Detailed Moho variations under Northeast China inferred from receiver function analyses and their tectonic implications
In this study we investigate detailed Moho variations beneath Northeast China by applying the arithmetic mean, back-projected and Fresnel-zone migration imaging methods to a total of 169,602 high-quality P-wave receiver functions from seismograms of 2903 teleseismic events recorded at 127 NECESSArray stations and 321 China Earthquake Administration stations. Our results show that the Moho depth variations are correlated with the surface geology in the study region. The Moho is deeper (~34.0–42.0 km) under the Great Xing'an range, the Lesser Xing'an range, the Zhangguangcai range, and the Changbaishan mountain, whereas ...
Source: Physics of the Earth and Planetary Interiors - February 13, 2020 Category: Physics Source Type: research

Editorial Board
Publication date: February 2020Source: Physics of the Earth and Planetary Interiors, Volume 299Author(s): (Source: Physics of the Earth and Planetary Interiors)
Source: Physics of the Earth and Planetary Interiors - February 11, 2020 Category: Physics Source Type: research

Two-phase magnetohydrodynamics: Theory and applications to planetesimal cores
Publication date: Available online 7 February 2020Source: Physics of the Earth and Planetary InteriorsAuthor(s): David Bercovici, Elvira MulyukovaAbstractCore freezing and resultant compositional convection are likely important drivers for dynamo activity in large terrestrial bodies like the Earth. The solidification of compositional mixtures, such as iron and sulfur, generates mush zones of partial melt at the freezing front, which can eject chemically buoyant or heavy liquid that then drives convection. For smaller bodies such as planetesimals in the asteroid belt, conditions for generating a dynamo are harder to achieve...
Source: Physics of the Earth and Planetary Interiors - February 7, 2020 Category: Physics Source Type: research

Changes in shear-wave splitting at the 2014 Bárðarbunga seismic crisis and dyke intrusion in Iceland compared with earthquakes and other eruptions
Publication date: Available online 1 February 2020Source: Physics of the Earth and Planetary InteriorsAuthor(s): Qiyu Hong, Stuart Crampin, Yuan GaoAbstractWe use shear-wave splitting (SWS) above small earthquakes to monitor stress-variations before the 2014 Bárðarbunga seismic crisis and dyke intrusion in central Iceland. SWS is sensitive to stress-induced variations in the internal geometry of the distributions of stress-aligned fluid-saturated microcracks pervading almost all crustal rocks. This allows stress-accumulation before both impending earthquakes and impending volcanic eruptions to be monitored and potentiall...
Source: Physics of the Earth and Planetary Interiors - February 2, 2020 Category: Physics Source Type: research

Fluctuation of the Earth's magnetic field elements in Mexico revealed by archive documents since 1587
Publication date: Available online 30 January 2020Source: Physics of the Earth and Planetary InteriorsAuthor(s): Avto Goguitchaichvili, Esteban Hernandez, Rafael Garcia, Rubén Cejudo, Gerardo Cifuentes, Miguel CervantesAbstractHistorical documents, archives and old photographic collections allowed to analyze 877 direct geomagnetic measurement data obtained by sailors (including pirates), United State Coast and Geodetic Survey and National Astronomical Observatory since 1587. The updated catalogue includes 844 values of magnetic declination, 495 of inclination, 467 of the horizontal intensity component (H) and 455 of the v...
Source: Physics of the Earth and Planetary Interiors - January 31, 2020 Category: Physics Source Type: research

Shear wave velocity structure of the upper-mantle beneath the northern Zagros collision zone revealed by nonlinear teleseismic tomography and Bayesian Monte-Carlo joint inversion of surface wave dispersion and teleseismic P-wave coda
Publication date: Available online 30 January 2020Source: Physics of the Earth and Planetary InteriorsAuthor(s): Meysam Mahmoodabadi, Farzam Yaminifard, Mohammad Tatar, Ayoub KavianiAbstractThe continental collision between the Arabian and Eurasian plates plays an important role in the geodynamical evolution of the Zagros and Iranian plateau. In order to investigate the upper mantle structure across the collision zone, we calculated the absolute and relative shear-wave velocity structure along a dense and long temporary seismic profile in NW Iran. The probabilistic 1-D absolute shear-wave velocity (Vs) depth profiles benea...
Source: Physics of the Earth and Planetary Interiors - January 31, 2020 Category: Physics Source Type: research

Imaging the 2–D crust and upper mantle structure of the Iranian plateau resolved by potential field and seismic data
In this study, the crust and upper mantle density distribution across the Iranian plateau along a ~1500 km profile are investigated using an integrated modeling of potential field data (gravity, geoid and topography) and by assuming local isostatic equilibrium. Our profile is initiated in Arabian platform and running through the main geological structures of Iran including Zagros orogen, Sanandaj – Sirjan Zone (SSZ), Urumieh – Dokhtar Magmatic Arc (UDMA), Central Iran (CI) block, Tabas/Lut blocks, and East Iranian Range (EIR). In the second step, in order to verify the integrated model, the 1–D S–wave absolute ve...
Source: Physics of the Earth and Planetary Interiors - January 31, 2020 Category: Physics Source Type: research

Presenting Meso-Cenozoic seismic sequential stratigraphy of the offshore Indus Basin Pakistan
Publication date: Available online 22 January 2020Source: Physics of the Earth and Planetary InteriorsAuthor(s): Majid Khan, Yike Liu, Syed Zaheer Ud DinAbstractPreserved deformed depositional sequences along passive continental margins are important repositories of natural resources as well as key laboratories for understanding rift-drift tectonics. With better post signal processing schemes, interpretation techniques, and potential data, imaging sedimentary basins along these margins has reached unique levels of refinement. This, in turn, has led to considerable improvement in unfolding the complex tectono-sedimentary hi...
Source: Physics of the Earth and Planetary Interiors - January 24, 2020 Category: Physics Source Type: research

Thermodynamic modeling of hydrous-melt–olivine equilibrium using exhaustive variable selection
Publication date: Available online 20 January 2020Source: Physics of the Earth and Planetary InteriorsAuthor(s): Kenta Ueki, Tatsu Kuwatani, Atsushi Okamoto, Shotaro Akaho, Hikaru IwamoriAbstractWater in silicate melt influences the phase relations of a hydrous-melt system. Given the importance of water in silicate melts, a quantitative thermodynamic understanding of the non-ideality of hydrous melt is necessary to properly model natural magmatic processes. This paper presents a novel method for quantitative thermodynamic modeling of hydrous-melt–olivine equilibrium. Specifically, a machine learning method, exhaustive va...
Source: Physics of the Earth and Planetary Interiors - January 21, 2020 Category: Physics Source Type: research

Detection of high P,T transformational faulting in Fe2SiO4 via in-situ acoustic emission: Relevance to deep-focus earthquakes
Publication date: Available online 20 January 2020Source: Physics of the Earth and Planetary InteriorsAuthor(s): Timothy Officer, Richard A. SeccoAbstractAt transition zone depths in subduction zones, deep-focus earthquakes (300–690 km depth) are thought to be associated with faulting that arises from phase transformations. In order to test the viability of this mechanism experimentally, an investigation was conducted on fayalite at high pressure, P, and high temperature, T, under deviatoric stress in order to initiate transformational faulting. Experiments were performed in a 3000-ton multi-anvil press using an 18/11 ...
Source: Physics of the Earth and Planetary Interiors - January 21, 2020 Category: Physics Source Type: research

A comparative study of deformation field due to center of dilatation and center of rotation in a viscoelastic half-space model
Publication date: Available online 17 January 2020Source: Physics of the Earth and Planetary InteriorsAuthor(s): Nishu Verma, Kuldip SinghAbstractClosed-form analytic expressions for the displacement and stress fields due to two axially symmetric sources, namely, the center of dilatation, and center of rotation in an elastic half-space are obtained using Galerkin vector approach. The correspondence principle of linear viscoelasticity is used to obtain the viscoelastic displacement and stress fields. A comparative study of both these sources has been done graphically. Our analysis revealed that the center of dilatation is m...
Source: Physics of the Earth and Planetary Interiors - January 18, 2020 Category: Physics Source Type: research

Upper mantle slab under Alaska: Contribution to anomalous core-phase observations on south-Sandwich to Alaska paths
Publication date: Available online 15 January 2020Source: Physics of the Earth and Planetary InteriorsAuthor(s): Daniel A. Frost, Barbara Romanowicz, Steve RoeckerAbstractObservations of travel time anomalies of inner core-sensitive PKPdf seismic body waves, as a function of path orientation with respect to the earth's rotation axis, have been interpreted as evidence of anisotropy in the inner core. Paths from earthquakes in the South Sandwich Islands to stations in Alaska show strongly anomalous travel times, with a large spread that is not compatible with simple models of anisotropy. Here we assess the impact of strong v...
Source: Physics of the Earth and Planetary Interiors - January 16, 2020 Category: Physics Source Type: research

Identification of paleomagnetic remanence carriers in ca. 3.47 Ga dacite from the Duffer Formation, the Pilbara Craton
Publication date: February 2020Source: Physics of the Earth and Planetary Interiors, Volume 299Author(s): Yoichi Usui, Masafumi Saitoh, Kenichiro Tani, Manabu Nishizawa, Takazo Shibuya, Chie Kato, Tomoyo Okumura, Teruhiko KashiwabaraAbstractThe ca. 3.47 Ga Duffer Formation has been considered to carry one of the oldest paleomagnetic records. Yet, the lack of rock magnetic data limits the interpretation of the nature of the remanence. We conducted a rock magnetic and paleomagnetic investigation on columnar dacite of the Duffer Formation. The main magnetic minerals are phenocrysts of titanomagnetite and magnetite, and secon...
Source: Physics of the Earth and Planetary Interiors - January 16, 2020 Category: Physics Source Type: research

Source parameters of the 1926 and 1927 Jersey earthquakes from historical, instrumental, and macroseismic data
Publication date: Available online 15 January 2020Source: Physics of the Earth and Planetary InteriorsAuthor(s): D. Amorèse, J. Benjumea, M. CaraAbstractEnglish Channel Islands are located off Normandy coast of France within an intraplate area not associated with high seismicity rate and active tectonics. However, in July 1926 a damaging and well-documented earthquake occurred there, followed by a strongly felt event in February 1927. In this paper, we reprocess macroseismic observations, analog seismograms and bulletin data in order to re-appraise the location and magnitude of these two earthquakes. We find that the macr...
Source: Physics of the Earth and Planetary Interiors - January 15, 2020 Category: Physics Source Type: research

One-dimensional seismic velocity model of the sub-basin of Chalco, Mexico
Publication date: Available online 8 January 2020Source: Physics of the Earth and Planetary InteriorsAuthor(s): Filiberto Vergara-Huerta, Jorge Aguirre-GonzálezAbstractIn this work, a one-dimensional (1-D) seismic velocity model is proposed for the central portion of the sub-basin of Chalco, located in the southeast (SE) sector of the basin of Mexico. The seismic model was integrated from spectral analysis of the seismic ambient vibrations (microtremors or seismic noise) records, through the methodologies of Modified Spatial Autocorrelation (MSPAC) and H/V spectral ratios.The one-dimensional (1-D) seismic model is the res...
Source: Physics of the Earth and Planetary Interiors - January 8, 2020 Category: Physics Source Type: research