Earth-Science Reviews最新文献

Caprock plays a critical role in the long-term safety of CO₂ geological storage, and breakthrough pressure serves as a key indicator for evaluating caprock sealing. The purpose of this review is to discuss the latest research progress in experimental testing and characterization models of caprock breakthrough pressure. First, this review provides a summary of the definitions and classifications of caprock sealing and breakthrough pressure. Comprehensive reviews of the measurement apparatuses, methods, influencing factors, characterization models, and caprock sealing thresholds related to breakthrough pressure are provided. In this article, we first review the measurement apparatuses, which include a static-state testing apparatus, triaxial-state testing apparatus, online computed tomography scanning apparatus, and micro/nanofluidic testing apparatus. Static-state and triaxial-state testing apparatuses are suitable for obtaining measurements of breakthrough pressure under in situ conditions. The step-by-step pressure method and residual pressure method are the most widely used measurement methods, but the results of the residual pressure method are 20% to 50% of those obtained by the step-by-step pressure method. We then found that the impact order of lithology on breakthrough pressure is gypsum or saltstone > mudstone or shale > limestone > argillaceous mudstone > muddy siltstone > igneous rock > sandstone, with a minimum threshold value of 2 MPa for caprock breakthrough pressure. For shale and gypsum, the breakthrough pressure of CO₂ is 50% to 80% that of CH₄ and 55% to 85% that of N₂. The breakthrough pressure of rock saturated with water is 2.3 to 6.5 times that of rock saturated with oil and 8.2 to 31.1 times that of rock saturated with air. Moreover, we review classical theoretical models and experimental empirical models for characterizing breakthrough pressure. Empirical models are more accurate than theoretical models for characterizing the actual breakthrough pressure, especially models relating to breakthrough pressure and permeability, which have been widely applied. We finally conclude that the Tarim Basin, Junggar Basin, Ordos Basin, Songliao Basin, and central Sichuan Basin have high caprock sealing capacities. Future research trends include rapid and accurate measurements of breakthrough pressure, characterization and application of breakthrough pressure across multiple scales, and development of models and standards for evaluating caprock sealing capacity.

Liquefaction is one of the earthquake-related hazards commonly experienced during earthquake occurrences in the Philippines. A database of liquefaction occurrences in the Philippines was developed through the analysis of historical documents, reports, catalogs, newspaper articles, and eyewitness interviews. A total of 808 liquefaction accounts were analyzed—798 of which were induced by 110 earthquakes that occurred from 1619 to 2020, with magnitudes ranging from M 5.1 to 8.3. The database also contains three undated liquefaction accounts from paleoseismic investigations, and seven liquefaction accounts related to four volcanic eruptions. The liquefaction occurrences in the accounts were analyzed in terms of their location quality, liquefaction features, probability ranking, and geomorphic units. We observed that liquefaction can occur repeatedly at the same sites that liquefied during past earthquakes and volcanic activities. This database may be used for seismic hazard studies and disaster risk reduction and mitigation purposes.

Various geoscientific processes in the shallow subsurface experience a temperature difference between the solid and the liquid or gaseous phase. Prominent examples include the injection of cold water into a hot host rock, the fast intrusion of supercritical CO2 from the mantle into shallower regions, or the rainwater infiltration into partially frozen soil. In such an absence of local thermal equilibrium between phases, heat transfer needs to be described explicitly by Newton's law of cooling and depends on the heat transfer coefficient and the specific heat transfer area between the involved phases. Despite various works, the quantification and the dissolution of dependencies of the heat transfer coefficient remain ambiguous. The study of heat transfer is separated between porous and fractured materials due to the different geometry, the applied flow rules, and common fields of applications. Identifying scenarios in which heat transfer effects in a local thermal non-equilibrium (LTNE) situation are relevant is already a challenging task but in past years more and more scenarios with persistent differences in phase temperatures were found. In this contribution, the mathematical governing equations for heat transfer between solid rock and moving fluid are given and various approaches of parameterization are discussed. This discussion of heat transfer includes various types of heat transfer mechanisms that can occur in the subsurface. Subsequently, the state of the art for heat transfer in porous and fractured media is presented with a special emphasis on resolving dependencies on geometry (grain size, fracture aperture) and flow velocity. Possible solution strategies addressing heat transfer in heterogeneous fractured porous media are presented, and possible applications with relevant LTNE effects are discussed with an outlook on future challenges in the field of geothermal energy exploitation and storage, shallow multi-phase infiltration scenarios, CO2 sequestration, and underground H2 storage.

Stromatoporoids are common shallow marine hypercalcified sponges in two major episodes with distinctive skeletal architectures: 1) Palaeozoic: Ordovician to Late Devonian; and 2) Mesozoic: Late Triassic to Cretaceous and rare Cenozoic, but not confirmed in Permian and earlier Triassic strata. Stromatoporoids appeared in Early to Middle Ordovician strata, important in buildups from late Middle Ordovician metazoan expansions (part of the Great Ordovician Biodiversification Event). Throughout the Palaeozoic, some stromatoporoid taxa occur across several palaeocontinents, and, if they are the same biological taxa, presumably migrated as larvae across oceans. Palaeozoic stromatoporoids suffered 5 events of decline; Event 1): end-Ordovician Mass Extinction; surviving forms are typical Silurian taxa, marking change of abundance from labechiid to clathrodictyid forms. Event 2): late Silurian to Early Devonian contraction: stromatoporoids became scarce with low generic diversity, presumably related to global sea-level fall. Intra-Silurian extinction events principally affected conodonts and graptolites, associated with positive carbon isotope excursions, but not stromatoporoids, likely because of their shallow marine benthic habit, contrasting pelagic oceanic planktonic and nektonic fauna influenced by oceanographic changes. Stromatoporoid expansion to their late Early to Middle Devonian (Eifelian and Givetian) acme, forming a major Phanerozoic global reef system, was likely linked to global sea-level rise, when epeiric seas expanded, but followed by Event 3): end-Givetian extinction, possibly related to cooling; Event 4): Frasnian-Famennian (FF) extinction; and Event 5): end-Devonian (Hangenberg Event) extinction; 4 and 5 may be related to sea-level fall, cooling, anoxia and potentially, magmatism. The apparent stratigraphic gap between end-Devonian and Triassic stromatoporoids was not extinction of Palaeozoic stromatoporoids, because rare Carboniferous examples in England, Russia, USA and Japan prove survival in shallow marine environments. Prior interpretation that stromatoporoid-grade sponges lost ability to calcify is unlikely, because chaetetid hypercalcified sponges expanded and built Carboniferous reefs. Important is that skeletal architectures of stromatoporoid and chaetetid hypercalcified sponges are regarded as ‘grades of organisation’ of the skeleton, lacking phyletic value; living stromatoporoid- and chaetetid-grade sponges occur in the classes Demospongiae and Calcarea based on their spicules. This implies that extinction of sponge taxa that just happened to have been stromatoporoid-grade hypercalcifiers may explain stromatoporoid loss in the end-Devonian, and may point to unpreserved crises in non-calcifying Porifera, noting poor sponge records in end-Devonian strata. Having also survived the end-Permian and end-Triassic extinctions, stromatoporoid-grade hypercalcification expanded again in the Jurassic, together with