Body Wave Traveltimes and A Spherically Symmetric P- and S-Wave Velocity Model

P and S Wave Velocity Determination

There are three general methods that can be used to determine formation velocities from full waveform logs. The first approach is to make use of the data from the entire waveform. This type of velocity analysis is performed either in the frequency domain (I.e. f-k analysis or the two station method) or in the time domain (I.e. velocity spectral analysis). The second approach is to identify the ...

A P wave velocity model of Earth ' s core

Present Earth core models derived from the retrieval of global Earth structure are based on absolute travel times, mostly from the International Seismological Centre (ISC), and/or free-oscillation eigenfrequencies. Many core phase data are left out of these constructions, e.g., PKP differential travel times, amplitude ratios, and waveforms. This study is an attempt to utilize this additional in...

Stability of Spherically Symmetric Wave Maps

We study Wave Maps from R2+1 to the hyperbolic plane H2 with smooth compactly supported initial data which are close to smooth spherically symmetric initial data with respect to some H1+μ, μ > 0. We show that such Wave Maps don’t develop singularities in finite time and stay close to the Wave Map extending the spherically symmetric data(whose existence is ensured by a theorem of Christodoulou-T...

Spherically symmetric inhomogeneous bianisotropic media: Wave propagation and light scattering

Self-similar spherically symmetric wave maps coupled to gravity

We investigate spherically symmetric continuously self-similar (CSS) solutions in the SU(2) sigma model coupled to gravity. Using mixed numerical and analytical methods, we provide evidence for the existence (for small coupling) of a countable family of regular CSS solutions. This fact is argued to have important implications for the ongoing studies of black hole formation in the model.