Recent seismological studies suggest that slab detachment has occurred in the Mediterranean and New Hebrides subduction zones. Subducted slabs these regions are recognized to be torn at depths ranging from 100 300 km, presumably caused by lateral migration of tear along strike slab. To investigate physical mechanism particular its migration, we constructed a viscoelastic three‐dimensional finite element model introduced small initial one side We investigated spatio‐temporal variations state...

Abstract We apply a three‐step approach to estimate three‐dimensional (3‐D) P wave attenuation ( Q p −1 ) structure beneath northeastern Japan. First, corner frequencies of earthquakes are determined using the spectral‐ratio method for S‐coda waves. Then, whole‐path terms, t *, and site‐amplification factors simultaneously estimated by joint inversion. The set * is finally inverted 3‐D structure. results show that mantle wedge has low in fore arc high back arc. A depth profile back‐arc...

We estimated spatiotemporal slip distributions from three long-term slow events (L-SSEs) that occurred beneath the Bungo Channel at convergent plate boundary between subducting oceanic Philippine Sea and continental Amurian in southwest Japan 1997 1998, 2002 2004 2009 2011. For this purpose, we employed an inversion method using a Bayesian Information Criterion (ABIC), which included following prior constraints: spatial distribution was smooth to some extent, directions were mostly oriented...

Abstract We investigated temperature and mantle flow distributions associated with subduction of the Philippine Sea (PHS) plate beneath southwest Japan, by constructing a three‐dimensional parallelepiped model incorporating past clockwise rotation, bathymetry plate, distribution subducting velocity within its slab. The geometry was inferred from contemporary seismic studies used as slab guide integrated historical rotation into 3‐D simulation. Using model, we estimated realistic...

In this study, we investigated the relationships among occurrence regions of megathrust earthquakes and slow earthquakes, estimated interplate temperatures, dehydration processes at plate interface in subduction zone Cocos Mexico, with a focus on Guerrero seismic gap. For purpose, performed series 3-D thermomechanical numerical simulations based combination multiple unknown model parameters. Comparing temperature field for optimal region phenomena, along slab surface where tend to occur is...

The spatial distribution of the strength interplate coupling between subducting Philippine Sea and overlying continental plates in Tokai district, central Japan, was investigated detail through inversion analysis geodetic data using Akaike's Bayesian Information Criterion (ABIC). used for are annual rates level changes (1972–1984) horizontal length (1977–1988), which presumably represent average crustal movements during interseismic period. result shows existence a strongly coupled region...

The Nankai subduction fault in southwest Japan is a plate boundary along which large megathrust earthquakes have repeatedly occurred. A previous 2-D thermal model suggested that the updip and downdip limits of seismogenic zone are closely related to temperature interface. We estimated new distribution for interface based on 3-D convection incorporates revised governing equations, temporal changes relative motion, shape subducted slab, variations basin evolution more heat flow data regions...

Abstract Although the thermal regime of interface between two overlapping subducting plates, such as those beneath Kanto, Japan, is thought to play an important role in affecting distribution interplate and intraslab earthquakes, estimation remains challenging date. We constructed a three‐dimensional (3‐D) convection model simulate subduction Pacific plate along Japan Trench Izu‐Bonin Trench, including Philippine Sea Kanto investigated slab water contents this complex tectonic setting. Based...

Abstract Slab detachment is a geophysical instability whose manifestation can be revealed by seismic tomography. Evidence of this phenomenon in the Dinarides/Hellenic and New Hebrides subduction zones. Subducted slabs these regions are torn horizontally at depths ranging from 100 to 300 km. We constructed viscoelastic three‐dimensional finite element model investigated state stress. found that an area with high stress concentration order several hundred MPa formed near tip tear inside slab,...

Abstract The SW Japan arc built by subduction of the Philippine Sea (PHS) plate exhibits uneven distribution volcanoes: thirteen Quaternary composite volcanoes form in western half this arc, Kyushu Island, while only two eastern half, Chugoku district. Reconstruction PHS back to 14 Ma, together with examinations based on thermal structure models constrained high-density heat flow data and a petrological model for dehydration reactions suggest that fluids are discharged actively at depths...

Abstract Long-term slow slip events (L-SSEs) have repeatedly occurred beneath the Bungo Channel in southwestern Japan with durations of several months to a couple years, recurrence interval approximately 6 years. We estimated spatiotemporal distributions 2018–2019 L-SSE by inverting processed GNSS time series data. This event was divided into two subevents, first on southwest side from 2018.3 2018.7 and second 2018.8 2019.4. Tectonic tremors became active downdip occurrence region when large...

Abstract The 30 May 2015 Chichi‐jima M8 earthquake is one of the largest deep focus earthquakes ever recorded and its depth 682 km puts it near base mantle transition zone. Before source mechanisms slip models this can be reliably assessed, a better understanding tectonic setting structures region origin required. Here we present evidence from receiver functions, method isolating subsurface material contrast with converted seismic waves, that initiated within upper zone, above significantly...

Abstract. We present a novel technique based on multi-resolutional clustering and nonlinear multi-dimensional scaling of earthquake patterns to investigate observed synthetic seismic catalogs. The data represent activities around the Japanese islands during 1997-2003. were generated by numerical simulations for various cases heterogeneous fault governed 3-D elastic dislocation power-law creep. At highest resolution, we analyze local cluster structures in space events two types catalogs using...