For decades, the growth of freely available seismic data has led to key discoveries about earthquakes and Earth’s properties. From crust to inner core, seismologists have sharpened the focus on key structures that enable inference on Earth’s internal dynamics, composition, and evolution. This presentation will address the continued increase in availability of data, the challenges to find, collect, and store them, and our efforts to collect every relevant seismogram on Earth, for improved Earth imaging.

Why care? While seismic imaging reveals Earth interior phenomena at the best possible resolution, most structures lack enough constraints to definitively understand their nature and origin. This includes massive lower mantle continental-sized Large Low Velocity Provinces (LLVPs), which are situated away from subduction (places where tectonic plates fall into the interior) and generally underly hot spot volcanoes. Sometimes over 1000 km thick, seismic evidence suggests LLVPs are compositionally different from the surrounding mantle. But what are they? And how well are they really imaged? At smaller scales Ultra-Low Velocity Zones (ULVZs) are thin (10’s of km) structures right at the CMB, probably partially molten and possibly also compositionally distinct. How do these structures relate to Earth’s formation, evolution, and mantle dynamics? What are they made of? How well are we seeing them? These questions and others require seismic analyses with the best and most abundant data possible. They require multidisciplinary approaches with mineral physicists, geodynamicists, geochemists, tectonicists, and others.

But how can we sharpen the focus? In this presentation I will highlight our inherent spatial and temporal biases in seismic imaging of these and other structures, where uneven sampling of Earth figures prominently in the challenges. To mitigate these, I’ll present our ongoing effort to bring big data to the table, with a focus on using every available seismogram, combined with measurements of unutilized seismic reverberations that sometimes echo and reflect their way around the entire planet. I’ll briefly mention the potential for machine learning and AI to uncover subtle waveform phenomena. Earth’s resonances and reverberations hold profound potential for advancing our understanding of planetary formation and evolution.