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Aerosol spatiotemporal dynamics, source analysis and influence mechanisms over typical drylands 典型旱地上空的气溶胶时空动态、来源分析和影响机制
IF 8.5 1区 地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-10-28 DOI: 10.1016/j.gsf.2024.101958
Yunfei Zhang , Xiangyue Chen , Fengtao Zhao , Qianrou Xia , Hanchen Xing , Mengdi Du
As globally important dust source areas, drylands not only have extremely fragile ecosystems that are exceptionally sensitive to global climate change but also have important implications for global warming and carbon cycling. However, the detailed dryland aerosol characteristics are not clear, especially the influence mechanisms of dryland aerosols, which are poorly understood. In this paper, Utilizing the Xinjiang Uygur Autonomous Region (XJ) as a target area, based on high spatial resolution aerosol optical depth (AOD) data, combined with the trend analysis, backward trajectory, source analysis, and machine learning methods, we systematically analyzed the multiscale dynamic characteristics of aerosols in XJ over a long period. Simultaneously, we also quantitatively explored the source distributions of high aerosols at typical sites at different time scales. Furthermore, we discussed the specific effects of natural and anthropogenic factors on aerosols in XJ and its subregions. The results show that 72.45% of the AOD in XJ presents an increasing trend from 2000 to 2019, 27.56% of which passed the significance test, mainly concentrated in northern Xinjiang (NXJ). The AOD in southern Xinjiang (SXJ) is the largest (0.240 ± 0.154), followed by eastern Xinjiang (EXJ) (0.157 ± 0.038), and the AOD in NXJ is the smallest (0.134 ± 0.028); however, the AOD in NXJ has the most obvious increasing trend, peaking in 2011, and the AOD in XJ remains low and stable at 5000 m elevation and above. The backward trajectory shows that nearly half of the potential paths of high AOD in SXJ are from the Taklamakan Desert, most of the potential paths in NXJ are from transboundary transmission, mostly through exposed lake beds, and most of the potential paths in EXJ are from the northwest, with characteristics similar to those of NXJ. The exposed lake beds provide salt dust, which further exacerbates the complexity and hazards of aerosols in NXJ and EXJ. The potential source areas for AOD in SXJ are concentrated in the northeast of the target site, those in NXJ are concentrated in the west of the target site, and those in EXJ are in the northwest and east. The AOD in SXJ (63.92%) and EXJ (74.83%) or XJ (57.77%) is dominated by natural factors, whereas the magnitude of AOD in NXJ (84.01%) is largely explained by anthropogenic factors.
作为全球重要的尘源地区,旱地不仅生态系统极其脆弱,对全球气候变化异常敏感,而且对全球变暖和碳循环也有重要影响。然而,详细的旱地气溶胶特征并不清楚,尤其是对旱地气溶胶的影响机制知之甚少。本文以新疆维吾尔自治区(XJ)为研究对象,基于高空间分辨率气溶胶光学深度(AOD)数据,结合趋势分析、回溯轨迹、源解析和机器学习等方法,系统分析了XJ地区气溶胶的长期多尺度动态特征。同时,我们还定量探索了不同时间尺度下典型站点的高气溶胶源分布。此外,我们还讨论了自然和人为因素对 XJ 及其子区域气溶胶的具体影响。结果表明,从 2000 年到 2019 年,新疆 72.45%的 AOD 呈上升趋势,其中 27.56%通过了显著性检验,主要集中在北疆(NXJ)。南疆(SXJ)的AOD最大(0.240±0.154),其次是东疆(EXJ)(0.157±0.038),北疆(NXJ)的AOD最小(0.134±0.028);但北疆(NXJ)的AOD上升趋势最明显,在2011年达到峰值,而XJ的AOD在海拔5000米及以上保持低位稳定。后向轨迹显示,SXJ地区近一半的高AOD潜在路径来自塔克拉玛干沙漠,NXJ地区的大部分潜在路径来自跨界传输,主要通过裸露的湖床,EXJ地区的大部分潜在路径来自西北部,其特征与NXJ相似。裸露的湖床提供了盐尘,进一步加剧了 NXJ 和 EXJ 地区气溶胶的复杂性和危害性。SXJ 的 AOD 潜在源区集中在目标地点的东北部,NXJ 的 AOD 潜在源区集中在目标地点的西部,EXJ 的 AOD 潜在源区集中在西北部和东部。SXJ(63.92%)和 EXJ(74.83%)或 XJ(57.77%)的 AOD 主要由自然因素造成,而 NXJ 的 AOD(84.01%)则主要由人为因素造成。
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引用次数: 0
Do we really need to drill through the intact ocean crust? 我们真的需要钻穿完整的海洋地壳吗?
IF 8.5 1区 地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-10-22 DOI: 10.1016/j.gsf.2024.101954
Yaoling Niu
We must persevere to drill through the intact ocean crust to fully address fundamental questions towards completion of the plate tectonics theory. The primary questions include: what is the ocean crust made up of, how thick is it and what is the petrological nature of the crust-mantle boundary (i.e., Mohorovičić discontinuity or Moho)? These questions may sound naive because they are widely believed to be well-understood facts, but they are not. Correctly, our current knowledge remains incomplete, and some popular misperceptions come from interpretations based on convenient assumptions. One assumption is that the ocean crust inferred from seismic data is of magmatic origin. Testing this assumption is a principal motivation of Project Mohole (1957–1966), attempting to drill intact ocean crust across the Moho into the mantle. Project Mohole failed because of its high cost, engineering challenges and insufficient tries, but the technologies developed made subsequent ocean drilling successful. However, answers to the original questions remain unsatisfactory. For example, seismic crust interpreted to be of magmatic origin is shown to have globally uniform thickness of 6.0 ± 1.0 km, but crust with such thickness at many slow-spreading ridge segments is dominated by serpentinized mantle peridotites exposed on seafloors. Therefore, the popular view on ocean ridge magmatism must be re-examined, which needs intact ocean crust drilling into the mantle. Drilling at geologically simple sites in the fast-spreading Pacific seafloor is most promising.
The US-led D/V JOIDES Resolution that has well served the scientific ocean drilling since 1985 is to retire by the end of 2024, but timely the Chinese geoscience community wishes to continue this international endeavor using the purpose-built D/V Meng Xiang to be in service in 2025. The international community is to gather in November 24–27, 2024, Guangzhou, China, to discuss strategies on where and how to successfully drill intact ocean crust across the Moho in coming years.
我们必须坚持不懈地钻探完整的大洋地壳,以充分解决基本问题,从而完成板块构造理论。主要问题包括:大洋地壳由什么构成,有多厚,地壳-地幔边界(即莫霍洛维奇不连续面或莫霍面)的岩石学性质如何?这些问题听起来可能很天真,因为人们普遍认为这些问题都是很好理解的事实,但事实并非如此。正确地说,我们目前的知识仍不完整,一些流行的误解来自基于简单假设的解释。其中一个假设是,从地震数据推断出的海洋地壳来源于岩浆。测试这一假设是莫霍尔计划(1957-1966 年)的主要动机,该计划试图钻探完整的洋壳,穿过莫霍尔进入地幔。由于成本高昂、工程困难和尝试不足,莫霍尔项目失败了,但所开发的技术使随后的大洋钻探取得了成功。然而,最初问题的答案仍不令人满意。例如,被解释为岩浆起源的地震地壳的全球均匀厚度为 6.0 ± 1.0 千米,但在许多缓慢扩张的海脊段,具有这种厚度的地壳主要是暴露在海床上的蛇纹岩化地幔橄榄岩。因此,必须重新审视关于洋脊岩浆活动的流行观点,这需要对地幔进行完整的洋壳钻探。自 1985 年以来一直为大洋科学钻探提供良好服务的美国 "乔伊德斯决议 "号钻井船将于 2024 年底退役,但中国地球科学界及时希望利用专门建造的 "梦翔 "号钻井船(将于 2025 年服役)继续这一国际努力。国际社会将于 2024 年 11 月 24 日至 27 日齐聚中国广州,就未来几年在何处以及如何成功钻探穿越莫霍面的完整洋壳展开战略讨论。
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引用次数: 0
Combined study of Au-bearing arsenopyrite of orogenic gold deposits (NE Asia): High resolution 3D X-ray computed tomography, LA-ICP-MS, and EMPA data 成因金矿床(亚洲东北部)含金黄砷矿的综合研究:高分辨率三维 X 射线计算机断层扫描、LA-ICP-MS 和 EMPA 数据
IF 8.5 1区 地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-10-18 DOI: 10.1016/j.gsf.2024.101953
Evgeny Naumov , Yuri Kalinin , Galina Palyanova , Lyudmila Kryuchkova , Viacheslav Voitenko , Vera Abramova , Franco Pirajno
The distribution of gold in small acicular arsenopyrite of a pyrite-arsenopyrite association from Suzdal (Eastern Kazakhstan), Olympiada (Yenisei Ridge, Russia) and large pseudorhombic arsenopyrite crystals from Bazovskoe (Yakutia, Russia) orogenic-type deposits were investigated. On orogenic gold deposits in NE Asia, occurring mainly in black shales, two productive stages of ore deposition are distinguished, which correspond to two morphological varieties of arsenopyrite. At the early stage, fine-grained acicular-prismatic arsenopyrite with invisible gold was deposited; at the late stage, tabular arsenopyrite in association with free visible gold was formed. The samples of gold-bearing arsenopyrite were analyzed using Scanning Electron Microscopy, Electron Microprobe Analyses, Atomic Absorption and Laser Ablation Inductively Coupled Plasma Mass Spectrometry in combination with High Resolution 3D X-ray Computed Tomography (HRXCT). HRXCT does not destroy the studied mineral during the investigation. That technique permits to do an estimation of the amount of gold inclusions in minerals or host rocks and draw reasonable conclusions about the gold content of the ores, to study in detail the distribution patterns of metal inclusions (associated with certain minerals, cracks, crystal growth faces, etc.) and to determine the form of the gold. It can be used to understanding of the genesis of productive mineral associations, and to developing optimal technological schemes for gold extraction.
研究了苏兹达尔(哈萨克斯坦东部)、奥林匹亚达(俄罗斯叶尼塞山脊)黄铁矿-砷黄铁矿联合体的小针状砷黄铁矿中金的分布情况,以及巴佐夫斯科(俄罗斯雅库特)造山型矿床的大假菱形砷黄铁矿晶体中金的分布情况。东北亚的造山型金矿床主要出现在黑色页岩中,矿石沉积分为两个生产阶段,与两种形态的黄铜矿相对应。在早期阶段,沉积的是含隐形金的细粒针状棱镜状黄砷矿;在晚期阶段,形成了与游离可见金有关的片状黄砷矿。我们使用扫描电子显微镜、电子微探针分析、原子吸收和激光烧蚀电感耦合等离子体质谱法,结合高分辨率三维 X 射线计算机断层扫描(HRXCT)对含金黄铜矿样品进行了分析。在研究过程中,HRXCT 不会破坏所研究的矿物。该技术可以估算矿物或主岩中金包裹体的数量,对矿石中的金含量得出合理的结论,详细研究金属包裹体的分布模式(与某些矿物、裂缝、晶体生长面等有关),并确定金的形态。它可用于了解高产矿物关联的成因,并制定最佳的提金技术方案。
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引用次数: 0
Late Triassic to Middle Jurassic magmatism in the Eastern Pontides (NE Türkiye): Evidence for divergent double subduction of Paleo-Tethys lithosphere 东庞提德山脉(图尔基耶东北部)晚三叠世至中侏罗世岩浆活动:古地台岩石圈分异双俯冲的证据
IF 8.5 1区 地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-10-06 DOI: 10.1016/j.gsf.2024.101952
Yener Eyuboglu , Ze Liu , Dicheng Zhu , Nilanjan Chatterjee , Liangliang Zhang , Jincheng Xie , Francis O. Dudas
The Meso-Cenozoic geodynamic evolution of northern Türkiye remains a subject of debate primarily due to a lack of systematic geological, geochemical, geochronological, and geophysical investigations. This paper presents comprehensive geochronological and geochemical data on the Late Triassic andesite porphyry, andesite breccia and quartz diorite porphyry, and the Middle Jurassic diabase, and amphibole-poor and amphibole-rich andesite porphyry from Çevrepınar Igneous Complex (Gümüşhane) in the southern part of the Eastern Pontides Orogenic Belt (EPOB), a well-preserved continental arc in the Alpine-Himalayan orogen. Zircon U–Pb geochronology indicates crystallization ages of ∼208–202 Ma (Rhaetian) for the Late Triassic rocks and ∼175–172 Ma (Aalenian) for the Middle Jurassic rocks. Whole-rock geochemical and Sr-Nd-Pb isotopic data, and zircon εHf(t) data indicate that both the Late Triassic and the Middle Jurassic rocks originated by low-degree melting of a spinel lherzolite lithospheric mantle source modified by subduction-related fluids and/or melts. Based on the new and published data, we suggest that the Late Triassic to Middle Jurassic arc magmatism in EPOB occurred as a result of southward subduction of the Paleo-Tethys oceanic lithosphere beneath the northern margin of Gondwana-Land. Late Triassic to Jurassic arc magmatism and basin evolution occurred synchronously in the northern and southern peripheries of the present-day Eastern Black Sea Basin, indicating divergent double subduction of the Paleo-Tethys oceanic lithosphere beneath the northern margin of Gondwana and southern margin of Laurasia during the Early Mesozoic.
由于缺乏系统的地质、地球化学、地质年代和地球物理调查,蒂尔基耶北部的中新生代地球动力演化仍是一个争论不休的话题。本文介绍了阿尔卑斯-喜马拉雅造山带中保存完好的大陆弧--东蓬提德造山带(EPOB)南部 Çevrepınar 火成岩群(Gümüşhane)中的晚三叠世安山斑岩、安山角砾岩和石英闪长岩斑岩以及中侏罗世辉长岩、贫闪长岩和富闪长岩斑岩的综合地质年代和地球化学数据。锆石U-Pb地质年代学显示,晚三叠世岩石的结晶年龄为208-202 Ma(雷蒂期),中侏罗世岩石的结晶年龄为175-172 Ma(阿伦期)。全岩地球化学和Sr-Nd-Pb同位素数据以及锆石εHf(t)数据表明,晚三叠世和中侏罗世岩石均起源于尖晶石蛭石岩石圈地幔源的低度熔融,并受到俯冲相关流体和/或熔体的改变。根据新的和已发表的数据,我们认为EPOB的晚三叠世至中侏罗世弧岩浆活动是冈瓦纳-陆地北缘下的古特提斯大洋岩石圈向南俯冲的结果。晚三叠世至侏罗纪弧形岩浆活动和盆地演化同步发生在现今东黑海盆地的北部和南部外围地区,这表明在早中生代时期,冈瓦纳大陆北缘和劳拉西亚大陆南缘下的古特提斯洋岩石圈发生了分异的双重俯冲。
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引用次数: 0
Two phases of granulite-facies metamorphism superimposied on retrograde eclogite: Constraints on the early Paleozoic tectonic evolution of the Qinling Orogenic Belt, central China 逆冲闪长岩叠加的两期花岗岩变质作用中国中部秦岭造山带早古生代构造演化的约束条件
IF 8.5 1区 地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-10-03 DOI: 10.1016/j.gsf.2024.101941
Bowen Bai , Danling Chen , Yunfei Ren , Xiaohui Zhu , Yunpeng Dong , Yuan Tang , Haijie Wang
Existing studies provide adequate petrological evidences on ca. 500 Ma ultra-high pressure (UHP) metamorphism in the North Qinling Orogenic Belt (NQOB) in central China, but the genesis of 470–420 Ma multi-phase granulite-facies metamorphism in the NQOB and their relationship with the ca. 500 Ma UHP metamorphism remain controversial, resulting in the early Paleozoic evolution of the Qinling Orogenic Belt (QOB) highly debatable. In this study, we present mafic granulites and host felsic gneisses with a “red-eye socket” texture from the Shuanglong area, eastern NQOB, which recorded two phases of granulite-facies metamorphism superimposing on former eclogite-facies metamorphism. The former eclogite-facies metamorphism is indicated by eclogite-facies zircon trace element patterns and 496–495 Ma zircon ages, which are the same with those of the HP–UHP eclogite-facies metamorphic rocks in NQOB. The first granulite-facies metamorphism occurred at 460–448 Ma is characterized by coarse-grained minerals in matrix. Compositions and zonings of these minerals define an anticlockwise P–T path involving a prograde stage (751–763 °C), a high-temperature peak stage (9.2 kbar and 864 °C), and a near-isobaric cooling retrograde stage (8.3 kbar and 818 °C). The second granulite-facies metamorphism occurred at 422–421 Ma is represented by coronal garnet and coexisting fine-grained mineral aggregates. Coronal garnet compositional zonings suggest a clockwise P–T path consisting of a high-pressure peak stage (9.5–11.2 kbar and 748–783 °C) and a decompressing and heating retrograde stage (9.2–9.5 kbar and 789–800 °C). Combining dating results of leucosomes in these rocks and existing data, we proposed a new model for early Paleozoic tectonic evolution of the NQOB. The North Qinling Terrane (NQT), probably separated from the South China Block (SCB) during the breakup of Rodinia, drifted northwards and underwent UHP metamorphism at 500 Ma and then rapidly exhumed to crust level. Later, the Shangdan Ocean subducted northwards beneath the exhumed NQT at 470–440 Ma, resulting in the first granulite-facies metamorphism and contemporaneous migmatization and magmatism. Finally, the closure of the Shangdan Ocean led to collision between the NQT and South Qinling Terrane/SCB and the second granulite-facies metamorphism and anatexis at 422–418 Ma.
现有研究为中国中部北秦岭造山带约500 Ma超高压变质作用提供了充分的岩石学证据,但北秦岭造山带470-420 Ma多相花岗岩质变质作用的成因及其与约500 Ma超高压变质作用的关系仍存在争议,导致古生代早期秦岭造山带的演化备受争议。500Ma超高压变质作用的关系仍存在争议,导致秦岭造山带早古生代演化备受争议。本研究揭示了北秦岭造山带东部双龙地区具有 "红眼凹陷 "纹理的黑云母花岗岩和寄主长英片麻岩,它们记录了花岗岩派变质作用与前独斜岩派变质作用叠加的两个阶段。锆英石痕量元素模式和496-495Ma锆英石年龄与北大堡地区HP-UHP黝帘石变质岩的锆英石痕量元素模式和496-495Ma锆英石年龄一致,表明了前黝帘石变质作用。第一次花岗岩-派变质作用发生在460-448 Ma,基质矿物为粗粒矿物。这些矿物的组成和分带确定了一条逆时针的 P-T 路径,包括一个顺行阶段(751-763 °C)、一个高温峰值阶段(9.2 千巴和 864 °C)以及一个接近等压冷却的逆行阶段(8.3 千巴和 818 °C)。第二次花岗岩成因变质发生在422-421 Ma,以日冕石榴石和共生细粒矿物集合体为代表。日冕石榴石成分分带显示了一条顺时针的P-T路径,包括高压峰值阶段(9.5-11.2千巴和748-783 °C)和减压加热逆行阶段(9.2-9.5千巴和789-800 °C)。结合这些岩石中白云母的测年结果和已有数据,我们提出了一个新的北秦岭早古生代构造演化模型。北秦岭地层可能在罗迪尼亚解体过程中从华南地块分离出来,向北漂移,在500Ma时经历了超高压变质作用,然后迅速出露到地壳水平。之后,商丹洋在470-440Ma时向北俯冲到被掘出的NQT之下,导致了第一次花岗岩质变质作用以及同期的岩浆移行作用。最后,商丹洋的关闭导致了北秦岭地层与南秦岭地层/SCB的碰撞,并在422-418Ma发生了第二次花岗岩-成因变质作用和岩浆作用。
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引用次数: 0
Paleogeographic significance of unknown hyperextended continental crust in South Atlantic conjugated margin 南大西洋共轭边缘未知超延伸大陆地壳的古地理意义
IF 8.5 1区 地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-10-01 DOI: 10.1016/j.gsf.2024.101934
C.D. Teixeira , T.J. Girelli , H. Serratt , H.O.S. Oliveira , M.F. Cruz , B. Conti , P. Rodriguez , F. Chemale Jr
The paleogeographic reconstruction of fragmented and dispersed continents often poses a challenge due to the lack of information regarding the nature of that extend beneath passive margin basins. To define the width of the continental crust beneath passive margin basins and its implications for paleogeographic reconstruction of conjugate continental margins, this study investigates the architecture of the stretched continental crust of the southern South Atlantic conjugate margin. The investigated region encompasses South Africa, Namibia, southern Brazil, and Uruguay, which were formed during the Mesozoic rifting of SW Gondwana. Employing a multi-tool approach combining seismic interpretation, gravity, magnetometry, and U-Pb isotopic data, the research aims to quantify the extension of stretched continental crust and its implications for plate reconstructions. The study reveals that the restored stretched crust spans at least 150 km, emphasizing the significance of considering connections between both margins for realistic paleogeographic reconstructions. Furthermore, the distinct U-Pb zircon age distribution patterns between SW Africa and SE South America reinforce the lack of direct connections despite their Gondwanan origin. The missing link estimated in this study is around 150 km, comparable in size to major mountain ranges such as the Andean or Urals. This work sheds light on critical aspects of Earth’s dynamic crustal evolution and emphasizes the need for comprehensive reconstructions considering stretched and eroded crust in the South Atlantic conjugate margin.
由于缺乏有关被动边缘盆地下延伸大陆地壳性质的信息,对支离破碎和分散的大陆进行古地理重建往往是一项挑战。为了确定被动边缘盆地下大陆地壳的宽度及其对共轭大陆边缘古地理重建的影响,本研究调查了南大西洋南部共轭边缘大陆地壳延伸的结构。研究区域包括南非、纳米比亚、巴西南部和乌拉圭,它们是在冈瓦纳西南部中生代断裂过程中形成的。研究采用多工具方法,结合地震解释、重力、磁力测量和 U-Pb 同位素数据,旨在量化拉伸大陆地壳的延伸及其对板块重建的影响。研究显示,恢复的拉伸地壳至少横跨 150 公里,这强调了考虑两个边缘之间的联系对于现实古地理重建的重要意义。此外,非洲西南部和南美洲东南部之间截然不同的 U-Pb 锆石年龄分布模式进一步说明,尽管它们起源于冈瓦纳山脉,但缺乏直接联系。本研究估计缺失的联系约为 150 公里,其大小与安第斯山脉或乌拉尔山脉等主要山脉相当。这项工作揭示了地球地壳动态演化的关键方面,并强调了考虑南大西洋共轭边缘地壳拉伸和侵蚀的全面重建的必要性。
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引用次数: 0
Linking basin-scale hydrology with climatic parameters in western Himalaya: Application of satellite data, temperature index modelling and in-situ observations 将喜马拉雅西部流域尺度的水文与气候参数联系起来:卫星数据、温度指数建模和现场观测的应用
IF 8.5 1区 地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-09-24 DOI: 10.1016/j.gsf.2024.101936
Smriti Srivastava , Mohd. Farooq Azam , Praveen Kumar Thakur
Due to limited spatial and temporal in-situ runoff data availability, Himalaya-Karakoram (HK) glaciohydrology has a significant knowledge gap between large-scale and small-scale runoff modelling studies. This study reconstructs longest basin-wide runoff series in Chandra-Bhaga Basin by applying a high-resolution glaciohydrological model SPHY (Spatial Processes in Hydrology) over 1950–2022. Two-tier model calibration is done using in-situ basin-wide runoff (1973–2006) and MODIS snow cover (2003–2018). Model validation is done against in-situ Chhota Shigri Glacier catchment-wide runoff (2010–2015). The modelled mean annual basin-wide runoff is 60.21 ± 6.17 m3/s over 1950–2022, with maximum runoff in summer-monsoon months, peaking in July (182.69 m3/s). Glacier runoff (ice melt + snowmelt over glacier) contributes maximum (39%) followed by equal contributions from snowmelt runoff from non-glacierized basin area and baseflow (25%), while rainfall-runoff contributes minimum (11 %) to total runoff. There is a significant volumetric increase by ∼7% from pre- (59.17 m3/s) to post-2000 (63.47 m3/s) mainly because of early onset of snowmelt post-2000 that resulted in a hydrograph shift by ∼25 days earlier in spring. The glacier runoff is overestimated by 3% from RGI 7.0 inventory compared to different manually delineated inventories over 1950–2022, because of higher glacierized area from RGI 7.0. The precipitation shows a negative trend, but total runoff shows a positive trend due to positive trend of temperature that resulted in more glacier runoff and rainfall-runoff for basin over last 72 years. Basin-wide runoff is mainly governed by summer temperature which directly controls the amount of glacier and snowmelt runoffs and is supported by summer rainfall. This study highlights importance of basin-scale model calibration with in-situ data in large scale studies and stresses the need for in-situ observations in high-altitude Himalayan region. Basin-scale calibrated model parameters are transferable to glacier catchment scale within Chandra-Bhaga Basin, showing the model robustness at a small catchment scale.
由于可获得的原位径流时空数据有限,喜马拉雅-喀喇昆仑山(HK)冰川水文学在大尺度和小尺度径流模型研究之间存在着巨大的知识差距。本研究通过应用 1950-2022 年期间的高分辨率冰川水文模型 SPHY(水文空间过程),重建了钱德拉-巴嘎盆地最长的全流域径流序列。利用全流域原位径流(1973-2006 年)和 MODIS 雪盖(2003-2018 年)对模型进行了两级校准。模型验证是根据原位 Chhota Shigri 冰川全流域径流(2010-2015 年)进行的。在 1950-2022 年期间,模拟的全流域年平均径流量为 60.21 ± 6.17 立方米/秒,夏季季风月份径流量最大,7 月份达到峰值(182.69 立方米/秒)。冰川径流(冰川上的融冰+融雪)在径流总量中所占比例最大(39%),其次是非冰川化流域的融雪径流和基流(25%),而降雨径流在径流总量中所占比例最小(11%)。从 2000 年前(59.17 立方米/秒)到 2000 年后(63.47 立方米/秒),径流量明显增加了 7%,这主要是因为 2000 年后融雪开始较早,导致春季水文变化提前了 25 天。由于 RGI 7.0 的冰川化面积较高,与 1950-2022 年人工划定的不同清单相比,RGI 7.0 清单高估了 3%的冰川径流。降水量呈负增长趋势,但总径流量呈正增长趋势,这是由于气温呈正增长趋势,导致过去 72 年流域的冰川径流量和降雨径流量增加。全流域的径流主要受夏季温度的影响,夏季温度直接控制冰川和融雪径流量,夏季降雨则为其提供支持。这项研究强调了在大规模研究中利用原位数据对流域尺度模型进行校核的重要性,并强调了在高海拔喜马拉雅地区进行原位观测的必要性。经流域尺度校准的模型参数可转移到 Chandra-Bhaga 流域内的冰川集水尺度,这表明模型在小集水尺度上具有稳健性。
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引用次数: 0
Does energy policy uncertainty matter for renewable energy and energy efficiency technologies? An affordable and clean energy perspective 能源政策的不确定性对可再生能源和能源效率技术有影响吗?从负担得起的清洁能源角度看问题
IF 8.5 1区 地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-09-16 DOI: 10.1016/j.gsf.2024.101932
Ugur Korkut Pata
Uncertainty can affect both macroeconomic indicators and the environment. Countries are implementing various energy policies to combat global warming, but these policies contain some uncertainties and contradictions. The environmental impact of uncertainties in energy policies is a research topic that has just begun to be investigated by researchers. This study examines the effects of energy policy uncertainty (ENERPU) on renewable energy R&D (RR&D), energy efficiency R&D (EER&D) and renewable energy consumption in the four countries with the highest RR&D expenditures (USA, Germany, Japan, and Spain). The study uses the novel multivariate quantile-on-quantile (M-QQR) approach from 2003m1 to 2022m9. The results of the study show: (i) The impact of ENERPU varies by quantile and country. (ii) ENERPU causes a decrease in renewable energy consumption and hinders RR&D expenditures. (iii) ENERPU increases EER&D. The Fourier quantile causality test confirms the robustness of the empirical results. Based on these findings, policymakers are recommended to minimize ENERPU and implement stable energy policies to develop the renewable energy sector and technologies.
不确定性既会影响宏观经济指标,也会影响环境。为了应对全球变暖,各国都在实施各种能源政策,但这些政策都存在一些不确定性和矛盾。能源政策的不确定性对环境的影响是研究人员刚刚开始研究的一个课题。本研究探讨了能源政策不确定性(ENERPU)对可再生能源研发(RR&D)、能源效率研发(EER&D)和可再生能源消费的影响,研究对象是 RR&D 支出最高的四个国家(美国、德国、日本和西班牙)。该研究采用了新颖的多变量质对质(M-QQR)方法,时间跨度为 2003m1 至 2022m9。研究结果表明:(i) ENERPU 的影响因量值和国家而异。(ii) ENERPU 导致可再生能源消费减少,阻碍了 RR&D 的支出。(iii) ENERPU 增加了 EER&D。傅立叶量子因果检验证实了实证结果的稳健性。基于这些结论,建议决策者尽量减少 ENERPU,并实施稳定的能源政策,以发展可再生能源行业和技术。
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引用次数: 0
Evaluation of environmental geochemical signatures due to RO rejects on arid agricultural farms and tangible solutions 对干旱农田反渗透废渣造成的环境地球化学特征的评估和切实可行的解决方案
IF 8.5 1区 地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-09-14 DOI: 10.1016/j.gsf.2024.101929
Harish Bhandary, Chidambaram Sabarathinam, Adnan Akber, Tariq Rashid, Dhanu Radha Samayamanthula, Yogeesha Jayaramu, Bedour Alsabti
The impact of reverse osmosis (RO) rejects in the groundwater presents a significant challenge in arid regions. This study collected groundwater samples, product water, and reverse osmosis brine (ROB) from evaporation ponds and analyzed them for major ions and trace elements. Test boreholes were drilled near the ROB site along the flow direction, and borehole sediment samples were collected. The samples were predominantly gravelly sand, and the depth to water level fluctuated around 30 m below ground level (bgl), with minerals mainly consisting of calcite, gypsum, and Quartz. Data loggers reflected a rise in water level (<22 m bgl) corresponding to higher electrical conductivity (>16 mS/Cm) during the cropping period in many locations, confirming the impact of ROB in groundwater. The results were further supported by enriched signatures of δ18O (∼ +1.5‰) and δ2H (∼ +15‰). The saturation index of the minerals reflected that carbonate minerals (Calcite > Dolomite) were saturated in the ROB relative to the groundwater. The vertical variation of mineral assemblages in the boreholes indicated gypsum precipitation in the capillary zone along with calcite and dolomite. The assemblage varies as the groundwater moves from the disposal site. The speciation of different compounds along the groundwater path indicated higher carbonate and sulfate species (CaCO3 > CaHCO3> CaSO4 > NaSO4 > MgSO4) near the disposal site, with variations along the flow direction. Considering the significant variation in temperature in the region (5 to 50 ℃), the water sample composition was modeled using PHREEQC, suggesting that the increase in temperature led to supersaturation of Epsomite and Gypsum compositions. The ROB was theoretically mixed with groundwater and product water in different proportions, and an optimum composition (10:90) for safe disposal was derived and tested fit for reuse in agriculture.
反渗透(RO)废水对地下水的影响是干旱地区面临的一项重大挑战。这项研究从蒸发池收集了地下水样本、产品水和反渗透盐水(ROB),并对其进行了主要离子和微量元素分析。在反渗透盐水站点附近沿水流方向钻了测试钻孔,并采集了钻孔沉积物样本。样本主要为砾质砂,水位深度在地面以下 30 米左右波动,矿物主要包括方解石、石膏和石英。数据记录器显示,在许多地点,水位上升(22 m bgl)与较高的电导率(16 mS/Cm)相对应,证实了地下水中 ROB 的影响。δ18O(∼ +1.5‰)和δ2H(∼ +15‰)的富集特征进一步证实了这一结果。矿物饱和度指数反映了相对于地下水而言,ROB 中的碳酸盐矿物(方解石和白云石)处于饱和状态。钻孔中矿物组合的垂直变化表明,石膏与方解石和白云石一起沉淀在毛细管区。随着地下水从弃置地点流出,矿物组合也随之变化。地下水流经路径上不同化合物的标示表明,弃置场附近的碳酸盐和硫酸盐种类(CaCO3 > CaHCO3> CaSO4 > NaSO4 > MgSO4)较多,并随水流方向而变化。考虑到该区域的温度变化很大(5 至 50 ℃),使用 PHREEQC 对水样成分进行了模拟,结果表明温度的升高导致了泻盐和石膏成分的过饱和。从理论上讲,ROB 与地下水和产品水以不同比例混合,得出了安全处置的最佳成分(10:90),并测试了是否适合在农业中重复使用。
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引用次数: 0
Melting temperature of iron under the Earth’s inner core condition from deep machine learning 从深度机器学习看地球内核条件下铁的熔化温度
IF 8.5 1区 地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-09-12 DOI: 10.1016/j.gsf.2024.101925
Fulun Wu , Shunqing Wu , Cai-Zhuang Wang , Kai-Ming Ho , Renata M. Wentzcovitch , Yang Sun

Constraining the melting temperature of iron under Earth’s inner core conditions is crucial for understanding core dynamics and planetary evolution. Here, we develop a deep potential (DP) model for iron that explicitly incorporates electronic entropy contributions governing thermodynamics under Earth’s core conditions. Extensive benchmarking demonstrates the DP’s high fidelity across relevant iron phases and extreme pressure and temperature conditions. Through thermodynamic integration and direct solid–liquid coexistence simulations, the DP predicts melting temperatures for iron at the inner core boundary, consistent with previous ab initio results. This resolves the previous discrepancy of iron’s melting temperature at ICB between the DP model and ab initio calculation and suggests the crucial contribution of electronic entropy. Our work provides insights into machine learning melting behavior of iron under core conditions and provides the basis for future development of binary or ternary DP models for iron and other elements in the core.

确定地球内核条件下铁的熔化温度对于理解地核动力学和行星演化至关重要。在这里,我们为铁建立了一个深电位(DP)模型,该模型明确纳入了在地核条件下支配热力学的电子熵贡献。广泛的基准测试证明了 DP 在相关铁相和极端压力与温度条件下的高保真性。通过热力学整合和直接的固液共存模拟,DP 预测了铁在内核边界的熔化温度,与之前的 ab initio 结果一致。这解决了之前 DP 模型和 ab initio 计算在内核边界铁熔化温度上的差异,并表明电子熵的关键作用。我们的工作为铁在内核条件下的机器学习熔化行为提供了见解,并为今后开发铁和内核中其他元素的二元或三元 DP 模型奠定了基础。
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引用次数: 0
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