Modelling regional-scale attenuation of seismic waves at ~1 Hz is challenging, especially when these waves propagate across both continental and oceanic crust. Recent developments in seismic imaging and modelling have provided us with the computational tools necessary to reconstruct these mixed settings using deterministic (coherent) and stochastic (coda) information. Here, we present new tomographic

Stable stratification at the top of the Earth's outer core has been suggested based upon seismic and geomagnetic observations, however, the origin of the layer is still unknown. In this paper we focus on a thermal origin for the layer and conduct a systematic study on the thermal evolution of the core. We develop a new numerical code to model the growth of thermally stable layers beneath the CMB, integrated

We conduct a systematic analysis of the frequency-moment distribution of earthquake populations in Wadati-Benioff zones, motivated by a three-fold increase in the available GlobalCMT database since the previous study by Okal and Kirby (1995), in which some datasets may have been undersampled. We use 100-km depths bins, processed with both least-squares and maximum-likelihood algorithms, and apply an

Seven new archeointensity data are obtained through the analysis of groups of pottery and kiln fragments from ceramic workshops unearthed in France, precisely dated from the High Middle Ages. The measurements are carried out using the Triaxe magnetometer, following a dedicated experimental protocol that takes into account the effects of anisotropy and cooling rate (CR) on thermoremanent magnetization

This paper summarizes the pattern of paleomagnetic secular variation (PSV) and excursions within MIS 6–7 (130–243 ka) from the western North Atlantic Ocean – ODP Sites 1060–1063. Composite high-resolution PSV records (both directions and relative paleointensity) have been developed for each site and inter-compared. There are 65 correlatable inclination features, 67 correlatable declination features

In 1799, Laplace derived the system of differential equations (now called Liouville-Euler) that fully describes the motions of the rotation axis of any celestial body. Laplace showed that only the gravitational forces and kinetic moments from other celestial bodies influence the rotation of any one of them. The equations involve three Euler angles that specify the motions of a body's rotation axis;

Here we report a detailed archaeomagnetic and rock-magnetic study of a pottery kiln from Burgos (Spain) to reconstruct its burning conditions and date its last use and abandonment age. During the course of a rescue archaeological excavation carried out in 2015 in the center of Burgos city, a medieval pottery workshop was discovered. Two well-preserved kilns appeared and archaeomagnetic analyses were

Complex geological structures and processes that took place in the Dharwar craton formation make it difficult to understand the evolution history. 3-D magnetotelluric inversion is a challenging task for the imaging of sub-surface structures. Data at 40 stations in a gridded fashion are used in this study for inversion. A controversy exists regarding the subduction polarity between the eastern and western

We obtained the 3D crustal velocity structure of the Central Alborz region in northern Iran using local earthquake tomography. We used P-wave arrival-time data recorded by stations from three national observatories consisting of the Iranian Seismological Center, the International Institute of Earthquake Engineering and Seismology, and the Tehran Disaster Management and Mitigation Organization along

Inference of thermodynamic state and full-spectrum mechanical behavior of the lithosphere and asthenosphere is a central problem in geophysics, implicating our understanding of the convection patterns, transient responses and chemical composition of the planet. Anelasticity is responsible for significant relaxation of stress associated with seismic wave propagation in the asthenosphere, while irreversible

Seismic anisotropy is a key observational tool for mapping flow in Earth's upper mantle. However, interpreting patterns of anisotropy relies on a firm understanding of the microphysical mechanisms that generate anisotropy. Here we discuss our current understanding of the generation of intrinsic and extrinsic seismic anisotropy in upper-mantle rocks. Intrinsic anisotropy results from the elastic anisotropy

We report experimental results on the bulk modulus of partially molten peridotite at mantle conditions, using a multi-anvil high pressure apparatus coupled with synchrotron X-ray radiation. A sinusoidal pressure at an amplitude of 180 MPa with period of 360 s is applied to the sample as a function of temperature. The sample volume derived from the X-ray radiograph also demonstrated sinusoidal variation

As a comment on Seismic Electric Signals (SES) and earthquakes: A review of an updated VAN method and competing hypotheses for SES generation and earthquake triggering, herein we present the analysis of time series gathered by three MT stations located in the Eastern Cordillera of Colombia, for evaluating the electric and magnetic fields during an interval of several days. Records allow estimating

Remanent magnetization and active magnetic fields have been detected for several telluric planetary bodies in the solar system (Earth, Mercury, Moon, Mars) suggesting the presence of core dynamos active at the early stages of the planet formation and variable lifetimes. Among the factors controlling the possibility of core dynamos generation, the dynamics of the surrounding silicate mantle and its

The Santorini-Amorgos zone is located in the central part of the Hellenic volcanic arc and is hosting eight large faults as well as Kolumbo and Santorini volcanic centers. The largest earthquake (Mw ~ 7.1) in the southern Aegean during the 20th century also occurred in this area on 9 July 1956. A total of 1868 crustal events were recorded by temporary networks during September 2002 to July 2004 and

The moment tensor inversion is a commonly-used method to interpret source mechanisms of microseismicity. In the inversion for real data (e.g. microseismicity recorded during hydraulic fracturing), the waveforms recorded by sensors can be the mixtures of signals and noise, or the superposition of signals generated by multiple sources. Then the traditional approach may result in inaccurate solutions

Volcanoes are complex systems that evolve in space and time as a result of their eruptive activity. Volcanic eruptions represent the ultimate expression of a complex interplay between internal and external processes that span across different time scales. Deciphering how internal and external processes interact at the time scale of eruptions may provide key insights on the temporal evolution of eruptions

The 2016 Pedernales earthquake (Mw 7.8), is part of the sequence of large earthquakes in Ecuador and Colombia: 1906 (~8.8 Mw), 1942 (Mw 7.8), 1958 (Mw 7.7), 1979 (Mw 8.2), all these events with a focal mechanism of the thrust fault type. In this research, we have obtained the seismic source distribution (indicating the presence of 2 main asperities), from inversion of teleseismic signals, as well as

Well-exposed lava sequences with available geochronological information may provide invaluable information on the fine characteristics of the Earth's magnetic field variation. A paleomagnetic study has been performed on twenty Pleistocene age, sub-horizontal lava flows in the Javakheti Highland (Lesser Caucasus). The sequence is formed by calc-alkaline basaltic lavas and is divided by a thin sedimentary