Rit (Vísindafélag Íslendinga) - 01.06.1967, Page 98

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seems to be some SW-NE trend in the magnetic pattern but
the distance between profiles is too great to allow the trac-
ing of the anomalies from one profile to the next with any
certainty except in the area SW of Reykjanes where the
strong central anomaly can be traced along the Reykjanes
Ridge. About 100 km from the coast this anomaly becomes
very weak. This may coincide with a change in direction
or lateral displacement of the ridge. What seems to be the
continuation of the central anomaly reaches the shore in the
volcanic belt at the SW tip of the Reykjanes Peninsula.
Fig. 1 shows some preliminary values for total magnetic
field anomalies along the 21 profiles. This rough map was
drawn by Dr. Serson before the actual computation started
to give a qualitative picture of the magnetic anomalies over
Iceland and may contain significant errors in position, am-
plitude and the regional field assumed. It is published here
with the kind permission of Dr. Serson while a detailed re-
port on this survey may be expected in the near future.
In the lower left hand comer of the map 8 profiles from
the publication of Heirtzler et al. (1966) have been added
for comparison. Serson’s map is a conical projection and the
map of Heirtzler et al. which originally was a Mercator’s
projection has been transformed photographically to conical
projection. The scale for magnetic intensity is about three
times smaller for the 8 profiles of Heirtzler et al. than on
Serson’s map. The larger values of magnetic anomalies along
Heirtzler’s profiles are due to a lower flight level. All profiles
have been corrected for global variation of the geomagnetic
field. The corresponding anomalies on the map of Heirtzler
et. al. are connected by dotted lines to show their linearity
and symmetry.
In 1964, shortly after the beginning of the Surtsey erup-
tion, the U.S. Oceanographic Office made an aeromagnetic
survey of the surrounding area of the volcano out to a di-
stance of 30—80 km. The survey was flown both at 600 and
1800 m altitude with track spacing of 1—4 km. No magnetic