S U M M A R Y The International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) continuously records acoustic waves in the 0.01–10Hz frequency band, known as infrasound. These waves propagate through the layered structure of the atmosphere. Coherent infrasonic waves are produced by a variety of anthropogenic and natural sources and their propagation is controlled by ...

The magnetostatic surface waves (MSSW) propagation in a layered structure composed of ferrite film covered by air and on top of metamaterial (MTM) placed on metal is discussed. Dispersion equations which relate the parameters of different layers are derived and used to analyse propagation of MSSW. It is found that the MSSW excitation band depends on the thickness of the MTM layer and ferrite la...

Exploiting the fine structure of strongly scattered surface waves could provide a wealth of new information in seismology, ultrasonics, acoustics and other fields that study wave propagation in highly heterogeneous media. Toward this end, we have made laboratory measurements of ultrasonic waves propagating in disordered media. Spectral-element simulations of these models provide us with a power...

Determining the propagation direction of waves in a wavefield is important in several seismic imaging techniques and applications. This can be achieved using the Poynting vector method, but it performs poorly when waves overlap, returning incorrect wave amplitude and direction. An alternative, the local slowness method, is capable of separating overlapping waves, but suffers from low angular re...

Accurate simulation of Rayleigh waves is of critical importance in a variety of geophysical applications, such as exploration geophysics, geotechnical characterization, and earthquake-related damage assessment. Based on recent works on staggered discontinuous Galerkin methods, we propose for the simulation of Rayleigh waves a new method which enjoys energy conservation and extremely low grid di...

Plans call for five T-phase stations to be installed as part of hydroacoustic segment of the International Monitoring System (IMS), for use in detecting nuclear explosions in the oceans. The ability to detect T-phase signals at the seismic T-phase stations relies on an understanding of the transition from ocean-borne acoustic energy to seismic energy. Observations of the seismic T-phase indicat...

The responses of the Ross Ice Shelf (RIS) to the 16 September 2015 8.3 (Mw) Chilean earthquake tsunami (>75 s period) and to oceanic infragravity (IG) waves (50–300 s period) were recorded by a broadband seismic array deployed on the RIS from November 2014 to November 2016. Here we show that tsunami and IG-generated signals within the RIS propagate at gravity wave speeds ( 70 m/s) as water-ice ...

Vegetation is an indispensable feature of most outdoor wireless channel environments. The interaction between radio waves and vegetation has been researched for several decades. Because of the complex structure of the foliage, composed of randomly oriented trunks, branches, twigs and leaves, the involved physical process in the propagation of the radiowave through vegetation is complex. Accurat...

SPECFEM3D_GLOBE is a spectral-element application enabling the simulation of global seismic wave propagation in 3D anelastic, anisotropic, rotating and self-gravitating Earth models at unprecedented resolution. A fundamental challenge in global seismology is to model the propagation of waves with periods between 1 and 2 seconds, the highest frequency signals that can propagate clear across the ...