Jökull - 01.01.2019, Blaðsíða 37

Einarsson
Figure 1. Index map of the volcanic zones of Iceland, showing the central volcanoes and their associated fissure
swarms (after Einarsson and Sæmundsson, 1987, as modified by Hjartardóttir et al. 2016a,b). K and H indicate
the location of the Katla and Hekla, respectively. Grímsvötn and Bárðarbunga are shown with G and B, Laki and
Krafla with La and Kr, Öræfajökull and Askja with Ö and A. WVZ, EVZ, NVZ are the Western, Eastern, and
Northern Volcanic Zones, RPOR is the Reykjanes Peninsula Oblique Rift, and SISZ is the transform South Ice-
land Seismic Zone. The Digital Elevation Model used is from the TanDEM-X of the German Aerospace Center.
Rivers and lakes are from the IS50 database of the National Land Survey of Iceland. – Yfirlitskort af eldstöðv-
arkerfum á Íslandi, megineldstöðvum og sprungusveimum tengdum þeim (Sæmundsson og Einarsson, 1987,
Hjartardóttir o. fl., 2016a,b). Helstu eldstöðvar eru sýndar: Katla (K), Hekla (H) Grímsvötn (G), Bárðarbunga
(B), Laki (La), Krafla (Kr), Öræfajökull (Ö), Askja (A). Einnig eru merktar helstu greinar flekaskilanna: Vestara
gosbeltið (WVZ), Eystra gosbeltið (EVZ), Norðurgosbeltið (NVZ), Reykjanesskábeltið (RPOR) og Skjálftabelti
Suðurlands (SISZ). Landslag er samkvæmt hæðarlíkaninu TanDEM-X frá Þýsku Geimferðastofnuninni og ár
og vötn samkvæmt gagnasafninu IS50 frá Landmælingum Íslands.
lated to the divergent boundaries and owe their ex-
istence more directly to the hot spot. Examples of
such off-rift or intraplate volcanoes are Katla, Eyja-
fjallajökull, and Öræfajökull. Hekla is more difficult
to classify. It is located at the junction between the
Eastern Volcanic Zone, a typical rift zone, and the
South Iceland Seismic Zone, that is a transform plate
boundary. And yet Hekla is not a typical rift volcano
(Einarsson, 2008). Its fissure swarm is rather imma-
ture and lacks the extensive normal faulting charac-
terizing the divergent segments of the plate bound-
aries. Furthermore, the petrology of its products is
36 JÖKULL No. 69, 2019