Pub Date : 2025-03-10DOI: 10.1146/annurev-earth-032320-064209
Jessica E. Tierney, Emily J. Judd, Matthew B. Osman, Jonathan M. King, Olivia J. Truax, Nathan J. Steiger, Daniel E. Amrhein, Kevin J. Anchukaitis
Reconstructions of past climates in both time and space provide important insight into the range and rate of change within the climate system. However, producing a coherent global picture of past climates is difficult because indicators of past environmental changes (proxy data) are unevenly distributed and uncertain. In recent years, paleoclimate data assimilation (paleoDA), which statistically combines model simulations with proxy data, has become an increasingly popular reconstruction method. Here, we describe advances in paleoDA to date, with a focus on the offline ensemble Kalman filter and the insights into climate change that this method affords. PaleoDA has considerable strengths in that it can blend multiple types of information while also propagating uncertainty. Drawbacks of the methodology include an overreliance on the climate model and variance loss. We conclude with an outlook on possible expansions and improvements in paleoDA that can be made in the upcoming years.▪ Paleoclimate data assimilation blends model and proxy information to enable spatiotemporal reconstructions of past climate change. ▪ This method has advanced our understanding of global temperature change, Earth's climate sensitivity, and past climate dynamics. ▪ Future innovations could improve the method by implementing online paleoclimate data assimilation and smoothers.
{"title":"Advances in Paleoclimate Data Assimilation","authors":"Jessica E. Tierney, Emily J. Judd, Matthew B. Osman, Jonathan M. King, Olivia J. Truax, Nathan J. Steiger, Daniel E. Amrhein, Kevin J. Anchukaitis","doi":"10.1146/annurev-earth-032320-064209","DOIUrl":"https://doi.org/10.1146/annurev-earth-032320-064209","url":null,"abstract":"Reconstructions of past climates in both time and space provide important insight into the range and rate of change within the climate system. However, producing a coherent global picture of past climates is difficult because indicators of past environmental changes (proxy data) are unevenly distributed and uncertain. In recent years, paleoclimate data assimilation (paleoDA), which statistically combines model simulations with proxy data, has become an increasingly popular reconstruction method. Here, we describe advances in paleoDA to date, with a focus on the offline ensemble Kalman filter and the insights into climate change that this method affords. PaleoDA has considerable strengths in that it can blend multiple types of information while also propagating uncertainty. Drawbacks of the methodology include an overreliance on the climate model and variance loss. We conclude with an outlook on possible expansions and improvements in paleoDA that can be made in the upcoming years.<jats:list list-type=\"bullet\"> <jats:list-item> <jats:label>▪</jats:label> Paleoclimate data assimilation blends model and proxy information to enable spatiotemporal reconstructions of past climate change. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> This method has advanced our understanding of global temperature change, Earth's climate sensitivity, and past climate dynamics. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Future innovations could improve the method by implementing online paleoclimate data assimilation and smoothers. </jats:list-item> </jats:list>","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"10 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143589779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-27DOI: 10.1146/annurev-earth-040523-114630
Kristin D. Bergmann, Francis A. Macdonald, Nicholas L. Swanson-Hysell
A long-term cooling trend through the Ordovician Period, from 487 to 443 Ma, is recorded by oxygen isotope data. Tropical ocean basins in the Early Ordovician were hot, which led to low oxygen concentrations in the surface ocean due to the temperature dependence of oxygen solubility. Elevated temperatures also increased metabolic demands such that hot shallow water environments had limited animal diversity as recorded by microbially dominated carbonates. As the oceans cooled through the Ordovician, animal biodiversity increased, leading to the Great Ordovician Biodiversification Event. The protracted nature of the cooling suggests that it was the product of progressive changes in tectonic boundary conditions. Low-latitude arc-continent collisions through this period may have increased global weatherability and decreased atmospheric CO2 levels. Additionally, decreasing continental arc magmatism could have lowered CO2 outgassing fluxes. The Ordovician long-term cooling trend culminated with the development of a large south polar ice sheet on Gondwana. The timescale of major ice growth and decay over the final 2 Myr of the Ordovician is consistent with Pleistocene-like glacial cycles driven by orbital forcing. The short duration of large-scale glaciation indicates a high sensitivity of ice volume to temperature with a strongly nonlinear response, providing a valuable analog for Neogene and future climate change. ▪ Oxygen isotope data record progressive and protracted cooling through the Ordovician leading up to the onset of Hirnantian glaciation. ▪ The gradual cooling trend is mirrored by an Ordovician radiation in biological diversity, consistent with temperature-dependent oxygen solubility and metabolism as a primary control. ▪ Long-term cooling occurred in concert with low-latitude arc-continent collisions and an increase in global weatherability. Although CO2 outgassing may have also decreased with an Ordovician decrease in continental arc length, in the modern, CO2 outgassing is variable along both continental and island arcs, leaving the relationship between continental arc length and climate uncertain. ▪ Evidence for significant ice growth is limited to less than 2 Myr of the Hirnantian Stage, suggesting a high sensitivity of ice growth to pCO2 and temperature. ▪ Independent estimates for ice volume, area, and sea level change during the Hirnantian glacial maximum are internally consistent and comparable to those of the Last Glacial Maximum.
{"title":"The Causes and Consequences of Ordovician Cooling","authors":"Kristin D. Bergmann, Francis A. Macdonald, Nicholas L. Swanson-Hysell","doi":"10.1146/annurev-earth-040523-114630","DOIUrl":"https://doi.org/10.1146/annurev-earth-040523-114630","url":null,"abstract":"A long-term cooling trend through the Ordovician Period, from 487 to 443 Ma, is recorded by oxygen isotope data. Tropical ocean basins in the Early Ordovician were hot, which led to low oxygen concentrations in the surface ocean due to the temperature dependence of oxygen solubility. Elevated temperatures also increased metabolic demands such that hot shallow water environments had limited animal diversity as recorded by microbially dominated carbonates. As the oceans cooled through the Ordovician, animal biodiversity increased, leading to the Great Ordovician Biodiversification Event. The protracted nature of the cooling suggests that it was the product of progressive changes in tectonic boundary conditions. Low-latitude arc-continent collisions through this period may have increased global weatherability and decreased atmospheric CO<jats:sub>2</jats:sub> levels. Additionally, decreasing continental arc magmatism could have lowered CO<jats:sub>2</jats:sub> outgassing fluxes. The Ordovician long-term cooling trend culminated with the development of a large south polar ice sheet on Gondwana. The timescale of major ice growth and decay over the final 2 Myr of the Ordovician is consistent with Pleistocene-like glacial cycles driven by orbital forcing. The short duration of large-scale glaciation indicates a high sensitivity of ice volume to temperature with a strongly nonlinear response, providing a valuable analog for Neogene and future climate change. <jats:list list-type=\"bullet\"> <jats:list-item> <jats:label>▪</jats:label> Oxygen isotope data record progressive and protracted cooling through the Ordovician leading up to the onset of Hirnantian glaciation. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> The gradual cooling trend is mirrored by an Ordovician radiation in biological diversity, consistent with temperature-dependent oxygen solubility and metabolism as a primary control. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Long-term cooling occurred in concert with low-latitude arc-continent collisions and an increase in global weatherability. Although CO<jats:sub>2</jats:sub> outgassing may have also decreased with an Ordovician decrease in continental arc length, in the modern, CO<jats:sub>2</jats:sub> outgassing is variable along both continental and island arcs, leaving the relationship between continental arc length and climate uncertain. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Evidence for significant ice growth is limited to less than 2 Myr of the Hirnantian Stage, suggesting a high sensitivity of ice growth to <jats:italic>p</jats:italic>CO<jats:sub>2</jats:sub> and temperature. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Independent estimates for ice volume, area, and sea level change during the Hirnantian glacial maximum are internally consistent and comparable to those of the Last Glacial Maximum. </jats:list-item> </jats:list>","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"15 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-21DOI: 10.1146/annurev-earth-040523-020630
Naomi M. Levine, Harriet Alexander, Erin M. Bertrand, Victoria J. Coles, Stephanie Dutkiewicz, Suzana G. Leles, Emily J. Zakem
The oceans contain large reservoirs of inorganic and organic carbon and play a critical role in both global carbon cycling and climate. Most of the biogeochemical transformations in the oceans are driven by marine microbes. Thus, molecular processes occurring at the scale of single cells govern global geochemical dynamics, posing a challenge of scales. Understanding the processes controlling ocean carbon cycling from the cellular to the global scale requires the integration of multiple disciplines including microbiology, ecology, biogeochemistry, and computational fields such as numerical models and bioinformatics. A shared language and foundational knowledge will facilitate these interactions. This review provides the state of knowledge on the role marine microbes play in large-scale ocean carbon cycling through the lens of observational oceanography and biogeochemical models. We conclude by outlining ways in which the field can bridge the gap between -omics datasets and ocean models to understand ocean carbon cycling across scales. ▪ -Omic approaches are providing increasingly quantitative insight into the biogeochemical functions of marine microbial ecosystems. ▪ Numerical models provide a tool for studying global carbon cycling by scaling from the microscale to the global scale. ▪ The integration of -omics and numerical modeling generates new understanding of how microbial metabolisms and community dynamics set nutrient fluxes in the ocean.
{"title":"Microbial Ecology to Ocean Carbon Cycling: From Genomes to Numerical Models","authors":"Naomi M. Levine, Harriet Alexander, Erin M. Bertrand, Victoria J. Coles, Stephanie Dutkiewicz, Suzana G. Leles, Emily J. Zakem","doi":"10.1146/annurev-earth-040523-020630","DOIUrl":"https://doi.org/10.1146/annurev-earth-040523-020630","url":null,"abstract":"The oceans contain large reservoirs of inorganic and organic carbon and play a critical role in both global carbon cycling and climate. Most of the biogeochemical transformations in the oceans are driven by marine microbes. Thus, molecular processes occurring at the scale of single cells govern global geochemical dynamics, posing a challenge of scales. Understanding the processes controlling ocean carbon cycling from the cellular to the global scale requires the integration of multiple disciplines including microbiology, ecology, biogeochemistry, and computational fields such as numerical models and bioinformatics. A shared language and foundational knowledge will facilitate these interactions. This review provides the state of knowledge on the role marine microbes play in large-scale ocean carbon cycling through the lens of observational oceanography and biogeochemical models. We conclude by outlining ways in which the field can bridge the gap between -omics datasets and ocean models to understand ocean carbon cycling across scales. <jats:list list-type=\"bullet\"> <jats:list-item> <jats:label>▪</jats:label> -Omic approaches are providing increasingly quantitative insight into the biogeochemical functions of marine microbial ecosystems. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Numerical models provide a tool for studying global carbon cycling by scaling from the microscale to the global scale. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> The integration of -omics and numerical modeling generates new understanding of how microbial metabolisms and community dynamics set nutrient fluxes in the ocean. </jats:list-item> </jats:list>","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"66 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-21DOI: 10.1146/annurev-earth-040523-115520
Stuart Henrys, Dan Bassett, Susan Ellis, Laura Wallace, Philip M. Barnes, Donna Eberhart-Phillips, Demian Saffer, Carolyn Boulton
The Hikurangi margin has been an important global focus for subduction zone research for the last decade. International Ocean Discovery Program drilling and geophysical investigations have advanced our understanding of megathrust slip behavior. Along and across the margin, detailed imaging reveals that the megathrust structure varies spatially and evolves over time. Heterogeneous properties of the plate boundary zone and overriding plate are impacted by the evolving nature of regional tectonics and inherited overriding plate structure. Along-strike variability in thickness of subducting sediment and northward increasing influence of seamount subduction strongly influence megathrust lithologies, fluid pressure, and permeability structure. Together, these exert strong control on spatial variations in coupling, slow slip, and seismicity distribution. Thicker incoming sediment, combined with a compressional upper plate, influences deeper coupling at southern Hikurangi, where paleoseismic investigations reveal recurring great (Mw > 8.0) earthquakes. ▪ The Hikurangi Subduction Zone is marked by large-scale changes in the subducting Pacific Plate and the overlying plate, with varied tectonic stress, crustal thickness, and sediment cover. ▪ The roughness of the lower plate influences the variability in megathrust slip behavior, particularly where seamounts enhance subduction of fluid-rich sediments. ▪ Variations in sediment composition impact the strength of the subduction interface, with the southern Hikurangi Subduction Zone exhibiting a more uniform megathrust fault. ▪ Properties of the upper plate influence fluid pressures and contribute to the observed along-strike variations in Hikurangi plate coupling and slip behavior.
过去十年来，希古朗伊边缘一直是全球俯冲带研究的一个重要焦点。国际大洋发现计划的钻探和地球物理调查加深了我们对巨岩滑动行为的了解。沿边缘和横跨边缘的详细成像显示，巨推结构在空间上各不相同，并随着时间的推移而演变。板块边界区和凌空板块的异质特性受到区域构造和继承的凌空板块结构不断演变的影响。俯冲沉积厚度的沿走向变化和海山俯冲向北的影响，对巨岩岩性、流体压力和渗透结构产生了强烈影响。这些因素共同对耦合、缓慢滑移和地震分布的空间变化产生了强有力的控制。较厚的入海沉积物，加上上层板块的压缩性，影响了希库兰芝南部更深的耦合，在那里进行的古地震调查揭示了反复发生的大（M w > 8.0）地震。 彦库朗伊俯冲带的特点是俯冲太平洋板块和上覆板块发生大规模变化，构造应力、地壳厚度和沉积物覆盖率各不相同。 下层板块的粗糙度影响着巨岩滑动行为的变化，特别是在海山加强富含流体沉积物的俯冲的地方。 沉积物成分的变化影响着俯冲界面的强度，南部的希库兰芝俯冲带表现出更均匀的大推力断层。 上层板块的特性影响流体压力，并导致所观测到的彦兰芝板块耦合和滑动行为的沿走向变化。
{"title":"How Subduction Margin Processes and Properties Influence the Hikurangi Subduction Zone","authors":"Stuart Henrys, Dan Bassett, Susan Ellis, Laura Wallace, Philip M. Barnes, Donna Eberhart-Phillips, Demian Saffer, Carolyn Boulton","doi":"10.1146/annurev-earth-040523-115520","DOIUrl":"https://doi.org/10.1146/annurev-earth-040523-115520","url":null,"abstract":"The Hikurangi margin has been an important global focus for subduction zone research for the last decade. International Ocean Discovery Program drilling and geophysical investigations have advanced our understanding of megathrust slip behavior. Along and across the margin, detailed imaging reveals that the megathrust structure varies spatially and evolves over time. Heterogeneous properties of the plate boundary zone and overriding plate are impacted by the evolving nature of regional tectonics and inherited overriding plate structure. Along-strike variability in thickness of subducting sediment and northward increasing influence of seamount subduction strongly influence megathrust lithologies, fluid pressure, and permeability structure. Together, these exert strong control on spatial variations in coupling, slow slip, and seismicity distribution. Thicker incoming sediment, combined with a compressional upper plate, influences deeper coupling at southern Hikurangi, where paleoseismic investigations reveal recurring great (<jats:italic>M</jats:italic> <jats:sub>w</jats:sub> > 8.0) earthquakes. <jats:list list-type=\"bullet\"> <jats:list-item> <jats:label>▪</jats:label> The Hikurangi Subduction Zone is marked by large-scale changes in the subducting Pacific Plate and the overlying plate, with varied tectonic stress, crustal thickness, and sediment cover. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> The roughness of the lower plate influences the variability in megathrust slip behavior, particularly where seamounts enhance subduction of fluid-rich sediments. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Variations in sediment composition impact the strength of the subduction interface, with the southern Hikurangi Subduction Zone exhibiting a more uniform megathrust fault. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Properties of the upper plate influence fluid pressures and contribute to the observed along-strike variations in Hikurangi plate coupling and slip behavior. </jats:list-item> </jats:list>","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"6 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-20DOI: 10.1146/annurev-earth-040523-014302
Nadir Jeevanjee, David J. Paynter, John P. Dunne, Lori T. Sentman, John P. Krasting
The notion of climate sensitivity has become synonymous with equilibrium climate sensitivity (ECS), or the equilibrium response of the Earth system to a doubling of CO2. But there is a hierarchy of measures of climate sensitivity, which can be arranged in order of increasing complexity and societal relevance and which mirror the historical development of climate modeling. Elements of this hierarchy include the well-known ECS and transient climate response and the lesser-known transient climate response to cumulative emissions and zero emissions commitment. This article describes this hierarchy of climate sensitivities and associated modeling approaches. Key concepts reviewed along the way include climate forcing and feedback, ocean heat uptake, and the airborne fraction of cumulative emissions. We employ simplified theoretical models throughout to encapsulate well-understood aspects of these quantities and to highlight gaps in our understanding and areas for future progress. ▪ There is a hierarchy of measures of climate sensitivity, which exhibit a range of complexity and societal relevance. ▪ Equilibrium climate sensitivity is only one these measures, and our understanding of it may have reached a plateau. ▪ The more complex measures introduce new quantities, such as ocean heat uptake efficiency and airborne fraction, which deserve increased attention.
{"title":"A Holistic View of Climate Sensitivity","authors":"Nadir Jeevanjee, David J. Paynter, John P. Dunne, Lori T. Sentman, John P. Krasting","doi":"10.1146/annurev-earth-040523-014302","DOIUrl":"https://doi.org/10.1146/annurev-earth-040523-014302","url":null,"abstract":"The notion of climate sensitivity has become synonymous with equilibrium climate sensitivity (ECS), or the equilibrium response of the Earth system to a doubling of CO<jats:sub>2</jats:sub>. But there is a hierarchy of measures of climate sensitivity, which can be arranged in order of increasing complexity and societal relevance and which mirror the historical development of climate modeling. Elements of this hierarchy include the well-known ECS and transient climate response and the lesser-known transient climate response to cumulative emissions and zero emissions commitment. This article describes this hierarchy of climate sensitivities and associated modeling approaches. Key concepts reviewed along the way include climate forcing and feedback, ocean heat uptake, and the airborne fraction of cumulative emissions. We employ simplified theoretical models throughout to encapsulate well-understood aspects of these quantities and to highlight gaps in our understanding and areas for future progress. <jats:list list-type=\"bullet\"> <jats:list-item> <jats:label>▪</jats:label> There is a hierarchy of measures of climate sensitivity, which exhibit a range of complexity and societal relevance. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Equilibrium climate sensitivity is only one these measures, and our understanding of it may have reached a plateau. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> The more complex measures introduce new quantities, such as ocean heat uptake efficiency and airborne fraction, which deserve increased attention. </jats:list-item> </jats:list>","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"22 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-20DOI: 10.1146/annurev-earth-040722-093345
Priyadarshi Chowdhury, Peter A. Cawood, Jacob A. Mulder
The emergence of continental crust above sea level influences Earth's surface environments and climate patterns, and it creates diverse habitats that promote biodiversity. Earth exhibits bimodal hypsometry with elevated continents and a submerged seafloor. However, it remains elusive when and how this unique feature was first established. The geological record suggests the presence of subaerial landmasses between ca. 3.8 and 2.4 billion years ago (Ga), but their spatial extent and longevity remain unclear. Further, the tectonic processes governing the proportion of continental land to ocean basins and topography during this period are poorly understood. Here, we synthesize a variety of geological and geochemical proxies to suggest that crustal emergence did occur in the early-to-mid Archean, primarily exposing precratonized volcanic crust for brief time periods. Stable continental crust on a regional scale (as cratons) began emerging around ca. 3.2–3.0 Ga, facilitated by the development of thick, stable cratonic lithospheres. Over hundreds of millions of years, voluminous magmatism within a plateau-type setting led to the formation of thick, felsic crust and depleted mantle keels, allowing cratons to rise above sea level via isostatic adjustment. The areal extent of emergent land increased from ca. 3.0 to 2.5 Ga owing to the formation of more cratons, likely coinciding with the onset of plate tectonics, and culminated around ca. 2.5–2.2 Ga when land surface area and freeboard conditions resembled those observed today. These newly emerged landmasses possibly played a critical role in oxygenating the atmosphere and oceans, cooling the climate, and promoting biodiversity during the late Archean to early Paleoproterozoic. ▪ Continental emergence marks a pivotal moment in Earth's history, impacting the planet's atmosphere, oceans, climate, and life evolution. ▪ We review the rock record to infer the timing, nature, and tectonic drivers of continental emergence on early Earth. ▪ Emergence on early Archean Earth was mostly transient, exposing primarily volcanic crust. ▪ First stable continental land formed at ca. 3.2–3.0 Ga due to the development of thick cratons and their isostatic adjustment. ▪ Emergent land area increased from ca. 3.0 to 2.5 Ga as more cratons formed and plate tectonics began.
{"title":"Subaerial Emergence of Continents on Archean Earth","authors":"Priyadarshi Chowdhury, Peter A. Cawood, Jacob A. Mulder","doi":"10.1146/annurev-earth-040722-093345","DOIUrl":"https://doi.org/10.1146/annurev-earth-040722-093345","url":null,"abstract":"The emergence of continental crust above sea level influences Earth's surface environments and climate patterns, and it creates diverse habitats that promote biodiversity. Earth exhibits bimodal hypsometry with elevated continents and a submerged seafloor. However, it remains elusive when and how this unique feature was first established. The geological record suggests the presence of subaerial landmasses between ca. 3.8 and 2.4 billion years ago (Ga), but their spatial extent and longevity remain unclear. Further, the tectonic processes governing the proportion of continental land to ocean basins and topography during this period are poorly understood. Here, we synthesize a variety of geological and geochemical proxies to suggest that crustal emergence did occur in the early-to-mid Archean, primarily exposing precratonized volcanic crust for brief time periods. Stable continental crust on a regional scale (as cratons) began emerging around ca. 3.2–3.0 Ga, facilitated by the development of thick, stable cratonic lithospheres. Over hundreds of millions of years, voluminous magmatism within a plateau-type setting led to the formation of thick, felsic crust and depleted mantle keels, allowing cratons to rise above sea level via isostatic adjustment. The areal extent of emergent land increased from ca. 3.0 to 2.5 Ga owing to the formation of more cratons, likely coinciding with the onset of plate tectonics, and culminated around ca. 2.5–2.2 Ga when land surface area and freeboard conditions resembled those observed today. These newly emerged landmasses possibly played a critical role in oxygenating the atmosphere and oceans, cooling the climate, and promoting biodiversity during the late Archean to early Paleoproterozoic. <jats:list list-type=\"bullet\"> <jats:list-item> <jats:label>▪</jats:label> Continental emergence marks a pivotal moment in Earth's history, impacting the planet's atmosphere, oceans, climate, and life evolution. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> We review the rock record to infer the timing, nature, and tectonic drivers of continental emergence on early Earth. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Emergence on early Archean Earth was mostly transient, exposing primarily volcanic crust. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> First stable continental land formed at ca. 3.2–3.0 Ga due to the development of thick cratons and their isostatic adjustment. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Emergent land area increased from ca. 3.0 to 2.5 Ga as more cratons formed and plate tectonics began. </jats:list-item> </jats:list>","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"81 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-20DOI: 10.1146/annurev-earth-040522-121945
S. Ruiz, S. Ide, B. Potin, R. Madariaga
Most seismicity in Latin America is controlled by the subduction process. Different zones have hosted earthquakes of magnitudes larger than Mw 8.5 that repeat every several centuries. Events around Mw 8.0 are more frequent; since the beginning of the twentieth century, some collocated earthquakes have occurred with differences of decades, which allows for comparison of old and modern seismological records. The rupture zones that have hosted mega-earthquakes continue to produce smaller earthquakes after three centuries. Therefore, the process of unlocking in the Latin America subduction zone occurs by giant (≥Mw 9.0), mega- (9.0 > Mw ≥ 8.5), and large (8.5 > Mw ≥ 7.5) earthquakes, and interaction between these events is not yet fully understood. We have less understanding of the earthquakes that occurred in the oceanic plates, which have not been correctly recorded due to poor seismological instrumentation and lack of knowledge about subduction during the first half of the twentieth century in Latin America. Slow earthquakes have been observed in some zones of Latin America, several of them with recurrence periods of a few years, as well as tectonic (nonvolcanic) tremors and low-frequency and very low-frequency earthquakes. How do these slow slip manifestations relate to ordinary earthquakes? This question is still difficult to answer for Latin America given the lack of dense geodetic and seismic networks that allow identification of all the slow earthquakes that likely occur more frequently than currently reported. ▪ Latin America subduction zones share similar seismic characteristics. They can host large-magnitude earthquakes and exhibit a variety of slow earthquakes. ▪ Giant earthquakes, with a magnitude greater than 9, have occurred so far in Chile, and mega-earthquakes have occurred in several Latin American countries. ▪ Additional slow earthquakes will be detected in Latin America as seismic and geodetic networks become denser.
{"title":"Fast and Slow Subduction Earthquakes in Latin America","authors":"S. Ruiz, S. Ide, B. Potin, R. Madariaga","doi":"10.1146/annurev-earth-040522-121945","DOIUrl":"https://doi.org/10.1146/annurev-earth-040522-121945","url":null,"abstract":"Most seismicity in Latin America is controlled by the subduction process. Different zones have hosted earthquakes of magnitudes larger than Mw 8.5 that repeat every several centuries. Events around Mw 8.0 are more frequent; since the beginning of the twentieth century, some collocated earthquakes have occurred with differences of decades, which allows for comparison of old and modern seismological records. The rupture zones that have hosted mega-earthquakes continue to produce smaller earthquakes after three centuries. Therefore, the process of unlocking in the Latin America subduction zone occurs by giant (≥Mw 9.0), mega- (9.0 > Mw ≥ 8.5), and large (8.5 > Mw ≥ 7.5) earthquakes, and interaction between these events is not yet fully understood. We have less understanding of the earthquakes that occurred in the oceanic plates, which have not been correctly recorded due to poor seismological instrumentation and lack of knowledge about subduction during the first half of the twentieth century in Latin America. Slow earthquakes have been observed in some zones of Latin America, several of them with recurrence periods of a few years, as well as tectonic (nonvolcanic) tremors and low-frequency and very low-frequency earthquakes. How do these slow slip manifestations relate to ordinary earthquakes? This question is still difficult to answer for Latin America given the lack of dense geodetic and seismic networks that allow identification of all the slow earthquakes that likely occur more frequently than currently reported. <jats:list list-type=\"bullet\"> <jats:list-item> <jats:label>▪</jats:label> Latin America subduction zones share similar seismic characteristics. They can host large-magnitude earthquakes and exhibit a variety of slow earthquakes. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Giant earthquakes, with a magnitude greater than 9, have occurred so far in Chile, and mega-earthquakes have occurred in several Latin American countries. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Additional slow earthquakes will be detected in Latin America as seismic and geodetic networks become denser. </jats:list-item> </jats:list>","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"50 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-15DOI: 10.1146/annurev-earth-111523-081635
Krista M. Soderlund, Sabine Stanley, Hao Cao, Michael A. Calkins, Matthew K. Browning
Intrinsic magnetic fields were once commonplace across our Solar System, and many planetary bodies have sustained active dynamos to the present day. The nature and behavior of these dynamos vary widely, however, reflecting the diverse internal conditions of planets as summarized in this review. For the terrestrial planets, the existence of active dynamos and/or ancient remanent magnetization recorded in crustal rocks, or lack thereof, lead to questions about their timing and power sources. Paleomagnetic studies reveal that many small bodies in the Solar System exhibit remanent magnetization, often attributed to ancient core dynamos with little known about the fluid dynamics. For the gas giants, their dipole-dominated magnetic fields and internal structures are relatively well-characterized, with dilute cores that are not centrally concentrated and other stable layers that likely affect the dynamo in ways that are not yet understood. For the ice giants, their multipolar magnetic fields and internal structures are unusual yet poorly constrained, to the extent that even the water-to-rock ratio is not well-known. Through adoption of a broader comparative planetology approach, the study of dynamos in exoplanets and cool stars enriches our understanding of dynamo theories. ▪ Planetary dynamos exhibit diverse magnetic fields shaped by their distinct physical and chemical conditions. ▪ The study of planets and stars connects planetary science, geophysics, and astrophysics, revealing shared dynamo processes. ▪ While significant progress has been made in understanding planetary and stellar magnetic fields, many puzzles still persist.
{"title":"Puzzles in Planetary Dynamos: Implications for Planetary Interiors","authors":"Krista M. Soderlund, Sabine Stanley, Hao Cao, Michael A. Calkins, Matthew K. Browning","doi":"10.1146/annurev-earth-111523-081635","DOIUrl":"https://doi.org/10.1146/annurev-earth-111523-081635","url":null,"abstract":"Intrinsic magnetic fields were once commonplace across our Solar System, and many planetary bodies have sustained active dynamos to the present day. The nature and behavior of these dynamos vary widely, however, reflecting the diverse internal conditions of planets as summarized in this review. For the terrestrial planets, the existence of active dynamos and/or ancient remanent magnetization recorded in crustal rocks, or lack thereof, lead to questions about their timing and power sources. Paleomagnetic studies reveal that many small bodies in the Solar System exhibit remanent magnetization, often attributed to ancient core dynamos with little known about the fluid dynamics. For the gas giants, their dipole-dominated magnetic fields and internal structures are relatively well-characterized, with dilute cores that are not centrally concentrated and other stable layers that likely affect the dynamo in ways that are not yet understood. For the ice giants, their multipolar magnetic fields and internal structures are unusual yet poorly constrained, to the extent that even the water-to-rock ratio is not well-known. Through adoption of a broader comparative planetology approach, the study of dynamos in exoplanets and cool stars enriches our understanding of dynamo theories. <jats:list list-type=\"bullet\"> <jats:list-item> <jats:label>▪</jats:label> Planetary dynamos exhibit diverse magnetic fields shaped by their distinct physical and chemical conditions. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> The study of planets and stars connects planetary science, geophysics, and astrophysics, revealing shared dynamo processes. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> While significant progress has been made in understanding planetary and stellar magnetic fields, many puzzles still persist. </jats:list-item> </jats:list>","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"21 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-15DOI: 10.1146/annurev-earth-040523-024053
Estella A. Atekwana, Joshua M. Feinberg, James M. Byrne
Geomagnetic methods allow us to explore the behavior of Earth's geodynamo, constrain Earth's composition and structure, and locate critical minerals and other resources essential for modern technologies and the energy transition. The magnetic properties of rocks and sediments are assumed to be stable and largely attributable to inorganic processes. This conventional view overlooks mounting evidence of microorganisms as key players in rock transformations and geological processes. Iron-bearing minerals are ubiquitous in most environments and are commonly used by microorganisms as electron donors and acceptors. Microorganisms modulate rock magnetic properties by creating, altering, and dissolving Fe-bearing minerals, potentially modifying the original magnetization, complicating interpretations of the magnetic record. This review provides an overview of biogenic pathways that modulate magnetic minerals and discusses common, yet underutilized, magnetic methods for capturing such behavior. Appreciating the influence of microbial activities on magnetic properties will improve our interpretations of Earth's geologic past and its elemental cycling. ▪ Microorganisms modulate rock magnetic properties, challenging traditional views of a geologically stable magnetic record formed solely by inorganic processes. ▪ Microbial iron cycling modulates magnetic properties modifying magnetic information recorded in rocks. ▪ Microbial processes may have impacted Earth's magnetic history more deeply than previously understood. ▪ Recognizing microbial contributions is critical for accurate interpretation of paleomagnetic and environmental magnetic records and could aid in the search for life on other planetary bodies.
{"title":"The Role of Microorganisms in Shaping Earth's Magnetic History","authors":"Estella A. Atekwana, Joshua M. Feinberg, James M. Byrne","doi":"10.1146/annurev-earth-040523-024053","DOIUrl":"https://doi.org/10.1146/annurev-earth-040523-024053","url":null,"abstract":"Geomagnetic methods allow us to explore the behavior of Earth's geodynamo, constrain Earth's composition and structure, and locate critical minerals and other resources essential for modern technologies and the energy transition. The magnetic properties of rocks and sediments are assumed to be stable and largely attributable to inorganic processes. This conventional view overlooks mounting evidence of microorganisms as key players in rock transformations and geological processes. Iron-bearing minerals are ubiquitous in most environments and are commonly used by microorganisms as electron donors and acceptors. Microorganisms modulate rock magnetic properties by creating, altering, and dissolving Fe-bearing minerals, potentially modifying the original magnetization, complicating interpretations of the magnetic record. This review provides an overview of biogenic pathways that modulate magnetic minerals and discusses common, yet underutilized, magnetic methods for capturing such behavior. Appreciating the influence of microbial activities on magnetic properties will improve our interpretations of Earth's geologic past and its elemental cycling. <jats:list list-type=\"bullet\"> <jats:list-item> <jats:label>▪</jats:label> Microorganisms modulate rock magnetic properties, challenging traditional views of a geologically stable magnetic record formed solely by inorganic processes. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Microbial iron cycling modulates magnetic properties modifying magnetic information recorded in rocks. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Microbial processes may have impacted Earth's magnetic history more deeply than previously understood. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> Recognizing microbial contributions is critical for accurate interpretation of paleomagnetic and environmental magnetic records and could aid in the search for life on other planetary bodies. </jats:list-item> </jats:list>","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"48 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-15DOI: 10.1146/annurev-earth-060923-115406
Steven Semken, Chris Mead, Kristen Foley, Thomas Ruberto, Geoffrey Bruce, Ariel D. Anbar
Field experiences are highly valued in geoscience education. However, logistical, financial, and accessibility challenges associated with fieldwork and rapid advancements in technology have all prompted geoscience educators to explore virtual field experiences (VFEs) as alternatives. Rigorous assessment of the effectiveness of VFEs has not kept pace with their implementation, but recent studies offer meaningful and actionable findings that can inform ongoing and future use of VFEs in geoscience education. We present a review of selected studies that address three significant aspects of this still-evolving modality. First, we examine current characterization and classification of VFEs. Second, we examine studies that evaluate the effectiveness of teaching with VFEs. Third, we extend this review to studies that compare VFEs with in-person field experiences (IPFEs). The studies we review demonstrate that VFEs are a valuable approach to teaching introductory geoscience content, even compared to IPFEs. ▪ Challenges associated with field geoscience education and improvements in technology have led geoscience educators to develop and implement virtual field experiences (VFEs) as teaching tools. ▪ VFEs are tested, practical, and effective alternatives to in-person field experiences in introductory geoscience education.
{"title":"Research on Teaching Geoscience with Virtual Field Experiences","authors":"Steven Semken, Chris Mead, Kristen Foley, Thomas Ruberto, Geoffrey Bruce, Ariel D. Anbar","doi":"10.1146/annurev-earth-060923-115406","DOIUrl":"https://doi.org/10.1146/annurev-earth-060923-115406","url":null,"abstract":"Field experiences are highly valued in geoscience education. However, logistical, financial, and accessibility challenges associated with fieldwork and rapid advancements in technology have all prompted geoscience educators to explore virtual field experiences (VFEs) as alternatives. Rigorous assessment of the effectiveness of VFEs has not kept pace with their implementation, but recent studies offer meaningful and actionable findings that can inform ongoing and future use of VFEs in geoscience education. We present a review of selected studies that address three significant aspects of this still-evolving modality. First, we examine current characterization and classification of VFEs. Second, we examine studies that evaluate the effectiveness of teaching with VFEs. Third, we extend this review to studies that compare VFEs with in-person field experiences (IPFEs). The studies we review demonstrate that VFEs are a valuable approach to teaching introductory geoscience content, even compared to IPFEs. <jats:list list-type=\"bullet\"> <jats:list-item> <jats:label>▪</jats:label> Challenges associated with field geoscience education and improvements in technology have led geoscience educators to develop and implement virtual field experiences (VFEs) as teaching tools. </jats:list-item> <jats:list-item> <jats:label>▪</jats:label> VFEs are tested, practical, and effective alternatives to in-person field experiences in introductory geoscience education. </jats:list-item> </jats:list>","PeriodicalId":8034,"journal":{"name":"Annual Review of Earth and Planetary Sciences","volume":"80 1","pages":""},"PeriodicalIF":14.9,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418201","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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