Fróðskaparrit - 01.01.1971, Page 1

Additional Gravity Observations
in The Faroe Islands
By Svend Saxov.*)
In a recent paper (Saxov, 1969) a detailed report is given
concerning gravimetric measurements including the definition
o-f the basic values of che main gravity stations in Tórshavn.
Three anomaly maps giving Free Air anomalies, Bouguer
anomalies, and Bouguer anomalies including terrain effect,
were also presented. By inspection of the maps it was found
worthwhile to make a denser net of gravity in different areas,
first of all in Mykines-Vágar, secondly in the southern part of
Streymoy, and thirdly in Sandoy. In conneotion with other
geophysical work a visit was paid to the islands in June—
July, 1970. Worden Master gravimeter No. 779 was employed
and in Fig. 1 the drift curves for the auxiMary stations Tórs-
havn 6 and Sørvágur A are given.
The gravimeter shows a negative drift rate for the first day
(which wiais exactly the same in the 1967 mieasunements), how-
ever, for the remaining time of the period the drift is almost
linear and of the order of 0.01 mGal per hour. The corre-
sponding figure in 1967 was 0.02 mGal per hour. In this con-
nection attention must be drawn to the faot that the gravimeter
was sent for repair in 1968 and a detailed study of the drift
values for the years 1967 to 1970 has revealed an hourly drift
value of about 0.02 mGal in 1967 and 1968, and about 0.01
mGal for 1969 and 1970 (Lind and Saxov, in preparation).
*) Laiboratory of Applied Geophysics, Aarhus University.
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