A. M. Morris, S. Lambart, M. A. Stearns, J. R. Bowman, M. T. Jones, G. Mohn, G. Andrews, J. Millett, C. Tegner, S. Chatterjee, J. Frieling, P. Guo, D. W. Jolley, E. H. Cunningham, C. Berndt, S. Planke, C. A. Alvarez Zarikian, P. Betlem, H. Brinkhuis, M. Christopoulou, E. Ferré, I. Y. Filina, D. T. Harper, J. Longman, R. P. Scherer, N. Varela, W. Xu, S. L. Yager, A. Agarwal, V. J. Clementi
While basaltic volcanism is dominant during rifting and continental breakup, felsic magmatism may be a significant component of some rift margins. During International Ocean Discovery Program (IODP) Expedition 396 on the continental margin of Norway, a graphite-garnet-cordierite bearing dacitic unit (the Mimir dacite) was recovered in two holes within early Eocene sediments on Mimir High (Site U1570), a marginal high on the Vøring Transform Margin. Here, we present a comprehensive textural, petrological, and geochemical study of the Mimir dacite in order to assess its origin and discuss the geodynamic implications. The major mineral phases (garnet, cordierite, quartz, plagioclase, alkali feldspar) are hosted in a fresh rhyolitic, vesicular, glassy matrix that is locally mingled with sediments. The major element chemistry of garnet and cordierite, the presence of zircon inclusions with inherited cores, and thermobarometric calculations all support an upper crustal metapelitic origin. While most magma-rich margin models favor crustal anatexis in the lower crust, thermobarometric calculations performed here show that the Mimir dacite was produced at upper-crustal depths (<5 kbar, 18 km depth) and high temperature (750–800°C) with up to 3 wt% water content. In situ U-Pb analyses on zircon inclusions give a magmatic crystallization age of 54.6 ± 1.1 Ma, consistent with emplacement that post-dates the Paleocene-Eocene Thermal Maximum. Our results suggest that the opening of the Northeast Atlantic was associated with a phase of low-pressure, high-temperature crustal anatexis preceding the main phase of magmatism.
{"title":"Evidence for Low-Pressure Crustal Anatexis During the Northeast Atlantic Break-Up","authors":"A. M. Morris, S. Lambart, M. A. Stearns, J. R. Bowman, M. T. Jones, G. Mohn, G. Andrews, J. Millett, C. Tegner, S. Chatterjee, J. Frieling, P. Guo, D. W. Jolley, E. H. Cunningham, C. Berndt, S. Planke, C. A. Alvarez Zarikian, P. Betlem, H. Brinkhuis, M. Christopoulou, E. Ferré, I. Y. Filina, D. T. Harper, J. Longman, R. P. Scherer, N. Varela, W. Xu, S. L. Yager, A. Agarwal, V. J. Clementi","doi":"10.1029/2023GC011413","DOIUrl":"https://doi.org/10.1029/2023GC011413","url":null,"abstract":"<p>While basaltic volcanism is dominant during rifting and continental breakup, felsic magmatism may be a significant component of some rift margins. During International Ocean Discovery Program (IODP) Expedition 396 on the continental margin of Norway, a graphite-garnet-cordierite bearing dacitic unit (the Mimir dacite) was recovered in two holes within early Eocene sediments on Mimir High (Site U1570), a marginal high on the Vøring Transform Margin. Here, we present a comprehensive textural, petrological, and geochemical study of the Mimir dacite in order to assess its origin and discuss the geodynamic implications. The major mineral phases (garnet, cordierite, quartz, plagioclase, alkali feldspar) are hosted in a fresh rhyolitic, vesicular, glassy matrix that is locally mingled with sediments. The major element chemistry of garnet and cordierite, the presence of zircon inclusions with inherited cores, and thermobarometric calculations all support an upper crustal metapelitic origin. While most magma-rich margin models favor crustal anatexis in the lower crust, thermobarometric calculations performed here show that the Mimir dacite was produced at upper-crustal depths (<5 kbar, 18 km depth) and high temperature (750–800°C) with up to 3 wt% water content. In situ U-Pb analyses on zircon inclusions give a magmatic crystallization age of 54.6 ± 1.1 Ma, consistent with emplacement that post-dates the Paleocene-Eocene Thermal Maximum. Our results suggest that the opening of the Northeast Atlantic was associated with a phase of low-pressure, high-temperature crustal anatexis preceding the main phase of magmatism.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023GC011413","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141536900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-04DOI: 10.1007/s00484-024-02726-1
Toshiaki Ichinose, Yi Pan, Yukiko Yoshida
The purpose of this study is to understand a physical mechanism to determine the surface temperature of clothes in calm and fine conditions of outdoors. We observed surface temperatures of polo shirts of the same material and design but different colors. The shirts were placed in unshaded and well-ventilated outdoor, open spaces on sunny summer days. The maximum difference between dark green or black and white was more than 15 °C during calm, fine weather and was greatest when the solar radiation was strong. If the transmission of solar radiation energy through a shirt is ignored to calculate the absorption by the shirt, the difference in solar radiation absorption due to different colors is as much as 24% in the maximum, and if considered, we concluded that an absorption difference of 34% led to a temperature difference of 15℃. When we compared the brightness of the colors, we found that the albedo of both the visible and NIR bands explained why the red and green colors were so different with respect to the surface temperatures we observed. The reflection in the NIR bands was also an important determinant of the surface temperature. An additional experiment using masks showed that the temperature difference between white and black was almost eliminated at a wind speed of ~ 3 m/s. The color of clothing is therefore a target for small-scale adaptation to climate change.
本研究的目的是了解在平静和晴朗的户外条件下确定衣服表面温度的物理机制。我们观察了材质和设计相同但颜色不同的 Polo 衫的表面温度。在阳光明媚的夏日,这些衬衫被放置在无遮挡、通风良好的室外空地上。在天气晴朗、风平浪静时,深绿色或黑色与白色之间的最大温差超过 15 °C,在太阳辐射强烈时温差最大。如果忽略太阳辐射能量通过衬衫的传输来计算衬衫的吸收,不同颜色对太阳辐射的吸收差异最大可达 24%,如果考虑到这一点,我们得出的结论是,34% 的吸收差异会导致 15℃的温差。当我们比较各种颜色的亮度时,我们发现可见光和近红外波段的反照率解释了为什么红色和绿色与我们观测到的表面温度如此不同。近红外波段的反射也是决定表面温度的一个重要因素。使用面罩进行的另一项实验表明,在风速约为 3 米/秒时,白色和黑色之间的温度差异几乎消失。因此,衣服的颜色是小规模适应气候变化的一个目标。
{"title":"Clothing color effect as a target of the smallest scale climate change adaptation.","authors":"Toshiaki Ichinose, Yi Pan, Yukiko Yoshida","doi":"10.1007/s00484-024-02726-1","DOIUrl":"https://doi.org/10.1007/s00484-024-02726-1","url":null,"abstract":"<p><p>The purpose of this study is to understand a physical mechanism to determine the surface temperature of clothes in calm and fine conditions of outdoors. We observed surface temperatures of polo shirts of the same material and design but different colors. The shirts were placed in unshaded and well-ventilated outdoor, open spaces on sunny summer days. The maximum difference between dark green or black and white was more than 15 °C during calm, fine weather and was greatest when the solar radiation was strong. If the transmission of solar radiation energy through a shirt is ignored to calculate the absorption by the shirt, the difference in solar radiation absorption due to different colors is as much as 24% in the maximum, and if considered, we concluded that an absorption difference of 34% led to a temperature difference of 15℃. When we compared the brightness of the colors, we found that the albedo of both the visible and NIR bands explained why the red and green colors were so different with respect to the surface temperatures we observed. The reflection in the NIR bands was also an important determinant of the surface temperature. An additional experiment using masks showed that the temperature difference between white and black was almost eliminated at a wind speed of ~ 3 m/s. The color of clothing is therefore a target for small-scale adaptation to climate change.</p>","PeriodicalId":588,"journal":{"name":"International Journal of Biometeorology","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141496802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hongjin Chen, Zhaokai Xu, Germain Bayon, Qingchao Fan, Philip A. E. Pogge von Strandmann, Wei Wang, Tianqi Sun, Tiegang Li
Despite the crucial role of the Southern Hemisphere (SH) westerlies in modulating modern and past climate evolution, little is known about their behavior and possible forcing mechanisms during the early Cenozoic. We probe changes in the hydroclimate of southwest Australia during 62–51 Ma, based on sedimentary proxy records from the International Ocean Discovery Program Site U1514 in the Mentelle Basin. Our results reveal a transition from a less humid climate to wetter conditions at mid–high latitudes starting from the early Eocene, which suggests poleward migration of the SH westerlies. This long-term trend is punctuated by short-lived events of aridification during the Mid-Paleocene Biotic Event and wetter intervals during the Paleocene-Eocene Thermal Maximum, indicating additional short-term meridional shifting of the westerlies. We propose that the evolution of SH westerlies was driven by the equator-to-pole temperature gradient regulated by global warming and ephemeral growth of the Antarctic ice sheet.
尽管南半球西风在调节现代和过去的气候演变中起着至关重要的作用,但人们对其在新生代早期的行为和可能的作用机制却知之甚少。我们根据门泰勒盆地国际大洋发现计划 U1514 站点的沉积代用记录,探究了澳大利亚西南部 62-51 Ma 期间水文气候的变化。我们的研究结果表明,从始新世早期开始,中高纬度地区的气候从湿度较低向湿润过渡,这表明了SH西风的向极迁移。在这一长期趋势中,古新世中期生物事件和古新世-始新世热极盛期间的干旱化和湿润化事件都是短暂的,这表明西风又发生了短期的经向移动。我们认为,受全球变暖和南极冰盖短暂增长的调节,赤道到极地的温度梯度推动了 SH 西风的演变。
{"title":"Meridional Shifts of the Southern Hemisphere Westerlies During the Early Cenozoic","authors":"Hongjin Chen, Zhaokai Xu, Germain Bayon, Qingchao Fan, Philip A. E. Pogge von Strandmann, Wei Wang, Tianqi Sun, Tiegang Li","doi":"10.1029/2024GL110182","DOIUrl":"https://doi.org/10.1029/2024GL110182","url":null,"abstract":"<p>Despite the crucial role of the Southern Hemisphere (SH) westerlies in modulating modern and past climate evolution, little is known about their behavior and possible forcing mechanisms during the early Cenozoic. We probe changes in the hydroclimate of southwest Australia during 62–51 Ma, based on sedimentary proxy records from the International Ocean Discovery Program Site U1514 in the Mentelle Basin. Our results reveal a transition from a less humid climate to wetter conditions at mid–high latitudes starting from the early Eocene, which suggests poleward migration of the SH westerlies. This long-term trend is punctuated by short-lived events of aridification during the Mid-Paleocene Biotic Event and wetter intervals during the Paleocene-Eocene Thermal Maximum, indicating additional short-term meridional shifting of the westerlies. We propose that the evolution of SH westerlies was driven by the equator-to-pole temperature gradient regulated by global warming and ephemeral growth of the Antarctic ice sheet.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL110182","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141536591","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}
We performed a passive seismic monitoring of the La Praz ∼14,000 m3 unstable slope (French Alps) spanning over 10 years. During the last 6 months prior to collapse, we detected a clear 24% decrease in the slope's fundamental resonance frequency, f0, caused by a reduction in overall rock mass stiffness. The combined study of f0 and slope deformation suggested the alternating importance of sudden brittle failure processes versus more ductile phases with possible sliding. Seismic monitoring revealed slope damage that remained ambiguous or undetected with ground surface deformation monitoring, and highlighted critical periods with intense damage. Only some of these critical damage periods could be related to clear external forcing factors such as intense rainfall episodes. These new insights into rock slope's structural condition at depth represent an asset for future monitoring systems. Surface deformation and passive seismic stiffness tracking combined could reveal active slopes with ongoing damage processes.
{"title":"Original Insights Into Rock Slope Damage Processes Until Collapse From Passive Seismic Monitoring","authors":"P. Bottelin, L. Baillet","doi":"10.1029/2024GL109139","DOIUrl":"10.1029/2024GL109139","url":null,"abstract":"<p>We performed a passive seismic monitoring of the La Praz ∼14,000 m<sup>3</sup> unstable slope (French Alps) spanning over 10 years. During the last 6 months prior to collapse, we detected a clear 24% decrease in the slope's fundamental resonance frequency, <i>f</i><sub>0</sub>, caused by a reduction in overall rock mass stiffness. The combined study of <i>f</i><sub>0</sub> and slope deformation suggested the alternating importance of sudden brittle failure processes versus more ductile phases with possible sliding. Seismic monitoring revealed slope damage that remained ambiguous or undetected with ground surface deformation monitoring, and highlighted critical periods with intense damage. Only some of these critical damage periods could be related to clear external forcing factors such as intense rainfall episodes. These new insights into rock slope's structural condition at depth represent an asset for future monitoring systems. Surface deformation and passive seismic stiffness tracking combined could reveal active slopes with ongoing damage processes.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL109139","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521539","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}
Lili Ren, Yang Yang, Hailong Wang, Pinya Wang, Xu Yue, Hong Liao
The climate commitment to achieving carbon neutrality before 2060 in China has been announced recently. In the context of pursuing carbon neutrality, sharing similar sources as greenhouse gases, aerosol particle and precursor emissions are projected to substantially decrease in China, which can potentially have a great impact on climate. Here, we investigate the effects of future aerosol reductions, because of achieving carbon neutrality, on solar and wind energy in China by using an earth system model. We show that significant reductions in aerosol emissions, particularly in eastern China, lead to increases in the surface downwelling shortwave radiation, surface air temperature and wind speed, which can further enhance the potential of solar and wind energy production. The findings underline that the pursuit of carbon neutrality can yield co-benefits of not only mitigating climate change and air pollution but also fortifying the stability of renewable energy sources.
{"title":"Co-Benefits of Mitigating Aerosol Pollution to Future Solar and Wind Energy in China Toward Carbon Neutrality","authors":"Lili Ren, Yang Yang, Hailong Wang, Pinya Wang, Xu Yue, Hong Liao","doi":"10.1029/2024GL109296","DOIUrl":"https://doi.org/10.1029/2024GL109296","url":null,"abstract":"<p>The climate commitment to achieving carbon neutrality before 2060 in China has been announced recently. In the context of pursuing carbon neutrality, sharing similar sources as greenhouse gases, aerosol particle and precursor emissions are projected to substantially decrease in China, which can potentially have a great impact on climate. Here, we investigate the effects of future aerosol reductions, because of achieving carbon neutrality, on solar and wind energy in China by using an earth system model. We show that significant reductions in aerosol emissions, particularly in eastern China, lead to increases in the surface downwelling shortwave radiation, surface air temperature and wind speed, which can further enhance the potential of solar and wind energy production. The findings underline that the pursuit of carbon neutrality can yield co-benefits of not only mitigating climate change and air pollution but also fortifying the stability of renewable energy sources.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL109296","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141536672","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}
Cassandra Seltzer, Maria-Gema Llorens, Andrew J. Cross
Seismology is increasingly used to infer the magnitude and direction of glacial ice flow. However, the effects of interstitial meltwater on seismic properties remain poorly constrained. Here, we extend previous studies on seismic anisotropy in temperate ices to consider the role of melt preferred orientation (MPO). We used the ELLE numerical toolbox to simulate microstructural shear deformation of temperate ice with variable MPO strength and orientation, and calculated the effective seismic properties of these numerical ice-melt aggregates. Our models demonstrate that even 3.5% melt volume is sufficient to rotate fast directions by up to 90°, to increase Vp anisotropy by up to +110%, and to modify Vs anisotropy by −9 to +36%. These effects are especially prominent at strain rates ≥3.17 × 10−12 s−1. MPO may thus obscure the geophysical signatures of temperate ice flow in regions of rapid ice discharge, and is therefore pivotal for understanding ice mass loss.
地震学越来越多地被用于推断冰川冰流的规模和方向。然而,间隙融水对地震特性的影响仍未得到很好的解释。在此,我们扩展了之前对温带冰层地震各向异性的研究,考虑了融水优先取向(MPO)的作用。我们使用 ELLE 数值工具箱模拟了 MPO 强度和取向可变的温带冰的微结构剪切变形,并计算了这些数值冰-熔体聚集体的有效地震特性。我们的模型表明,即使 3.5% 的熔体体积也足以使快速方向旋转 90°,使 Vp 各向异性增加 +110%,并使 Vs 各向异性改变 -9% 至 +36%。这些效应在应变速率≥3.17 × 10-12 s-1时尤为突出。因此,在冰快速排出的地区,MPO 可能会掩盖温带冰流的地球物理特征,因此对于了解冰的质量损失至关重要。
{"title":"Meltwater Orientations Modify Seismic Anisotropy in Temperate Ice","authors":"Cassandra Seltzer, Maria-Gema Llorens, Andrew J. Cross","doi":"10.1029/2024GL110131","DOIUrl":"https://doi.org/10.1029/2024GL110131","url":null,"abstract":"<p>Seismology is increasingly used to infer the magnitude and direction of glacial ice flow. However, the effects of interstitial meltwater on seismic properties remain poorly constrained. Here, we extend previous studies on seismic anisotropy in temperate ices to consider the role of melt preferred orientation (MPO). We used the ELLE numerical toolbox to simulate microstructural shear deformation of temperate ice with variable MPO strength and orientation, and calculated the effective seismic properties of these numerical ice-melt aggregates. Our models demonstrate that even 3.5% melt volume is sufficient to rotate fast directions by up to 90°, to increase Vp anisotropy by up to +110%, and to modify Vs anisotropy by −9 to +36%. These effects are especially prominent at strain rates ≥3.17 × 10<sup>−12</sup> s<sup>−1</sup>. MPO may thus obscure the geophysical signatures of temperate ice flow in regions of rapid ice discharge, and is therefore pivotal for understanding ice mass loss.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL110131","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141536665","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}
Stephanie Shahrzad, Emma K. Bramham, Sandra Piazolo, Mark Thomas, Paul K. Byrne
The heavily faulted Martian terrains of Ceraunius Fossae and Tractus Fossae, south of the Alba Mons volcano, have previously only been considered as parts of larger tectonic studies of Alba Mons, and consequently the complexity of the faulting remains unclear. As these terrains are in the midst of the large Tharsis volcanoes, the study of their surface deformation has the potential to help unravel the volcano-tectonic deformation associated with the growth of Tharsis as well as to decipher details of the magma-tectonic processes responsible for graben formation. Here, we distinguish between faults and collapse structures based on image and topographic evidence. We mapped ∼12,000 faults, which we grouped into three distinct fault groups based on orientation, morphology, and relative ages. These show a temporal evolution in the mapped fault orientations from NE to N-S to NW with associated changes in stress orientations. We also mapped collapse features and categorized them into four different groups: pit-crater chains, catenae, u-shaped troughs and chasmata. Examining the four collapse structure groups reveals that they are likely four progressive stages in the erosional evolution of pit-crater chains. Together, this revealed a structural history heavily influenced by lateral diking from both local (radial to Alba Mons, Pavonis Mons and Ascraeus Mons) and regional (radial to Tharsis) sources, and vertical diking from a proposed Ceraunius Fossae centered magma source. This, along with an updated crater size-frequency distribution analysis of the unit ages, reveals a highly active tectonic and magmatic environment south of Alba Mons in the Middle Amazonian.
{"title":"Amazonian Tectonic Evolution of Ceraunius and Tractus Fossae, Mars, and Implications for Local Magmatic Sources","authors":"Stephanie Shahrzad, Emma K. Bramham, Sandra Piazolo, Mark Thomas, Paul K. Byrne","doi":"10.1029/2023JE008123","DOIUrl":"https://doi.org/10.1029/2023JE008123","url":null,"abstract":"<p>The heavily faulted Martian terrains of Ceraunius Fossae and Tractus Fossae, south of the Alba Mons volcano, have previously only been considered as parts of larger tectonic studies of Alba Mons, and consequently the complexity of the faulting remains unclear. As these terrains are in the midst of the large Tharsis volcanoes, the study of their surface deformation has the potential to help unravel the volcano-tectonic deformation associated with the growth of Tharsis as well as to decipher details of the magma-tectonic processes responsible for graben formation. Here, we distinguish between faults and collapse structures based on image and topographic evidence. We mapped ∼12,000 faults, which we grouped into three distinct fault groups based on orientation, morphology, and relative ages. These show a temporal evolution in the mapped fault orientations from NE to N-S to NW with associated changes in stress orientations. We also mapped collapse features and categorized them into four different groups: pit-crater chains, catenae, u-shaped troughs and chasmata. Examining the four collapse structure groups reveals that they are likely four progressive stages in the erosional evolution of pit-crater chains. Together, this revealed a structural history heavily influenced by lateral diking from both local (radial to Alba Mons, Pavonis Mons and Ascraeus Mons) and regional (radial to Tharsis) sources, and vertical diking from a proposed Ceraunius Fossae centered magma source. This, along with an updated crater size-frequency distribution analysis of the unit ages, reveals a highly active tectonic and magmatic environment south of Alba Mons in the Middle Amazonian.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023JE008123","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141536674","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}
Pub Date : 2024-07-04DOI: 10.1038/s41612-024-00704-3
Zhuoying Li, Wen Zhou
Tropical cyclones (TCs) have experienced poleward migration in recent years, but whether this exists in future projections with high-resolution climate models remains unclear. This study investigates the poleward migration of TCs over the western North Pacific (WNP) using CMIP6-HighResMIP models. We first assess the model performance in TC genesis frequency and latitude, which differ greatly from the observations, especially in winter and spring due to misinterpretation of extratropical storms. In this study, we put forward a revised constrained detection method based on the sea surface temperature (SST) and the atmospheric conditions to resolve this bias. Results indicate that the revised detection method has good performance in capturing the annual cycle of TC genesis frequency and latitude. Future projections constrained by this method show that the latitude of TC genesis and lifetime maximum intensity (LMI) both undergo a poleward shift, with the former being more significant. Spatial changes in the dynamic potential genesis index and large-scale environment could explain this shift. The regional changes of Hadley circulation and the role of global warming and internal variability are also discussed.
{"title":"Poleward migration of tropical cyclones over the western North Pacific in the CMIP6-HighResMIP models constrained by observations","authors":"Zhuoying Li, Wen Zhou","doi":"10.1038/s41612-024-00704-3","DOIUrl":"10.1038/s41612-024-00704-3","url":null,"abstract":"Tropical cyclones (TCs) have experienced poleward migration in recent years, but whether this exists in future projections with high-resolution climate models remains unclear. This study investigates the poleward migration of TCs over the western North Pacific (WNP) using CMIP6-HighResMIP models. We first assess the model performance in TC genesis frequency and latitude, which differ greatly from the observations, especially in winter and spring due to misinterpretation of extratropical storms. In this study, we put forward a revised constrained detection method based on the sea surface temperature (SST) and the atmospheric conditions to resolve this bias. Results indicate that the revised detection method has good performance in capturing the annual cycle of TC genesis frequency and latitude. Future projections constrained by this method show that the latitude of TC genesis and lifetime maximum intensity (LMI) both undergo a poleward shift, with the former being more significant. Spatial changes in the dynamic potential genesis index and large-scale environment could explain this shift. The regional changes of Hadley circulation and the role of global warming and internal variability are also discussed.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":null,"pages":null},"PeriodicalIF":8.5,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00704-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141537084","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}
Rutger W. A. Siemes, Trang Minh Duong, Bas W. Borsje, Suzanne J. M. H. Hulscher
Estuaries worldwide are susceptible and adapting to climate change (CC) impacts from both the river and coastal boundaries. Furthermore, engineering efforts are undertaken to improve flood safety, to claim land for human use or for port operations, which change estuary morphology. This paper aims to gain an understanding of the combined effects of CC and human interventions on the estuarine-wide morphological response by analyzing the sediment infilling of highly engineered estuaries. A schematized process-based morphodynamic model is used (Delft3D-FM, in 2DH), resembling a highly engineered estuary in the Rhine-Meuse Delta, The Netherlands. Three types of changes were implemented, both in isolation and in combination: (a) local interventions (changing channel depth or wetland area), (b) upstream human interventions (changing fluvial sediment supply) and (c) extreme CC scenarios (with projections for the future forcings and bathymetry). Results show that a CC scenario can elicit both positive and negative changes in the estuary's sediment budget. The direction and magnitude of the change depend on the local intervention and can align with the effect of the local intervention, intensifying its impact. The combined effects can even reverse the sign of the sediment budget. This stresses the need of analyzing CC impacts in combination with human interventions. Additionally, a relationship was identified which quantifies how a change in peak flow velocity due to both local interventions and sea-level rise affects the annual sediment budget. These findings can help determine how local interventions affect morphodynamics of engineered estuaries in present and future climates.
全世界的河口都很容易受到气候变化(CC)的影响,并正在适应来自河流和沿海地区的影响。此外,为提高防洪安全、为人类使用土地或港口运营而进行的工程努力也改变了河口的形态。本文旨在通过分析高度工程化河口的沉积物填充情况,了解 CC 和人为干预对整个河口形态响应的综合影响。本文使用了一个基于过程的示意形态动力学模型(Delft3D-FM,2DH 中),该模型类似于荷兰莱茵河-缪斯河三角洲的一个高度工程化河口。该模型单独或结合实施了三类变化:(a) 局部干预(改变河道深度或湿地面积),(b) 上游人为干预(改变河道沉积物供应),(c) 极端 CC 情景(预测未来的作用力和水深)。结果表明,CC 情景可引起河口沉积物预算的正负变化。变化的方向和幅度取决于当地的干预措施,并可能与当地干预措施的效果一致,从而加剧其影响。综合效应甚至会扭转沉积物预算的符号。这强调了结合人类干预措施分析气候变化影响的必要性。此外,还确定了一种关系,可量化当地干预措施和海平面上升导致的峰值流速变化如何影响年度沉积物预算。这些发现有助于确定地方干预措施在当前和未来气候条件下如何影响工程河口的形态动力学。
{"title":"Climate Change Can Intensify the Effects of Local Interventions: A Morphological Modeling Study of a Highly Engineered Estuary","authors":"Rutger W. A. Siemes, Trang Minh Duong, Bas W. Borsje, Suzanne J. M. H. Hulscher","doi":"10.1029/2023JF007595","DOIUrl":"https://doi.org/10.1029/2023JF007595","url":null,"abstract":"<p>Estuaries worldwide are susceptible and adapting to climate change (CC) impacts from both the river and coastal boundaries. Furthermore, engineering efforts are undertaken to improve flood safety, to claim land for human use or for port operations, which change estuary morphology. This paper aims to gain an understanding of the combined effects of CC and human interventions on the estuarine-wide morphological response by analyzing the sediment infilling of highly engineered estuaries. A schematized process-based morphodynamic model is used (Delft3D-FM, in 2DH), resembling a highly engineered estuary in the Rhine-Meuse Delta, The Netherlands. Three types of changes were implemented, both in isolation and in combination: (a) local interventions (changing channel depth or wetland area), (b) upstream human interventions (changing fluvial sediment supply) and (c) extreme CC scenarios (with projections for the future forcings and bathymetry). Results show that a CC scenario can elicit both positive and negative changes in the estuary's sediment budget. The direction and magnitude of the change depend on the local intervention and can align with the effect of the local intervention, intensifying its impact. The combined effects can even reverse the sign of the sediment budget. This stresses the need of analyzing CC impacts in combination with human interventions. Additionally, a relationship was identified which quantifies how a change in peak flow velocity due to both local interventions and sea-level rise affects the annual sediment budget. These findings can help determine how local interventions affect morphodynamics of engineered estuaries in present and future climates.</p>","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023JF007595","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141536566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Russell P. Callahan, Mong-Han Huang, Amanda Donaldson, Berit Hudson-Rasmussen, Margaret Zimmer
The creation of fractures in bedrock dictates water movement through the critical zone, controlling weathering, vadose zone water storage, and groundwater recharge. However, quantifying connections between fracturing, water flow, and chemical weathering remains challenging because of limited access to the deep critical zone. Here we overcome this challenge by coupling measurements from borehole drilling, groundwater monitoring, and seismic refraction surveys in the central California Coast Range. Our results show that the subsurface is highly fractured, which may be driven by the regional geologic and tectonic setting. The pervasively fractured rock facilitates infiltration of meteoric water down to a water table that aligns with oxidation in exhumed rock cores and is coincident with the adjacent intermittent first-order stream channel. This work highlights the need to incorporate deep water flow and weathering due to pervasive fracturing into models of catchment water balances and critical zone weathering, especially in tectonically active landscapes.
{"title":"Geologic and Tectonic Controls on Deep Fracturing, Weathering, and Water Flow in the Central California Coast Range","authors":"Russell P. Callahan, Mong-Han Huang, Amanda Donaldson, Berit Hudson-Rasmussen, Margaret Zimmer","doi":"10.1029/2024GL109129","DOIUrl":"10.1029/2024GL109129","url":null,"abstract":"<p>The creation of fractures in bedrock dictates water movement through the critical zone, controlling weathering, vadose zone water storage, and groundwater recharge. However, quantifying connections between fracturing, water flow, and chemical weathering remains challenging because of limited access to the deep critical zone. Here we overcome this challenge by coupling measurements from borehole drilling, groundwater monitoring, and seismic refraction surveys in the central California Coast Range. Our results show that the subsurface is highly fractured, which may be driven by the regional geologic and tectonic setting. The pervasively fractured rock facilitates infiltration of meteoric water down to a water table that aligns with oxidation in exhumed rock cores and is coincident with the adjacent intermittent first-order stream channel. This work highlights the need to incorporate deep water flow and weathering due to pervasive fracturing into models of catchment water balances and critical zone weathering, especially in tectonically active landscapes.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL109129","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521627","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}