We estimated the spatial and temporal evolution of preceding aseismic slip from January 2003 to 2011, coseismic Tohoku earthquake, postseismic after earthquake based on global positioning system (GPS) data. Time‐dependent analysis indicates offshore Miyagi Fukushima prefectures 2004 associated with a series subduction earthquakes that overlap area. These areas are centered between centers afterslip prefecture, while they off prefecture. The timing moment magnitude nine (M w 9) ‐class appears...

We provide here a preliminary analysis of the ionospheric perturbations observed after 11 March 2011 Tohoku Earthquake using GPS-derived Total Electron Content (TEC) technique. Such anomalies are routinely seismic events magnitude Mw = 6 and more. Here, we use high density wide coverage Japanese Global Positioning System (GPS) network GEONET to image ionosphere just main shock. describe with exceptional extension in amplitude duration. As already seen earlier events, first intense signal is...

come from teaching and research institutions in France or abroad, public private centers.L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques niveau recherche, publiés ou non, émanant des établissements d'enseignement recherche français étrangers, laboratoires publics privés. Detection modeling of Rayleigh wave induced patterns the ionosphere

The large displacement induced by the 2011 M 9.0 off Pacific coast of Tohoku Earthquake was observed GPS stations permanent Earth Observation Network system (GEONET) in northeastern Japan. characterized eastward and subsidence coastal area. horizontal exceeded 5.3 m, which is largest ever detected GEONET. mainshock followed a sequence aftershocks. We processed data through kinematic positioning strategy to clarify deformation, including deformation caused mainshock, with high temporal...

Phreatic eruptions are caused by pressurization of geothermal fluid sources at shallow levels. They relatively small compared to typical magmatic eruptions, but can be very hazardous. However, owing their magnitudes, occurrences difficult predict. Here we show the detection locally distributed ground inflation preceding a phreatic eruption Hakone volcano, Japan, through application interferometric synthetic aperture radar analysis. The proceeded slow speed ∼5 mm/month with spatial size ∼200...

Summary Detailed investigations of aseismic slow slip events (SSEs) are crucial for estimating the strain budget and SSE mechanisms within subduction zones. The Suruga Trough, which includes Tokai seismic gap, is an important area in Japan from a hazardous perspective. However, history this trough following 2011 Tohoku earthquake difficult to determine as result post-seismic deformation caused by earthquake. In study, we provided detailed imaging interplate Trough after Earthquake applying...

GPS kinematic time series are analyzed to estimate slip distributions for the Mw 9.0 2011 off Pacific coast of Tohoku Earthquake sequence. Empirical orthogonal function (EOF) analysis is employed enhance signal-to-noise ratio original series. The coseismic, and subsequent postseismic, deformations foreshock can be described by a single mode, suggesting that extent source both events must similar. total moment magnitude afterslip following estimated 7.1 with decay 0.63 days. was larger its...

SUMMARY We successfully detected widely distributed ground displacements for the 2023 Kahramanmaraş, Turkey, earthquakes by conducting interferometric synthetic aperture radar (InSAR) analyses using a ScanSAR observation mode. Major deformation extended approximately 350 and 150 km along southern northern strands bifurcating in west of East Anatolian Fault, produced main shock largest aftershock. The map reveals that ruptures propagated on Erkenek, Pazarcık Amanos segments strand Çardak...

Abstract During the 2000 eruption of Miyakejima volcano in Japan, step‐like tilt changes (TC) generally accompanied by very long period (VLP) seismic signals with a pulse‐like shape and widths ∼50 s were repeatedly observed (TC/VLP events). Kinematic GPS time series for investigated order to detect displacements associated these events. We found that kinematic could be interpreted as superposition following features: (1) displacement TC/VLP events, source which possibly corresponded shallow...

In magnetotelluric (MT) studies, the observed response function (the MT impedance) usually suffers from galvanic distortions due to near-surface inhomogeneities. Removal of these effects is essential obtain an accurate model subsurface electrical conductivity structure. Galvanic distortion expressed by a simple real tensor multiplying undistorted regional impedance. The problem still remains how solve ensuing linear equations in order determine and then methods presented widely applied...

Abstract Our 3‐D electrical resistivity model clearly detects particular subsurface features for magmatism associated with subduction of the Philippine Sea Plate (PSP) in three regions: a southern and northern volcanic region, nonvolcanic region on island Kyushu. We apply inversion analyses geomagnetic transfer function data short‐period band, combination results previous that was determined by using Network‐Magnetotelluric response longer‐period band as an initial present to improve...

Abstract Long-term deformation of Kusatsu-Shirane and Asama volcanoes in central Japan were investigated using Global Navigation Satellite System (GNSS) measurements. Large postseismic caused by the 2011 Tohoku earthquake—which obscures long-term volcanic deformation—was effectively removed approximating other recent tectonic terms quadrature geographical eastings/northings. Subsequently, source parameters estimated Markov Chain Monte Carlo (MCMC) method linear inversion, employing an...

The anomalous vertical movements observed in Tsukuba and their relevance to groundwater level changes are investigated. First, we investigated the coordinate time series of an IGS station TSKB w.r.t. a nearby stable site found that has strong correlation with deep wells. Next, those GPS antenna attached at tip VLBI TSKB. We is decomposed into components have 1) high shallow wells, 2) air‐temperature. Poroelastic aquifers due thermal expansion likely for mechanisms these correlations.

We developed a semi-analytical method to evaluate the effect of second-order ionospheric correction on GPS positioning. This is based positioning error simulation by Geiger and Santerre in which, assuming continuous distribution satellites, normal equation formed estimate taking all contributions ranging visible satellites into account. Our successfully reproduced averaged time-series three IGS sites which comparable rigorous simulation. then evaluated determination reference frame....

Abstract We propose a new method for real-time uncertainty monitoring of earthquake and volcano source models using data from the global navigation satellite system (GNSS) explore its application concerning observation station placement. The Geospatial Information Authority Japan operates two main types GNSS earth network (GEONET) coordinates crustal deformation on different time scales: post-processing analysis values GEONET rapid (REGARD). REGARD uses Markov Chain Monte Carlo (MCMC) termed...

We compared the mass variations from Gravity Recovery and Climate Experiment (GRACE) with those measured by bottom pressure recorders (BPRs) deployed as tsunami gauges. Prior to comparison, we estimated degree‐1 Stokes coefficients loading method using both GPS GRACE data. successfully recovered that are consistent satellite laser ranging analysis model. found use of data in significantly mitigates aliasing effect unmodeled higher‐degree deformations. Then, five BPRs have been part...

We quantitatively estimate the spurious annual vertical deformations due to mismodelling of tropospheric delays over Japan, through a numerical simulation. For this purpose, we simulate GPS data for present-day satellite distributions, using realistic cumulative that are calculated ray tracing and weather models. To obtain deformations, simulated then analysed by same processing software analysis strategies as those used in observed data. In estimated it is found amplitudes increase toward...

The effect of nontidal ocean mass loading is investigated as a possible cause for the seasonal variability observed in vertical components GPS‐derived site coordinates tropical Pacific islands. origin sea level changes (MOSLCs) are estimated by subtracting steric height at buoys from net measured satellite altimetry. Assuming linear relationship between MOSLCs closest and GPS movements, coherences admittances estimated. We found evidence that movements caused three out four sites. occasional...

The analysis of global positioning system (GPS) data shows an increase in the westward ground velocity Iwate, northeast Japan, from around 2003, after a period roughly constant crustal deformation rate. spatiotemporal study time series displacements reveals that slip deficit rate increased slightly 2001 to 2003 at deeper part source region 1994 Sanriku‐oki earthquake. has been considerable since January and area expanded, now covers This indicates restoration rate, which was affected by...

Abstract To understand the subduction dynamics around Kyushu Island, Southwest Japan Arc, distribution of fluids is imaged by resolving three‐dimensional (3‐D) electrical resistivity structure beneath a subregion island, including volcanic and nonvolcanic areas. The region in central situated between two regions with numerous Quaternary structures along front aligned N30°E related to Philippine Sea Plate. Two source areas slow slip events lie at depths 20–40 km eastern coast Kyushu, whereas...