Geoscience Reference
In-Depth Information
Chapter 8
D. K. Bird, G. Gisladottir, and D. Dominey-Howes
INTRODUCTION
Katla volcano, located beneath the Myrdalsjökull ice cap in southern Iceland, is
capable of producing catastrophic jökulhlaup. The Icelandic Civil Protection (ICP),
in conjunction with scientists, local police, and emergency managers, developed
mitigation strategies for possible jökulhlaup produced during future Katla eruptions.
These strategies were tested during a full-scale evacuation exercise in March 2006. A
positive public response during a volcanic crisis not only depends upon the public's
knowledge of the evacuation plan but also their knowledge and perception of the pos-
sible hazards. To improve the effectiveness of residents' compliance with warning and
evacuation messages, it is important that emergency management officials understand
how the public interpret their situation in relation to volcanic hazards and their poten-
tial response during a crisis and apply this information to the ongoing development
of risk mitigation strategies. We adopted a mixed methods approach in order to gain
a broad understanding of residents' knowledge and perception of the Katla volcano in
general, jökulhlaup hazards specifically and the regional emergency evacuation plan.
This entailed field observations during the major evacuation exercise, interviews with
key emergency management officials and questionnaire survey interviews with local
residents. Our survey shows that despite living within the hazard zone, many residents
do not perceive that their homes could be affected by a jökulhlaup, and many partici-
pants who perceive that their homes are safe, stated that they would not evacuate if
an evacuation warning was issued. Alarmingly, most participants did not receive an
evacuation message during the exercise. However, the majority of participants who
took part in the exercise were positive about its implementation. This assessment of
resident knowledge and perception of volcanic hazards and the evacuation plan is the
first of its kind in this region. Our data can be used as a baseline by the ICP for more
detailed studies in Iceland's volcanic regions.
The Icelandic term “jökulhlaup” is defi ned as a sudden burst of meltwater from
a glacier and may occur for a period of several minutes to several weeks (Björnsson,
2002). All confi rmed historic eruptions of Katla, the volcano underlying the
Myrdalsjökull ice cap in southern Iceland (Figure 1), have produced jökulhlaup
(Thordarson and Larsen, 2007). A Katla eruption can melt through the ~400 m of ice
covering the Katla caldera in 1-2 hr, producing a catastrophic jökulhlaup with a peak
discharge of 100,000-300,000 m
3
s
−1
(Björnsson, 2002).
Transporting volcanic debris and large ice blocks, jökulhlaup have been the most
serious hazard during historic Katla eruptions but not the only hazard. Local comm-
unities 30 km from the eruption site have been subjected to heavy tephra fallout and
