The origin of secondary microseism Love waves

Lucia Gualtieri, Etienne Bachmann, Frederik J. Simons, Jeroen Tromp

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

The interaction of ocean surface waves produces pressure fluctuations at the seafloor capable of generating seismic waves in the solid Earth. The accepted mechanism satisfactorily explains secondary microseisms of the Rayleigh type, but it does not justify the presence of transversely polarized Love waves, nevertheless widely observed. An explanation for two-thirds of the worldwide ambient wave field has been wanting for over a century. Using numerical simulations of global-scale seismic wave propagation at unprecedented high frequency, here we explain the origin of secondary microseism Love waves. A small fraction of those is generated by boundary force-splitting at bathymetric inclines, but the majority is generated by the interaction of the seismic wave field with three-dimensional heterogeneity within the Earth.We present evidence for an ergodic model that explains observed seismic wave partitioning, a requirement for full-wave field ambient-noise tomography to account for realistic source distributions.

Original languageEnglish (US)
Pages (from-to)29504-29511
Number of pages8
JournalProceedings of the National Academy of Sciences of the United States of America
Volume117
Issue number47
DOIs
StatePublished - Nov 24 2020

All Science Journal Classification (ASJC) codes

  • General

Keywords

  • Computational seismology
  • Love waves
  • Ocean-solid Earth interaction
  • Seismic ambient noise

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