Crustal structure of southeast Australia from teleseismic receiver functions

Abstract. In an effort to improve our understanding of the seismic character of the crust beneath southeast Australia and how it relates to the tectonic evolution of the region, we analyse teleseismic earthquakes recorded by 24 temporary and 8 permanent broadband stations using the receiver function method. Due to the proximity of the temporary stations to Bass Strait, only 13 of these stations yielded usable receiver functions, whereas seven permanent stations produced receiver functions for subsequent analysis. Crustal thickness, bulk seismic velocity properties, and internal crustal structure of the southern Tasmanides – an assemblage of Palaeozoic accretionary orogens that occupy eastern Australia – are constrained by H–κ stacking and receiver function inversion, which point to the following: a ∼ 39.0 km thick crust; an intermediate–high Vp/Vs ratio (∼ 1.70–1.76), relative to ak135; and a broad (> 10 km) crust–mantle transition beneath the Lachlan Fold Belt. These results are interpreted to represent magmatic underplating of mafic materials at the base of the crust. a complex crustal structure beneath VanDieland, a putative Precambrian continental fragment embedded in the southernmost Tasmanides, that features strong variability in the crustal thickness (23–37 km) and Vp/Vs ratio (1.65–193), the latter of which likely represents compositional variability and the presence of melt. The complex origins of VanDieland, which comprises multiple continental ribbons, coupled with recent failed rifting and intraplate volcanism, likely contributes to these observations. stations located in the East Tasmania Terrane and eastern Bass Strait (ETT + EB) collectively indicate a crust of uniform thickness (31–32 km), which clearly distinguishes it from VanDieland to the west. Moho depths are also compared with the continent-wide AusMoho model in southeast Australia and are shown to be largely consistent, except in regions where AusMoho has few constraints (e.g. Flinders Island). A joint interpretation of the new results with ambient noise, teleseismic tomography, and teleseismic shear wave splitting anisotropy helps provide new insight into the way that the crust has been shaped by recent events, including failed rifting during the break-up of Australia and Antarctica and recent intraplate volcanism.

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Crustal structure of southeast Australia from teleseismic receiver functions

10.5194/se-2020-74 ◽

2020 ◽

Author(s):

Mohammed Bello ◽

David G. Cornwell ◽

Nicholas Rawlinson ◽

Anya M. Reading ◽

Othaniel K. Likkason

Keyword(s):

Crustal Structure ◽

Tectonic Evolution ◽

Poisson’S Ratio ◽

Seismic Velocity ◽

Receiver Function ◽

Receiver Functions ◽

Poisson's Ratio ◽

Southeast Australia ◽

South Central ◽

Eastern Australia

Abstract. In an effort to improve our understanding of southeast Australia’s enigmatic tectonic evolution, we analyse teleseismic earthquakes recorded by 24 temporary and 8 permanent broadband stations using the receiver function method. Crustal thickness, bulk seismic velocity and internal crustal structure of the southern Tasmanides – an assemblage of Palaeozoic accretionary orogens that occupy eastern Australia – are constrained by our new results which point to: (1) a 39.0 ± 0.5 km thick crust, a relatively high Poisson’s ratio (0.262 ± 0.014) and a broad (> 10 km) crust-mantle transition beneath the Lachlan Fold Belt. This is interpreted to represent magmatic underplating of mafic materials at the base of the crust; (2) a complex crustal structure beneath VanDieland, a postulated Precambrian continental fragment embedded in the southernmost Tasmanides, where the crust thickens (37.5 ± 1.2 km) towards the northern tip of the microcontinent as it enters south central Victoria but thins south into Bass Strait (30.5 ± 2.1 km), before once again becoming thicker beneath western Tasmania (33.5 ± 1.9 km). The thinner crust beneath Bass Strait can be attributed to lithospheric stretching that resulted from the break-up of Antarctica and Australia and the opening of the Tasman Sea; (3) stations located in the East Tasmania Terrane and eastern Bass Strait (ETT+EB) collectively indicate crust of uniform thickness (∼ 33 km) and a slightly broad Moho transition that reflect a possible underplating event associated with a Palaeozoic subduction system. The relative uniformity of Vp/Vs and Poisson’s ratio in VanDieland – suggesting uniformity in composition – could be used in support of the VanDieland microcontinental model that explains the tectonic evolution of southeast Australia.

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Mapping crustal structure of the Nechako–Chilcotin plateau using teleseismic receiver function analysis,

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2013-0147 ◽

2014 ◽

Vol 51 (4) ◽

pp. 407-417 ◽

Cited By ~ 2

Author(s):

H.S. Kim ◽

J.F. Cassidy ◽

S.E. Dosso ◽

H. Kao

Keyword(s):

Wave Velocity ◽

Crustal Structure ◽

Velocity Structure ◽

Receiver Function ◽

Function Analysis ◽

Crustal Thickness ◽

Receiver Functions ◽

S Wave ◽

Low Velocity ◽

Velocity Models

This paper presents results of a passive-source seismic mapping study in the Nechako–Chilcotin plateau of central British Columbia, with the ultimate goal of contributing to assessments of hydrocarbon and mineral potential of the region. For the present study, an array of nine seismic stations was deployed in 2006–2007 to sample a wide area of the Nechako–Chilcotin plateau. The specific goal was to map the thickness of the sediments and volcanic cover, and the overall crustal thickness and structural geometry beneath the study area. This study utilizes recordings of about 40 distant earthquakes from 2006 to 2008 to calculate receiver functions, and constructs S-wave velocity models for each station using the Neighbourhood Algorithm inversion. The surface sediments are found to range in thickness from about 0.8 to 2.7 km, and the underlying volcanic layer from 1.8 to 4.7 km. Both sediments and volcanic cover are thickest in the central portion of the study area. The crustal thickness ranges from 22 to 36 km, with an average crustal thickness of about 30–34 km. A consistent feature observed in this study is a low-velocity zone at the base of the crust. This study complements other recent studies in this area, including active-source seismic studies and magnetotelluric measurements, by providing site-specific images of the crustal structure down to the Moho and detailed constraints on the S-wave velocity structure.

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Probing layered arc crust in the Lesser Antilles using receiver functions

Royal Society Open Science ◽

10.1098/rsos.180764 ◽

2018 ◽

Vol 5 (11) ◽

pp. 180764 ◽

Cited By ~ 2

Author(s):

David Schlaphorst ◽

Elena Melekhova ◽

J-Michael Kendall ◽

Jon Blundy ◽

Joan L. Latchman

Keyword(s):

Crustal Structure ◽

Receiver Function ◽

Crustal Thickness ◽

Receiver Functions ◽

Lesser Antilles ◽

The North ◽

Seismological Data ◽

History Of ◽

Mohorovičić Discontinuity ◽

Inversion Modelling

Oceanic arcs can provide insight into the processes of crustal growth and crustal structure. In this work, changes in crustal thickness and composition along the Lesser Antilles Arc (LAA) are analysed at 10 islands using receiver function (RF) inversions that combine seismological data with v P /v S ratios estimated based on crustal lithology. We collected seismic data from various regional networks to ensure station coverage for every major island in the LAA from Saba in the north to Grenada in the south. RFs show the subsurface response of an incoming signal assuming horizontal layering, where phase conversions highlight discontinuities beneath a station. In most regions of the Earth, the Mohorovičić discontinuity (Moho) is seismically stronger than other crustal discontinuities. However, in the LAA we observe an unusually strong along-arc variation in depth of the strongest discontinuity, which is difficult to explain by variations in crustal thickness. Instead, these results suggest that in layered crust, especially where other discontinuities have a stronger seismic contrast than the Moho, H– k stacking results can be easily misinterpreted. To circumvent this problem, an inversion modelling approach is introduced to investigate the crustal structure in more detail by building a one-dimensional velocity–depth profile for each island. Using this method, it is possible to identify any mid-crustal discontinuity in addition to the Moho. Our results show a mid-crustal discontinuity at about 10–25 km depth along the arc, with slightly deeper values in the north (Montserrat to Saba). In general, the depth of the Moho shows the same pattern with values of around 25 km (Grenada) to 35 km in the north. The results suggest differences in magmatic H 2 O content and differentiation history of each island.

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No polarity switch? Continental subduction of European crust below the Eastern Alps imaged by receiver functions

10.5194/egusphere-egu2020-13785 ◽

2020 ◽

Author(s):

Stefan Mroczek ◽

Frederik Tilmann ◽

Xiaohui Yuan ◽

Jan Pleuger ◽

Ben Heit

Keyword(s):

Receiver Function ◽

Eastern Alps ◽

Receiver Functions ◽

Opposite Polarity ◽

Seismic Network ◽

Study Region ◽

Teleseismic Tomography ◽

Minimum Depth ◽

The Alps ◽

Receiver Function Method

In the Eastern Alps, teleseismic tomography suggests that there is a switch from European subduction in the west to Adriatic subduction in the east. The dense SWATH-D seismic network is located in the central-eastern Alps between around 10&#176;E and 14.5&#176;E where a change in the dip direction was suggested to occur (e.g. Lippitsch et al. 2003; Mitterbauer et al. 2011). The receiver function method is particularly sensitive to velocity contrasts and so is suited to imaging the interfaces associated with subduction. New receiver function migrations from SWATH-D stations (supplemented by the AlpArray Seismic Network and the EASI profile) show no evidence for Adriatic subduction in the Eastern Alps. Instead, a southward dipping interface [or pair of interfaces with opposite polarity] which we interpreted as subducting&#160; European lower crust can be traced below the Eastern Alps to a minimum depth of 120 km along the extent of SWATH-D. This suggests that in the Alps the polarity flip in subduction does not occur or is located east of our study region beyond 14.25&#176;E, much further east than tomography suggests.

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Receiver function imaging of the 410 and 660 km discontinuities beneath the Australian continent

Geophysical Journal International ◽

10.1093/gji/ggz525 ◽

2019 ◽

Vol 220 (3) ◽

pp. 1481-1490

Author(s):

Kailun Ba ◽

Stephen S Gao ◽

Kelly H Liu ◽

Fansheng Kong ◽

Jianguo Song

Keyword(s):

Reference Model ◽

Receiver Function ◽

Thermal Anomaly ◽

Receiver Functions ◽

Earth Model ◽

Supporting Evidence ◽

Controversial Issues ◽

Eastern Australia ◽

Australian Continent ◽

Normal Thickness

SUMMARY To provide constraints on a number of significant controversial issues related to the structure and dynamics of the Australian continent, we utilize P-to-S receiver functions (RFs) recorded by 182 stations to map the 410 and 660 km discontinuities (d410 and d660, respectively) bordering the mantle transition zone (MTZ). The RFs are stacked in successive circular bins with a radius of 1° under a non-plane wave front assumption. The d410 and d660 depths obtained using the 1-D IASP91 earth model show a systematic apparent uplifting of about 15 km for both discontinuities in central and western Australia relative to eastern Australia, as the result of higher seismic wave speeds in the upper mantle beneath the former area. After correcting the apparent depths using the Australian Seismological Reference Model, the d410 depths beneath the West Australia Craton are depressed by ∼10 km on average relative to the normal depth of 410 km, indicating a positive thermal anomaly of 100 K at the top of the MTZ which could represent a transition from a thinner than normal MTZ beneath the Indian ocean and the normal MTZ beneath central Australia. The abnormally thick MTZ beneath eastern Australia can be adequately explained by subducted cold slabs in the MTZ. A localized normal thickness of the MTZ beneath the Newer Volcanics Province provides supporting evidence of non-mantle-plume mechanism for intraplate volcanic activities in the Australian continent.

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Deep deformation process of the NE Tibetan Plateau: evidence from receiver function imaging

10.5194/egusphere-egu2020-7581 ◽

2020 ◽

Author(s):

yifang chen ◽

jiuhui chen

Keyword(s):

Tibetan Plateau ◽

Seismic Velocity ◽

Receiver Function ◽

Decisive Role ◽

Deformation Mode ◽

Receiver Functions ◽

Tibet Plateau ◽

The Tibetan Plateau ◽

Waveform Data ◽

The North

The deformation of Qilian Orogenic Belt, which is the uplifting front of the northeastern Tibet Plateau, plays a decisive role in understanding the dynamic process of the area uplift. Many of the tectonic processes models of the Tibetan Plateau growth, which are based on geophysical and geological studies, have been conducted in recent years. However, the deformation mode of northeastern Tibetan Plateau (NETP) remains controversial for lack of sufficient proofs. We used teleseismic waveform data collected from the China Array seismic experiment during 2013-2015 and QL temporary stations during 2016-2017. In this study, we used the 3-D Common Conversion Point (CCP) technique (with the P/S receiver functions) to obtain detailed seismic velocity discontinuities structure of lithosphere beneath the NETP and Alxa block. Our preliminary results can be summarized as follows: 1) The Lithosphere asthenosphere boundary (LAB) lies at a depth pf 110-140 km in Alxa platform, deepens below the North Qilian mountain (160-170 km ) which has been inserted by lithosphere of Central Qilian, between the South Qilian suture zone (SQL) and the north of the Songpan-Ganzi Terranes (160-170 km). 2) The main features in the crust include offset of Moho beneath NQLF, shallower crust thickness below between the NQLF and LSSF and a continuous positive interface over the Moho in the north of the LSSF. 3) According to our observation and previous studies, we suppose that lithosphere had been passive underthrust and localized crust had been shortened and thickened in the NETP.

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Imaging the Moho and Main Himalayan Thrust beneath the Kumaon Himalaya: constraints from receiver function analysis

Geophysical Journal International ◽

10.1093/gji/ggaa478 ◽

2020 ◽

Vol 224 (2) ◽

pp. 858-870

Author(s):

Devajit Hazarika ◽

Somak Hajra ◽

Abhishek Kundu ◽

Meena Bankhwal ◽

Naresh Kumar ◽

...

Keyword(s):

Poisson’S Ratio ◽

Receiver Function ◽

Function Analysis ◽

Crustal Thickness ◽

Receiver Functions ◽

P Wave ◽

Poisson's Ratio ◽

Kumaon Himalaya ◽

Receiver Function Analysis ◽

Lower Crustal

SUMMARY We analyse P-wave receiver functions across the Kumaon Himalaya and adjoining area to constrain crustal thickness, intracrustal structures and seismic velocity characteristics to address the role of the underlying structure on seismogenesis and geodynamic evolution of the region. The three-component waveforms of teleseismic earthquakes recorded by a seismological network consisting of 18 broad-band seismological stations have been used for receiver function analysis. The common conversion point (CCP) depth migrated receiver function image and shear wave velocity models obtained through inversion show a variation of crustal thickness from ∼38 km in the Indo-Gangetic Plain to ∼42 km near the Vaikrita Thrust. A ramp (∼20°) structure on the Main Himalayan Thrust (MHT) is revealed beneath the Chiplakot Crystalline Belt (CCB) that facilitates the exhumation of the CCB. The geometry of the MHT observed from the receiver function image is consistent with the geometry revealed by a geological balanced cross-section. A cluster of seismicity at shallow to mid-crustal depths is detected near the MHT ramp. The spatial and depth distribution of seismicity pattern beneath the CCB and presence of steep dipping imbricate faults inferred from focal mechanism solutions suggest a Lesser Himalayan Duplex structure in the CCB above the MHT ramp. The study reveals a low-velocity zone (LVZ) with a high Poisson's ratio (σ ∼0.28–0.30) at lower crustal depth beneath the CCB. The high value of Poisson's ratio in the lower crust suggests the presence of fluid/partial melt. The shear heating in the ductile regime and/or decompression and cooling associated with the exhumation of the CCB plausibly created favorable conditions for partial melting in the lower crustal LVZ.

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Constraining crustal structure in the presence of sediment: a multiple converted wave approach

Geophysical Journal International ◽

10.1093/gji/ggz298 ◽

2019 ◽

Vol 219 (1) ◽

pp. 313-327 ◽

Cited By ~ 1

Author(s):

Erin Cunningham ◽

Vedran Lekic

Keyword(s):

Wave Velocity ◽

Seismic Velocity ◽

Seismic Station ◽

Sedimentary Basins ◽

Crustal Thickness ◽

Receiver Functions ◽

P Wave ◽

Converted Wave ◽

P Wave Velocity ◽

Multiple Data Sets

SUMMARY Receiver functions are sensitive to sharp seismic velocity variations with depth and are commonly used to constrain crustal thickness. The H–κ stacking method of Zhu & Kanamori is often used to constrain both the crustal thickness (H) and ${V_P}$/${V_S}$ ratio ($\kappa $) beneath a seismic station using P-to-s converted waves (Ps). However, traditional H–κ stacks require an assumption of average crustal velocity (usually ${V_P}$). Additionally, large amplitude reverberations from low velocity shallow layers, such as sedimentary basins, can overprint sought-after crustal signals, rendering traditional H–$\ \kappa $ stacking uninterpretable. We overcome these difficulties in two ways. When S-wave reverberations from sediment are present, they are removed by applying a resonance removal filter allowing crustal signals to be clarified and interpreted. We also combine complementary Ps receiver functions, Sp receiver functions, and the post-critical P-wave reflection from the Moho (SPmp) to remove the dependence on an assumed average crustal ${V_P}$. By correcting for sediment and combining multiple data sets, the crustal thickness, average crustal P-wave velocity and crustal ${V_P}$/${V_S}$ ratio is constrained in geological regions where traditional H–$\ \kappa $ stacking fails, without making an initial P-wave velocity assumption or suffering from contamination by sedimentary reverberations.

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Crustal thickness estimation in Indonesia using receiver function method

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/873/1/012086 ◽

2021 ◽

Vol 873 (1) ◽

pp. 012086

Author(s):

M F Fauzi ◽

A Anggraini ◽

A Riyanto ◽

D Ngadmanto ◽

W Suryanto

Keyword(s):

Receiver Function ◽

Vertical Component ◽

Crustal Thickness ◽

Radial Component ◽

Receiver Functions ◽

Frequency Noise ◽

Seismic Wave Velocity ◽

The North ◽

Central Java ◽

Receiver Function Method

Abstract The existence of seismic wave velocity difference in the Earth crust and mantle creates the possibility to use earthquake data for estimating the crustal thickness utilizing the Ps conversion phase in the boundary. The radial component signal was deconvolved from the vertical component in the frequency domain to estimate receiver function for Indonesia region. We implemented the water level deconvolution techniques with a Gaussian filter of 2.5 Hz to eliminate the high frequency noise in the receiver function. The H-k stacking technique was performed to all receiver functions from each event to predict the crustal thickness and the Vp/Vs ratio below the stations. We analyzed ten azimuthally distributed teleseismic earthquakes recorded by 108 stations of BMKG. The result shows that the crustal thickness in Indonesia varies from 20 to 39.9 km. The western part of Sumatera, northern part of Sulawesi Island, and North Maluku region show generally thinner crust with value about 20 to 25 km. The North Sumatera, Central Java, and East Java show a considerably thicker crust of up to 36 km. Furthermore, our result also reveals a difference of crustal thickness about 5 km with the previous studies.

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The Crustal Structure of the Eastern Marmara Region Using Receiver Function Analysis

10.5194/egusphere-egu2020-4689 ◽

2020 ◽

Author(s):

Pınar Büyükakpınar ◽

Mustafa Aktar

Keyword(s):

Fault Zone ◽

Receiver Function ◽

Function Analysis ◽

Joint Inversion ◽

Crustal Thickness ◽

Receiver Functions ◽

Gradual Transition ◽

Marmara Region ◽

The North ◽

Receiver Function Analysis

This study focuses on the crust of the Eastern Marmara in order to understand of how much the structure is influenced by the tectonic history and also by the activity of the NAF. Recent studies have claimed that the crustal thickness varies significantly on the north and south of the NAF, which is assumed to indicate the separation line between Eurasian and Anatolian Plates. The present study aims to reevaluate the claim above, using newly available data and recently developed tools. The methods used during the study are the receiver function analysis and surface wave analysis. The first one is more intensively applied, since the second one only serves to introduce stability constraint in the inversions. Data are obtained from the permanent network of KOERI and from PIRES arrays.&#160; The main result of the study indicates that the receiver functions for the stations close to the fault zone are essentially very different from the rest and should be treated separately. They show signs of complex 3D structures of which two were successfully analyzed by forward modeling (HRTX and ADVT). A dipping shallow layer is seen to satisfy the major part of the azimuthal variation at these two stations. For the stations off the fault on the other hand, the receiver functions show a more stable behavior and are analyzed successfully by classical methods. CCP stacking, H-k estimation, single and joint inversion with surface waves, are used for that purpose. The results obtained from these totally independent approaches are remarkably consistent with each other. It is observed that the crustal thickness does not vary significantly neither in the NS, nor in the SW direction. A deeper Moho can only be expected on two most NE stations where a gradual transition is more likely than a sharp boundary (SILT and KLYT). The structural trends, although not significant, are generally aligned in the EW direction.&#160; In particular, a slower lower crust is observed in the southern stations, which is possibly linked to the mantle upwelling and thermal transient of the Aegean extension. Otherwise neither the velocity, nor the thickness of the crust does not imply any significant variation across the fault zone, as was previously claimed.

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