Greinar (Vísindafélag Íslendinga) - 01.01.1951, Page 42

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In the beginning of our work, we were especially inte-
rested in getting a line of measurements from Reykjavik,
across the volcanic zone of the Reykjanes peninsula, to
the lowlands of the middle south.
In two working days, we measured at about 30 points
along two lines: one from Reykjavik to Hella, a distance
of 100 km. with two short lines down to the coast at
Stokkseyri—Eyrarbakki, and at Þykkvibær. The other
line was led from Keflavik to Grindavik.
While the stations were selected by us, the measure-
ments were carried out by geophysicist M. Munck gravi-
metrist of the French Expedition with one of the Wes-
tem Geophysical Company gravimeters used by the ex-
pedition in Greenland.
Participants on these trips were also geophysicist Joset,
head of the seismic section of the French expedition, and
his assistant, Lassus Debat.
The measured points were all marked (silver bronze
numbers) and later, during the summer, a precision ni-
vellement of the points between Reykjavik and Selfoss
was carried out by the State Electricity Authority in
Reykjavik.
For other points, the accuracy of the topographic map
of Iceland was thought to be sufficient for our purpose.
For the reduction, measurements of specific gravity,
especially of the rocks of Kambar, were done by Thor-
steinn Thorsteinsson, geologist of the State Electricity
Authority. In accord with his results a density of 2.2 was
adopted for the Bouguer reduction of the points.
In October, the French expedition called in Reykjavik
on their return from Greenland, and now M. Munck
offered to work with us for one week with the same appa-
ratus as before.
During this week we made two main journeys with the
gravimeter, one in the middle south, especially with the
aim of clearing up the gravity conditions in the main area
of thermal activity in Arnessysla. The other extended from
Hella (our easternmost point in the spring) to Kirkju-