Jökull - 01.12.1977, Blaðsíða 64

&Bad Harzburg — 981,180.40 mgal
o \o
í>*
cr> c\
2
o
Sh S
.s i
C3 C
'' «
IT3
s «
S ^
5m b/)
bo R
g ■£
8
O 8
5h s*»
Oh
-S
-S s
5 50
— ~s
. c
bc
s s
or the corresponding gravity value for Hann-
over (no. 21 629 A)
Sllannover = 981,277.30 mgal.
For transformation into the International
Gravity Standardization Net 1971 — IGSN 71 —
(Morelli et al. 1974) a correction of — 14.97 mgal
must be applied (Schleusener et al. 1976).
The gravity of Akureyri has been derived
from numerous gravity connections between
European Stations (especially Hannover) of the
world gravity net and Reykjavík/Akureyri, in
the years 1964 to 1975. In 1976, the gravity dif-
ference between Hannover and Reykjavík/Ak-
ureyri has been controlled, the results are given
in Table 1.
From the observations in 1976, we obtain for
Reykjavík, 21941 A, and Akureyri, 60932:
Sleykjavík 21941 L = 982,278.34 ± 0.03 mgal
+ 1,63
(Schleusener et al. 1974)
E, ,• o,„a, a = 982,279.97 ± 0.03 mgal
o leykjavik 21941 A 0
g.tkureyri 60932 = 982,348.42 ± 0.04 mgal
The r. m. s. e. include the calibration error
(± 0.02 mgal) and the residuals resulting from
the evaluation of the gravity differences in
Table 1 (± 0.02 mgal). The reference station
Hannover is introduced as errorless. We find,
that the indicated gravity changes between
Hannover and Icelancl, in the period 1964/
1975—1976 (increase of gravity of Iceland re-
spectively to the Continent) are not significant.
Instrument readings have been transformecl
to mgal-units using the manufacturers convers-
ion tables. Transformation to the gravity scale
of the IGSN71 was carried out by linear calibra-
tion faclors, derived in 1975 frorn observations
between IGSN71 stations in the respective
gravity range. The calibration factors are
for the connection Hannover—Reykjavík
LCR 79: YT9 = 1.00063 ± 0.00002
I.CR 85: Ygr, = 1.00001 ± 0.00004
62 JÖKULL 27. ÁR