Structure of the crust and upper mantle beneath the Bransfield Strait (Antarctica) using P receiver functions

The Bransfield Strait is a tectonically active region located between the South Shetland archipelago (SSI) and the Antarctic Peninsula (AP), characterised by the presence of an incipient back-arc spreading ridge driven by on-going slab rollback of the Phoenix plate under the Antarctic and Shetland plates. Twelve broad-band seismic stations deployed in the region are used to obtain P-wave receiver functions from teleseismic earthquakes to improve the current understanding of the crust and upper mantle structures. This includes the depth and spatial variability of the Moho discontinuity, the average crustal Vp/Vs ratio and the thickness of the Mantle Transition Zone (MTZ). Results reveal a highly variable crustal thickness in the South Shetland block, ranging from ~30 km near the SW and NE ends of the South Shetland Trench to ~15 km in the central Bransfield Basin (Deception Island), where the highest Vp &#8260; Vs ratios in the region are reached (> 2). In contrast, the AP displays typical and homogeneous continental crust characteristics with an average crustal thickness of ~34 km and Vp/Vs ~1.77. A low velocity zone (LVZ) is identified under all stations suggesting partial melting in the upper mantle beneath the lithosphere, which is widespread throughout the region and not only confined to the mantle wedge above the subducted Phoenix oceanic slab. There is evidence of magmatic underplating under the SSB in accordance with the LVZ together with the active volcanism and the high crustal Vp/Vs ratio in the area. The Phoenix oceanic slab is inferred to subduct steeply, as the MTZ appears already thickened under the AP.

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Seismic imaging of the crust and upper mantle using regularized joint receiver functions, frequency–wave number filtering, and multimode Kirchhoff migration

Journal of Geophysical Research Atmospheres ◽

10.1029/2004jb003430 ◽

2005 ◽

Vol 110 (B5) ◽

Cited By ~ 36

Author(s):

David Wilson

Keyword(s):

Upper Mantle ◽

Seismic Imaging ◽

Receiver Functions ◽

Wave Number ◽

Crust And Upper Mantle ◽

Frequency Wave ◽

Kirchhoff Migration

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ScanArray - Seismological study of the connection between topographic change and deep structure in Fennoscandia

10.5194/egusphere-egu21-14385 ◽

2021 ◽

Author(s):

Hans Thybo ◽

Nevra Bulut ◽

Michael Grund ◽

Alexandra Mauerberger ◽

Anna Makushkina ◽

...

Keyword(s):

Baltic Shield ◽

Upper Mantle ◽

Deep Structure ◽

Broad Band ◽

Receiver Functions ◽

High Mountain ◽

Mountain Range ◽

S Wave ◽

Crust And Upper Mantle ◽

The Baltic

The Baltic Shield is located in northern Europe. It was formed by amalgamation of a series of terranes and microcontinents during the Archean to the Paleoproterozoic, followed by significant modification in Neoproterozoic to Paleozoic time. The Baltic Shield includes a high mountain range, the Scandes, along its western North Atlantic coast, despite being a stable craton located far from any active plate boundary. The ScanArray international collaborative program has acquired broad band seismological data at 192 locations in the Baltic Shield during the period between 2012 and 2017. The main objective of the program is to provide seismological constraints on the structure of the lithospheric crust and mantle as well as the sublithospheric upper mantle. The new information will be applied to studies of how the lithospheric and deep structure affects observed fast topographic change and geological-tectonic evolution of the region. The recordings are of very high quality and are used for analysis by suite of methods, including P- and S-wave receiver functions for the crust and upper mantle, surface wave and ambient noise inversion for seismic velocity, body wave P- and S- wave tomography for upper mantle velocity structure, and shear-wave splitting measurements for obtaining bulk anisotropy of the upper and lower mantle. Here we provide a short overview of the data acquisition and initial analysis of the new data with focus on parameters that constrain the fast topographic change in the Scandes. &#160;

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The Crust and Upper Mantle Structure of Central and West Antarctica From Bayesian Inversion of Rayleigh Wave and Receiver Functions

Journal of Geophysical Research Solid Earth ◽

10.1029/2017jb015346 ◽

2018 ◽

Vol 123 (9) ◽

pp. 7824-7849 ◽

Cited By ~ 24

Author(s):

Weisen Shen ◽

Douglas A. Wiens ◽

Sridhar Anandakrishnan ◽

Richard C. Aster ◽

Peter Gerstoft ◽

...

Keyword(s):

Rayleigh Wave ◽

Upper Mantle ◽

Receiver Functions ◽

Bayesian Inversion ◽

Mantle Structure ◽

West Antarctica ◽

Crust And Upper Mantle ◽

Upper Mantle Structure

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Imaging crust and upper mantle seismic structure in the southwestern United States using teleseismic receiver functions

The Leading Edge ◽

10.1190/1.1564528 ◽

2003 ◽

Vol 22 (3) ◽

pp. 232-237 ◽

Cited By ~ 40

Author(s):

David Wilson ◽

Richard Aster ◽

Keyword(s):

United States ◽

Upper Mantle ◽

Receiver Functions ◽

Seismic Structure ◽

Southwestern United States ◽

Crust And Upper Mantle

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Post-critical SsPmp and its applications to Virtual Deep Seismic Sounding (VDSS) – 2: 1-D imaging of the crust/mantle and joint constraints with receiver functions

Geophysical Journal International ◽

10.1093/gji/ggz370 ◽

2019 ◽

Vol 219 (2) ◽

pp. 1334-1347 ◽

Cited By ~ 1

Author(s):

Tianze Liu ◽

Simon L Klemperer ◽

Gabriel Ferragut ◽

Chunquan Yu

Keyword(s):

Upper Mantle ◽

Receiver Functions ◽

Deep Seismic Sounding ◽

Moho Depth ◽

Joint Analysis ◽

Crust And Upper Mantle ◽

Slave Craton ◽

Single Station ◽

Seismic Sounding ◽

Novel Method

SUMMARY Virtual Deep Seismic Sounding (VDSS) has emerged as a novel method to image the crust–mantle boundary (CMB) and potentially other lithospheric boundaries. In Part 1, we showed that the arrival time and waveform of post-critical SsPmp, the post-critical reflection phase at the CMB used in VDSS, is sensitive to several different attributes of the crust and upper mantle. Here, we synthesize our methodology of deriving Moho depth, average crustal Vp and uppermost-mantle Vp from single-station observations of post-critical SsPmp under a 1-D assumption. We first verify our method with synthetics and then substantiate it with a case study using the Yellowknife and POLARIS arrays in the Slave Craton, Canada. We show good agreement of crustal and upper-mantle properties derived with VDSS with those given by previous active-source experiments and our own P receiver functions (PRF) in our study area. Finally, we propose a PRF-VDSS joint analysis method to constrain average crustal Vp/Vs ratio and composition. Our PRF-VDSS joint analysis shows that the southwest Slave Craton has an intermediate crustal composition, most consistent with a Mesoarchean age.

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Seismic images of crust and upper mantle in Central Iran (from Jiroft to Ashtian) via teleseismic waves

Contributions to Geophysics and Geodesy ◽

10.31577/congeo.2020.50.4.1 ◽

2020 ◽

Vol 50 (4) ◽

Author(s):

Shahireh JAVADI ◽

Fataneh TAGHIZADEH-FARAHMAND ◽

Mohammad Reza GHEITANCHI

Keyword(s):

Upper Mantle ◽

Plate Tectonics ◽

Receiver Functions ◽

Central Iran ◽

Arabian Plate ◽

High Signal ◽

Detailed Knowledge ◽

Crust And Upper Mantle ◽

Linear Profile ◽

Short Period

A detailed knowledge of the thickness of crust and upper mantle structure is important for understanding a plate tectonics and geodynamics in the region. We use body wave for detecting details of the subsurface structure. The information in this research is collected from a seismic linear profile that extends across the Sanandaj-Sirjan metamorphic zone in seismic states of Central Iran and Zagros. We compute P receiver functions to investigate crustal and upper mantle discontinuities. We use teleseismic events (mb ≥ 5.5, 30° < Δ < 95°) registered between 1996 and 2018 and recorded at 10 short-period stations with 3 components and 17 broadband stations with high signal to noise ratio. The observed depth of Moho in the study area is approximately 50 km and rises to 70 km at the end of the seismic linear profile beneath Sanandaj-Sirjan zone. In Central Iran, depths discontinuities in the transition zone are shown by the reference model of deviation, which can be attributed to the convergence of Arabian plate with the Central Iran plateau. Also, the study area was identified as geothermal susceptibility by SUNA and this observation was confirmed.

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