Global Surface Wave Tomography Using Seismic Hum | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

Twitter

Aller au compte twitter

  Global Surface Wave Tomography Using Seismic Hum

Type de publication:

Journal Article

Source:

Science, Volume 326, Ticket 5949, p.112-112 (2009)

ISBN:

0036-8075

Numéro d'accès:

ISI:000270355600045

URL:

http://www.sciencemag.org/content/326/5949/112

Mots-clés:

UMR 7154 ; Sismologie

Résumé:

The development of global surface wave tomography using earthquakes has been crucial to exploration of the dynamic status of Earth’s deep. It is naturally believed that only large earthquakes can generate long-period seismic waves that penetrate deep enough into Earth for such exploration. The discovery of seismic hum, Earth’s background free oscillations, which are randomly generated by oceanic and/or atmospheric disturbances, now provides an alternative approach. We present results of global upper-mantle seismic tomography using seismic hum and without referring to earthquakes. At periods of 100 to 400 seconds, the phase-velocity anomalies of Rayleigh waves are measured by modeling the observed cross-correlation functions between every pair of stations from among 54 globally distributed seismic stations. The anomalies are then inverted to obtain the three-dimensional S-wave velocity structure in the upper mantle. Our technique provides a new means for exploring the three-dimensional structure of the interior of terrestrial planets with an atmosphere and/or oceans, particularly Mars.

Notes:

Nishida, Kiwamu Montagner, Jean-Paul Kawakatsu, Hitoshi