We describe an R package cts for fitting a modified form of continuous time autoregressive model, which can be particularly useful with unequally sampled time series. The estimation is based on the application of the Kalman filter. The paper provides the methods and algorithms implemented in the package, including parameter estimation, spectral analysis, forecasting, model checking and Kalman s...

An interactive surface editing framework that is well suited to the needs of geophysical modelers and interpreters is described. This surface editing framework allows a non-expert user to quickly create complicated surfaces by combining two simple concepts: deformation and cutting. Deformations change the geometry of a surface and allow a user to model continuous geologic horizons. Cutting chan...

Studies over the past decade have reported power-law distributions for the areas of terrestrial lakes and Arctic melt ponds, as well as fractal relationships between their areas and coastlines. Here we report similar fractal structure of ponds in a tidal flat, thereby extending the spatial and temporal scales on which such phenomena have been observed in geophysical systems. Images taken during...

Many geophysical flow or wave propagation problems can be modeled with two-dimensional depth-averaged equations, of which the shallow water equations are the simplest example. We describe the GeoClaw software that has been designed to solve problems of this nature, consisting of open source Fortran programs together with Python tools for the user interface and flow visualization. This software ...

Critical concepts from three different fields, elasticity, plasmonics and metamaterials, are brought together to design a metasurface at the geophysical scale, the resonant metawedge, to control seismic Rayleigh waves. Made of spatially graded vertical subwavelength resonators on an elastic substrate, the metawedge can either mode convert incident surface Rayleigh waves into bulk elastic shear ...

[1] We assess the accuracy of horizontal velocity estimates from the Basin and Range Geodetic Network (BARGEN), a continuous GPS network that has been in operation since 1996. To make this quantitative assessment, we use a procedure that we term the ‘‘whole-error’’ method. In this method, the measure of the velocity errors is the root-mean-square (RMS) residual velocity relative to a simple geo...

In addition to being observable in laboratory experiments, internal wave beams are reported in geophysical settings, which are characterized by nonuniform density stratifications. Here, we perform a combined theoretical and experimental study of the propagation of internal wave beams in nonuniform density stratifications. Transmission and reflection coefficients, which can differ greatly for di...

The present work envisages the possible geometry of a contaminated plume of groundwater near hospital facilities by combining GIS (Geographic Information System) and geophysical methods. The rock underlying the soil and thin sedimentary cover of the study area is moderately fractured quartzite, which makes aquifers vulnerable to pollution. The GIS methodology is used to calculate the area that ...

Busstop, a spatio-temporal GIS prototype for geophysical studies, is presented. It includes a metadata representation system, a visualisation subsystem, and a spatio-temporal extension of a classical map algebra. It also takes an active approach to integration with existing non-GIS data handling and analysis programs. Busstop has been used for minor geophysical case studies with some success, b...