Open AccessTravel time analysis of P waves arising from six underground nuclear explosion at Novaya Zemlya
Author(s) -
A. Bottari,
B. Federico
Publication year - 2010
Publication title -
annals of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 60
eISSN - 2037-416X
pISSN - 1593-5213
DOI - 10.4401/ag-4815
Subject(s) - geology , discontinuity (linguistics) , seismology , mantle (geology) , travel time , nuclear explosion , p wave , geophysics , geodesy , physics , nuclear physics , engineering , medicine , mathematical analysis , mathematics , transport engineering , cardiology , atrial fibrillation
SUMMARY. - The analysis of the travel times of the P waves generated by
six underground nuclear explosions in Novaya Zemlya shows notable early
arrivals (oo4sec) at the Fennoscandia stations. These observations, together
with a marked linear dependence of the travel times on the epicentral distance
throughout the interval 8.5 < / J ° < 20.4. were evaluated with the aim of producing
a satisfactory model for the upper mantle of the Baltic zone. In particular,
there appears a considerable mantle zone with almost uniform velocity, or at
least, with not of increasing velocity. This mantle zone is delimited above by a
discontinuity at the 86 km depth (v = 8.45 km/sec), and delimited below by the
«20° discontinuity» (h = 507 km; v = 10.56 km/sec).
The proposed model is amply verified on the basis of the foreseen travel
times compared with the corresponding ones, observed from a fair number of
impulses associated with teleseismic Pn, noticeable as far as 40°, and from phases
reflected and refracted on the discontinuity at 507 km
six underground nuclear explosions in Novaya Zemlya shows notable early
arrivals (oo4sec) at the Fennoscandia stations. These observations, together
with a marked linear dependence of the travel times on the epicentral distance
throughout the interval 8.5 < / J ° < 20.4. were evaluated with the aim of producing
a satisfactory model for the upper mantle of the Baltic zone. In particular,
there appears a considerable mantle zone with almost uniform velocity, or at
least, with not of increasing velocity. This mantle zone is delimited above by a
discontinuity at the 86 km depth (v = 8.45 km/sec), and delimited below by the
«20° discontinuity» (h = 507 km; v = 10.56 km/sec).
The proposed model is amply verified on the basis of the foreseen travel
times compared with the corresponding ones, observed from a fair number of
impulses associated with teleseismic Pn, noticeable as far as 40°, and from phases
reflected and refracted on the discontinuity at 507 km