Jökull - 01.01.2015, Blaðsíða 102

Snævarr Guðmundsson og fl.
8. mynd. Landsat 8 gervitunglamyndir sýna að fremsti hluti Hoffellsjökuls hefur verið að brotna upp síðustu ár.
Rauð lína er dregin um jökuljaðarinn af LiDAR hæðalíkani frá árinu 2010 til vinstri (Jóhannesson og fl., 2011).
Myndir í miðju og til hægri sýna breytingar haustið 2015. Rauða örin bendir á hvar jökullinn hefur brotnað upp.
– A Landsat 8 image of the calving snout of Hoffellsjökul (September 25th and November 12th, 2015). The red
line shows the margin in 2010 based on a LiDAR image.
GLACIER CHANGES BY EASTERN
HOFFELLSJÖKULL IN 2015
In the autumn 2015 notable land erosion and glacier
changes occurred at the eastern lateral margin of Hof-
fellsjökull, an outlet glacier of Vatnajökull ice cap,
Southeast Iceland. The cause points to a period of
heavy rainfall in late October/early November. A con-
sequential flood in the primary rivers of the Gjávatn
lagoon drainage basin excavated its paths near the
small lagoons of Múlavatn and Gjávatn. Concurrently
the latter disappeared and a question arises whether
outburst (jökulhlaups) might have been triggered by
the sudden floods of rain water into the lagoons. No
firm indication of a jökulhlaup on the lowland was
however reported, that might be distinguished from
water accumulation resulting from the simultaneous
precipitation period. Satellite images also presents ice
break-up in the terminal lagoon of Hoffellsjökull at
same time but it might be a result of other causes.
REFERENCES
Jónsson, E. 2004. Í veröld jökla, sanda og vatna. Í Björns-
son, H., E. Jónsson og S. Runólfsson (ritstj.), Jökla-
veröld 11–86, Skrudda, Reykjavík.
Björnsson, H. 2009. Jöklar á Íslandi. Bókaútgáfan Opna.
Reykjavík.
Björnsson, H. og F. Pálsson 2004. Jöklar í Hornafirði. Í
Björnsson, H., E. Jónsson og S. Runólfsson (ritstj.),
Jöklaveröld 125–164, Skrudda, Reykjavík.
Jóhannesson, T., H. Björnsson, F. Pálsson, O. Sigurðsson
og Þ. Þorsteinsson 2011. LiDAR mapping of the
Snæfellsjökull ice cap, western Iceland. Jökull 61,
19–32.
102 JÖKULL No. 65, 2015