TY - JOUR
T1 - The origin of secondary microseism Love waves
AU - Gualtieri, Lucia
AU - Bachmann, Etienne
AU - Simons, Frederik J.
AU - Tromp, Jeroen
N1 - Publisher Copyright:
© 2020 National Academy of Sciences. All rights reserved.
PY - 2020/11/24
Y1 - 2020/11/24
N2 - 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.
AB - 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.
KW - Computational seismology
KW - Love waves
KW - Ocean-solid Earth interaction
KW - Seismic ambient noise
UR - http://www.scopus.com/inward/record.url?scp=85096883134&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85096883134&partnerID=8YFLogxK
U2 - 10.1073/pnas.2013806117
DO - 10.1073/pnas.2013806117
M3 - Article
C2 - 33168742
AN - SCOPUS:85096883134
SN - 0027-8424
VL - 117
SP - 29504
EP - 29511
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 47
ER -