Jökull - 01.01.2010, Page 105

The Kerlingar fault, Northeast Iceland
fault is related to processes that affected the zone as a
whole rather than more localized rifting events of in-
dividual fissure swarms. We point out that the location
of the fault coincides with a rapid change in crustal
thickness (Figure 2) (Staples et al. 1997). Thus, the
areas west and east of the fault may have reacted dif-
ferently to crustal load changes in the Pleistocene and
in the beginning of the Holocene.
METHODS
We mapped the Kerlingar fault and its surroundings
from SPOT and ASTER satellite images, and from
aerial photographs. We obtained the SPOT images
from the National Land Survey of Iceland (Land-
mælingar), the ASTER images from the US/Japan
ASTER project, and the aerial photographs from
Aerial Photographs corp. (Loftmyndir ehf.). The im-
ages have different resolutions: the SPOT images
have a resolution of 10 m/pixel, the ASTER images
15 m/pixel and the aerial photographs 0.5 m/pixel. Al-
though the satellite images have less resolution than
the aerial photographs, they are useful as they show
different aspects of the geological structures than the
aerial photographs (i.e. different solar angle and dif-
ferent contrast). As an example, the Kerlingar fault
is particularly well delineated on some of the ASTER
satellite images, especially those taken under winter
condition and low sun angle (e.g. October 11th 2003,
Figure 3).
A 4.3 km long section of the fault was investigated
in the field, mainly to ascertain the sense of faulting
and to estimate vertical offset of some of the fault seg-
ments. Transects across the fault were measured in a
few places by GPS-instruments.
Figure 2. Best fit P-wave velocity model by Staples et al. (1997) along the FIRE seismic array line. A
part of this line is shown in Figure 1. Thin black lines mark abrupt changes in crustal thickness at the
NVZ-EFB boundary. A vertical black line 55 km east of Krafla indicates the approximate location of the
Kerlingar fault, whereas the horizontal red line spans a 30 km wide arcuate area of hyaloclastite ridges at
the NVZ-EFB boundary. – Jarðlagasnið eftir bylgjubrotsmælilínu FIRE verkefnisins samkvæmt Staples et al.
(1997). Staðsetning hluta þversniðsins er sýnd á 1. mynd. Svarta línan bendir á hvar Kerlingamisgengið sker
þversniðið, rauða línan þar fyrir neðan spannar móbergshryggina á austurmörkum Norðurgosbeltisins.
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