Crust and upper mantle structure of the New Madrid Seismic Zone: Insight into intraplate earthquakes

Chen, Chuanxu; Zhao, Dapeng; Wu, Shiguo

doi:10.1016/j.pepi.2014.01.016

Cited by 55 publications

(70 citation statements)

References 50 publications

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“…We conclude that the earthquake swarms are apt to occur in the transition strip between high-and low-velocity zones coinciding with the fault zones, in agreement with the predecessors' studies (e.g. Chen et al 2014;Su et al 2016;Qi et al 2006); moreover, the distribution of the earthquake swarms is generally controlled by these faults. Further, continuous seismic activity is also a manifestation of the tectonic activity of the faults.…”

Section: S-wave Velocity Images Of the Tangshan Regionsupporting

confidence: 91%

Crustal structure beneath Liaoning province and the Bohai Sea and its adjacent region in China based on ambient noise tomography

2017

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The velocity structure of the crust beneath Liaoning province and the Bohai sea in China was imaged using ambient seismic noise recorded by 73 regional broadband stations. All available three-component time series from the 12-month span between January and December 2013 were cross-correlated to yield empirical Green's functions for Rayleigh and Love waves. Phasevelocity dispersion curves for the Rayleigh waves and the Love waves were measured by applying the frequencytime analysis method. Dispersion measurements of the Rayleigh wave and the Love wave were then utilized to construct 2D phase-velocity maps for the Rayleigh wave at 8-35 s periods and the Love wave at 9-32 s periods, respectively. Both Rayleigh and Love phase-velocity maps show significant lateral variations that are correlated well with known geological features and tectonics units in the study region. Next, phase dispersion curves of the Rayleigh wave and the Love wave extracted from each cell of the 2D Rayleigh wave and Love wave phase-velocity maps, respectively, were inverted simultaneously to determine the 3D shear wave velocity structures. The horizontal shear wave velocity images clearly and intuitively exhibit that the earthquake swarms in the Haicheng region and the Tangshan region are mainly clustered in the transition zone between the low-and high-velocity zones in the upper crust, coinciding with fault zones, and their distribution is very closely associated with these faults. The vertical shear wave velocity image reveals that the lower crust downward to the uppermost mantle is featured by distinctly high velocities, with even a high-velocity thinner layer existing at the bottom of the lower crust near Moho in central and northern the Bohai sea along the Tanlu fault, and these phenomena could be caused by the intrusion of mantle material, indicating the Tanlu fault could be just as the uprising channel of deep materials.

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Section: S-wave Velocity Images Of the Tangshan Regionsupporting

confidence: 91%

Crustal structure beneath Liaoning province and the Bohai Sea and its adjacent region in China based on ambient noise tomography

2017

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“…A hotter than normal lithospheric mantle has also been proposed to account for the New Madrid Seismic zone in the eastern USA on the basis of surface heat flow data (Liu and Zoback, 1997). The low velocity anomaly (up to 6%) imaged by P-wave tomography between 80 and 200 km depth beneath the New Madrid Seismic zone corroborates this model (Chen et al, 2014).…”

Section: Accepted Manuscriptmentioning

confidence: 79%

Heterogeneity and anisotropy in the lithospheric mantle

2015

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International audienceThe lithospheric mantle is intrinsically heterogeneous and anisotropic. These two properties govern the repartition of deformation, controlling intraplate strain localization and development of new plate boundaries. Geophysical and geological observations provide clues on the types, ranges, and characteristic length scales of heterogeneity and anisotropy in the lithospheric mantle. Seismic tomography points to variations in geothermal gradient and hence in rheological behavior at scales of hundreds of km. Seismic anisotropy data substantiate anisotropic physical properties consistent at scales of tens to hundreds of km. Receiver functions imply lateral and vertical heterogeneity at scales < 10 km, which might record gradients in composition or anisotropy. Observations on naturally deformed peridotites establish that compositional heterogeneity and Crystal Preferred Orientations (CPOs) are ubiquitous from the mm to the km scales. These data allow discussing the processes that produce/destroy heterogeneity and anisotropy and constraining the time scales over which they are active. This analysis highlights: (i) the role of deformation and reactive percolation of melts and fluids in producing compositional and structural heterogeneity and the feedbacks between these processes, (ii) the weak mechanical effect of mineralogical variations, and (iii) the low volumes of fine-grained microstructures and difficulty to preserve them. In contrast, olivine CPO and the resulting anisotropy of mechanical and thermal properties are only modified by deformation. Based on this analysis, we propose that strain localization at the plate scale is, at first order, controlled by large-scale variations in thermal structure and in CPO-induced anisotropy. In cold parts of the lithospheric mantle , grain size reduction may contribute to strain localization, but the low volume of fine-grained domains limits this effect

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“…Many high-resolution seismic images have been obtained and we are beginning to narrow down the mantle structure, particularly beneath the western US, to the scale of~200 km (e.g., Becker, 2012;Chen et al, 2014Chen et al, , 2015. The tectonic involution of western US, including the active subduction of the Juan der Fuca plate, extensive subduction-related volcanism and intraplate volcanism (e.g., the Yellowstone hotspot), as well as mountain building, was thoroughly discussed and many models have been proposed on the basis of slab-mantle interactions revealed by the seismic images (e.g., Becker, 2012;Tian and Zhao, 2012b;Chen et al, 2015).…”

Section: North Americamentioning

confidence: 99%

Seismic anisotropy tomography: New insight into subduction dynamics

2016

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Body-wave and surface-wave tomography, receiver-function imaging, and shear-wave splitting measurements have shown that seismic anisotropy and heterogeneity coexist in all parts of subduction zones, providing important constraints on the mantle flow and subduction dynamics. P-wave anisotropy tomography is a new but powerful tool for mapping three-dimensional variations of azimuthal and radial seismic anisotropy in the crust and mantle. P-wave azimuthal-anisotropy tomography has been applied widely to the Circum-Pacific subduction zones, Mainland China and North America, whereas P-wave radial-anisotropy tomography was applied to only a few areas including Northeast Japan, Southwest Japan and North China Craton. These studies have revealed complex anisotropy in the crust and mantle lithosphere associated with the surface geology and tectonics, anisotropy reflecting subduction-driven corner flow in the mantle wedge, frozen-in fossil anisotropy in the subducting slabs formed at the mid-ocean ridge, as well as olivine fabric transitions due to changes in water content, stress and temperature. Shear-wave splitting tomography methods have been also proposed, but their applications are still limited and preliminary. There is a discrepancy between the surface-wave and body-wave tomographic models in radial anisotropy of the mantle wedge beneath Japan, which is a puzzle but an intriguing topic for future studies.

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Crust and upper mantle structure of the New Madrid Seismic Zone: Insight into intraplate earthquakes

Cited by 55 publications

References 50 publications

Crustal structure beneath Liaoning province and the Bohai Sea and its adjacent region in China based on ambient noise tomography

Crustal structure beneath Liaoning province and the Bohai Sea and its adjacent region in China based on ambient noise tomography

Heterogeneity and anisotropy in the lithospheric mantle

Seismic anisotropy tomography: New insight into subduction dynamics

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