Earth-Science Reviews最新文献

Critical Zone Observatories (CZOs) have been established initially in natural environments to monitor CZ processes. A new generation of CZOs has been extended to human-modified landscapes to address the impacts of climate change and human-caused actions such as erosion, droughts, floods, and water resource pollution. This review focuses on numerous plot, field, and regional scale studies conducted in the CZO facilities distributed across the China Loess Plateau (CLP). The CLP CZO features the world's largest and deepest loess deposits, highly disturbed by human activities, and consists of a longitudinal series of monitoring sites. This observation system consists of plot, slope, watershed, and regional observatories and is promoted by large-scale comprehensive experiments to achieve multiscale observations. Deep soil boreholes, hydro-geophysical tools, multiple tracers-based techniques, proximal and remote sensing techniques, and automatic monitoring equipment are implemented to monitor CZ processes. Observation and modeling of critical hydrological and biogeochemical processes (e.g., water, nutrients, carbon, and microbial activities) in land surface and deep loess deposits across CLP CZOs have unveiled crucial insights into human-environment interactions and sustainability challenges. Large-scale ecological efforts such as revegetation and engineering such as check dam construction have effectively mitigated flood and soil erosion while enhancing deep soil carbon sequestration. However, these interventions can yield both benefits and drawbacks, impacting deep soil water, groundwater recharge, and agricultural production. Converting arable cropland to orchards for increased income has raised nitrate accumulation in the deep vadose zone, posing a risk of groundwater pollution. These findings, combined with the CZ data, have identified knowledge exchange opportunities to unravel diverse factors within the relations of agriculture, ecosystem, and environment. These could directly improve local livelihoods and eco-environmental conditions by optimizing land use and management practices, increasing water use efficiency, and reducing fertilizer application. These efforts contribute towards Sustainable Development Goals (SDGs) and environmental policies. Overall, studies within the CLP have provided significant scientific advancements and guidance on managing CZ processes and services with regional SDGs, that may be transferable to other highly disturbed regions of the world.

Coastal wetlands play a vital role in carbon (C) sequestration, named ‘blue carbon’. The review aims to disentangle the processes and influencing factors, including elevated atmospheric CO₂, global climate warming, sea level rise and anthropogenic activities. Firstly, we provided an overview of C processes, including input, output, and deposition, in coastal wetlands. We then summarized the impacts of different factors on C processes by modifying soil physicochemical properties, plant growth, vegetation type, and microbial community composition. Vegetation composition was a major contributor to C inputs, and C outputs was mainly controlled by microbial decomposition. Increased atmospheric CO₂ concentration and associated climate warming often enhanced vegetation growth, while climate warming also promoted soil C decomposition. As a result, C storage could increase under mild warming conditions in the short-term, but decrease in the long-term as the severity of warming intensifies. Elevated salinity, caused by sea level rise, can be harmful to plant growth and inhibit organic C decomposition because of the reduced biomass and the weakened metabolic capacity of microorganisms. Most of human activities, such as reclamation, can lead to less C input and more C output, resulting in decreased C storage in coastal wetlands. Additionally, we also illustrate various coastal wetland restoration methods aimed at enhancing C sequestration, including legal frameworks, scientific theories, vegetation management, hydrological restoration, and other relevant constructions. Vegetation management could benefit plant growth and enhance C input effectively, and hydrological restoration can maintain the harmonious development of coastal wetland ecosystems. Other constructions, including breakwater, spillway, and dredged material, could protect coastal wetlands, especially facing sea level rise. This review offers valuable theoretical support and scientific references for the sustainable development and management of coastal wetlands in a changing climate.

In the face of escalating anthropogenic impacts stemming from urbanization and industrialization, our study delves into the critical realm of potentially toxic elements (PTEs) contamination in soil, unraveling a complex web of interactions that imperil soil environments and their vital microbial and enzymatic activities. Unlike organic pollutants, PTEs resist microbial degradation and their presence disrupts soil microbial and enzymatic activities, affecting the nutrient cycle and plant growth. There is a need to find effective nature-based solutions for addressing soil contamination with PTEs; this quest has led to increased interest in bioremediation, utilizing bacteria, fungi, algae, and plants for sustainable environmental cleanup. While previous reviews have addressed general principles about the bioremediation of PTEs contaminated soils, there are no critical reviews which have been published about the current state of the microbe-assisted phytoremediation (MAP). Particularly, this review aims at meticulously examining the understudied roles of diverse microbes-archaea, bacteria, and fungi in the rhizosphere of hyperaccumulators under PTEs stress. In doing so, it also expands our understanding of the plant root microbiome's contribution to phytoremediation of PTEs in hyperaccumulator plants. We focus on how PTE pollution influences plant signaling pathways, root exudate profiles, and subsequent interactions with diverse microbial communities. Also, we discuss the behavior of archaea towards MAP, filling a significant gap in current understanding. Moreover, we comprehensively analyze how microbial communities interact with hyperaccumulators, and discuss the most recent research that expands beyond the known role of organic acid producers to explore how a wider range of diverse phytobiome collaborates with plants to detoxify PTEs, influencing biogeochemical cycles in intriguing ways. This review examines the biochemical and molecular mechanisms that promote plant growth, offering a comprehensive perspective on the present knowledge and future prospects in this field. By synthesizing existing knowledge, this review provides insights into effective strategies for remediating PTEs-polluted soils. The findings are relevant for researchers, environmental scientists, and policymakers, guiding future efforts to address the growing issue of PTEs contamination and its impact on soil ecosystems.

The evolution of ideas concerning the origin of volcanic activity is far from being simple. Nevertheless, an examination of the main lines of thought about volcanism throughout history allows us to identify general trends that explain why some hypotheses were accepted at a given time, even when there was contemporary evidence suggesting critical problems of those hypotheses. Throughout history, it is observed that the form in which new pieces of evidence have been incorporated into existing paradigms has played a critical role in the development of new concepts. However, it can also be established that the drive to make new discoveries has not been accompanied always by the immediate assimilation of that evidence in the corpus of scientific research. Thus, competing ideas or hypotheses sometimes have co-existed for many years. A current example of such debates concerns the plate vs. plume origin of volcanic activity on our planet. In this work I examine this issue from a methodological point of view that combines a historical perspective with rigorous definitions of causality. The historical approach helps us to understand aspects of the debate that otherwise might be too sensitive to point out without spurring partisan reactions. The examination of causality relations serves to appreciate the many implications that the discovery of volcanic activity beyond Earth should have brought to the forefront of the debate, but that, for many reasons, has failed to do so. By combining both methodological perspectives, I present a new framework upon which questions such as “Do all intraplate volcanoes on Earth are produced by the action of mantle plumes?” can be addressed without the risk of falling into circular arguments. The framework outlined here, therefore, presents a viable alternative that could help us focus future efforts to fully understand aspects of the volcano-tectonic relationship that are difficult to appreciate given the current plate and plume paradigms.

The intricate convergence of tectonic plates and the interplay between landmasses and oceans in subduction zones give rise to marine geo-hazards, encompassing catastrophic events in marine environments, posing significant risks to ecosystems, coastal communities and infrastructure. The Makran Subduction Zone (MSZ), with its remarkable history of devastating earthquakes and tsunamis, is a subject of significant attention from both academic and industrial sectors in recent decades. In this comprehensive review, we investigated various marine geo-hazards in the north Arabian Sea (NAS), particularly those associated with the MSZ, providing valuable insights for risk mitigation in the coastal regions with a population of over 45 million. The review employed bibliometric methods to comprehensively analyze relevant publications from databases such as Web of Science, Scopus, and China National Knowledge Infrastructure. By conducting a systematic review of 133 publications, this study deepens our understanding associated with MSZ, uncovering 07 distinct categories of geo-hazards. The earthquakes and tsunamis hazards have received extensive attention, with a tentative recurrence interval of around 500 years, while the remaining categories, including seabed fluid flows, mud-volcanism, sub-marine mass movements, subsidence, and erosion, were similarly explored in their respective order. The eastern side of the MSZ demonstrated greater instability compared to the western side, attributed to the ongoing subduction process. The ‘Gang of Four’, consisting of faults, has been identified as a primary causative factor for seismic activity in the NAS, largely influenced by transpressional tectonics. The identified geo-hazards exhibit complex interdependencies, where the initiation of one hazard can amplify the severity of another. An integrated approach is essential for assessment of the complex and interrelated risks and hazards. The research emphasizes the significance of long-term seafloor observatories in the MSZ for real-time monitoring, enabling proactive management and mitigation strategies to address these geo-hazards effectively.

Greenhouse gas emissions have led to severe global climate change, and countries around the world are taking measures to mitigate the greenhouse effect caused by carbon emissions. Carbon dioxide capture, utilization and storage (CCUS) is emerging as a large-scale greenhouse gas emission reduction technology and can potentially become an important means to mitigate the greenhouse effect in the future. There are a series of problems in the implementation of this technology, among which the geomechanical problems due to the thermal effect should not be neglected. This paper summarizes the non-isothermal processes in CCUS and the impacts and hazards caused by the thermal effects of non-isothermal processes. We show that CO₂ injection and sequestration will experience heat exchange with high-temperature formations and wellbores, exothermic dissolution, cooling by the Joule–Thomson effect, exothermic adsorption and exothermic hydrate formation when CO₂ replaces CH₄. These non-isothermal processes can lead to risks including reservoir stability, fault activation and induced seismicity. Thermal effects can also alter reservoir characteristics, such as the effect on CO₂ injection and storage efficiency. This work presents the challenges and future perspectives of thermodynamic studies in CCUS, which will help to fully understand the thermal effects and risks in CCUS and provide a reference for future CCUS operation, monitoring, and research.

The structure and dynamics of the upper mantle control tectonics, seismicity, magmatism, and the development of mineral deposits. Seismic tomography maps spatial variations in seismic velocity and offers essential information on the variations of temperature in the mantle, the thickness and mechanical strength of the lithosphere, and the convection patterns below it. Thanks to the growth in the station coverage, tomographic models of Asia reveal increasingly detailed structures, in particular in its best-sampled parts. Here, we present a new waveform tomography model, ASIA2024, constrained by massive global and regional datasets. The data coverage used to construct ASIA2024 is maximised across the hemisphere centred at Asia. In China, in particular, dense national network data enhances the sampling. Our waveform tomography extracts structural information from surface waves and from S and multiple S body waves. The effects of errors are suppressed by statistical and targeted outlier analyses and the removal of the least mutually consistent data. Extensive comparisons of contemporary tomographic models reveal both consensus features and differences between models and demonstrate relative advantages of different approaches and data types. ASIA2024 advances the resolution of the imaging compared to the state of the art at the scale of the continent. A prominent high-velocity anomaly at lithospheric depths shows the Indian cratonic lithosphere underthrusting and subducting beneath Tibet. In the transition zone below the plateau, a fragmented high-velocity anomaly indicates lithospheric remnants, probably from different phases of subduction. The lithosphere beneath most diamondiferous kimberlites—originally emplaced on thick cratonic lithosphere—is observed to be still thick at present. Relatively low velocities at kimberlite locations are indicative of craton-lithosphere thinning and are detected beneath northwestern Siberian Craton (Siberian Traps) and most of the Indian Shield (Deccan Traps and surroundings), with the exception of the intact cratonic lithosphere beneath northeastern Dharwar Craton. This suggests that the mantle plumes responsible for the traps have eroded the deep cratonic lithosphere. Thin lithosphere and recent basaltic volcanism are observed in eastern Sino-Korean and Yangtze Cratons, with subduction, stretching, and rifting likely to have weakened and modified their cratonic roots. Cenozoic basalts are found exclusively where the lithosphere is observed to be thin. Beneath the Hainan volcanic region, a low-velocity anomaly is observed throughout the upper mantle, consistent with the previously proposed Hainan Plume feeding the magmatism. The shape of the anomaly indicates a complex morphology of the upwelling. Low-velocity anomalies in the mantle transition zone beneath the Hangai Dome and southern Siberian Craton are consistent with hot upwelling(s) and horizontal asthenospheric flow feeding t