Tahun Terbit

2009

On Earth, oceanic plates subduct beneath a variety of overriding plate (OP) styles, from relatively thin and negatively buoyant oceanic OPs to thick and neutrally/positively buoyant continental OPs. The inclusion of an OP in numerical models of self-consistent sub duction has been shown to reduce the rate that subducting slabs roll back relative to the equivalent single plate models. We use dyn…

The spatial coherence structure of 30 infrasound array detections, with source-to-receiver ranges of 25–6500km, has been measured within the 0.25–1Hz passband. The data were recorded at International Monitoring System (IMS) microbarograph arrays with apertures of between 1 and 4 km. Such array detections are of interest for Comprehensive Nuclear-TestBan Treaty monitoring. The majority of ar…

Monte Carlo solutions to the radiative transfer equations are used to model translational and rotational motion seismogram envelopes in random elastic media with deterministic background structure assuming multiple anisotropic scattering. Observation and modelling of the three additional components of rotational motions can provide independent information about wave propagation in the Earth’s…

Tahun Terbit

2009

Global parametric sensitivity analysis of a complete seismic risk scenario is performed by means of the response surface method based on sparse Chebyshev polynomial expansion. Hazard model, described via a mixed technique combining Green’s function and stochastic methods, is used to simulate free-field seismic records. Vulnerability model, based on the period-dependent damage spectra, i…

Tahun Terbit

2009

How fast should animals move when trying to survive? Although many studies have examined how fast animals can move, the fastest speed is not always best. For example, an individual escaping from a predator must run fast enough to escape, but not so fast that it slips and falls. To explore this idea, we developed a simple mathematical model that predicts the optimal speed for an individual runni…

Electrodes installed on active landslides and vulnerable earthworks to monitor changes in resistivity associated with moisture dynamics can be subject to movement. This affects the geoelectrical data and leads to errors in the resulting electrical resistivity tomography (ERT) images. This paper demonstrates the selection of appropriate ERT measurements to provide sensitivity to electrode displa…

Reaching sub-salt hydrocarbon targets in the deeper part of the Gulf of Mexico requires drilling through a salt canopy. The suture zones in the salt canopy are potential drilling hazards due to anomalous pressure behaviour of entrapped sediments. The P´olyavector field of coalescing salt sheets inside the canopy is used to explain suture formation and distinguish between upright and incl…