Structural and geological characteristics of a “seismic gap” in the central part of the Kuril Island Arc

Kulinich, R; Karp, Baruch; Baranov, Boris; Lelikov, E. P.; Karnaukh, V. N.; Валитов, М. Г.; Николаев, С. М.; Kolpashchnikova, T. N.; Tsoi, I. B.

doi:10.1134/s1819714007010022

Cited by 25 publications

(14 citation statements)

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“…The stresses transmitted through the fore arc may thus be greater in regions where aseismic ridges subduct, but why is deformation associated with these stresses focused near the volcanic arc? In Kamchatka [ Wang , ; Kulinich et al ., ], Sumatra [ Sieh and Natawidjaja , ], and Nicaragua [ Turner et al ., ], the partitioning of oblique convergence onto strike‐slip faults coincident with the arc may reflect the higher heat‐fluxes and mechanical weakening of the lithosphere. We suggest thermal weakening may also result in compressional deformation being focused here, resulting in uplift and broadening of the volcanic arc.…”

Section: Discussionmentioning

confidence: 99%

Gravity anomalies, crustal structure, and seismicity at subduction zones: 1. Seafloor roughness and subducting relief

Bassett

Watts

2015

Geochem Geophys Geosyst

125

133

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An ensemble averaging technique is used to remove the long-wavelength topography and gravity field from subduction zones. >200 residual bathymetric and gravimetric anomalies are interpreted within fore arcs, many of which are attributed to the tectonic structure of the subducting plate. The residual-gravimetric expression of subducting fracture zones extends >200 km landward of the trench axis. The bathymetric expression of subducting seamounts with height 1 km and area 500 km 2 (N536), and aseismic ridges (N>10), is largest near the trench (within 70 km) and above shallow subducting slab depths (SLAB1.0 <17 km). Subducting seamounts are similar in wavelength, amplitude, and morphology to unsubducted seamounts. Morphology, spatial distributions, and reduced levels of seismicity are considered inconsistent with mechanical models proposing wholesale decapitation, and the association of subducting seamounts with large-earthquakes. Subducting aseismic ridges are associated with uplift and steepening of the outer fore arc, a gradual reduction in residual bathymetric expression across the inner fore arc, and a local increase in the width and elevation of the volcanic-arc/orogen. These contrasting expressions reflect the influence of margin-normal variations in rigidity on where and how the upper plate deforms, both to accommodate subducting relief and in response to stresses transmitted across the plate interface. The outer fore arc and arc have lower rigidity due to fracturing and thermal weakening, respectively. Similar associations with complex earthquakes and fault creep suggest aseismic ridge subduction may also be accommodated by the development and evolution of a broad fracture network, the geometrical strength of which may exceed the locking strength of a smooth fault.

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Section: Discussionmentioning

confidence: 99%

Gravity anomalies, crustal structure, and seismicity at subduction zones: 1. Seafloor roughness and subducting relief

Bassett

Watts

2015

Geochem Geophys Geosyst

125

133

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“…The Vityaz Ridge occupies the Kuril Islands fore arc (Figure ). This ridge was a site of sedimentation and active volcanism throughout the Eocene and early Oligocene, subsidence throughout the Late Oligocene and Neogene, and Pliocene‐Pleistocene volcanic rocks associated with transverse faults crossing the Vityaz Ridge are analogous to the tholeitic and calc‐alkali volcanic rocks of the Kuril arc [ Laverov et al ., ; Kulinich et al ., ; Lelikov and Emelyanova , ]. This TPFR extends over >1000 km and is expressed in the residual free‐air gravity field as a seaward verging triangular prism with an amplitude and half‐wavelength of ∼200 mGal and ∼100 km, respectively.…”

Section: Fore‐arc Structure: Trench‐parallel Fore‐arc Ridgesmentioning

confidence: 99%

“…Thin gray dashed lines show fracture zones [ Matthews et al ., ]. Solid and dashed red lines mark strike‐parallel [ Kimura , ] and extensional [ Kulinich et al ., ] faults accommodating fore‐arc sliver translation. (b) Residual free‐air gravity anomaly showing a correlation between the landward limit of thrust earthquakes and the TPFR crest (thick black dash).…”

Section: Fore‐arc Structure: Trench‐parallel Fore‐arc Ridgesmentioning

confidence: 99%

Gravity anomalies, crustal structure, and seismicity at subduction zones: 2. Interrelationships between fore‐arc structure and seismogenic behavior

Bassett

Watts

2015

Geochem Geophys Geosyst

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An ensemble-averaging technique is used to remove the long-wavelength topography and gravity field associated with subduction zones. Short-wavelength residual anomalies are attributed to the tectonic structure of subducting and overthrusting plates. A paired (positive-negative) fore-arc anomaly is observed consisting of a long (>1000 km), linear, trench-parallel ridge landward of the deep-sea-terrace basin. Ridges have amplitudes of 1500-3000 m and 160-240 mGal, wavelengths of 150-200 km, and high gravity anomaly to topography ratios (50-75 mGal km 21 ). The ridge crests correlate with the downdip limit of coseismic slip and strong interplate coupling and in Cascadia, the updip limit of tremor epicenters. The ridge crest may be interpreted as defining the boundary between the velocity-weakening and seismogenic region of the subduction interface and the downdip frictional transition zone. In Tonga-Kermadec, the Kuril Islands and Chile landward ridges are associated with extinct volcanic arcs. Paired anomalies are attributed to the preferential subduction erosion of the outer fore arc and a spatially varying combination of (a) lower crustal underplating beneath the inner fore arc, (b) the transformation of interseismic strain into permanent geologic strain via faulting, folding, or buckling of the inner fore arc, and (c) the relative trenchward migration of extinct volcanic arcs in regions operating with a net crustal deficit. Along-strike transitions in fore-arc morphology and seismogenic behavior are related to preexisting crustal structure of subducting and overthrusting plates. Fore arcs have the added potential of recording the time-integrated response of the upper plate to subduction processes, and fore-arc structure should be considered in tandem with seismological observations.

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“…An interarc basin separates the GKR from the Vityaz Ridge and LKR. The Central Kuril "seis mic gap" located eastward from the Urup and Oneko tan Islands is a zone of the active spreading and destruction of the consolidated basement [11]. Trans verse to Simushir Island, the ridge is divided by this zone into the southern and northern plateaus.…”

Section: Brief Geological-geomorphological Characteristicsmentioning

confidence: 99%

“…Some results have already been published [11,14,15]. The study of the mineral composition of the sedimentary and vol canosedimentary rocks allowed us to distinguish four complexes of different ages and to suggest a strati graphic scheme of the Cenozoic sedimentary cover [13,15].…”

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confidence: 95%

Late Mesozoic and Cenozoic volcanosedimentary complexes from the submarine Vityaz Ridge, the Island Arc slope of the Kuril-Kamchatka trench, and its evolution

Terekhov

Mozherovsky

Tsoy

et al. 2012

Russ. J. of Pac. Geol.

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This paper describes the volcanosedimentary complexes of different ages (Late Cretaceous-Early Paleocene, Paleocene-Eocene (?), Oligocene-Early Miocene, and Pliocene-Pleistocene) that compose the basement and sedimentary cover of the submarine Vityaz Ridge. It was found that the Upper Cretaceous sedimentary rocks from the basement of the Vityaz Ridge (felsic) and the Lesser Kuril Ridge (mafic) have dif ferent compositions. Matrix mineral assemblages corresponding to the smectite and corrensite stages of epi genesis of Cenozoic rocks were distinguished, and a scheme of the Late Cretaceous-Pleistocene geological evolution of the region was proposed.

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Structural and geological characteristics of a “seismic gap” in the central part of the Kuril Island Arc

Cited by 25 publications

References 1 publication

Gravity anomalies, crustal structure, and seismicity at subduction zones: 1. Seafloor roughness and subducting relief

Gravity anomalies, crustal structure, and seismicity at subduction zones: 1. Seafloor roughness and subducting relief

Gravity anomalies, crustal structure, and seismicity at subduction zones: 2. Interrelationships between fore‐arc structure and seismogenic behavior

Late Mesozoic and Cenozoic volcanosedimentary complexes from the submarine Vityaz Ridge, the Island Arc slope of the Kuril-Kamchatka trench, and its evolution

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