KIT | KIT-Bibliothek | Impressum | Datenschutz

Velocity Structure of the Subducted Yakutat Terrane, Alaska: Insights From Guided Waves

Coulson, S.; Garth, T.; Rietbrock, Andreas 1
1 Geophysikalisches Institut (GPI), Karlsruher Institut für Technologie (KIT)


Dispersed $\textit{P}$ wave arrivals from intermediate‐depth earthquakes in the Alaskan subduction zone provide insight into the low‐velocity structure of the subducting oceanic crust. $\textit{P}$ wave arrivals from 41 earthquakes in the eastern section of the arc show significant guided wave dispersion, with high‐frequency (>1 Hz) energy delayed by up to 2–3 s. We simulate this dispersion using a 2‐D finite difference waveform propagation model, systematically varying both $\textit{P}$ wave velocity and low‐velocity layer thickness parameters to find the lowest misfit between the observed and synthetic waveforms. We infer a 6 to 10 km thick low‐velocity layer with a $\textit{P}$ wave velocity contrast of 7–15% with the overriding mantle, velocities which cannot be entirely accounted for by metamorphosed mid‐ocean ridge basalt compositions. We postulate that this structure is the remnant of the subducted Yakutat terrane, significantly thinned at depth by metamorphism or delamination of material during subduction.

Verlagsausgabe §
DOI: 10.5445/IR/1000091760
Veröffentlicht am 27.02.2019
DOI: 10.1002/2017GL076583
Zitationen: 3
Web of Science
Zitationen: 3
Zitationen: 3
Cover der Publikation
Zugehörige Institution(en) am KIT Geophysikalisches Institut (GPI)
KIT-Zentrum Klima und Umwelt (ZKU)
Publikationstyp Zeitschriftenaufsatz
Publikationsmonat/-jahr 04.2018
Sprache Englisch
Identifikator ISSN: 0094-8276
KITopen-ID: 1000091760
Erschienen in Geophysical research letters
Verlag John Wiley and Sons
Band 45
Heft 8
Seiten 3420–3428
Vorab online veröffentlicht am 16.04.2018
Nachgewiesen in Dimensions
Web of Science
KIT – Die Forschungsuniversität in der Helmholtz-Gemeinschaft
KITopen Landing Page