Jökull - 01.12.1985, Qupperneq 82

OBSERVATIONS ON A RAPID CHANGE IN
THE THERMAL AND CHEMICAL CHAR-
ACTERISTICS OF SUBGLACIAL DRAIN-
AGE FROM KVERKJÖKULL
A marked change in the thermal and conductivity
characteristics of the main outflow stream from Kverk-
jökull was noticed on llth August. Prior to this date,
the temperature of waters emerging from the glacier
had been in the usual (cold) range typical of proglacial
streams. Measurements from the small outflow stream
to the east of the main stream showed that on 10
August, water temperatures ranged between 0 and
2.5°C and electrical conductivities between 1.0 to 9.0
uS/cm.
Sometime during the afternoon of 11 August, how-
ever, the waters emerging from the cavern experienced
a marked increase in temperature (the precise time of
the change is not known, since the group were examin-
ing the Hveradalur hot spring area on that day).
Measurements from the nearby small stream indicated
that on the same day water temperatures ranged
between 0 to 3.5°C, and electrical conductivities
between 7.0 to 55.0 pS/cm. No apparent change in the
flow regime of the small stream occured, but a notice-
able reduction of flow occured in the main stream.
80 JÖKULL 35. ÁR