MuRAT3: A new generation of Multi-ResolutionAttenuation Tomography.

Seismic attenuation has long been an important measurable property of rocks, valuable for eliminating path information from source models and understanding seismic hazards. Over the last 30 years, total attenuation and its two primary components—seismic scattering and absorption—have emerged as state-of-the-art tomographic attributes ranging from planets to the core, to the lithosphere, to rocks. Following the rise of seismic interferometry, stochastic seismic wavefields, once the exclusive domain of the “Heterogeneous Earth” community, have now become vital data for attenuation tomography in tectonic and volcanic settings.

Despite the importance of seismic tomography for Earth Sciences, few open-access codes combine the rigorous treatment of seismic data with novel tomographic tools in a collaborative environment. MuRAT has been a complete solution for seismic attenuation, scattering, and absorption imaging since 2014. It includes modules that provide coherent- and incoherent-wave forward models based on ray theory and radiative transfer equations that seismologists can define using simple SAC files. Fully coded in Matlab^©, it links to community-wide inversion packages and is thought of as a fully cooperative environment based on GitHub. The package has been applied to all crustal scales, from stable continental regions to hundreds-meter- active surveys in volcanic areas.

MuRAT3 (https://github.com/LucaDeSiena/MuRAT) is the first full 3D release of this code. It is specifically designed to integrate state-of-the-art forward-modelling tools from seismology to push current frequency and scale boundaries in seismic attenuation imaging. Here, I will present the last benchmark in attenuation imaging, illustrating how the code works, its success stories, its limitations, and the direction to follow to mitigate them.