Summary
Relative arrival times at the Uppsala tripartite seismograph array station are used to determinedT/dΔ and ray azimuth for some 200 compressional phases. Corrections, although very small, are applied for station elevations, telephonic transmission delays and array geometry. The computeddT/dΔ and ray azimuths are further corrected to remove the effect of lateral heterogeneity immediately beneath the array station. Errors indT/dΔ and azimuth are considered from a partly theoretical, partly empirical approach. They amount to about 0.18 sec/deg indT/dΔ and 1.6° in azimuth. Standard deviations in epicentral locations are empirically determined to be about 2° due to slowness error and less than 1.5° due to azimutherror; or about 250 km overall. These figures compare favourably with other, more costly, arrays.
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Brown, R.J. Slowness and azimuth at the Uppsala array. PAGEOPH 105, 759–769 (1973). https://doi.org/10.1007/BF00875825
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DOI: https://doi.org/10.1007/BF00875825