A5075778736- earthquake and tectonic studies
- Seismic Imaging and Inversion Techniques
- High-pressure geophysics and materials
- Seismic Waves and Analysis
- Geological and Geophysical Studies
- Geological and Geochemical Analysis
- Seismology and Earthquake Studies
- Geological Studies and Exploration
- Marine and fisheries research
- Geochemistry and Geologic Mapping
- Methane Hydrates and Related Phenomena
- Earthquake Detection and Analysis
- Geological Modeling and Analysis
- Geological formations and processes
- Geomagnetism and Paleomagnetism Studies
- Fish Ecology and Management Studies
- Geophysics and Sensor Technology
- Hydrocarbon exploration and reservoir analysis
- Coral and Marine Ecosystems Studies
- Geophysics and Gravity Measurements
- Hydraulic Fracturing and Reservoir Analysis
- Geological and Geophysical Studies Worldwide
- Island Studies and Pacific Affairs
- Ichthyology and Marine Biology
- Underwater Acoustics Research
University of Cambridge
2017-2025
Australian National University
2007-2021
University of Aberdeen
2014-2021
Royal Holloway University of London
2021
University of Tasmania
2013-2018
Australian Maritime College
1998-2017
Bristol Royal Infirmary
2008
Monash University
1998-2001
Commonwealth Scientific and Industrial Research Organisation
1990-1996
We present a novel method for joint inversion of receiver functions and surface wave dispersion data, using transdimensional Bayesian formulation. This class algorithm treats the number model parameters (e.g. layers) as an unknown in problem. The dimension space is variable Markov chain Monte Carlo (McMC) scheme used to provide parsimonious solution that fully quantifies degree knowledge one has about seismic structure (i.e constraints on model, resolution, trade‐offs). level data noise...
The fast marching method (FMM) is a grid based numerical scheme for tracking the evolution of monotonically advancing interfaces via finite-difference solution eikonal equation. Like many other techniques, FMM only capable finding first-arriving phase in continuous media; however, it distinguishes itself by combining both unconditional stability and rapid computation, making truly practical velocity fields arbitrary complexity. aim this paper to investigate potential later arriving phases...
Summary A meaningful interpretation of seismic measurements requires a rigorous quantification the uncertainty. In an inverse problem, data noise determines how accurately observations should be fit, and ultimately level detail contained in recovered model. common problem tomography is difficulty quantifying uncertainties, thus required fit. Traditionally, complexity solution model (defined by both number basis functions regularization) defined arbitrarily user prior to inversion with only...
Abstract Relocation of earthquakes recorded by the agency for meteorology, climatology and geophysics (BMKG) in Indonesia inversions global positioning system (GPS) data reveal clear seismic gaps to south island Java. These may be related potential sources future megathrust region. To assess expected inundation hazard, tsunami modeling was conducted based on several scenarios involving large tsunamigenic generated ruptures along segments The worst-case scenario, which two spanning Java...
The accurate prediction of seismic traveltimes is required in many areas seismology, including the processing reflection profiles, earthquake location, and tomography at a variety scales. In this paper, we present two applications recently developed grid-based numerical scheme for tracking evolution monotonically advancing interfaces, via finite-difference solution eikonal equation, known as fast marching method (FMM). Like most other practical techniques, FMM only capable locating...
Traditional grid‐based eikonal schemes for computing traveltimes are usually confined to obtaining first arrivals only. However, later can be numerous and of greater amplitude, making them a potentially valuable resource practical applications such as seismic imaging. The aim this paper is introduce method tracking multivalued wavefronts composed any number reflection refraction branches in layered media. A finite‐difference solver known the fast marching (FMM) used propagate from one...
We present a practical grid-based method in 3-D spherical coordinates for computing multiple phases comprising any number of reflection and transmission branches heterogeneous layered media. The new scheme is based on multistage approach which treats each layer that the wave front enters as separate computational domain. A finite-difference eikonal solver known fast-marching (FMM) reinitialized at interface to track evolving either back into incident or through adjacent layer. Unlike...
Sensitivity analysis with synthetic models is widely used in seismic tomography as a means for assessing the spatial resolution of solutions produced by, most cases, linear or iterative nonlinear inversion schemes. The common type reconstruction test so-called checkerboard which model comprises an alternating pattern higher and lower wave speed (or some other property such attenuation) 2-D 3-D. Although originally introduced application to large inverse problems formal covariance could not...
Since 2004 more than 7000 km of full-crustal reflection profiles have been collected across Australia to give a total 11 000 km, providing valuable new constraints on crustal structure. A further set hitherto unexploited results comes from 150 receiver functions distributed the continent, mostly portable sites. These data sets provide dramatic increase in coverage compared with previous studies, and reveal complex structure Australian continent considerable detail. comprehensive model for...
Research Article| December 01, 2014 On the origin of recent intraplate volcanism in Australia D. Rhodri Davies; Davies 1Research School Earth Sciences, The Australian National University, Canberra, ACT 0200, Search for other works by this author on: GSW Google Scholar Nicholas Rawlinson 2School Geosciences, University Aberdeen, Aberdeen AB24 3UE, Scotland, UK Author and Article Information Publisher: Geological Society America Received: 17 Jul Revision 02 Sep Accepted: 03 First Online: 09...
Abstract We apply a novel 3‐D multiobservable probabilistic tomography method that we have recently developed and benchmarked, to directly image the thermochemical structure of Colorado Plateau surrounding areas by jointly inverting P wave S teleseismic arrival times, Rayleigh dispersion data, Bouguer anomalies, satellite‐derived gravity gradients, geoid height, absolute (local dynamic) elevation, surface heat flow data. The temperature compositional structures recovered our inversion reveal...
ABSTRACT Seismic tomography is the most abundant source of information about internal structure Earth at scales ranging from a few meters to thousands kilometers. It constrains properties active volcanoes, earthquake fault zones, deep reservoirs and storage sites, glaciers ice sheets, or entire globe. contributes outstanding societal problems related natural hazards, resource exploration, underground storage, many more. The recent advances in seismic are being translated nondestructive...
Adaptive stacking provides a powerful and rapid procedure for estimating the residual patterns across network of seismic stations. The approach exploits predictions from some propagation model to achieve an approximate alignment traces, which are then stacked form reference trace. Iterative improvement alignment, by comparison trace with each station trace, leads direct estimate residuals model. Our implementation is fast robust in presence significant noise waveforms different character....
In 2001 and 2002, a temporary array of 72 seismic recorders was deployed across northern Tasmania (SE Australia), with the aim imaging underlying crust upper mantle using three‐dimensional (3‐D) teleseismic tomography. Using recently developed adaptive stacking technique, 6520 relative P wave arrival time residuals have been picked from 101 distant earthquake records spanning 5 month period. A novel iterative nonlinear tomographic procedure based on subspace inversion scheme fast marching...
The maximum earthquake magnitude recorded for subduction zone plate boundaries varies considerably on Earth, with some segments producing giant thrust earthquakes (e.g. Chile, Alaska, Sumatra–Andaman, Japan) and others relatively small Mariana, Scotia). Here we show how such variability might depend various parameters. We present 24 physical parameters that characterize these zones in terms of their geometry, kinematics, geology dynamics. have investigated correlations between the moment...
[1] The island of Tasmania, at the southeast tip Australia, is an ideal natural laboratory for ambient noise tomography, as surrounding oceans provide energetic and relatively even distribution sources. We extract Rayleigh wave dispersion curves from continuous records 104 stations with ∼15 km separation. Unlike most passive experiments this type, which observe very little coherent below a 5 s period, we clearly detect energy periods short 1 s, thanks largely to close proximity oceanic...
During the last 20 years, seismic tomography has frequently been used to provide information on structure of lithosphere beneath Australian continent. New tomographic models are presented using two complementary seismological techniques in order illustrate current state-of-knowledge. Surface wave is ideal method obtain velocity variations across whole The latest use data from over 13 000 source–receiver paths, allowing a higher resolution than previous studies same technique. In Western...
Abstract We present the first continental‐scale seismic model of lithosphere and underlying mantle beneath Southeast Asia obtained from adjoint waveform tomography (often referred to as full‐waveform inversion or FWI), using data filtered at periods 20 150 s. Based on >3,000 hr analyzed gathered ∼13,000 unique source‐receiver pairs, we image isotropic P ‐wave velocity, radially anisotropic S velocity density via an iterative non‐linear that begins a 1‐D reference model. At each iteration,...