The seismoacoustic wavefield: A new paradigm in studying geophysical phenomena

The field of seismoacoustics is emerging as an important discipline in its own right, owing to the value of colocated seismic and infrasound arrays that sample elastic energy propagating in both the solid Earth and the atmosphere. The fusion of seismic and infrasonic data provides unique constraints for studying a broad range of topics including the source physics of natural and man-made events, interaction of mechanical waves in Earth's crust and atmosphere, source location and characterization, and inversion of atmospheric and shallow subsurface properties. This review article traces the seismoacoustic wavefield from source to receiver. Beginning at the source, we review the latest insights into the physics of natural and anthropogenic sources that have arisen from the analysis of seismoacoustic data. Next, a comparative review of 3-D models of the atmosphere and solid Earth and the latest algorithms for modeling the propagation of mechanical waves through these media provides the framework for a discussion of the seismoacoustic path. The optimal measurement of seismic and acoustic waves, including a discussion of instrumentation, as well as of array configurations and regional networks, is then outlined. Finally, we focus on broad research applications where the analysis of seismoacoustic data is starting to yield important new results, such as in the field of nuclear explosion monitoring. This review is intended to provide a primer on the field of seismoacoustics for seismologists or acousticians, while also providing a more general review of what constraints seismoacoustics can uniquely provide for understanding geophysical phenomena.