Thomas (Tom) Wilson
University of Canterbury, New Zealand
+ NZ and international research team
Overview of the talk
1.
Ash Impacts Research Programme
 Why bother with the gritty grey stuff...?
2. Stakeholder engagement and collaboration
 New Zealand’s arrangements
1.
Case Study – Tongariro eruption: August 2012
 Lessons: successes and fails
Societal vulnerability to
volcanic hazards
 Proximal Hazards: such as lava flows,
pyroclastic density currents, etc.
 usually assumed to be totally destructive...
 probably not...but mitigation usually site
avoidance/evacuation
 Volcanic ash falls are a bit different
 potentially affect very large areas at varying
intensities (e.g. thicknesses)
 exotic event (rare -- mysterious)
 ash can have highly variable properties


Between different eruptions
Within the same eruption
Context – Ash Impacts
• Volcanic ash impacts are the most likely volcanic hazard to
affect the most people during an explosive eruption
• Typically disruptive, rather than destructive
•
Although they can potentially create a variety of unique impacts
• Cascading impacts of ashfall can be overlooked in
emergency plans
Or….
• Due to the wide range of potential ash sources and
characteristics it becomes complicated estimating what
impacts will be…
Ash fall may be highly directional
Ash fall thickness & grainsize usually decrease with distance from the vent
Ash fall may be
highly directional
Ash fall thickness &
grainsize usually
decrease with
distance from the
vent
Context – Ash Impacts: Puyehue-Cordon Caulle
• Recent large (and small) explosive volcanic eruptions are
causing increasing levels of societal and economic impact
Bariloche, Argentina
Situation normal
NASA Earth Observatory
Context – Ash Impacts
Recent experience in New Zealand and beyond indicates volcanic
risk scientists need to give:
• Timely and often highly specialized impact and mitigation
information to stake-holders and end-users
• Non-crisis period
Integrated, on-going and dynamic risk reduction and readiness strategies with all
stakeholders are optimal
Yet, there is regular change of personnel, organizations and arrangements…etc
•
•
• Crisis period
•
•
•
Scientists often scrambling into the field to collect data.
Reduces (or negates) their ability to share information in a timely manner
Diversity of potential impacts makes it hard to make robust, meaningful
estimates to stake-holders
NZ Volcanic Advisory Group
Auckland
SAG
Taranaki
SAG
NZ
SAG
“Calderas”
SAG
Central
Plateau
SAG
Critical
Infrastructure
Primary
Industries
Volcanic
Impacts
Study Group
Health
Emergency
Management
Eruption
response
arrangements
Volcanic
Impacts
Research
Conduit to
international
expertise
(e.g. IVHHN)
Role
VISG
Risk
Reduction
e.g. Loss
modelling
Engagement
with
stakeholders
- National
- Internationally
Funded by Nat Haz
Research Platform
with contribution
from Lifeline Groups
Advice
during a
crisis
Research context- volcanic impact
research
 Over the past 15 years the NZ team (with international collaborators) has
aimed to undertake a sustained and systematic approach to volcanic
impact assessment
 Critical infrastructure (lifelines) – water supplies, electricity, wastewater




and storm-water, land and air transport, telecommunications
Ash cleanup and disposal
Primary industries and rural communities
Social impacts
Emergency management
 Reconnaissance trips to impacted areas
 Empirical, laboratory-based testing of critical infrastructure components
(VATLAB)
Reconnaissance Trips
1) How did impacts unfold in real situations,
 what were main problems,
 what was resilient/tolerant (just as important)
 what mitigation actions were effective,
 previous preparedness,
 lessons learned, adaptive behaviours, etc
2) Trips conducted at various time intervals afterwards
3) Trips range from small scale (1 person), to larger multi-
disciplinary teams
4) Emphasis on collaborating with local authorities,
scientists, and utility managers
5) COV6 output – development of standardised impact
assessment procedures
Recon Trips: by volcano & year visited
Redoubt 1996; 2010
Eldfell (Heimaey) 2008
Shinmoedake
2011
Etna
2003
Sakurajima
2001
Pacaya
2010
Pinatubo
2007
Merapi
2006
Tungurahua
2005; 2010
Lapevi
2003-05
Ruapehu
1995-96
Puyehue Cordon-Caulle
2012
Hudson
2008
Chaiten
2009
2008 Chaiten eruption, Chile
Ash induced infrastructure failure in Futaleufu, Chile
(2,000 residents - temporary evacuation)
• Water supply compromised
• Power supply cut
• Roads disrupted by thick ashfalls
• Health concerns
Compounded effects
Evacuation duration: 1-12 months
General findings for
infrastructure managers
 Volcanic ash falls are regarded as exotic events which are rarely
planned for
 The unique and complex characteristics of volcanic ash can
create a range of possible direct and indirect impacts
 Possibly leading to complex, cascading effects
 Difficult management challenge
 Disruptive rather than catastrophically damaging
 Many infrastructure systems will tolerate volcanic ash...up to a
point
 Need detailed understanding of what will be the likely impacts at
varying levels of hazard intensity
 Detailed understanding of how to build resiliency into the systems
 Value of a systematic and on-going programme
What pops up time after time...
 Health (most important!)
 What does ash do to me….to my children?
 What will ash do to water supplies?
 What impact will it have on food?
 Farming
 What will ash do to my animals?
 What will ash do to my crops?
 How can I remediate the damage?
 How much Fluoride is in the ash?
 Infrastructure
 Wow – this ash stuff was hard to clean up.
 More time & $$ than expected
 Didn’t expect those impacts
 Wish we had planned for this…
Outputs from this research?
 Emphasis on preparedness, mitigation strategies,
practical advice
 Considered, accurate, responsive
 Strong focus on end user needs
Traditional approach to volcanic impact
assessment
 This ‘scenario’ approach has suited
dealing with the multiple properties of
ash which may cause impacts
 Thickness?
 Grainsize?
 Abrasiveness?
 Leachate?
 Density?
 Conductivity?
Desire for quantification
Two main drivers:
 Engineers want specific parameters
 design resilient facilities
 planning emergency operational procedures
 Move towards quantitative risk assessment models
 Modelling likely impacts/losses at variable hazard
intensities (fragility functions)
 Scenario based approach was found to be limited
 Quantitative risk assessment is extremely data hungry
 Requires extensive impact datasets of each hazard at
a range of intensities and for each of the different
types of infrastructure


Some of the impact data is highly perishable
Too many variables
Probability of Occurrence (%)
100
90
80
70
Contaminated with
3mm ash
60
50
40
Wet
30
20
Dry
10
Wet
0
1
10
100
Ash Thickness (mm)
1000
Dry
Combined
Solution:
1. Increase frequency, duration and
objectives of reconnaissance impact
assessment trips to every type of eruption
style possible

Impractical – time and $$$
2. Undertake quantitative testing in a
laboratory under controlled conditions 
informed by the recon trips findings



More time and cost effectiveness
Can explore range of hazard intensities and
critical components/systems
Similar approach to earthquake
engineering
Our ‘little’ test: 6 August 2012 eruption
of Te Maari craters, Tongariro
Subduction video
Tongariro
Volcanic
Centre
Photo- James Cowlyn
Our “little” test...
 In the context of New Zealand’s largest geoscience
response: Canterbury earthquake sequence
 Major investment in volcanic risk management over
the past 15 years (since 1995-96 Ruapheu eruption)
 Volcanic hazard analysis
 Volcanic surveilliance (GeoNet)
 Starting to think about risk
 DEVORA project
Tongariro Eruptive History: our grumbly uncle
 How often ?
130 eruptions over the past 4,000 years
–
–
–
–
1 eruption every 30 years on average
Most from Ngauruhoe
Last eruption 1975 Ngauruhoe
Te Maari craters = 7 eruptions between
1820-1920. None since...until 2012
 How big ?
 Mostly small phreatic and
phreatomagmatic explosions and lavas
 Sub-plinian and plinian eruptions are
possible but rare
 ‘Grumbly personality’
 Earthquake swarms at Ngaurohoe but
not previously at Tongariro
Earthquake swarm mid July
Alert Level changed 20 July 2012
 Low magnitude
earthquake swarms are
not uncommon on
New Zealand volcanoes
and usually do not
result in eruption
Tongariro – Pre-event Seismicity
However, this earthquake swarm did result in eruption
Unusual seismicity began 1 month before eruption, then tailed off….
Shallow earthquakes – associated with fluid movement
What happened
Aug 6/7th ?
First actions?
 Ash fall sampling!!
 Massey University and GNS Science deployed at ~1am in the
morning
 UC team flew out within 12 hours
 Check out the volcanic monitoring data
 More earthquakes?
 What is the gas chemistry?
 What deformation has occurred?
 Communicate what had happened
 Public + media
 Emergency management (Civil Defence, Councils, etc.)
 Other Stakeholders, e.g. MPI, MoH, Fonterra, Federate Farmers, etc
You are XXX what aviation level ?
The landscape
“permanently”
changed
Debris flow
Steam pressure- Build up
Magma or no magma ?
Thanks to Shane Cronin &
Massey group
Tongariro ‘Highway”
 70,000 people cross per year
Blocks, Bombs, and Ash
We were Lucky
 On a sunny summers day there maybe 600 people on
the trail.
 Maybe 100 people in the area affected by Blocks,
Bombs and Ash
• Ketetahi hut frequent place to stop for a rest and
the beds are usually full at night.
Ash-downwind
Images thanks to Shane Cronin group at Massey
Ash Hazard?
 Infrastructure
 Roads
Ash Hazard?
HUMAN
HEALTH
 Respiratory
hazards?
 Drinking Water
Supplies?
 Turbidity
 Chemical
contamination
Ash Hazard?
 AGRICULTURE
 Fears of Fluoride
 Same level as Ruapehu
 Small amount of ash
 Lots of rainfall
Ash Hazard?
 Infrastructure
 Electricity
Contaminated with
3mm of ash
Contaminated with
3mm of ash
Lessons
 Ash mapping
 Preparation key
 Take more samples!!
 Stakeholder and media interest – incredible
 Standardised ash analysis protocol
 Health and Agriculture


Particle size
Leachates
 Infrastructure: Electricity, Water bodies, Geotech properities
 Science Priorities...coordination, gaps?
 Advisory Groups. GNS and the Universities
 Infrastructure - Good
 Agriculture - Average
 Health - Poor
Summary
 Ash...our exotic hazard...?
 Disruptive as much as damaging
 Expectations of geohazard/risk science and from geohazard/risk
science need to be known, established, dynamic, transparent
and well-practised!
 Change of focus from hazard to risk
 Protocols and well governed (and resourced) advisory groups are
essential in crisis and non-crisis periods
 Science coordination (for public good). Trust. Existing
relationships
 Timely, responsive, accurate advice
Thank you!
 Acknowledgements
 Gill Jolly and the Volcanology group at GNS
 GeoNet and the Earthquake Commission
 Shane Cronin and Volcanic Risk Solutions, Massey
University
 CoUGARS
What does this
really mean?
92%
Future Eruptive
Scenario for
Tongariro
6%
2%
No Eruption
Most likely
Ruapehu - 1996
Similar in size and
style to 6 August
2012 eruption
Small Eruption
Strombolian to
Vulcanian
Larger Eruption
(VEI 2-4)
Least likely
Sub-Plininan to
Plinian (VEI 4-6)
Science assessment: 19 Sept 2012
Mt Spurr, Alaska
1992