scholarly journals Radial anisotropy in East Asia from multimode surface wave tomography

2021 ◽  
Author(s):  
M. Witek ◽  
S.‐J. Chang ◽  
D.Y. Lim ◽  
S. Ning ◽  
J. Ning
Keyword(s):  
Surface Wave ◽  
East Asia ◽  
Surface Wave Tomography ◽  
Radial Anisotropy ◽  
Wave Tomography

High Resolution Surface Wave Tomography in East Asia and West Pacific Marginal Sea

2002 ◽  
Vol 45 (5) ◽  
pp. 679-698 ◽  
Author(s):  
Jie-Shou ZHU ◽  
Ja-Min CAO ◽  
Xue-Lin CAI ◽  
Zhong-Qiong YAN ◽  
Xiao-Lin CAO
Keyword(s):  
Surface Wave ◽  
High Resolution ◽  
East Asia ◽  
Surface Wave Tomography ◽  
West Pacific ◽  
Marginal Sea ◽  
Wave Tomography

Radial anisotropy in Valhall from ambient noise surface wave tomography of Scholte and Love wave

2015 ◽  
Author(s):  
Gaurav Tomar* ◽  
Nikolai M. Shapiro ◽  
Satish Singh ◽  
Jean-Paul Montagner ◽  
Aurelien Mordret
Keyword(s):  
Surface Wave ◽  
Love Wave ◽  
Ambient Noise ◽  
Surface Wave Tomography ◽  
Radial Anisotropy ◽  
Wave Tomography

scholarly journals Ambient noise surface wave tomography of marginal seas in east Asia

2017 ◽  
Vol 1 (1) ◽  
pp. 13-25 ◽  
Author(s):  
Qing Wang ◽  
◽  
XiaoDong Song ◽  
JianYe Ren ◽  
◽  
...  
Keyword(s):  
Surface Wave ◽  
East Asia ◽  
Ambient Noise ◽  
Surface Wave Tomography ◽  
Marginal Seas ◽  
Wave Tomography

scholarly journals Surface-wave tomography of the Emeishan large igneous province (China): Magma storage system, hidden hotspot track, and its impact on the Capitanian mass extinction

Geology ◽  
2021 ◽  
Author(s):  
Yiduo Liu ◽  
Lun Li ◽  
Jolante van Wijk ◽  
Aibing Li ◽  
Yuanyuan V. Fu
Keyword(s):  
Surface Wave ◽  
Mass Extinction ◽  
Storage System ◽  
Large Igneous Province ◽  
Surface Wave Tomography ◽  
Magma Storage ◽  
Emeishan Large Igneous Province ◽  
Igneous Province ◽  
Radial Anisotropy ◽  
Wave Tomography

Large igneous provinces (LIPs) are commonly associated with mass extinctions. However, the precise relations between LIPs and their impacts on biodiversity is enigmatic, given that they can be asynchronous. It has been proposed that the environmental impacts are primarily related to sill emplacement. Therefore, the structure of LIPs’ magma storage system is critical because it dictates the occurrence and timing of mass extinction. We use surface-wave tomography to image the lithosphere under the Permian Emeishan large igneous province (ELIP) in southwestern China. We find a northeast-trending zone of high shear-wave velocity (Vs) and negative radial anisotropy (Vsv > Vsh; v and h are vertically and horizontally polarized S waves, respectively) in the crust and lithosphere. We rule out the possibilities of rifting or orogenesis to explain these seismic characteristics and interpret the seismic anomaly as a mafic-ultramafic, dike-dominated magma storage system of the ELIP. We further propose that the anomaly represents a hidden hotspot track that was emplaced before the ELIP eruption. A zone of higher velocity but less-negative radial anisotropy, on the hotspot track but to the northeast of the eruption center in the Panxi region, reflects an elevated proportion of sills emplaced at the incipient stage of the ELIP. Liberation of poisonous gases by the early sill intrusions explains why the mid-Capitanian global biota crisis preceded the peak ELIP eruption by 2–3 m.y.

scholarly journals The lithosphere-asthenosphere boundary observed with USArray receiver functions

2012 ◽  
Vol 4 (1) ◽  
pp. 1-31 ◽  
Author(s):  
P. Kumar ◽  
X. Yuan ◽  
R. Kind ◽  
J. Mechie
Keyword(s):  
Surface Wave ◽  
Receiver Function ◽  
The United States ◽  
Receiver Functions ◽  
Function Technique ◽  
Surface Wave Tomography ◽  
Entire Area ◽  
S Receiver Function ◽  
The Usa ◽  
Wave Tomography

Abstract. The dense deployment of seismic stations so far in the western half of the United States within the USArray project provides the opportunity to study in greater detail the structure of the lithosphere-asthenosphere system. We use the S receiver function technique for this purpose which has higher resolution than surface wave tomography, is sensitive to seismic discontinuities and has no problems with multiples like P receiver functions. Only two major discontinuities are observed in the entire area down to about 300 km depth. These are the crust-mantle boundary (Moho) and a negative boundary which we correlate with the lithosphere-asthenosphere boundary (LAB) since a low velocity zone is the classical definition of the seismic observation of the asthenosphere by Gutenberg (1926). Our S receiver function LAB is at a depth of 70–80 km in large parts of westernmost North America. East of the Rocky Mountains its depth is generally between 90 and 110 km. Regions with LAB depths down to about 140 km occur in a stretch from northern Texas over the Colorado Plateau to the Columbia Basalts. These observations agree well with tomography results in the westernmost USA and at the east coast. However, in the central cratonic part of the USA the tomography LAB is near 200 km depth. At this depth no discontinuity is seen in the S receiver functions. The negative signal near 100 km depth in the central part of the USA is interpreted by Yuan and Romanowicz (2010) or Lekic and Romanowicz (2011) as a recently discovered mid lithospheric discontinuity (MLD). A solution for the discrepancy between receiver function imaging and surface wave tomography is not yet obvious and requires more high resolution studies at other cratons before a general solution may be found. Our results agree well with petrophysical models of increased water content in the asthenosphere, which predict a sharp and shallow LAB also in continents (Mierdel et al., 2007).

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