Pub Date : 2024-01-12DOI: 10.1146/annurev-earth-031621-111700
Mark A. Kendrick
Each of the halogens constrains a different aspect of volatile cycling in the solid Earth. F is moderately incompatible in the mantle and has a low mobility at Earth's surface, meaning that it is preferentially retained in the mantle and continental crust. In contrast, Cl, Br, and I are strongly incompatible and highly soluble. Chloride is the dominant anion in seawater and many geofluids and a major component of evaporite minerals. Br and I are essential for life and significantly incorporated into organic matter that accumulates in marine sediments. Surficial fluids circulated into continental and oceanic crust incorporate surface-derived halogens into alteration minerals. As a result, subducting slabs and arc lavas are weakly enriched in F and strongly enriched in Cl, Br, and I. Subduction has maintained mantle Cl and Br concentrations at relatively constant levels since Earth's early differentiation, but mantle I/Cl has decreased over time. ▪ Halogen abundances on the early Earth were affected by I partitioning into Earth's core and possible loss of hydrophilic Cl, Br, and I in an early formed ocean. ▪ Halogens are powerful tracers of subduction zone processes on the modern Earth, with Cl, Br, and I having a dominantly subducted origin in Earth's mantle. ▪ The deep subduction cycles of Cl, Br, and I are more similar to that of H2O than they are to F, but the geochemical cycle of each halogen differs in detail. ▪ Halogen abundance ratios and stable isotope ratios vary systematically in Earth's surface reservoirs, meaning that halogens are powerful tracers of geological fluids and melts.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
每种卤素都对固体地球中的挥发循环有不同方面的影响。F 在地幔中具有中度不相容性，在地球表面的流动性较低，这意味着它优先保留在地幔和大陆地壳中。相比之下，Cl、Br 和 I 具有强烈的不相容性和高溶解性。氯化物是海水和许多地球流体中的主要阴离子，也是蒸发岩矿物的主要成分。溴和碘是生命所必需的，并大量融入海洋沉积物中积累的有机物中。循环到大陆和大洋地壳中的地表流体将地表衍生的卤素纳入蚀变矿物中。因此，俯冲板块和弧状熔岩中 F 的富集程度较低，而 Cl、Br 和 I 的富集程度较高。自地球早期分异以来，俯冲作用使地幔中 Cl 和 Br 的富集程度保持在相对稳定的水平，但地幔中 I/Cl 的富集程度则随着时间的推移而降低。早期地球上的卤素丰度受到 I 分入地核以及早期形成的海洋中亲水性 Cl、Br 和 I 可能流失的影响。卤素是现代地球俯冲带过程的强大示踪剂，Cl、Br 和 I 主要来源于地球地幔的俯冲。与 F 相比，Cl、Br 和 I 的深俯冲周期与 H2O 更为相似，但每种卤素的地球化学周期在细节上都有所不同。卤素丰度比和稳定同位素比在地球表面储层中有系统地变化，这意味着卤素是地质流体和熔体的强大示踪剂。《地球与行星科学年刊》第 52 卷的最终在线出版日期预计为 2024 年 5 月。修订后的预计日期请参见 http://www.annualreviews.org/page/journal/pubdates。
{"title":"Halogen Cycling in the Solid Earth","authors":"Mark A. Kendrick","doi":"10.1146/annurev-earth-031621-111700","DOIUrl":"https://doi.org/10.1146/annurev-earth-031621-111700","url":null,"abstract":"Each of the halogens constrains a different aspect of volatile cycling in the solid Earth. F is moderately incompatible in the mantle and has a low mobility at Earth's surface, meaning that it is preferentially retained in the mantle and continental crust. In contrast, Cl, Br, and I are strongly incompatible and highly soluble. Chloride is the dominant anion in seawater and many geofluids and a major component of evaporite minerals. Br and I are essential for life and significantly incorporated into organic matter that accumulates in marine sediments. Surficial fluids circulated into continental and oceanic crust incorporate surface-derived halogens into alteration minerals. As a result, subducting slabs and arc lavas are weakly enriched in F and strongly enriched in Cl, Br, and I. Subduction has maintained mantle Cl and Br concentrations at relatively constant levels since Earth's early differentiation, but mantle I/Cl has decreased over time. ▪ Halogen abundances on the early Earth were affected by I partitioning into Earth's core and possible loss of hydrophilic Cl, Br, and I in an early formed ocean. ▪ Halogens are powerful tracers of subduction zone processes on the modern Earth, with Cl, Br, and I having a dominantly subducted origin in Earth's mantle. ▪ The deep subduction cycles of Cl, Br, and I are more similar to that of H<jats:sub>2</jats:sub>O than they are to F, but the geochemical cycle of each halogen differs in detail. ▪ Halogen abundance ratios and stable isotope ratios vary systematically in Earth's surface reservoirs, meaning that halogens are powerful tracers of geological fluids and melts.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"86 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139431177","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 : 2024-01-12DOI: 10.1146/annurev-earth-032320-090307
Arlene M. Fiore, Loretta J. Mickley, Qindan Zhu, Colleen B. Baublitz
The hydroxyl radical (OH) largely controls the tropospheric self-cleansing capacity by reacting with gases harmful to the environment and human health. OH concentrations are determined locally by competing production and loss processes. Lacking strong observational constraints, models differ in how they balance these processes, such that the sign of past and future OH changes is uncertain. In a warmer climate, OH production will increase due to its water vapor dependence, partially offset by faster OH-methane loss. Weather-sensitive emissions will also likely increase, although their net impact on global mean OH depends on the balance between source (nitrogen oxides) and sink (reactive carbon) gases. Lightning activity increases OH, but its response to climate warming is of uncertain sign. To enable confident projections of OH, we recommend efforts to reduce uncertainties in kinetic reactions, in measured and modeled OH, in proxies for past OH concentrations, and in source and sink gas emissions. ▪ OH is strongly modulated by internal climate variability despite its lifetime of a few seconds at most, with implications for interpreting trends in methane. ▪ Improved kinetic constraints on key reactions would strengthen confidence in regional and global OH budgets, and in the response of OH to climate change. ▪ Future OH changes will depend on uncertain and compensating processes involving weather-sensitive chemistry and emissions, plus human choices. ▪ Technological solutions to climate change will likely impact tropospheric oxidizing capacity and merit further study prior to implementation.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
{"title":"Climate and Tropospheric Oxidizing Capacity","authors":"Arlene M. Fiore, Loretta J. Mickley, Qindan Zhu, Colleen B. Baublitz","doi":"10.1146/annurev-earth-032320-090307","DOIUrl":"https://doi.org/10.1146/annurev-earth-032320-090307","url":null,"abstract":"The hydroxyl radical (OH) largely controls the tropospheric self-cleansing capacity by reacting with gases harmful to the environment and human health. OH concentrations are determined locally by competing production and loss processes. Lacking strong observational constraints, models differ in how they balance these processes, such that the sign of past and future OH changes is uncertain. In a warmer climate, OH production will increase due to its water vapor dependence, partially offset by faster OH-methane loss. Weather-sensitive emissions will also likely increase, although their net impact on global mean OH depends on the balance between source (nitrogen oxides) and sink (reactive carbon) gases. Lightning activity increases OH, but its response to climate warming is of uncertain sign. To enable confident projections of OH, we recommend efforts to reduce uncertainties in kinetic reactions, in measured and modeled OH, in proxies for past OH concentrations, and in source and sink gas emissions. ▪ OH is strongly modulated by internal climate variability despite its lifetime of a few seconds at most, with implications for interpreting trends in methane. ▪ Improved kinetic constraints on key reactions would strengthen confidence in regional and global OH budgets, and in the response of OH to climate change. ▪ Future OH changes will depend on uncertain and compensating processes involving weather-sensitive chemistry and emissions, plus human choices. ▪ Technological solutions to climate change will likely impact tropospheric oxidizing capacity and merit further study prior to implementation.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"110 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139431179","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 : 2024-01-02DOI: 10.1146/annurev-earth-040722-100453
Fu-Yuan Wu, Qiu-Li Li, Yi Chen, Sen Hu, Zong-Yu Yue, Qin Zhou, Hao Wang, Wei Yang, Heng-Ci Tian, Chi Zhang, Jin-Hua Li, Lin-Xi Li, He-Jiu Hui, Chun-Lai Li, Yang-Tin Lin, Xian-Hua Li, John W. Delano
The Chinese spacecraft Chang'e-5 (CE-5) landed on the northern Ocean Procellarum and returned 1,731 grams of regolith. The CE-5 regolith is composed mostly of fragments of basalt, impact glass, agglutinates, and mineral fragments. The basalts could be classified as of a low-Ti and highly fractionated type based on their TiO2 content of ∼5.3 wt% and Mg# of ∼28. Independent of petrographic texture, the CE-5 basalts have a uniform eruption age of 2,030 ± 4 Ma, demonstrating that the Moon remained volcanically active until at least ∼2.0 Ga. Although the CE-5 landing site lies within the so-called Procellarum KREEP [potassium (K), rare earth elements (REE), and phosphorus (P)] Terrane, neither the CE-5 basalts nor the mantle source regions of those basalts were enriched in KREEP components, such as incompatible elements, water, sulfur, or chlorine. Therefore, it would be a new and stimulating task in the future to look for the triggering mechanism of the young volcanism on the Moon. ▪ The CE-5 spacecraft returned 1,731 grams of lunar regolith in December 2020. It was the first new lunar sample since the last collection in August 1976. ▪ CE-5 regolith is basaltic in chemical composition, with only ∼1% highland materials of anorthosite, Mg suite, alkali suite, and KREEP. ▪ The CE-5 basalt is low Ti and highly differentiated. It was extruded at ∼2.0 Ga, being the youngest lunar basalt identified so far from the Moon. ▪ The triggering mechanism of the ∼2.0 Ga lunar volcanism is not clearly understood because its mantle source was dry and contained low abundances of KREEP elements.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
{"title":"Lunar Evolution in Light of the Chang'e-5 Returned Samples","authors":"Fu-Yuan Wu, Qiu-Li Li, Yi Chen, Sen Hu, Zong-Yu Yue, Qin Zhou, Hao Wang, Wei Yang, Heng-Ci Tian, Chi Zhang, Jin-Hua Li, Lin-Xi Li, He-Jiu Hui, Chun-Lai Li, Yang-Tin Lin, Xian-Hua Li, John W. Delano","doi":"10.1146/annurev-earth-040722-100453","DOIUrl":"https://doi.org/10.1146/annurev-earth-040722-100453","url":null,"abstract":"The Chinese spacecraft Chang'e-5 (CE-5) landed on the northern Ocean Procellarum and returned 1,731 grams of regolith. The CE-5 regolith is composed mostly of fragments of basalt, impact glass, agglutinates, and mineral fragments. The basalts could be classified as of a low-Ti and highly fractionated type based on their TiO<jats:sub>2</jats:sub> content of ∼5.3 wt% and Mg# of ∼28. Independent of petrographic texture, the CE-5 basalts have a uniform eruption age of 2,030 ± 4 Ma, demonstrating that the Moon remained volcanically active until at least ∼2.0 Ga. Although the CE-5 landing site lies within the so-called Procellarum KREEP [potassium (K), rare earth elements (REE), and phosphorus (P)] Terrane, neither the CE-5 basalts nor the mantle source regions of those basalts were enriched in KREEP components, such as incompatible elements, water, sulfur, or chlorine. Therefore, it would be a new and stimulating task in the future to look for the triggering mechanism of the young volcanism on the Moon. ▪ The CE-5 spacecraft returned 1,731 grams of lunar regolith in December 2020. It was the first new lunar sample since the last collection in August 1976. ▪ CE-5 regolith is basaltic in chemical composition, with only ∼1% highland materials of anorthosite, Mg suite, alkali suite, and KREEP. ▪ The CE-5 basalt is low Ti and highly differentiated. It was extruded at ∼2.0 Ga, being the youngest lunar basalt identified so far from the Moon. ▪ The triggering mechanism of the ∼2.0 Ga lunar volcanism is not clearly understood because its mantle source was dry and contained low abundances of KREEP elements.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"28 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139081550","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 : 2024-01-02DOI: 10.1146/annurev-earth-031621-113343
Imran A. Rahman, Samuel Zamora
Echinoderms are a major group (phylum) of invertebrate animals with a rich fossil record stretching back to the Cambrian period, approximately 518 million years ago. While all modern species are characterized by pentaradial (i.e., fivefold) symmetry, Cambrian echinoderms also include taxa with different types of symmetry (e.g., bilateral symmetry). These distinct forms were present from very early in the phylum's history, demonstrating that the initial diversification of echinoderm body plans was extremely rapid. The phylogenetic relationships of Cambrian echinoderms have long been debated, hindering efforts to reconstruct the evolution of the phylum, but recent analyses have consistently recovered bilaterally symmetrical forms as the earliest-diverging echinoderms. This reveals the sequence of character acquisition in echinoderm evolution, indicating that radial symmetry is a derived character of the group, which evolved after the acquisition of a mineralized skeleton. Cambrian echinoderms were adapted to diverse modes of life, with ecology an important factor shaping their early evolution. However, the reasons why echinoderms evolved their unique pentaradial body plan remain unclear. ▪ The Cambrian fossil record provides valuable insights into the origin and early evolution of echinoderms over half a billion years ago. ▪ Cambrian echinoderms were morphologically diverse, with several extinct groups exhibiting character combinations that distinguish them from living species. ▪ Phylogenetic analyses of bilateral, asymmetrical, triradial, and pentaradial fossils have allowed us to decipher the assembly of the modern echinoderm body plan. ▪ Echinoderms became ecologically diverse early in their history, with varied modes of feeding, locomotion, and attachment.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
{"title":"Origin and Early Evolution of Echinoderms","authors":"Imran A. Rahman, Samuel Zamora","doi":"10.1146/annurev-earth-031621-113343","DOIUrl":"https://doi.org/10.1146/annurev-earth-031621-113343","url":null,"abstract":"Echinoderms are a major group (phylum) of invertebrate animals with a rich fossil record stretching back to the Cambrian period, approximately 518 million years ago. While all modern species are characterized by pentaradial (i.e., fivefold) symmetry, Cambrian echinoderms also include taxa with different types of symmetry (e.g., bilateral symmetry). These distinct forms were present from very early in the phylum's history, demonstrating that the initial diversification of echinoderm body plans was extremely rapid. The phylogenetic relationships of Cambrian echinoderms have long been debated, hindering efforts to reconstruct the evolution of the phylum, but recent analyses have consistently recovered bilaterally symmetrical forms as the earliest-diverging echinoderms. This reveals the sequence of character acquisition in echinoderm evolution, indicating that radial symmetry is a derived character of the group, which evolved after the acquisition of a mineralized skeleton. Cambrian echinoderms were adapted to diverse modes of life, with ecology an important factor shaping their early evolution. However, the reasons why echinoderms evolved their unique pentaradial body plan remain unclear. ▪ The Cambrian fossil record provides valuable insights into the origin and early evolution of echinoderms over half a billion years ago. ▪ Cambrian echinoderms were morphologically diverse, with several extinct groups exhibiting character combinations that distinguish them from living species. ▪ Phylogenetic analyses of bilateral, asymmetrical, triradial, and pentaradial fossils have allowed us to decipher the assembly of the modern echinoderm body plan. ▪ Echinoderms became ecologically diverse early in their history, with varied modes of feeding, locomotion, and attachment.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"17 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139081760","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 : 2023-12-08DOI: 10.1146/annurev-earth-040722-104845
Mathias Mistretta Pires
Most terrestrial large mammals went extinct on different continents at the end of the Pleistocene, between 50,000 and 10,000 years ago. Besides the loss in species diversity and the truncation of body mass distributions, those extinctions were even more impactful to interaction diversity. Along with each extinction, dozens of ecological interactions were lost, reorganizing species interaction networks, which attained species-poor configurations with low functional redundancy. Extinctions of most large herbivores impacted energy flow and the rates of nutrient cycling, reconfiguring ecosystem-level networks. Because large mammals have high mobility, their loss also shortened seed-dispersal distance and reduced nutrient diffusivity, disrupting spatial networks. This review examines the recent advances in understanding how different types of ecological networks have been restructured by megafaunal extinctions and how this reorganization affected ecosystem functions. ▪ Megafaunal extinctions resulted in the loss of multiple ecological interactions in terrestrial systems. ▪ Interaction loss reshaped different types of ecological networks including food webs and spatial networks. ▪ The reorganization of ecological networks changed how terrestrial ecosystems are structured and function.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
{"title":"The Restructuring of Ecological Networks by the Pleistocene Extinction","authors":"Mathias Mistretta Pires","doi":"10.1146/annurev-earth-040722-104845","DOIUrl":"https://doi.org/10.1146/annurev-earth-040722-104845","url":null,"abstract":"Most terrestrial large mammals went extinct on different continents at the end of the Pleistocene, between 50,000 and 10,000 years ago. Besides the loss in species diversity and the truncation of body mass distributions, those extinctions were even more impactful to interaction diversity. Along with each extinction, dozens of ecological interactions were lost, reorganizing species interaction networks, which attained species-poor configurations with low functional redundancy. Extinctions of most large herbivores impacted energy flow and the rates of nutrient cycling, reconfiguring ecosystem-level networks. Because large mammals have high mobility, their loss also shortened seed-dispersal distance and reduced nutrient diffusivity, disrupting spatial networks. This review examines the recent advances in understanding how different types of ecological networks have been restructured by megafaunal extinctions and how this reorganization affected ecosystem functions. ▪ Megafaunal extinctions resulted in the loss of multiple ecological interactions in terrestrial systems. ▪ Interaction loss reshaped different types of ecological networks including food webs and spatial networks. ▪ The reorganization of ecological networks changed how terrestrial ecosystems are structured and function.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"13 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138559259","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 : 2023-12-08DOI: 10.1146/annurev-earth-031621-070316
Sara B. Pruss, Benjamin C. Gill
The beginning of the Phanerozoic saw two biological events that set the stage for all life that was to come: ( a) the Cambrian Explosion (the appearance of most marine invertebrate phyla) and ( b) the Great Ordovician Biodiversification Event (GOBE), the subsequent substantial accumulation of marine biodiversity. Here, we examine the current state of understanding of marine environments and ecosystems from the late Ediacaran through the Early Ordovician, which spans this biologically important interval. Through a compilation and review of the existing geochemical, mineralogical, sedimentological, and fossil records, we argue that this interval was one of sustained low and variable marine oxygen levels that both led to animal extinction and fostered biodiversification events throughout the Cambrian and Early Ordovician. Therefore, marine ecosystems of this interval existed on the edge—with enough oxygen to sustain them but with the perennial risk of environmental stressors that could overwhelm them.▪ We review the current research on geochemistry and paleontology of the Cambrian and Early Ordovician periods. ▪ Low and oscillating oxygen levels in the marine realm promoted diversification and evolutionary innovation but also drove several extinction events. ▪ Taphonomic modes and marine authigenic pathways that were abundant in the Cambrian were supported by oceans that were persistently less oxygenated than today's oceans.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
{"title":"Life on the Edge: The Cambrian Marine Realm and Oxygenation","authors":"Sara B. Pruss, Benjamin C. Gill","doi":"10.1146/annurev-earth-031621-070316","DOIUrl":"https://doi.org/10.1146/annurev-earth-031621-070316","url":null,"abstract":"The beginning of the Phanerozoic saw two biological events that set the stage for all life that was to come: ( a) the Cambrian Explosion (the appearance of most marine invertebrate phyla) and ( b) the Great Ordovician Biodiversification Event (GOBE), the subsequent substantial accumulation of marine biodiversity. Here, we examine the current state of understanding of marine environments and ecosystems from the late Ediacaran through the Early Ordovician, which spans this biologically important interval. Through a compilation and review of the existing geochemical, mineralogical, sedimentological, and fossil records, we argue that this interval was one of sustained low and variable marine oxygen levels that both led to animal extinction and fostered biodiversification events throughout the Cambrian and Early Ordovician. Therefore, marine ecosystems of this interval existed on the edge—with enough oxygen to sustain them but with the perennial risk of environmental stressors that could overwhelm them.▪ We review the current research on geochemistry and paleontology of the Cambrian and Early Ordovician periods. ▪ Low and oscillating oxygen levels in the marine realm promoted diversification and evolutionary innovation but also drove several extinction events. ▪ Taphonomic modes and marine authigenic pathways that were abundant in the Cambrian were supported by oceans that were persistently less oxygenated than today's oceans.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"6 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138559300","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 : 2023-10-12DOI: 10.1146/annurev-earth-040522-102129
Jeanne L. Hardebeck, Andrea L. Llenos, Andrew J. Michael, Morgan T. Page, Max Schneider, Nicholas J. van der Elst
Aftershocks can compound the impacts of a major earthquake, disrupting recovery efforts and potentially further damaging weakened buildings and infrastructure. Forecasts of the probability of aftershocks can therefore aid decision-making during earthquake response and recovery. Several countries issue authoritative aftershock forecasts. Most aftershock forecasts are based on simple statistical models that were first developed in the 1980s and remain the best available models. We review these statistical models and the wide-ranging research to advance aftershock forecasting through better statistical, physical, and machine-learning methods. Physics-based forecasts based on mainshock stress changes can sometimes match the statistical models in testing but do not yet outperform them. Physical models are also hampered by unsolved problems such as the mechanics of dynamic triggering and the influence of background conditions. Initial work on machine-learning forecasts shows promise, and new machine-learning earthquake catalogs provide an opportunity to advance all types of aftershock forecasts. ▪ Several countries issue real-time aftershock forecasts following significant earthquakes, providing information to aid response and recovery. ▪ Statistical models based on past aftershocks are used to compute aftershock probability as a function of space, time, and magnitude. ▪ Aftershock forecasting is advancing through better statistical models, constraints on physical triggering mechanisms, and machine learning. ▪ Large high-resolution earthquake catalogs provide an opportunity to advance physical, statistical, and machine-learning aftershock models.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
{"title":"Aftershock Forecasting","authors":"Jeanne L. Hardebeck, Andrea L. Llenos, Andrew J. Michael, Morgan T. Page, Max Schneider, Nicholas J. van der Elst","doi":"10.1146/annurev-earth-040522-102129","DOIUrl":"https://doi.org/10.1146/annurev-earth-040522-102129","url":null,"abstract":"Aftershocks can compound the impacts of a major earthquake, disrupting recovery efforts and potentially further damaging weakened buildings and infrastructure. Forecasts of the probability of aftershocks can therefore aid decision-making during earthquake response and recovery. Several countries issue authoritative aftershock forecasts. Most aftershock forecasts are based on simple statistical models that were first developed in the 1980s and remain the best available models. We review these statistical models and the wide-ranging research to advance aftershock forecasting through better statistical, physical, and machine-learning methods. Physics-based forecasts based on mainshock stress changes can sometimes match the statistical models in testing but do not yet outperform them. Physical models are also hampered by unsolved problems such as the mechanics of dynamic triggering and the influence of background conditions. Initial work on machine-learning forecasts shows promise, and new machine-learning earthquake catalogs provide an opportunity to advance all types of aftershock forecasts. ▪ Several countries issue real-time aftershock forecasts following significant earthquakes, providing information to aid response and recovery. ▪ Statistical models based on past aftershocks are used to compute aftershock probability as a function of space, time, and magnitude. ▪ Aftershock forecasting is advancing through better statistical models, constraints on physical triggering mechanisms, and machine learning. ▪ Large high-resolution earthquake catalogs provide an opportunity to advance physical, statistical, and machine-learning aftershock models.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"8 31","pages":""},"PeriodicalIF":14.9,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49697705","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 : 2023-08-02DOI: 10.1146/annurev-earth-031621-075925
K. Anderson, T. Shea, K. Lynn, E. Montgomery‐Brown, D. Swanson, M. Patrick, B. Shiro, C. Neal
The science of volcanology advances disproportionately during exceptionally large or well-observed eruptions. The 2018 eruption of Kīlauea Volcano (Hawai‘i) was its most impactful in centuries, involving an outpouring of more than one cubic kilometer of basalt, a magnitude 7 flank earthquake, and the volcano's largest summit collapse since at least the nineteenth century. Eruptive activity was documented in detail, yielding new insights into large caldera-rift eruptions; the geometry of a shallow magma storage-transport system and its interaction with rift zone tectonics; mechanisms of basaltic tephra-producing explosions; caldera collapse mechanics; and the dynamics of fissure eruptions and high-volume lava flows. Insights are broadly applicable to a range of volcanic systems and should reduce risk from future eruptions. Multidisciplinary collaboration will be required to fully leverage the diversity of monitoring data to address many of the most important outstanding questions. ▪ Unprecedented observations of a caldera collapse and coupled rift zone eruption yield new opportunities for advancing volcano science. ▪ Magma flow to a low-elevation rift zone vent triggered quasi-periodic step-like collapse of a summit caldera, which pressurized the magma system and sustained the eruption. ▪ Kīlauea's magmatic-tectonic system is tightly interconnected over tens of kilometers, with complex feedback mechanisms and interrelated hazards over widely varying time scales. ▪ The eruption revealed magma stored in diverse locations, volumes, and compositions, not only beneath the summit but also within the volcano's most active rift zone. Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
{"title":"The 2018 Eruption of Kīlauea: Insights, Puzzles, and Opportunities for Volcano Science","authors":"K. Anderson, T. Shea, K. Lynn, E. Montgomery‐Brown, D. Swanson, M. Patrick, B. Shiro, C. Neal","doi":"10.1146/annurev-earth-031621-075925","DOIUrl":"https://doi.org/10.1146/annurev-earth-031621-075925","url":null,"abstract":"The science of volcanology advances disproportionately during exceptionally large or well-observed eruptions. The 2018 eruption of Kīlauea Volcano (Hawai‘i) was its most impactful in centuries, involving an outpouring of more than one cubic kilometer of basalt, a magnitude 7 flank earthquake, and the volcano's largest summit collapse since at least the nineteenth century. Eruptive activity was documented in detail, yielding new insights into large caldera-rift eruptions; the geometry of a shallow magma storage-transport system and its interaction with rift zone tectonics; mechanisms of basaltic tephra-producing explosions; caldera collapse mechanics; and the dynamics of fissure eruptions and high-volume lava flows. Insights are broadly applicable to a range of volcanic systems and should reduce risk from future eruptions. Multidisciplinary collaboration will be required to fully leverage the diversity of monitoring data to address many of the most important outstanding questions. ▪ Unprecedented observations of a caldera collapse and coupled rift zone eruption yield new opportunities for advancing volcano science. ▪ Magma flow to a low-elevation rift zone vent triggered quasi-periodic step-like collapse of a summit caldera, which pressurized the magma system and sustained the eruption. ▪ Kīlauea's magmatic-tectonic system is tightly interconnected over tens of kilometers, with complex feedback mechanisms and interrelated hazards over widely varying time scales. ▪ The eruption revealed magma stored in diverse locations, volumes, and compositions, not only beneath the summit but also within the volcano's most active rift zone. Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"24 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87806425","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 : 2023-05-31DOI: 10.1146/annurev-earth-032320-110452
Di‐Cheng Zhu, Qing Wang, R. Weinberg, Peter A. Cawood, Zhidan Zhao, Z. Hou, X. Mo
The continental crust in the overriding plate of the India-Asia collision zone in southern Tibet is characterized by an overthickened layer of felsic composition with an underlying granulite-eclogite layer. A large data set indicates that this crust experienced magmatism from 245 to 10 Ma, as recorded by the Gangdese Batholith. Magmatism was punctuated by flare-ups at 185−170, 90−75, and 55−45 Ma caused by a combination of external and internal factors. The growth of this crust starts with a period dominated by fractional crystallization and the formation of voluminous (ultra)mafic arc cumulates in the lower crust during subduction, followed by their melting during late-subduction and collision, due to changes in convergence rate. This combined accumulation-melting process resulted in the vertical stratification and density sorting of the Gangdese crust. Comparisons with other similarly thickened collision zones suggests that this is a general process that leads to the stabilization of continental crust. ▪ The Gangdese Batholith records the time-integrated development of the world's thickest crust, reaching greater than 50 km at 55–45 Ma and greater than 70 km after 32 Ma. ▪ The Gangdese Batholith records three magmatic flare-ups in response to distinct drivers; the last one at 55−45 Ma marks the arrival of India. ▪ Magmatism was first dominated by fractional crystallization (accumulation) followed by crustal melting: the accumulation-melting process. ▪ Accumulation-melting in other collision zones provides a general process for vertical stratification and stabilization of continental crust.
{"title":"Continental Crustal Growth Processes Recorded in the Gangdese Batholith, Southern Tibet","authors":"Di‐Cheng Zhu, Qing Wang, R. Weinberg, Peter A. Cawood, Zhidan Zhao, Z. Hou, X. Mo","doi":"10.1146/annurev-earth-032320-110452","DOIUrl":"https://doi.org/10.1146/annurev-earth-032320-110452","url":null,"abstract":"The continental crust in the overriding plate of the India-Asia collision zone in southern Tibet is characterized by an overthickened layer of felsic composition with an underlying granulite-eclogite layer. A large data set indicates that this crust experienced magmatism from 245 to 10 Ma, as recorded by the Gangdese Batholith. Magmatism was punctuated by flare-ups at 185−170, 90−75, and 55−45 Ma caused by a combination of external and internal factors. The growth of this crust starts with a period dominated by fractional crystallization and the formation of voluminous (ultra)mafic arc cumulates in the lower crust during subduction, followed by their melting during late-subduction and collision, due to changes in convergence rate. This combined accumulation-melting process resulted in the vertical stratification and density sorting of the Gangdese crust. Comparisons with other similarly thickened collision zones suggests that this is a general process that leads to the stabilization of continental crust. ▪ The Gangdese Batholith records the time-integrated development of the world's thickest crust, reaching greater than 50 km at 55–45 Ma and greater than 70 km after 32 Ma. ▪ The Gangdese Batholith records three magmatic flare-ups in response to distinct drivers; the last one at 55−45 Ma marks the arrival of India. ▪ Magmatism was first dominated by fractional crystallization (accumulation) followed by crustal melting: the accumulation-melting process. ▪ Accumulation-melting in other collision zones provides a general process for vertical stratification and stabilization of continental crust.","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"1 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2023-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77855309","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 : 2023-05-31DOI: 10.1146/annurev-earth-031621-061221
A. Rhoden
Mimas, the smallest and innermost of Saturn's mid-sized moons, has a heavily cratered surface devoid of the intricate fracture systems of its neighbor, Enceladus. However, Cassini measurements identified a signature of an ocean under Mimas’ ice shell, although a frozen ice shell over a rocky interior could not be ruled out. The Mimas ocean hypothesis has stimulated inquiry into Mimas’ geologic history and orbital evolution. Here, we summarize the results of these investigations, which (perhaps surprisingly) are consistent with an ocean-bearing Mimas as long as it is geologically young. In that case, a ring origin for Mimas is favored over primordial accretion. An independently developed model for the formation of a gap in Saturn's rings provides a potential mechanism for generating a late-stage ocean within Mimas and may have assisted in the development of Enceladus’ ocean and associated geologic activity. Rather than a battered relic, Mimas may be the youngest ocean moon in the Saturn system, destined to join Enceladus as an active world in the future. The presence of oceans within Saturn's mid-sized moons also has implications for the habitability of Uranus’ moons; the Uranus system was chosen as the highest priority target for the next NASA Flagship-class mission. ▪ Models of Mimas’ tides and rotation state support a present-day internal ocean. ▪ Mimas’ craters, impact basin, and lack of widespread tectonism are compatible with a stable/warming ocean. ▪ The formation of the Cassini Division within Saturn's rings provides a potential pathway to a present-day ocean within Mimas. ▪ If Mimas has an ocean today, it is geologically young.
{"title":"Mimas: Frozen Fragment, Ring Relic, or Emerging Ocean World?","authors":"A. Rhoden","doi":"10.1146/annurev-earth-031621-061221","DOIUrl":"https://doi.org/10.1146/annurev-earth-031621-061221","url":null,"abstract":"Mimas, the smallest and innermost of Saturn's mid-sized moons, has a heavily cratered surface devoid of the intricate fracture systems of its neighbor, Enceladus. However, Cassini measurements identified a signature of an ocean under Mimas’ ice shell, although a frozen ice shell over a rocky interior could not be ruled out. The Mimas ocean hypothesis has stimulated inquiry into Mimas’ geologic history and orbital evolution. Here, we summarize the results of these investigations, which (perhaps surprisingly) are consistent with an ocean-bearing Mimas as long as it is geologically young. In that case, a ring origin for Mimas is favored over primordial accretion. An independently developed model for the formation of a gap in Saturn's rings provides a potential mechanism for generating a late-stage ocean within Mimas and may have assisted in the development of Enceladus’ ocean and associated geologic activity. Rather than a battered relic, Mimas may be the youngest ocean moon in the Saturn system, destined to join Enceladus as an active world in the future. The presence of oceans within Saturn's mid-sized moons also has implications for the habitability of Uranus’ moons; the Uranus system was chosen as the highest priority target for the next NASA Flagship-class mission. ▪ Models of Mimas’ tides and rotation state support a present-day internal ocean. ▪ Mimas’ craters, impact basin, and lack of widespread tectonism are compatible with a stable/warming ocean. ▪ The formation of the Cassini Division within Saturn's rings provides a potential pathway to a present-day ocean within Mimas. ▪ If Mimas has an ocean today, it is geologically young.","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"9 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2023-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80702588","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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