Figure from the paper.
Effect of source and source-receiver geometry selection on the Earth’s inter-source correlogram using earthquakes Mw≥6.5 between 2000 and 2020. Left panel (a) reveals correlogram using all earthquakes, whereas right panel (b) employs only those earthquakes with source mechanisms and receiver geometries for which constructive interference is expected. Phase names of coherent signals are labeled in white. Credit: Wang and Tkalčić [2023], Figure 3(a,b)
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: Journal of Geophysical Research: Solid Earth

Inter-receiver cross-correlograms formed from seismograms at different receivers recording a common, diffuse wavefield are now routinely assembled to approximate the Earth’s Green’s function and extract important information on subsurface structure. Diffuse wavefields can include the ambient noise field in studies of shallow Earth structure or the earthquake late coda (about 3 to 9 hours after an event’s origin time) in deeper investigations.

In principle, inter-source cross-correlograms formed from seismograms recording the late coda of different earthquakes at a common receiver should provide comparable information on deep Earth structure but efforts to-date have proven largely unsuccessful. Wang and Tkalčić [2023] demonstrate that careful selection of earthquakes based on source radiation pattern and source-receiver geometry is required to ensure constructive interference leading to emergence of physical arrivals. Since inter-source correlograms can be formed using a single receiver, the authors’ approach affords new opportunities for probing the interiors of both the Earth and other planetary bodies.

Citation: Wang, S., & Tkalčić, H. (2023). On the formation of global inter-source correlations and applications to constrain the interiors of the Earth and other terrestrial planets. Journal of Geophysical Research: Solid Earth, 128, e2023JB027236.

—Michael Bostock, Editor, JGR: Solid Earth

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