Volcanoes - Ministry of Civil Defence and Emergency Management

Ashfall from the 1995 Mt. Ruapehu eruption had an impact on a number of lifeline utilities, as well as on animals and plants. Photo: GNS Lloyd Homer.
other biota, as evident from the lasting negative effects
of eruption of Taupo on the native fish distribution in
the North Island in 186 AD (about 1800 years ago).
MITIGATION MEASURES FOR VOLCANIC HAZARDS
Most volcanoes have long intervals between
damaging eruptions, ranging from years to many
centuries. The management of volcanic hazards can
therefore be divided into four distinct time frames.
Non-eruptive rest times represent the most common
situation and afford the best opportunity to develop
mitigation strategies and prepare society for an
eruption. The time around an eruption crisis can
divided into three periods: pre-eruption, eruption and
post-eruption (or recovery).
NON-ERUPTIVE PERIODS
The requirement to mitigate natural hazards in
New Zealand is covered by the Resource Management
Act (1991) which seeks to provide a structure for
natural hazard management that focuses responsibilities
and requires effective means of control to be adopted.
Implementation of this is carried out by regional and
territorial authorities through regional policy statements,
regional plans, district plans and resource consents. The
Regional Policy Statements and regional/district plans of
volcanic areas should recognize explicitly that parts of
these regions are susceptible to hazards associated with
future volcanic eruptions. Such zones, for example,
those close to potential vents and/or on vulnerable flood
plains, need to be identified. The new Civil Defence
Emergency Management (CDEM) Act 2002 and the
associated National CDEM Strategy establishes a vision
for a “Resilient New Zealand – strong communities
understanding and managing their hazards” and calls
for increased community awareness, understanding and
participation in CDEM; reduced risk from hazards; and
an enhanced national capability to manage emergencies
and recover from disasters. For New Zealand to achieve
these goals the CDEM sector requires a sound research
base that addresses the spectrum from understanding
the physical phenomena of natural hazards to an
understanding of the impacts of these hazards from a
social, economic and cultural perspective.
Once the vulnerability has been assessed,
mitigation strategies can be developed. Three types of
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TEPHRA
June 2004