Jökull - 01.01.2009, Page 90

Sigurjón Jónsson
-15˚ -14˚ -13˚
65˚
65.5˚
T
rack 187
T
ra
ck
4
24

Neskaups-
staður
T
ra
ck
1
95
Loðmundar-
Egilsstaðir
Eyvindarárdalur
Fig. 3a
Fig. 5a
Figure 1. Map of East Iceland showing the coverage of one ascending (dashed) and two descending (solid
rectangles) ERS/Envisat frames, with the large arrows indicating the corresponding satellite flying and look
directions. Locations of towns and villages are shown as small solid gray rectangles and circles. – Kort af
Austurlandi sem sýnir útlínur ERS og Envisat radarmynda sem notaðar voru í verkefninu (stórir ferhyrningar).
Örvarnar sýna flug- og radarstefnu gervitunglanna á ferð sinni eftir fallandi og rísandi brautum.
to specifically study known unstable slopes (Þófi in
Seyðisfjörður, Urðarbotn above Neskaupstaður, Al-
menningur in North Iceland), and (3) to survey both
East and North Iceland to search for other creeping
slopes that may exist.
In this paper I present the results from East Ice-
land. I begin by discussing the general conditions of
InSAR and the satellite radar data availability for the
region and then I then describe the results from Þófi in
Seyðisfjörður and from other areas were slope creep
was discovered.
RADAR DATA AND PROCESSING
The satellite radar data used in this study are from the
ERS-1, ERS-2, and Envisat satellites operated by the
European Space Agency (ESA). ERS-1 was launched
in 1991 and was operated for nine years or until 2000.
ERS-2 and Envisat were launched in 1995 and 2002,
respectively, and both are still in operation. However,
the precise pointing of the ERS-2 radar antenna failed
in 2001 and since then ERS-2 data are of limited use
for radar interferometry. All these satellites transmit
radar signals at C-band (wavelength≈ 5.6 cm) that in-
90 JÖKULL No. 59