New insight into Cainozoic sedimentary basins and Palaeozoic suture zones in southeast Australia from ambient noise surface wave tomography

Abstract

Detailed images of Rayleigh wave group velocity are derived from ambient seismic noise recorded by WOMBAT, a large rolling seismic array project in southeast Australia. Group velocity maps sensitive to crustal structure exhibit low velocity anomalies in the presence of sedimentary basins and recent hot‐spot volcanism, and high velocities in regions of out‐cropping metamorphic and igneous rocks. Distinct and well‐constrained patches of low velocity within the Murray Basin provide new insight into the spatial extent and possible composition of pre‐Tertiary infra‐basins. In a broader tectonic context, our results show little evidence for the Palaeozoic building blocks of the southeast Australian continent that have been inferred from geological mapping and potential field data. This may mean that apparent changes in basement terrane near the surface are not associated with major changes in composition at depth.

Seismic interferometry and ambient noise tomography in the British Isles

“…The tomographic maps they produced agree well with the known geology and previous seismic studies in the region. Since then, surface wave tomography using interferometric Rayleigh and Love waves, commonly referred to as ambient noise tomography, has become an increasingly employed method to successfully produce subsurface velocity models on regional and continental scales in areas such as the United States (Bensen et al, 2008; Lin et al, 2008;Shapiro et al, 2005;Sabra et al, 2005b;Liang and Langston, 2008), Australia (Arroucau et al, 2010;Rawlinson et al, 2008;Saygin and Kennett, 2010), New Zealand (Lin et al, 2007;Behr et al, 2010), Antarctica (Pyle et al, 2010), Iceland (Gudmundsson et al, 2007), China (Zheng et al, 2008;Li et al, 2009;Zheng et al, 2010), South Africa , Europe (Villaseñ or et al, 2007;Yang et al, 2006), South Korea (Cho et al, 2007) the Tibetan Plateau (Yao et al, 2006(Yao et al, , 2008Li et al, 2009), and in this paper, Scotland.…”

Crustal surface wave velocity structure of the east Albany-Fraser Orogen, Western Australia, from ambient noise recordings

“…For determining phase velocities, we relied on a semi-automated approach (modified from Arroucau et al 2010;Young et al 2011) that picks phase velocity dispersion curves from plots of phase velocity against period (after Yao et al 2006). We first carefully handpicked an average dispersion curve, based on which a corridor of 'sensible' velocities was established.…”

“…Group velocities were determined using frequency-time analysis (FTAN, e.g. Levshin et al 1992) and a phase-matched filtering approach (Levshin & Ritzwoller 2001;Arroucau et al 2010;Young et al 2011) on the envelope of the symmetric component (averaged causal and acausal parts) of the empirical Green's functions. Only cross-correlograms between stations with a spatial separation larger than 3 wavelengths were used for the retrieval of dispersion curves (e.g.…”

Beneath Bass Strait: Linking Tasmania and Mainland Australia using Ambient Seismic Noise

“…Subsequently, detailed images of the lithosphere structure in various parts of the world have been obtained by exploiting this class of data (Shapiro & Campillo, 2005;Yang et al, 2007;Bensen et al, 2009;Arroucau et al, 2010;Young et al, 2011;Saygin & Kennett, 2010, 2012. It turns out that long term cross-correlation of the background noise recorded at two stations produces an estimate of the Rayleigh surface wave (from the vertical component or Love wave from the horizontals) packet (known as the empirical the Green's function) that is equivalent to the signal that would arrive at one station if the source waveform were a delta function located at the other station.…”