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pure and applied geophysics

, Volume 109, Issue 1, pp 1623–1637 | Cite as

Slowness and azimuth at the Uppsala array

Part 2: Structural Studies
  • R. James Brown
Article

Summary

From the Uppsala tripartite array,dT/dΔ and azimuth are determined for 181P and 24PKP phases. Near-surface lateral inhomogeneity is found from azimuth deviations to be small, equivalent to <3° dip on the Moho. Slowness, corrected for this structure, is divided into two azimuthal groups: from an ‘Asian’ group are indicated higherP velocities in the lower mantle and a lowerP-velocity gradient in the uppermost mantle, probably a low-velocity layer; the remainingdT/dΔ, from N, W and S azimuths, indicate a more normal velocity profile. There is evidence for a narrow zone of rapid transition between these two structural groups along the Arctic-Soviet continental margin. The few core phases indicate aBolt, rather than aJeffreys, type of core model.

Keywords

Azimuth Lower Mantle Apparent Velocity Uppermost Mantle Mantle Structure 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Birkhäuser-Verlag 1973

Authors and Affiliations

  • R. James Brown
    • 1
  1. 1.Seismological InstituteUppsala 1Sweden

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