Fróðskaparrit - 01.01.1976, Side 23

Seismic Refraction Measurements around the Faeroe Islands 31
APPENDIX
The appendix contains three tables:
First table gives positions etc. for shots that were observed on the
Faeroe Islands together with the positions of the Faeroe stations and a
few ship stations. The positions of the Faeroe stations Fl. .F5 are given as
»mean values« with an error about 100 m. The positions of the drifting
ship stations are rough mean values and they have not been used for
calculation of the distances; otherwise the positions at sea can be expected
to have errors less than 1 km in most cases (see Smith 1974 and Smith &
Bott 1975).
Second table contains travel times for first arrivals observed at thc
Faeroese stations. Each observation is given as 3 numbers which are
(starting from above): distance (km), travel time (s) and azimuth (degrees)
of the shot. The arrivals have been classified according to the letter which
succeeds the travel time; the classification is highly subjective but it gives
an indication of the possibility that late arrivals have been picked etc.
Third table contains some intercept times and apparent velocities. The
travel times were corrected for water depth and shot depth in the
following manner: by use of the formula for time terms the shot was
moved to the surface of the sea, and the sea water of velocity 1.5 km/s
was substituted by a fictitious material of velocity 4.5 km/s; the assumed
refractor velocity is given as v . The estimated standard deviation of the
observed travel times is given as »s. d.« and the number of observations is
given as N.