Jökull - 01.01.2014, Blaðsíða 126

Ingibjörg Jónsdóttir og fl.
supported detailed mapping of the lava flow (Sæm-
undsson, 1991) after each eruption phase (Karl Grön-
vold, pers. comm.). Harris (1997, 2013) used NOAA
AVHRR images to estimate active regions within the
Krafla lava flow in 1985 and calculated effusion rates
from the vents, showing how images in relatively low
geometric resolution could be utilized to monitor vol-
canic eruptions in Iceland in near-real time and with
high time resolution.
The Icelandic Meteorological Office (IMO) has
received images from the weather satellites from 1967
(Garðarsson, 1999), initially through the Keflavík Air
Base and since 1985 from a receiving station at the
institute. The images were mainly used in connec-
tion with the weather services, but also for studying
other features, such as eruption plumes and sea ice.
A weather radar was established in 1990 at Reykjanes
and later near Egilsstaðir (IMO, 2014).
The focus of this paper is on real-time monitor-
ing of volcanic eruptions using satellite images, but
it should be noted that within the field of remote
sensing, other techniques are becoming more widely
used, such as INSAR interferometry (Sigmundsson,
2010, 2014), multibeam measurements in lakes and
the ocean (Ármann Höskuldsson and Bryndís Brands-
dóttir pers. comm., 2014), as well as RADAR and LI-
DAR observations from the ground (Richard F. Yeo
pers. comm., 2014).
Data availability
It is only in recent years that real time satellite mon-
itoring has become practical, with images becoming
available immediately after acquisition. The num-
ber of satellites has increased, carrying sensors and
scanners that provide data that various institutes make
available through the web, in many cases free of
charge. Figure 1 gives an overview of the most com-
mon satellites used for monitoring such events in Ice-
land, though there is not scope here to describe each
data source in detail (see Lillesand et al., 2008). Many
are omitted, all geostationary satellites for examples
since they have a limited relevance for studying such
events at high latitudes, though it should be noted that
having high temporal resolution (15 minutes), they
give good overview over the development of plumes
that cover large geographical areas.
TI
R
O
S
N
IM
B
U
S
N
O
A
A
A
V
H
R
R
LA
N
D
SA
T-
1
2
3
LA
N
D
SA
T-
4
5
LA
N
D
SA
T-
7
LA
N
D
SA
T-
8
SP
O
T-
1
2
3
4
5
EO
-1
TE
R
R
A
/A
Q
U
A
SU
O
M
I N
P
P
EN
V
IS
A
T
R
A
D
A
R
SA
T
SE
N
TI
N
EL
-1
1960
Askja 1961
1962
Surtsey 1963
Surtsey 1964
Surtsey 1965
Surtsey 1966
Surtsey 1967
1968
1969
Hekla 1970
1971
1972
Heimaey/Eldfell 1973
1974
Krafla 1975
1976
Krafla 1977
1978
1979
Hekla, Krafla 1980
Hekla, Krafla 1981
1982
Grímsvötn 1983
Krafla 1984
1985
1986
1987
1988
1989
1990
Hekla 1991
1992
1993
1994
1995
Bárðarbunga/Gjálp 1996
1997
Grímsvötn 1998
1999
Hekla 2000
2001
2002
2003
Grímsvötn 2004
2005
2006
2007
2008
2009
Fimmv., Eyjafjallajökull 2010
Grímsvötn 2011
2012
2013
Bárðarb./Nornahraun 2014
Figure 1. Confirmed volcanic eruptions in Iceland
from 1960–2014 and a brief summary of some of
the satellite data available for a given year. TIROS,
NOAA AVHRR, TERRA/AQUA and SUOMI NPP
have provided daily images. LANDSAT 1–8, SPOT
1–7 and EO-1 can provide images on a sub weekly
time scale. RADARSAT, ENVISAT and SENTINEL-
1 provided radar imagery. – Yfirlit yfir gervitungl sem
notuð hafa verið til eftirlits með eldgosum á Íslandi.
126 JÖKULL No. 64, 2014