Matches in SemOpenAlex for { <https://semopenalex.org/work/W2776331473> ?p ?o ?g. }
- W2776331473 endingPage "31" @default.
- W2776331473 startingPage "19" @default.
- W2776331473 abstract "We measured more than three thousand differential travel-times and amplitude ratios of PKPBC, PKPBC-diff, PKPAB and PKPDF phases in the epicentral distance range [149°-171°], from high quality records of globally distributed broadband stations. In particular, this is the largest collection of differential measurements of PKPBC-diff compared to PKPDF, extending by ∼10° the epicentral distance range in which the diffracted PKPBC phase has been observed globally. We used forward modelling of waveforms using the Direct Solution Method combined with a grid-search approach to explore attenuation and P-velocity structure in the vicinity of the inner core boundary (ICB) that can explain our observations. We find that, in order to simultaneously explain differential travel times and amplitude ratios of PKPBC, PKPBC-diff with respect to PKPDF out to distances of 165°, while fitting PKPAB/PKPDF within measurement errors, it is necessary to introduce a ∼450km zone of reduced bulk quality factor (Qκ∼600) at the base of the outer core, while Qκ is close to 200 in a layer ∼150km thick at the top of the inner core. Concurrently, the P-velocity in the last 100 km of the outer-core is on average about 0.5% slower than in the reference model AK135, while it is about 0.5% faster in the top 150 km of the inner-core, resulting in a P-velocity jump at the inner core boundary slightly higher than in model AK135. However, this model underpredicts PKPBC-diff/PKPDF amplitude ratios at distances larger than 165°. Reducing Qκ even further in the last 100 km of the outer-core (down to Qκ = 50) provides a good fit to these data but it is not compatible with measurements of PKiKP/PKPDF amplitude ratios in the distance range 120–140°. We also considered a previously assembled global collection of “M phase” data. The M phase is a large energy in the coda of the PKPBC and PKPBC-diff that is not predicted by current 1D reference seismic models, but most likely originates at the base of the outer-core. Our preferred model predicts the presence of an M phase, but significantly underestimates its amplitude. In order to explain the large amplitude of the M-phase and that of PKPBC-diff at distances larger than 165° without significantly affecting PKiKP amplitudes, it seems necessary to invoke a process that would produce strong scattering for diffracted phases in the immediate vicinity of the ICB, on the outer core side. Clusters of solid particles suspended in the fluid core or topography of the ICB are possible candidates that should be explored further." @default.
- W2776331473 created "2018-01-05" @default.
- W2776331473 creator A5006414615 @default.
- W2776331473 creator A5018901527 @default.
- W2776331473 creator A5089907342 @default.
- W2776331473 date "2018-02-01" @default.
- W2776331473 modified "2023-10-17" @default.
- W2776331473 title "Observation of core sensitive phases: Constraints on the velocity and attenuation profile in the vicinity of the inner-core boundary" @default.
- W2776331473 cites W1497301599 @default.
- W2776331473 cites W1560271163 @default.
- W2776331473 cites W1564878202 @default.
- W2776331473 cites W1632007184 @default.
- W2776331473 cites W1913469372 @default.
- W2776331473 cites W1963655915 @default.
- W2776331473 cites W1967887959 @default.
- W2776331473 cites W1968605185 @default.
- W2776331473 cites W1980711001 @default.
- W2776331473 cites W1981185706 @default.
- W2776331473 cites W1986442555 @default.
- W2776331473 cites W1986684569 @default.
- W2776331473 cites W1987153981 @default.
- W2776331473 cites W1993880938 @default.
- W2776331473 cites W1994097125 @default.
- W2776331473 cites W1999986729 @default.
- W2776331473 cites W2002825617 @default.
- W2776331473 cites W2004568421 @default.
- W2776331473 cites W2014121409 @default.
- W2776331473 cites W2016070709 @default.
- W2776331473 cites W2017972421 @default.
- W2776331473 cites W2024053736 @default.
- W2776331473 cites W2026384960 @default.
- W2776331473 cites W2036632590 @default.
- W2776331473 cites W2037887709 @default.
- W2776331473 cites W2038626316 @default.
- W2776331473 cites W2045320355 @default.
- W2776331473 cites W2048422278 @default.
- W2776331473 cites W2054731083 @default.
- W2776331473 cites W2055765557 @default.
- W2776331473 cites W2056444630 @default.
- W2776331473 cites W2057115708 @default.
- W2776331473 cites W2057371440 @default.
- W2776331473 cites W2062221814 @default.
- W2776331473 cites W2074197835 @default.
- W2776331473 cites W2076156308 @default.
- W2776331473 cites W2077710319 @default.
- W2776331473 cites W2083222974 @default.
- W2776331473 cites W2084012486 @default.
- W2776331473 cites W2095076131 @default.
- W2776331473 cites W2099061126 @default.
- W2776331473 cites W2099739900 @default.
- W2776331473 cites W2102993538 @default.
- W2776331473 cites W2103113534 @default.
- W2776331473 cites W2109180755 @default.
- W2776331473 cites W2114492757 @default.
- W2776331473 cites W2122449740 @default.
- W2776331473 cites W2124760520 @default.
- W2776331473 cites W2129946449 @default.
- W2776331473 cites W2130623304 @default.
- W2776331473 cites W2131994049 @default.
- W2776331473 cites W2132538856 @default.
- W2776331473 cites W2135159355 @default.
- W2776331473 cites W2136986672 @default.
- W2776331473 cites W2144192095 @default.
- W2776331473 cites W2145657680 @default.
- W2776331473 cites W2147188706 @default.
- W2776331473 cites W2163277767 @default.
- W2776331473 cites W2164970633 @default.
- W2776331473 cites W2167248243 @default.
- W2776331473 cites W2169599618 @default.
- W2776331473 cites W2169683220 @default.
- W2776331473 cites W2170345619 @default.
- W2776331473 cites W2175964799 @default.
- W2776331473 cites W2241265827 @default.
- W2776331473 cites W2296973377 @default.
- W2776331473 cites W2315510692 @default.
- W2776331473 cites W641438867 @default.
- W2776331473 cites W2061601556 @default.
- W2776331473 cites W2114872785 @default.
- W2776331473 doi "https://doi.org/10.1016/j.pepi.2017.12.008" @default.
- W2776331473 hasPublicationYear "2018" @default.
- W2776331473 type Work @default.
- W2776331473 sameAs 2776331473 @default.
- W2776331473 citedByCount "5" @default.
- W2776331473 countsByYear W27763314732018 @default.
- W2776331473 countsByYear W27763314732019 @default.
- W2776331473 countsByYear W27763314732023 @default.
- W2776331473 crossrefType "journal-article" @default.
- W2776331473 hasAuthorship W2776331473A5006414615 @default.
- W2776331473 hasAuthorship W2776331473A5018901527 @default.
- W2776331473 hasAuthorship W2776331473A5089907342 @default.
- W2776331473 hasConcept C120665830 @default.
- W2776331473 hasConcept C121332964 @default.
- W2776331473 hasConcept C127313418 @default.
- W2776331473 hasConcept C13280743 @default.
- W2776331473 hasConcept C134306372 @default.
- W2776331473 hasConcept C159985019 @default.
- W2776331473 hasConcept C165801399 @default.
- W2776331473 hasConcept C180205008 @default.