Seismics - Science topic

Thesis (Tokyo University, 1984)

The recent seismic events in Syria highlight the necessity of studying and evaluating the seismic re-sponse of structures to save lives. Liquid storage tanks have a major role, and their operational integri-ty must be maintained following seismic events. Therefore, it is essential to evaluate the performance and study the seismic behavior for its....

Fluids in the crust may build pressure through a variety of mechanisms. This buildup can activate nearby faults, which then serve as conduits for fluid flow and as valves for pressure release. The rapid pressure drop promotes mineral precipitation and fault sealing, allowing the cycle to restart. While evidence of this cyclical interplay between fa...

This study investigates how the seismic demands of non-structural components (NSCs) are influenced by both their attachment ductility and the nonlinear behavior of supporting structures. The research focuses on acceleration demands at various building elevations and evaluates component damage states according to Hazus guidelines. Incremental dynami...

Adobe masonry structures which are among the traditional structures, are affected by many parameters like other masonry structures. These parameters include material, workmanship, mortar, support condition, wall direction, wall slenderness and opening properties. Those parameters are important because they affect the seismic performance significant...

This paper presents the effects of simulated seismic and wind loading rates on the performance of mass timber connections and light wood frame connections/systems. Monotonic tests and reversed cyclic tests were conducted on Cross Laminated Timber (CLT) connections, specifically spline joints, hold-down connections, and angle brackets. Furthermore,...

Globally, the construction industry is a major source of carbon emissions. Studies show that using low-carbon engineered wood in building sector help reducing environmental impact. However, hybrid structures system may be an efficiency and economical solutions comparing with full timber structures in high seismic zone. In this study, an existing bu...

The occurrence time and magnitude of injection-induced seismicity are influenced by engineering factors, such as wellhead pressure, injection location, injection volume, and injection rate. Understanding the relationship between injection operations and seismic magnitude is of great significance for optimizing industrial production and reducing ear...

We conducted two geophysical surveys in Kijiyama geothermal field using optical fibers in geothermal wells. We obtained temperature-depth profiles using DTS (Distributed Temperature Sensor) and seismic records by DAS (Distributed Acoustic Sensor) and surface seismic seismometers for twenty-four seismic excitations surrounding the wellhead. The temp...

In 2021, we conducted a seismic exploration around the Mori Geothermal Power Plant in Hokkaido, Japan, by the distributed acoustic sensing (DAS) method using the optical fiber in a geothermal well. Although we obtained the caldera shape Vp depth structure and seismic reflection image of this field, the structure was two-dimensional due to the limit...

The DISSIPABLE pilot/demonstration project [1] aimed to promote buildings with low-cost, dissipative, and easily replaceable energy-dissipation devices, enhancing economic efficiency and long-term post-seismic resilience. These devices allow for the preservation of primary structural components, avoiding replacement or demolition after high-magnitu...

The life-cycle environmental impacts of buildings extend beyond their initial construction, where post-hazard repairs and demolitions can contribute substantially to buildings' operational impacts. Life cycle assessment (LCA) provides a quantitative approach to calculating environmental impact indicators , such as global warming potential (GWP). Ne...

The Coupled Shear Wall (CSW) is a widely used lateral resistance system in medium to high-rise buildings, known for its efficiency in mitigating seismic wind forces. Its features, including high shear stiffness, strong energy dissipation, enhanced ductility, and robustness, help minimize lateral deformations. This study investigates the dynamic pro...

Many existing high-rise buildings in Japan conform to outdated codes and require seismic retrofit to meet current standards. While installing additional seismic devices is a proven solution, these devices usually bring additional stiffness, alter dynamic characteristics of structures and exacerbate uneven stress distribution. This paper proposes a...

Kijiyama geothermal field, DAS, geothermal structure, seismic reflection structure, We conducted two geophysical surveys in Kijiyama geothermal field using optical fibers in geothermal wells in 2022 and 2024. We obtained temperature-depth profiles using DTS (Distributed Temperature Sensor) and seismic records by DAS (Distributed Acoustic Sensor) an...

In 2021, we conducted geophysical exploration at Nigorikawa of Mori town, in Hokkaido, Japan by borehole optical fiber system in the geothermal borehole of the Mori Power Plant. We analyzed the seismic data acquired by distributed acoustic sensing (DAS) and surface geophones. The results were described in Kasahara et al., (2022). The Vp structure a...

Full-waveform inversion (FWI) of seismic data is a powerful method for estimating high-resolution models of the subsurface. This method requires an accurate initial model and low-frequency data to avoid cycle skipping. In the absence of this information, FWI is doomed to fail as it is likely to converge in local misfit minima. With the recent advan...

. Accurate short-term earthquake prediction requires not simply relying on seismic background, ionospheric anomalies, or electromagnetic signals, but a deep understanding of the physical mechanisms that precede an earthquake at a specific location and time. While many precursors are already known, earlier studies did not attempt to systematically c...

In this study, we propose a locally resonant seismic metamaterial (SM) inspired by gyroid-typed triply periodic minimal surfaces. This novel SM with a lattice constant of only 2.0 m achieves an ultrawide and ultralow-frequency bandgap of 0–47.05 Hz, covering the frequencies of typical seismic waves completely. Calculations for homogeneous half-spac...

In this study, we introduce a novel migration and inversion framework inspired by path integral formulations in wave physics. Drawing on principles from our companion paper, A Path Integral Formulation of Wave Optics: From Spatial Interference to Temporal Effects (Singh, 2025), we demonstrate the application of path summation concepts to seismic im...

A surge in the infrastructure development, in populated regions, has compelled the construction of Reinforced Concrete (RC) buildings to be made over pile foundations when the underlying soil deposit is weak or loose. Individual piles in the foundation system can exhibit significant inelasticity and contribute to the modification in the inelastic r...

Ambient seismic noise consists of continuous vibrations randomly excited in time and space, mostly at the Earth's surface, by natural and anthropogenic dynamic phenomena. Noise has long been considered a contaminant of seismic impulse responses from earthquakes or man-made explosions. The deterministic nature of the wave equation, together with the...

Rapid urbanization and increasingly complex building designs have led to a rise in structural irregularities, significantly affecting seismic performance. Plan irregularities often induce torsional effects, placing additional stress on structural elements. Slabs play a crucial role in load distribution and stability, particularly in irregular build...

Shortly before the 2021 Fagradalsfjall eruption tomographic images indicated a large high Vp/Vs anomaly with a top at about 9 km depth directly below the ongoing seismic swarm. Using volcanotectonic principles we interpret this anomaly as part of the roof of a magma reservoir which, furthermore, ruptured on 24 February 2021. The roof rupture result...

The enrichment of deep coalbed methane (CBM) in the Jiaxian block of the Ordos Basin is strongly influenced by the sealing capacity of coal seam roofs and floors, which play a pivotal role in CBM preservation under conditions of high temperature and pressure. Despite its importance, the mechanisms underlying the sealing capacity remain poorly under...

In Europe, many countries have territories with the seismotectonic active areas-Italy, Greece, Romania etc. As we know, the special government and commercial organizations made many attempts to solve the seismic risk assessment problems in these countries using many different devices for solving these problems by estimating the seismic risk. All po...

Dilapidated ancient brick pagodas face collapse risks under extreme weather. Using Shanxi’s Ganying Pagoda (second-floor damage and separated bodies) as a case, this study evaluates three reinforcement strategies: steel frame core tube (Case 1), base isolation (Case 2), and their combination (Case 3). Nonlinear dynamic analyses under far-field/near...

Accurately modeling fractures in wave-propagation simulations is challenging due to their small scale relative to other features. While equivalent-media models can approximate fracture-induced anisotropy, they fail to capture their discrete influence on wave propagation. To address this limitation, the Interior-Penalty Discontinuous Galerkin Method...

In this book chapter, we discuss recent advances in data-driven approaches for inverse problems. In particular, we focus on the \emph{paired autoencoder} framework, which has proven to be a powerful tool for solving inverse problems in scientific computing. The paired autoencoder framework is a novel approach that leverages the strengths of both da...

This paper investigates the variation of internal forces induced by earthquakes in circular tunnels constructed in the soil of clay layers at different depths and the compatibility of existing dynamic analysis methods. Therefore, two-dimensional full dynamic analyses were carried out with seven earthquake input motions at three depths. Subsequently...

Strike-slip faults are closely related to the enrichment of hydrocarbon resources, with a series of large oil and gas fields associated with strike-slip faults discovered in regions such as the Ordos Basin in China and the West Siberian Basin. The Ediacaran hydrocarbon resources in the Sichuan Basin are abundant. Identifying strike-slip faults and...

Long-term earthquake catalogs can offer valuable constraints for investigating fault geometry and locking patterns at depth, which are crucial for assessing seismic hazard. However, there is still a scarcity of long-term, high-precision earthquake catalogs for the Anninghe-Daliangshan-Zemuhe Fault (ADZF). Based on the abundant phase data from Xicha...

Slow slip events (SSEs) have been observed in many subduction zones and are understood to result from frictional unstable slip on the plate interface. The diversity of their characteristics and the fact that interplate slip can also be seismic suggest that frictional properties are heterogeneous. We are however lacking methods to determine spatial...

The seismic attributes provide valuable information about the geological structures and help interpreting structural styles and identifying potential faults specially whose vertical throw falls below seismic resolution of the subsurface. By extracting quantitative measurements from seismic data, these attributes provide insightful information about...

Nepal is one of the hotspots for disaster and is ranked as 11th most vulnerable country in the world for earthquake. As Nepal lies in the seismic prone area with frequent occurrence of devastating earthquakes, so the buildings need to be designed and constructed for seismic safety. The 2015 Gorkha earthquake highlighted the vulnerability of many...

Real-time hybrid testing (RTHT) is an experimental technique for efficiently analyzing the dynamic responses of seismic structures. Since most parts of the tested structure are numerical simulated and only selected structural components are physically tested in RTHT, the costs and actuator power demands of RTHT are considerably lower than those of...

In this paper, we develop a modern Fortran code to approximate network cross-correlation coefficients for seismic event detection. The code is available via an online repository. The algorithm exhibits efficient memory usage, small output size, and amenability to parallelization. Although exact NCC values are not calculated, the accuracy is deemed...

An estimate of the trigger effect of the proton flux on seismicity was obtained. The proton flux time series with a time step of 5 min, 2000–2024, was analyzed. In each time interval of 5 days, statistics of the proton flux time series were calculated: mean values, logarithm of kurtosis, spectral slope, singularities spectrum support width, wavelet...

This study proposes new strategies for the semi-active control of the dynamic response of a plan-wise asymmetrical structural system using viscoelastic devices. Different from some literature proposals, these innovative strategies are designed to be immediately interpretable, aiming to optimize the different terms of the energy balance equation thr...

To make efficient use of land resources and minimize the seismic destruction of structures in the ground fissures zone, the shaking table tests and 3-dimensional numerical calculation of the soil were completed, based on the ground fissures site in Xi’an (Class II, with the shear wave velocity Vs ranging from 250 m/s to 500 m/s). Influence laws of...

We calculate cross-component correlations and receiver functions from teleseismic earthquakes recorded by a dense seismic nodal array deployed in the central Vienna Basin, Austria. The two methods show similar results. Those results highlight two main layer boundaries between the surface and 15 km depth. We attribute the first layer boundary to the...

From a macroseismic investigation of earthquakes ranging between 45 and 150 km in depth and magnitudes Mw ≥ 5.0 since year 2000, related to the South American-Atlantic (SAA) subduction in the region of the southeastern Caribbean STEP, we have determined that the cities of Ciudad Guayana and Ciudad Bolívar, sitting at the northernmost edge of compet...

The occurrence of earthquakes may have catastrophic and devastating consequences for the inhabitants of the place where they occur. Some regions are characterized by the high frequency of this type of natural phenomenon. Such is the case of Ecuador, a country with a high seismic index due to its location in a subduction zone between the Pacific Pla...

This study investigates ceramic panels’ static and pseudo-static behavior secured with an anchor and epoxy resin adhesive to enhance their load-bearing capacity and safety. The influence of different anchor implantation positions was evaluated through experimental tests and numerical simulations, focusing on the static behavior of independent ceram...

The March 11, 2011 Tōhoku Earthquake and the tsunami it generated was a classic case of natural hazards such as severe ground motion and seismic sea waves coming into contact with human society to produce a multi-dimensional natural disaster. Throughout Japanese history, writers often initially referred to such events as “unprecedented.” As time pa...

Since 2018, the research team has been investigating and developing a prototype sensor for recording seismic activity. An upgrade has been developed and must be evaluated, primarily to monitor ambient noise activities in the geothermal environment. This study aims to determine the group velocity of Rayleigh waves using ambient noise tomography (ANT...

Thailand has been in crisis since an armed forces coup overthrew Prime Minister Thaksin Shinawatra in September 2006, ultimately forcing him into exile. Although his opponents used fair means and foul to keep various incarnations of Thaksin's party out of power, his sister Yingluck Shinawatra became Thailand's first female prime minister following...

The investigation and analysis of building damage is the most direct and effective method to reveal its mechanism, but the statistics and analysis of building damage sample data near surface faults are obviously insufficient. Therefore, based on the influencing factors of building damage near surface faults, this article predicts the structural dam...

Onsite earthquake early warning (EEW) techniques, relying on single-station seismic wave measurements, have demonstrated efficacy in mitigating damage caused by destructive earthquakes. Traditionally, these methods leverage diverse P-wave attributes from the initial seismic wave seconds subsequent to the trigger event to estimate earthquake intensi...

Reliable characterization of subsurface fracture information within the oil-bearing reservoirs plays an essential role in reservoir description, particularly in assessing the fracture density and fluid storage capacity. Fracture density indicates the spatial distribution and extent of fracture development, which is traditionally estimated indirectl...

The webinar aims to provide harmonized recommendations for seismic modeling and tools for interpreting results emerged from a benchmark exercise within the scope of Subtask 10.3 of the 2022-2024 DPC-ReLUIS project in Italy. For this purpose, the in-plane response of eight URM walls was simulated by pushover analysis on different Finite Element and...

The construction of buildings on sloping terrain in seismically active regions presents significant challenges due to structural irregularities and soil-structure interaction (SSI). Understanding the seismic behavior of such buildings is crucial for improving structural resilience and ensuring safety. However, previous studies have primarily focuse...

Owing to the special configurations of the culvert–frame combined underground structure, discrepant responses at different portions of the structure arise when earthquakes strike in the longitudinal direction. This paper presents other experiments when shaking along the lateral direction and comparing structural dynamic responses between these two...

Shear walls significantly improve story shear, base shear, and stiffness compared to structures without them. Seven models with T, C, H-shaped shear walls at soft story and full height were analysed (zone factor (Z = 0.16), IS 456:2000) to compare their seismic performance. Full-height shear walls (T, C, H) significantly boost story shear over soft...

Puntos Clave del Análisis Extremo Modelado Térmico Crudo Piso Térmico: Destrucción total de kerógeno en 8km del centro (¡zona muerta!). Techo Óptimo: "Sweet spot" periférico (15-25km) donde se genera petróleo sin cracking. Porosidad "Explosiva" pero Impredecible Brechas ganan +300% porosidad... pero con heterogeneidad extrema (0.001-500 mD). S...

In the last decade, several observations of peculiar seismic and geodetic phases preceding large earthquakes have been documented. Despite being a posteriori, these observations provide a better understanding of the processes involved in the nucleation of earthquakes. In this study, we investigate the foreshocks and the pre-seismic phase of the M$_...

Based on a questionnaire survey conducted in the Yushu area, China, this study shows that for Tibetans, framing an earthquake as a punishment, will, or trial from gods may have similar connotations. Namely, the topology of positive and negative disaster attributions may not be applicable to Tibetans. Furthermore, in Tibetans’ belief systems regardi...

Long-dormant volcanic provinces remain excellent proxies in studying active edifices. The Monts Dore volcanic province (French Massif Central) has been recently the site of a unique seismic episode. Geophysical surveys were conducted at different horizontal and vertical spatial scales. Magnetic anomalies highlight mechanical heterogeneities consist...

Los puentes son estructuras esenciales de las redes viales y deben tener el menor daño estructural ante sismos. Esta investigación estimó el desempeño sísmico y el daño global de la estructura del Puente Santa María de Nieva, ubicado en Amazonas, Perú. Para ello se emplearon dos métodos analíticos no lineales: el análisis estático no lineal – pusho...

This study presents a design method and detailing for seismic retrofitting of moment connections in box and wideflange columns. The proposed connection attaches each beam flange to the column flange using T-shaped Stiffeners, and the top and bottom cover plates are eliminated due to poor welding quality. The seismic performance of the proposed conn...

This paper deals with two particular examples using the coupled-mode method for exact computation of physically interesting field components or partial waves of seismo-acoustic wave-fields. The first example concerns three-dimensional sound propagation from a point source in an underwater canyon-like environment. Computation of partial waves and ap...

In view of the limitation of generalization ability faced by deep learning in fault identification, especially in the case of complex underground geological conditions and variable seismic data characteristics, it is often ineffective to directly use the network based on synthetic data training for fault prediction of real data. To overcome this ch...

This research explores the improvement of tsunami occurrence forecasting with machine learning predictive models using earthquake-related data analytics. The primary goal is to develop a predictive framework that integrates a wide range of data sources, including seismic, geospatial, and ecological data, toward improving the accuracy and lead times...

Using a quasi-elastostatic description of a seismic activation region, it is explained how accelerating seismic release preceding a major earthquake can be quantified with a 2D linear sigma model. Initial evidence for model validity is provided by deriving previously reported deviation of seismic activation earthquake occurence statistics from Gute...

Numerical modeling approach to support the future Seismic Microzonation of Dushanbe, Tajikistan

In marine seismic surveys, weak signals can be overlaid by stronger signals or even random noise. Detecting these signals can be challenging, especially when they are close to each other or partially overlapping. Several normalization methods have already been proposed, but they often lead to distortion. In this paper, we show that the unwrapped in...

Simplified seismic analyses of embankment dams are sometimes used for seismic deformation analyses and post-seismic stability assessments, generally for low-consequence dams and levees, or during the screening phase of risk assessments, or for planning for more detailed studies of high consequence dams and levees. However, there are serious limitat...

Opposite‐direction oceanic wave interactions at the ocean surface generate microseisms between 0.1 and ∼ ${\sim} $0.5 Hz, known as secondary microseisms (SM). SM recordings aid in imaging Earth's crust, but they also impede monitoring seismic signals due to tectonic activities. Thus, quantification of SM energy would benefit research in both areas....

The seismic behavior of pile-supported structures is influenced by complex interactions between inertial force and kinematic force mainly drawn by soil properties and superstructure characteristics. This study aims to investigate the combined effects of inertial and kinematic interaction on the dynamic response of pile foundations under seismic loa...

Shallow seismic surveys can play an important role in sustainable urban planning as well as monitoring of geological changes, contributing to climate resilience and the sustainable management of terrestrial ecosystems. A typical seismic layout involves devices (essentially senders and receivers) that transmit signals among themselves. Such layouts...

The radii and masses of many giant exoplanets imply their interiors each contain more than $\sim$100 $M_\oplus$ of solids. A large metal content may arise when a giant planet grows by colliding and merging with multiple $\sim$10 $M_\oplus$ solid cores. Here we show that a giant impact with a young gas giant excites long-lived seismic oscillations t...

Seismic data acquisition inevitably faces disruptions from various environmental sources, such as factories, machinery, and highways. These disturbances introduce anomalous amplitudes in seismic data, significantly compromising the signal-to-noise ratio (SNR). At present, the primary approach for denoising such noise involves direct attenuation whe...

Forward modelling of seismic wavefields is a cornerstone of geophysical studies, aiding in subsurface characterization and exploration. In this study, we introduce a Physics-Enhanced Deep Fourier-Attention Network (PE-DFAN) to simulate the forward process from physical property differences to wavefields, addressing the limitations of conventional n...

In this paper, curved-ray travel time approximation, paired with the Constrained Velocity Inversion (CVI) technique, is used in prestack time migration to enhance subsurface imaging in the Cauvery Offshore Basin, India. Traditional travel time approximation approaches based on 2nd-order and 4th-order provide travel time errors at far offset in the...

Multi-story buildings with vertical irregularities often experience uneven load distribution, which can affect the structural performance under lateral loads, especially seismic forces. Such irregularities, such as varying column and beam dimensions between floors, can lead to significant increases in displacement and deformation on the upper floor...

This research deals with the review of former research that made to solve the challenges and complexities of both static and dynamic soil structure interaction through discussing advanced computational models and their applications and exploring methods of solving the challenges of soil structure interaction in foundation engineering to provide a g...

The fast and accurate calculation of seismic wave traveltimes has important applications in geophysics. However, solving the eikonal equations in transversely isotropic with a tilted axis (TTI) media presents significant challenges due to its complex nonlinearity.Traditional methods for solving these equations in TTI media involve using various ite...

Volcanic earthquakes provide a wealth of information about the magmatic system. Monitoring volcanic seismicity is one of the primary methods used by volcano observatories globally, including at Soufri`ere Hills Volcano, Montserrat. Computed earthquake locations represent the optimal solution given the information available, and vary depending on th...

Fiber-optic Distributed Acoustic Sensing (DAS) technology has recently garnered significant attention across various fields, including engineering, oil exploration, and seismological research. Compared to traditional geophones, DAS offers the advantages of high-resolution data acquisition through dense spatial sampling and ease of deployment in cha...

The traditional distinction of magma-poor and magma-rich margins is challenged by the presence of significant late-stage rift-related magmatism in certain margins, such as the South China Sea (SCS). We use numerical modelling to investigate the conditions and processes that lead to crustal melting and the formation of high-velocity lower crustal la...

The study focuses on locating the Collalto underground gas storage (UGS) in the eastern Southern Alps of Northern Italy through seismic attenuation tomography. At a local scale, the absorption model highlights the methane-rich volume (Collalto UGS) as notably attenuative, indicating the method's effectiveness in detecting fluids. It also reveals d...

Seismic full-waveform inversion (FWI) aims to reconstruct high-resolution velocity models of the subsurface from seismic data. However, it is known to face the problem of ill-posedness and has difficulties in reconstructing deep, low-illumination regions. To overcome these challenges, we use a migration image to regularize the FWI problem. In contr...

Expensive computation of the conventional sparse Radon transform limits its use for effective transformation of 3D anisotropic seismic data cubes. We introduce a fast algorithm for azimuthally anisotropic 3D Radon transform with sparsity constraints, allowing effective transformation of seismic volumes corresponding to arbitrary anisotropic inhomog...

A minor earthquake, known as earth tremor, often occurs in areas prone to seismic activity. However, there is a notable gap in knowledge about earth tremors, with little documentation conducted before 1987, but a series of notable events between 1990 and 2000 prompted researchers to delve deeper into the study of earth tremors in Nigeria. Therefore...