Dekkers , Juan C. Larrasoaña , Keiji Horikawa , Chijun Sun , Liang Ning , André Bahr , Yanan Zhang , Debo Zhao , Jiabo Liu , Wenyue Xia , Jingyu Zhang , Sheng Yang , Hai Li , Qingsong Liu
The millennial-scale hydroclimate variability in East Asia has been debated for a long time due to the lack of reliable precipitation records from southern China and inconsistent model simulations. Here, we reconstruct a 40-kyr rainfall record for southern China and Taiwan based on enviro-magnetic and clay mineral proxy parameters from a northern South China Sea marine sediment core. Both proxies suggest reduced East Asian Summer Monsoon (EASM) precipitation in the southern China-Taiwan region during North Atlantic cooling episodes. After integration with other EASM precipitation records and modeling results, we conclude that the spatial precipitation pattern across Southeast Asia is closely related to the strength of the Pacific Walker Circulation. This interpretation is supported by a model simulation that emphasizes the role of the Walker Circulation in transferring North Atlantic climate variability to the East Asian hydroclimate. Our findings contribute to resolving the disparities between precipitation proxies and model simulations in Southeast Asia.
{"title":"Pacific Walker Circulation modulated millennial-scale East Asian summer monsoon rainfall variability over the past 40 kyr","authors":"Yi Zhong , Yuxing Liu , Xiaojing Du , Xiaoxu Shi , Xing Xu , Zhengyao Lu , Stefanie Kaboth-Bahr , Mark J. Dekkers , Juan C. Larrasoaña , Keiji Horikawa , Chijun Sun , Liang Ning , André Bahr , Yanan Zhang , Debo Zhao , Jiabo Liu , Wenyue Xia , Jingyu Zhang , Sheng Yang , Hai Li , Qingsong Liu","doi":"10.1016/j.gloplacha.2024.104676","DOIUrl":"10.1016/j.gloplacha.2024.104676","url":null,"abstract":"<div><div>The millennial-scale hydroclimate variability in East Asia has been debated for a long time due to the lack of reliable precipitation records from southern China and inconsistent model simulations. Here, we reconstruct a 40-kyr rainfall record for southern China and Taiwan based on enviro-magnetic and clay mineral proxy parameters from a northern South China Sea marine sediment core. Both proxies suggest reduced East Asian Summer Monsoon (EASM) precipitation in the southern China-Taiwan region during North Atlantic cooling episodes. After integration with other EASM precipitation records and modeling results, we conclude that the spatial precipitation pattern across Southeast Asia is closely related to the strength of the Pacific Walker Circulation. This interpretation is supported by a model simulation that emphasizes the role of the Walker Circulation in transferring North Atlantic climate variability to the East Asian hydroclimate. Our findings contribute to resolving the disparities between precipitation proxies and model simulations in Southeast Asia.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104676"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841258","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2024.104688
Jackson C. McCaffrey , Stephen J. Gallagher , Malcolm W. Wallace , Tanita Averes , Stanislaus G. Fabian , Katja Lindhorst , Lars Reuning , Sebastian Krastel
The tropical North West Shelf of Australia hosts a diverse range of modern reefs. Six shelf edge isolated atolls are present north of 18°S including: Ashmore Reef, Scott Reef and Seringapatam Reef, and three Rowley Shoals. The Ningaloo Reef is a fringing reef around the North West Cape at 22°S. All of these reefs are the remnants of a vast 2000 km long barrier reef that drowned during the Late Miocene (∼10 Ma). Despite extensive hydrocarbon exploration in the region, the history of these isolated reefs is not well known. Seismic analyses combined with stratigraphic analyses of International Ocean Discovery Site U1464 near the Rowley Shoals has revealed that these modern isolated atolls have a complex evolution related to climate and tectonism as they managed to survive on their Miocene barrier reef foundation.
The first Miocene reefs (∼17 Ma) near the Rowley Shoals were isolated small, mound-shaped features. These evolved into a barrier reef by the Middle Miocene (∼16 Ma). However, by the Late Miocene (∼10 Ma) this barrier reef backstepped landward, evolved into isolated mounds/atolls and drowned prior to the Miocene-Pliocene boundary (∼6 Ma) largely due regional tectonic subsidence. Early Pliocene reef expansion (∼4.6 Ma) led to the growth of four isolated atolls (the Rowley Shoals) related to local faulting and Early Pliocene warmth. Subsequently a second Pliocene reef growth phase occurred from ∼3.5 to 3 Ma when eastern Indian Ocean sea surface temperatures cooled by ∼4 °C due to Indonesian Gateway constriction and a reduced Leeuwin Current. By the Pleistocene (∼2.4 Ma) one the four Rowley Shoals had drowned. Strong sea level variability, together with Indonesian Throughflow constriction and reduction in intensity of the Leeuwin Current after 2.4 Ma may have led to enhanced cooling and regional upwelling. These factors may have been sufficient to cause local drowning of the southerly fourth Rowley Shoal while the more northerly three Shoals survived until present.
{"title":"The Rowley Shoals atolls: Remnants of a Miocene great barrier reef on the north-west Australian margin","authors":"Jackson C. McCaffrey , Stephen J. Gallagher , Malcolm W. Wallace , Tanita Averes , Stanislaus G. Fabian , Katja Lindhorst , Lars Reuning , Sebastian Krastel","doi":"10.1016/j.gloplacha.2024.104688","DOIUrl":"10.1016/j.gloplacha.2024.104688","url":null,"abstract":"<div><div>The tropical North West Shelf of Australia hosts a diverse range of modern reefs. Six shelf edge isolated atolls are present north of 18°S including: Ashmore Reef, Scott Reef and Seringapatam Reef, and three Rowley Shoals. The Ningaloo Reef is a fringing reef around the North West Cape at 22°S. All of these reefs are the remnants of a vast 2000 km long barrier reef that drowned during the Late Miocene (∼10 Ma). Despite extensive hydrocarbon exploration in the region, the history of these isolated reefs is not well known. Seismic analyses combined with stratigraphic analyses of International Ocean Discovery Site U1464 near the Rowley Shoals has revealed that these modern isolated atolls have a complex evolution related to climate and tectonism as they managed to survive on their Miocene barrier reef foundation.</div><div>The first Miocene reefs (∼17 Ma) near the Rowley Shoals were isolated small, mound-shaped features. These evolved into a barrier reef by the Middle Miocene (∼16 Ma). However, by the Late Miocene (∼10 Ma) this barrier reef backstepped landward, evolved into isolated mounds/atolls and drowned prior to the Miocene-Pliocene boundary (∼6 Ma) largely due regional tectonic subsidence. Early Pliocene reef expansion (∼4.6 Ma) led to the growth of four isolated atolls (the Rowley Shoals) related to local faulting and Early Pliocene warmth. Subsequently a second Pliocene reef growth phase occurred from ∼3.5 to 3 Ma when eastern Indian Ocean sea surface temperatures cooled by ∼4 °C due to Indonesian Gateway constriction and a reduced Leeuwin Current. By the Pleistocene (∼2.4 Ma) one the four Rowley Shoals had drowned. Strong sea level variability, together with Indonesian Throughflow constriction and reduction in intensity of the Leeuwin Current after 2.4 Ma may have led to enhanced cooling and regional upwelling. These factors may have been sufficient to cause local drowning of the southerly fourth Rowley Shoal while the more northerly three Shoals survived until present.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104688"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905669","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}
Net Primary Productivity (NPP) is an index for assessing ecosystem services and productivity on land. However, previous studies focused solely on NPP changes across ecological regions, overlooking the comparative advantage of the impacts of land changes and climatic variations on various forms of NPP as indicators of ecosystem degradation and restoration across different eco-political milieux. This study comparatively analyzed land cover changes and examined NPP trends and their effects using Mann-Kendall Theil-Sen slopes, the Pearson correlation, and advanced geostatistical methods in the Lake Chad Basin (LCB) and the Aral Sea Basin (ASB). We found that from 2000 to the present and projected to 2030, cropland is expected to expand by 2.20 %, leading to a reduction of shrubland by −2.40 % in LCB. Likewise, a probable increase of 1.1 % in grassland is expected to further reduce waterbodies in ASB by −1.5 %. These potential changes are the resultant effect of the present human-induced NPP (HNPP) reduction of −5.92gC/m2/yr across 2.44 × 103 km2 and 29.84gC/m2/yr across 14.32× 103 km2, indicating human-dominated degradation (HDD) in LCB. Whereas, in ASB, the influence of HNPP by −8.12 gC/m2/yr across 14.32 × 103 km2 and by 4.00gC/m2/yr across 7.24× 103 km2 indicate incipient human-dominated restoration scenarios. Consequent to the warming temperature, climate fluctuations are characterized by HDD in LCB, whereas in ASB, they are characterized by climate-induced degradation. Apprehending these evolving dynamics in endorheic lakes can provide insight into potential restoration trajectories for future land degradations.
{"title":"Combined impacts of land change and climate variability on ecosystem net primary productivity in arid regions","authors":"Emeka Edwin Igboeli , Ogbue Chukwuka , Friday Uchenna Ochege , Chukwuemeka Anthony Onyekwelu , Qing Ling , Chukwuedozie Ajaero , Rafiq Hamdi , Mijanur Rahman , Alphonse Kayiranga , Geping Luo","doi":"10.1016/j.gloplacha.2024.104682","DOIUrl":"10.1016/j.gloplacha.2024.104682","url":null,"abstract":"<div><div>Net Primary Productivity (NPP) is an index for assessing ecosystem services and productivity on land. However, previous studies focused solely on NPP changes across ecological regions, overlooking the comparative advantage of the impacts of land changes and climatic variations on various forms of NPP as indicators of ecosystem degradation and restoration across different eco-political milieux. This study comparatively analyzed land cover changes and examined NPP trends and their effects using Mann-Kendall Theil-Sen slopes, the Pearson correlation, and advanced geostatistical methods in the Lake Chad Basin (LCB) and the Aral Sea Basin (ASB). We found that from 2000 to the present and projected to 2030, cropland is expected to expand by 2.20 %, leading to a reduction of shrubland by −2.40 % in LCB. Likewise, a probable increase of 1.1 % in grassland is expected to further reduce waterbodies in ASB by −1.5 %. These potential changes are the resultant effect of the present human-induced NPP (HNPP) reduction of −5.92gC/m<sup>2</sup>/yr across 2.44 × 10<sup>3</sup> km<sup>2</sup> and 29.84gC/m<sup>2</sup>/yr across 14.32× 10<sup>3</sup> km<sup>2</sup>, indicating human-dominated degradation (HDD) in LCB. Whereas, in ASB, the influence of HNPP by −8.12 gC/m<sup>2</sup>/yr across 14.32 × 10<sup>3</sup> km<sup>2</sup> and by 4.00gC/m<sup>2</sup>/yr across 7.24× 10<sup>3</sup> km<sup>2</sup> indicate incipient human-dominated restoration scenarios. Consequent to the warming temperature, climate fluctuations are characterized by HDD in LCB, whereas in ASB, they are characterized by climate-induced degradation. Apprehending these evolving dynamics in endorheic lakes can provide insight into potential restoration trajectories for future land degradations.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104682"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142884640","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2024.104687
Kaikai Wu , Xuefa Shi , Shengfa Liu , Franck Bassinot , Christophe Colin , Hui Zhang , Che Abd. Rahim Mohamed
Marine concretions are an important source of information regarding resources, climate, and environment. However, the genesis of ferruginous concretions on the continental shelf remains unclear. In this study, we present the radiocarbon ages (AMS14C), elemental compositions, and mineral compositions of ferruginous concretions obtained from a gravity core on the central Sunda Shelf. The results indicate that the formation ages of ferruginous concretions range from 10.5 to 7.5 cal ka BP from the bottom to the top of the core. The predominant mineral identified in these concretions is goethite, which cements clay and other minerals in colloidal form. Notably, Fe, Si, and Al display distinct ring-band rhythmic variations. Our study suggests that ferruginous concretions are formed in subaerial and aqueous environments, with a weathered stiff clay layer serving as the main stratum for concretion development. During periods of low sea levels (before 10.5 cal ka BP), paleo-channels likely provided fluctuating wet and dry conditions for the formation of light and dark concentric layers within ferruginous concretions. Between 10.5 and 7.5 cal ka BP, the Sunda Shelf was gradually inundated, leading to the partial transport of concretions from nearby channels. Subsequently, after 7.5 cal ka BP, the paleo-channels became completely submerged, halting the formation of ferruginous concretions on the Sunda Shelf. Meanwhile, ferruginous concretions on the seafloor became mixed with sediments and marine organisms due to hydrodynamic sorting. The presence of ferruginous concretions can serve as an indicator of paleo-channel locations, aiding in the reconstruction of paleo-channel systems during periods of low sea level on the shallow continental shelf.
海洋沉积物是有关资源、气候和环境信息的重要来源。然而，大陆架上含铁结块的成因仍不清楚。本文报道了巽他陆架中部重力岩心中含铁结块的放射性碳年龄（AMS14C）、元素组成和矿物组成。结果表明，铁质结核的形成年龄从岩心底部到顶部为10.5 ~ 7.5 cal ka BP。在这些固结物中发现的主要矿物是针铁矿，它以胶体形式粘合粘土和其他矿物。值得注意的是，铁、硅和铝显示出明显的环带节奏变化。研究表明，含铁结垢形成于陆基和水环境中，风化硬化粘土层是结垢发育的主要地层。在低海平面时期（10.5 cal ka BP之前），古河道可能为含铁结岩内明暗同心层的形成提供了波动的干湿条件。在10.5 ~ 7.5 cal ka BP之间，巽他陆架逐渐被淹没，导致附近河道的部分凝块被搬运。随后，在7.5 cal ka BP之后，古河道完全被淹没，停止了巽他陆架上铁质结核的形成。同时，由于水动力分选，海底的含铁结块与沉积物和海洋生物混合在一起。含铁结块的存在可以作为古河道位置的指示物，有助于浅陆架低海平面时期古河道系统的重建。
{"title":"The origin of ferruginous concretions on the Sunda Shelf (SE Asia) and its environmental implications","authors":"Kaikai Wu , Xuefa Shi , Shengfa Liu , Franck Bassinot , Christophe Colin , Hui Zhang , Che Abd. Rahim Mohamed","doi":"10.1016/j.gloplacha.2024.104687","DOIUrl":"10.1016/j.gloplacha.2024.104687","url":null,"abstract":"<div><div>Marine concretions are an important source of information regarding resources, climate, and environment. However, the genesis of ferruginous concretions on the continental shelf remains unclear. In this study, we present the radiocarbon ages (AMS<sup>14</sup>C), elemental compositions, and mineral compositions of ferruginous concretions obtained from a gravity core on the central Sunda Shelf. The results indicate that the formation ages of ferruginous concretions range from 10.5 to 7.5 cal ka BP from the bottom to the top of the core. The predominant mineral identified in these concretions is goethite, which cements clay and other minerals in colloidal form. Notably, Fe, Si, and Al display distinct ring-band rhythmic variations. Our study suggests that ferruginous concretions are formed in subaerial and aqueous environments, with a weathered stiff clay layer serving as the main stratum for concretion development. During periods of low sea levels (before 10.5 cal ka BP), paleo-channels likely provided fluctuating wet and dry conditions for the formation of light and dark concentric layers within ferruginous concretions. Between 10.5 and 7.5 cal ka BP, the Sunda Shelf was gradually inundated, leading to the partial transport of concretions from nearby channels. Subsequently, after 7.5 cal ka BP, the paleo-channels became completely submerged, halting the formation of ferruginous concretions on the Sunda Shelf. Meanwhile, ferruginous concretions on the seafloor became mixed with sediments and marine organisms due to hydrodynamic sorting. The presence of ferruginous concretions can serve as an indicator of paleo-channel locations, aiding in the reconstruction of paleo-channel systems during periods of low sea level on the shallow continental shelf.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104687"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905666","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2025.104694
Haibo He , Zaihua Liu , Jingan Chen , Dongli Li , Yuyouting Wang , Yongqiang Han , Xing Liu , Hailong Sun , Quan Chen , Wenfang Cao
Lakes exhibit a biological pump (BP) effect, akin to marine systems, acting as a carbon sequestration mechanism. In karst lakes, the BP works in synergy with a more efficient carbonate pump (CP), enhancing phosphorus (P) removal. This synergy provides a plausible explanation for the observed P enrichment in karst lake sediments. It is hypothesized that an enhanced BP effect drives the CP, accelerating the co-precipitation of carbonates with P, resulting in the accumulation of calcium-bound P compounds (CaP). However, these hypotheses remain largely unquantified and unverified. Research into centennial-scale multi-proxy sedimentary records from Fuxian Lake, a representative karst lake in China, showed significant correlations among organic and inorganic carbon, including contents, fluxes, and isotopic profiles, demonstrating the interplay between the BP and the CP. Carbonate δ18O data further support the conclusion that the BP is the primary driver of the CP. Moreover, a strong correlation (r > 0.6, P < 0.0001) between organic-inorganic carbon proxies and sedimentary P has been identified. Compared to phytoplankton, submerged plants significantly boost P co-precipitation (forming CaP) through the BP mechanism by facilitating a more efficient CP. CaP, the main component within stable sedimentary P reservoirs, saw a post-1950 burial flux increase to 3.5 times that of the preceding period, reaching 0.24 g P m−2 yr−1. This underscores the CP's effectiveness in P sequestration under increased anthropogenic pressure. Given the uniquely high weathering rates, Ca2+, pH, and dissolved inorganic carbon content of karst lakes, we suggest that their strong BP effect, combined with the CP, significantly enhances P removal, offering an autogenic solution to eutrophication.
湖泊表现出生物泵（BP）效应，类似于海洋系统，作为碳固存机制。在喀斯特湖泊中，BP与更高效的碳酸盐泵（CP）协同工作，增强了磷(P)的去除。这种协同作用为观察到的喀斯特湖泊沉积物中磷的富集提供了合理的解释。假设BP效应的增强驱动CP，加速碳酸盐与P的共沉淀，导致钙结合P化合物（CaP）的积累。然而，这些假设在很大程度上仍未被量化和验证。通过对中国代表性喀斯特湖泊抚仙湖100年多代沉积记录的研究，发现有机碳和无机碳在含量、通量和同位素剖面等方面具有显著的相关性，证明了BP与CP之间的相互作用。碳酸盐岩δ18O数据进一步支持了BP是CP的主要驱动因素的结论。0.6, P <；0.0001)，有机质-无机碳代用物与沉积P之间存在差异。与浮游植物相比，沉水植物通过BP机制显著促进P共降水（形成CaP），促进更有效的CP。CaP是稳定沉积P储层的主要成分，其埋藏通量在1950年后增加到前一时期的3.5倍，达到0.24 g P m−2 yr−1。这强调了在人为压力增加的情况下，CP在固磷方面的有效性。鉴于喀斯特湖泊独特的高风化速率、Ca2+、pH和溶解无机碳含量，我们认为它们强大的BP效应，加上CP，显著增强了P的去除，为富营养化提供了自源解决方案。
{"title":"Enhanced biological pump and carbonate pump synergy: The primary pathway for phosphorus clearance in the century-long dynamics of a karst lake","authors":"Haibo He , Zaihua Liu , Jingan Chen , Dongli Li , Yuyouting Wang , Yongqiang Han , Xing Liu , Hailong Sun , Quan Chen , Wenfang Cao","doi":"10.1016/j.gloplacha.2025.104694","DOIUrl":"10.1016/j.gloplacha.2025.104694","url":null,"abstract":"<div><div>Lakes exhibit a biological pump (BP) effect, akin to marine systems, acting as a carbon sequestration mechanism. In karst lakes, the BP works in synergy with a more efficient carbonate pump (CP), enhancing phosphorus (P) removal. This synergy provides a plausible explanation for the observed P enrichment in karst lake sediments. It is hypothesized that an enhanced BP effect drives the CP, accelerating the co-precipitation of carbonates with P, resulting in the accumulation of calcium-bound P compounds (Ca<img>P). However, these hypotheses remain largely unquantified and unverified. Research into centennial-scale multi-proxy sedimentary records from Fuxian Lake, a representative karst lake in China, showed significant correlations among organic and inorganic carbon, including contents, fluxes, and isotopic profiles, demonstrating the interplay between the BP and the CP. Carbonate δ<sup>18</sup>O data further support the conclusion that the BP is the primary driver of the CP. Moreover, a strong correlation (<em>r</em> > 0.6, <em>P</em> < 0.0001) between organic-inorganic carbon proxies and sedimentary P has been identified. Compared to phytoplankton, submerged plants significantly boost P co-precipitation (forming Ca<img>P) through the BP mechanism by facilitating a more efficient CP. Ca<img>P, the main component within stable sedimentary P reservoirs, saw a post-1950 burial flux increase to 3.5 times that of the preceding period, reaching 0.24 g P m<sup>−2</sup> yr<sup>−1</sup>. This underscores the CP's effectiveness in P sequestration under increased anthropogenic pressure. Given the uniquely high weathering rates, Ca<sup>2+</sup>, pH, and dissolved inorganic carbon content of karst lakes, we suggest that their strong BP effect, combined with the CP, significantly enhances P removal, offering an autogenic solution to eutrophication.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104694"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142975634","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}
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