Auckland Sitting On Active Volcano
AUCKLAND SITTING ON ACTIVE VOLCANIC FIELD
Scientist Researchers - Institute of Geological and Nuclear Sciences:
New Zealand's biggest city, Auckland, sits
on an active volcanic field
that could produce a new
volcano at any time, say researchers.
"Scenarios being
considered include an eruption forming an offshore
island, one in the Tamaki Estuary, and three within 2km
of the central
business district. Each case is expected
to result in the evacuation of
100,000 to 150,000 people
and major disruption to commerce and
services." says
project co-ordinator David Johnston
An investment of the
Public Good Science Fund has enabled scientists
to work
with the Auckland Regional Council to better understand the
field and the hazards posed by such a volcano.
The
group from the Institute of Geological and Nuclear
Sciences(GNS)
has developed five realistic eruption
scenarios to illustrate what could
happen to Auckland's
population, infrastructure and environment.
"Risk
assessment of each scenario has revealed the extent of the
social
and economic impact on the Auckland community,"
says Dr Johnston.
The research has also noted the
importance of building relationships
among a range of
organisations and community agencies representing
vulnerable groups.
Dr Johnston says the first of
Auckland's 50 volcanoes started to
appear about 140,000
years ago.
"The life of the volcanic field is estimated
at one million years so,
geologically speaking, the
field is still young. There has been a trend
to bigger
and more frequent eruptions around Auckland in the past
20,000 years. Rangitoto, the youngest and biggest
volcano, formed
about 600 years ago."
"The lack of
surface activity can lead to the false impression that the
Auckland volcanic field is extinct. But the hot spot of
magma deep
below the city remains active and will almost
certainly send up another
volcano in the future."
"
The next eruption is unlikely to occur at an existing
volcano.
Auckland tends to produce "single episode"
volcanoes - after the
eruption the volcanic plumbing
seals off and blocks the flow of future
magma."
GNS,
in partnership with Massey University, is also researching
how
much people know and understand about the
vulnerability of New
Zealand to natural hazards. They
are also evaluating methods of
improving the
effectiveness of hazard education programmes.