Present-day deformation across the southwest Japan arc: Oblique subduction of the Philippine Sea plate and lateral slip of the Nankai forearc

Tabei, Takao; Hashimoto, Manabu; Miyazaki, S.; Ohta, Yusaku

doi:10.1186/bf03352471

Cited by 23 publications

(19 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Median Tectonic Line (MTL) is the most prominent feature on the island of Shikoku and serves as one of the world's type examples of a structure that allows slip partitioning at a subduction zone by accommodating right‐lateral motion arising from oblique convergence at the Nankai Trough [e.g., Fitch , 1972; Tabei et al , 2002, 2003]. We model the MTL as a structure with variable dip, ranging from 45°N to vertical, following the AIST active fault map and generally consistent with the interpretation of seismic reflection data [e.g., Ito et al , 1996].…”

Section: Resultsmentioning

confidence: 99%

Geodetic imaging of plate motions, slip rates, and partitioning of deformation in Japan

Loveless¹,

Meade²

2010

J. Geophys. Res.

304

321

View full text Add to dashboard Cite

[1] Interseismic deformation in Japan results from the combined effects of tectonic processes including rotation of crustal blocks and the earthquake cycle process of elastic strain accumulation about upper plate faults and subduction zone interfaces. We use spherical linear block theory constrained by geodetic observations from densely spaced Global Positioning System (GPS) stations to estimate plate motions, fault slip rates, and spatially variable interplate coupling on the Japan-Kuril, Sagami, and Nankai subduction zones. The reference model developed in this paper consists of 20 blocks, produces a mean residual velocity magnitude of 1.84 mm/yr at 950 stations, and accounts for 96% of the observed interseismic deformation signal. We estimate fault slip rates in excess of 15 mm/yr along the Niigata-Kobe Tectonic Zone and Itoigawa-Shizuoka Tectonic Line through central Japan, confirming their hypothesized roles as major tectonic boundaries. Oblique convergence across the Nankai Trough is partitioned, with 3/4 of the $30 mm/yr of trench-parallel motion accommodated by strike-slip motion on the subduction interface and the remaining 1/4 accommodated by right-lateral slip on the Median Tectonic Line. In contrast, our models suggest negligible slip partitioning in eastern Hokkaido, where oblique slip on the Japan-Kuril subduction interface accommodates all of the trench-parallel component of relative plate motion. Inferred spatial variations in the rake and magnitude of slip deficit on subduction zone interfaces reflect the influences of megathrust geometry and earthquake cycle processes such as enhanced elastic strain accumulation about seismic asperities and coseismic sense fault motion indicative of silent slip events or afterslip following large earthquakes.

show abstract

Section: Resultsmentioning

confidence: 99%

Geodetic imaging of plate motions, slip rates, and partitioning of deformation in Japan

Loveless¹,

Meade²

2010

J. Geophys. Res.

304

321

View full text Add to dashboard Cite

show abstract

“…The task of delineating the plates, microplates, or crustal blocks present in central Japan and determining their relative velocities is complicated by the much larger strain rates associated with interseismic loading than with secular plate motions [ Wang , 2000; Henry et al , 2001; Mazzotti et al , 2001; Miyazaki and Heki , 2001; Tabei et al , 2003]. Conversely, the stresses associated with interseismic locking are much smaller than the secular tectonic stresses on which they are superimposed: The former are typically estimated to be of the order of 0.1–1 MPa [e.g., Zhao et al , 2004], whereas midcrustal differential stresses inferred from extrapolations of deep borehole measurements exceed 100 MPa [ Townend and Zoback , 2000], as predicted by frictional faulting theory for hydrostatic fluid pressure conditions [ Sibson , 1974; Brace and Kohlstedt , 1980].…”

Section: Introductionmentioning

confidence: 99%

Stress, strain, and mountain building in central Japan

2006

View full text Add to dashboard Cite

[1] The work described here has two key objectives: to investigate the geometric relationships between the principal directions of crustal stress and crustal strain rate in central Japan and to evaluate how crustal stresses are related to the rates of horizontal strain produced by different tectonic processes. Specifically, we consider the extent to which tectonic stress directions reflect transient deformation produced by interseismic subduction thrust locking. The axis of maximum horizontal compressive stress obtained from focal mechanism inversion agrees well with the axis of greatest contractional strain rate in central and southwest Japan only after the effects of interseismic strain accumulation on geodetic observations have been accounted for according to an elastic dislocation model of subduction thrust locking. The residual deformation, which is presumed to represent net upper plate deformation, is broadly confined to the area of pronounced topography in central Japan and is consistent with the deformation expected for horizontal motion of the Amurian plate with respect to northeastern Honshu. These observations suggest that part of the apparent discrepancy between crustal stress and strain rate directions reported by previous authors stems from a comparison of parameters representing processes occurring on different timescales. In this case, the strain rates associated with cyclic subduction zone locking are not reflected in the crustal stress field; conversely, longterm horizontal motion between northeast and southwest Japan exerts a stronger influence on the crustal stress field and neotectonic mountain-building processes in central Japan than do intermittent subduction zone earthquakes.

show abstract

“…Sagiya et al (2002b) studied the Itoigawa-Shizuoka Tectonic Line fault zone, and Miura et al (2002) studied deformation of the Ou backbone range. Tabei et al ( , 2003 operated a campaign-type GPS array across the Shikoku and Chugoku district in the north-south direction, studying the deformation associated with the Median Tectonic Line.…”

Section: Inter-seismic Deformation and Slip Deficit Distributionmentioning

confidence: 99%

A decade of GEONET: 1994–2003 —The continuous GPS observation in Japan and its impact on earthquake studies—

2014

View full text Add to dashboard Cite

The dense continuous GPS network of Japan, now called GEONET, has been operated since 1994 by the Geographical Survey Institute. GEONET provides precise daily coordinates of all the stations, with which displacement rates and strain rates are calculated nationwide. Various characteristics of tectonic deformation in the Japanese Islands have been revealed. GEONET is also quite useful in earthquake studies, precisely detecting co-seismic, post-seismic, and inter-seismic deformation signals. These observations are utilized to infer physical processes at earthquake sources. Slow slip events on plate boundaries have been found from GPS data. Such slow events provide an important constraint on the mechanism of faulting. On the other hand, there has been no success in detecting pre-seismic deformation. Lack of a precursory signal before the 2003 Tokachi-Oki (M8.0) earthquake has posed a serious question to short-term earthquake prediction. GEONET enables a good linkage between monitoring and modeling studies, opening a possibility of practical data assimilation. For further contribution to earthquake studies, it is necessary to continue GEONET with high traceability on the details in observation and analysis.

show abstract

Present-day deformation across the southwest Japan arc: Oblique subduction of the Philippine Sea plate and lateral slip of the Nankai forearc

Cited by 23 publications

References 10 publications

Geodetic imaging of plate motions, slip rates, and partitioning of deformation in Japan

Geodetic imaging of plate motions, slip rates, and partitioning of deformation in Japan

Stress, strain, and mountain building in central Japan

A decade of GEONET: 1994–2003 —The continuous GPS observation in Japan and its impact on earthquake studies—

Contact Info

Product

Resources

About