Transcript L24VolcHazards

GEOS 470R/570R Volcanology
L24, 20 April 2015
 Handing out
 PowerPoint slides for today

Volcano movie night

Pompeii, Wednesday, 29 Apr 2015, 6 pm
“I have found that most people are about as happy
as they make their minds up to be.”
--Abraham Lincoln
Readings from textbook

For L24 from Lockwood and Hazlett
(2010) Volcanoes—Global Perspectives
Chapter 14

For L25 from Lockwood and Hazlett
(2010) Volcanoes—Global Perspectives
Chapter 15
Assigned reading

For L24, 20 April 2015
Voight, B., 1990, The 1985 Nevado del Ruiz
volcano catastrophe: Anatomy and
retrospection: Journal of Volcanology and
Geothermal Research, v. 44, p. 349-386.
Last time: Petrologic synthesis;
Volcanic hazards, I.




Petrologic synthesis
 Review of rock suites
 Silicic
 Intermediate
 Mafic
 Ultramafic and non-silicate
Hazard, vulnerability, and risk
Risk identification, analysis, reduction, transfer, and education
Volcanic hazards







Lava flows
Ballistic ejecta and tephra falls
Pyroclastic flows and surges and rock/debris avalanches
Catastrophic failure of caldera lakes
Lahars, mudflows, and jökulhlaups
Earthquakes, ground deformation, air shocks, tsunamis, lightning
Volcanic gases and aerosols
Next time: Volcanic hazards, II.
Multi-dimensional continuum of
magma compositions
Earth’s petrologic universe
 Arbitrary subdivisions
 Given multiplicity of factors, might not
expect there to be a perfect correlation of
magma composition to tectonic setting

Silicic I

Biotite high-silica rhyolite/granite (Ia)
 Bishop Tuff, Glass Mtn, Mono-Inyo, Pine Grove, Henderson

Biotite high-silica rhyolite/granite zoned to intermediate
compositions (IIa)
 Fraction, Ammonia Tanks, and Rainier Mesa Tuffs of the
southern Nevada volcanic field

Topaz rhyolite/granite
 Thomas Range, Wah Wah Mtns

Calcic silicic rocks
 Whakamaru (Taupo)

Peraluminous silicic rocks
 Macusani
 “S-type magmas”
Silicic II

Fayalite-chevkinite high-silica rhyolite/granite (Ib)
 Lava Creek Tuff (LCT) and Huckleberry Ridge Tuff (HRT) of the
Yellowstone volcanic field
 “A-type magmas”

Fayalite-chevkinite high-silica rhyolite/granite zoned to intermediate
compositions (IIb)
 Tshirege Member of the Bandelier Tuff from Valles caldera, Jemez Mtns
 “A-type magmas”

Peralkaline, silica-oversaturated silicic rocks, zoned from comendite
to subalkaline rhyodacite
 Spearhead Member of the Thirsty Canyon Tuff, Tala Tuff of Sierra La
Primavera, Mexico, Tuff of Devine Canyon

Peralkaline, silica-oversaturated silicic rocks, zoned from comendite
to trachyte
 Grouse Canyon Member of the Belted Range Tuff, Kane Wash Tuff

Strongly peralkaline, silicic to intermediate rocks, with low-silica
comendite, pantellerite, and trachyte
 Pantelleria, Menengai, Fantale, Socorro, Gran Canaria, Terceira
Intermediate I

Rhyolite / gap / zoned intermediate
 VTTS Tuff at Katmai-Novarupta
 “I-type magmas”

Zoned intermediate
 Shikotsu, Mazama, Aso-4, Aniakchak, Krakatau,
Quizapu
 “I-type magmas”

Monotonous intermediate
 Monotony, Fish Canyon, Snowshoe Mountain, Mt.
Jefferson, Loma Seca
 “I-type magmas”

High-K calc-alkalic to shoshonitic
 El Chichón, Egan Range, Absaroka
Intermediate II

Boninites (high-Mg andesites)
 Chichi-jima, Cape Vogel

Adakites (sodic andesites and dacites of
trondhjemite-tonalite-granodiorite suite)
 Adak, Vizcaino Peninsula, Mindanao, Cayambe

Igneous charnockites (pigeonite-bearing silicic
rocks)
 Magic Reservoir, Bruneau-Jarbidge, Yardea dacite
 “C-type magmas”

Alkalic, silica-undersaturated intermediate rocks
(phonolite-trachyte)
Mafic I

Tholeiitic basalts of mid-ocean ridge basalts (MORBs)
 Mid-Atlantic Ridge, East Pacific Rise

Olivine tholeiites and Fe-rich derivatives: ferrobasalt,
ferroandesite
 Iceland (volcanic island straddling spreading center)

Continental flood basalts (quartz tholeiites and Fe-rich
differentiates)
 Columbia River (~16 Ma), Ethiopia (~25 Ma), North Atlantic (~59
Ma), Deccan (~66 Ma), Paraná-Etendeka ( ~132 Ma), Karoo
(~183 Ma), Central Atlantic (~200 Ma), Siberia (~248 Ma),
Keweenawan (~1095 Ma), Coppermine River and MacKenzie
(~1267 Ma)

Plateau basalts (high-Al basalts)
 Snake River Plain

Tholeiitic arcs (low-K series)
 Tonga-Kermadec
Mafic II

Oceanic Islands
 Entirely tholeiitic (Galapagos)
 Mostly tholeiitic with lesser alkaline capping (Hawaii)




Pre-shield stage (alkaline basalt)
Shield-forming (tholeiitic basalt)
Post-shield alkaline suite (alkaline basalt, hawaiite,
mugearite, benmoreite)
Post-erosion stage (alkaline basalt, basanite, nephelinite,
melilitite)
 Mostly to entirely alkaline (Gran Canaria, Terceira,
Tahiti, Tristan da Cunha)


Mildly alkaline olivine basalts (OIBs) and sodic differentiates
(hawaiite, mugearite, benmoreite, trachyte)—Terceira
(Azores)
Highly alkaline, silica-undersaturated basanite and
differentiaties (phono-tephrite, tephriphonolite, phonolite)—
Tristan da Cunha
Ultramafic

Carbonatite-nephelinite complexes
Ol Doinyo Lengai, Shombole

Primitive, silica-undersaturated, mafic to
ultramafic
Lamprophyres
Lamproites
Orangeites and kimberlites
Limburgite

Komatiites
Definition of Risk

Hazard
Annualized probability of the specific hazard,
e.g., tephra fall, lahar

Vulnerability
Average degree of loss on scale of 0.0 to 1.0
to elements exposed to hazard (e.g.,
humans, agriculture, buildings)

Risk
Hazard X Vulnerability = Risk
Blong, 2000, p. 1216
Stages of risk management
Risk identification
 Risk analysis
 Risk reduction
 Risk transfer

Blong, 2000
Risk identification: Hazards







Lava flows
Ballistic ejecta
Tephra falls
Pyroclastic flows
Pyroclastic surges
Lahars
Jökulhlaups







Rock/debris
avalanches
Earthquakes
Ground deformation
Tsunamis
Air shocks
Lightning
Gases and aerosols
Blong, 2000, p. 1218
Lava flows




Temperatures above ignition points of many materials
Velocities from a few tens of m / hr to 60 km / hr
Bury or crush
objects in their
path
Follow topographic
depressions
 Can be tens of km long

Noxious haze from
sustained eruptions
P. Kresan
Blong, 2000, Table 1
Ballistic ejecta
>10 km radius of vent
 High impact energies
 Densities <3 t / m3
 Fresh bombs above ignition temperatures
of many materials

Blong, 2000, Table 1
Tephra falls










Downwind transport velocity >10 to <100 km / hr
Exponential decrease in thickness downwind
Can extend >1000 km downwind
Lapilli and ash (<64 mm diameter) are at thermal
equilibrium
Can produce impenetrable darkness
Compacts to half initial thickness in a few days
Surface crusting encourages runoff
Abrasive, conductive, and magnetic
Airborne ash is a special hazard to aviation
Ash accumulations on slopes of volcanoes can create
debris-flow hazards that may extend for several
decades to centuries after eruptions
Blong, 2000, Table 1; Pareschi et al., 2000
Hazards to jet
engines

Particles and acid aerosols are
concentrated by engine
compressor
 Metal surfaces quickly
abraded
 Fuel nozzles clog

Operating temperatures of
engines (1400°C) can melt
volcanic glass particles
 Melted ash coats and sticks to
turbine blades, causing engine
to shut down automatically

Pilot should decrease power to
engines to lower temperature
 Not gun engines to escape
cloud, which raises engine T
Fisher et al., 1997, Fig. 8-4
Pyroclastic flows






Concentrated gas-solid dispersion
Flow velocities up to 160 m / s
Emplacement temperatures <100 to >900°C
Small flows travel 5 - 10 km down topographic
lows
Large flows travel 50 - 100 km
Large flows climb topographic obstructions
 At obstructions or bends in channels, lighter weight,
intensely hot, upper part of density current can
separate from lower part and move up hill
Blong, 2000, Table 1; Fisher, 1999, p. 98
Pyroclastic surges
Low concentration but high kinetic energy
 Radius of deposition 10 – 15 km
 Climb topographic obstructions
 Emplacement velocities >10’s of m / s

Blong, 2000, Table 1
Failure of caldera lakes


Calderas are natural reservoirs
These reservoirs commonly sit at high elevation
 Great hazards

Some contain volumes that are comparable to
that in large natural reservoirs
 Crater Lake, OR
 Atitlán, Guatemala
 Katmai

1.9 x 1010 m3
4.0 x 1010 m3
3.3 x 109 m3
Rims may be prone to failure
Waythomas et al., 1996
Lahars








Generated with rainfalls <10 mm / hr
Bulk fluid densities 2 – 2.4 t / m3; sediment
content 75-90 wt%
Peak flow rates >10,000 m3 / s
Velocities >10 m / s not uncommon
Increase turbidity and chemical contamination in
water bodies
Rapid aggradation, incision, or lateral migration
Travel distances up to 10’s of km
Hazard may continue for months or years after
eruption
Blong, 2000, Table 1
Mudflows

Aerial view of the Acaban
River channel
 As it passes through
Angeles City near Clark Air
Base
 On 12 August

Mudflows caused
collapse of main bridges
 Note makeshift bridges for
pedestrians at lower left
NOAA Mt Pinatubo-1991 Set, #16; photo
by T.J. Casadevall, U. S. Geological
Survey
Jökulhlaups


Can occur with little
or no warning
Discharges may be
>100,000 m3 / s
Blong, 2000, Table 1
Smellie, 2000,
Fig. 3
Outburst flood (toe of glacier at top)
Rock and debris avalanches/
directed blast/sector collapse

Sector collapse
 Minimum volume of 10 –
20 m3

Transport
 Travel distances to >30 km

Deposits
 Cover an areas >100 km2

Emplacement velocities
 Up to 100 m / s


Create topography, pond
lakes
Can produce tsunamis in
coastal areas
Blong, 2000, Table 1
Press and Siever, 2001, p. 111
Earthquakes




Maximum Modified Mercalli intensity of 8 or less
Damage limited to small areas
Damage dependent on subgrade conditions
Much stronger for caldera-related eruptions
 Even small calderas or craters, as for Pinatubo
 Exacerbates other issues, like collapse of buildings
due to ash/water accumulations, as at Pinatubo
Modified from Blong, 2000, Table 1
Volcano-related earthquake damage



Destruction of older brick structures in Pozzuoli, Bay of Naples, Italy
Caused by earthquakes related to volcanic unrest at Campi Flegrei, 19821984
Involved increased seismicity and 1.8 m of ground uplift but no eruption
Peterson and
Tilling, 2000, Fig. 8
Ground deformation
Damage limited to 10 - 20 km radius
 Subsidence may affect 100’s of km2

From Table 1 of Blong, 2000
Bay of Naples, Italy


Pozzuoli, Italy, at or near the center of the Campanian caldera that
erupted the Campanian ignimbrite 37 ka
Area is site of repeated inflation and subsidence; some structures
historically have bobbed several meters above and below sea level
Fisher, 1999, Fig. 25
Ground deformation at Pozzuoli, Italy




Buttressed buildings
in Pozzuoli, April
1984
Many buildings
cracked
Buildings pushed out
of line so that doors
and windows would
not open
Many inhabitants
forced to evacuate to
tent and trailer
camps
Fisher, 1999, Fig. 26
Tsunamis

Tsunami:
Japanese for “harbor wave” or “seismic sea
wave” (public’s “tidal wave,” though unrelated
to tides)
Open ocean travel rate >800 km / hr
 Exceptionally, waves to >30 m
 Inundation velocities 1 – 8 m / s
 Triggered by variety of volcanic events

Modified from Blong, 2000, Table 1
Augustine volcano, Cook Inlet, AK



West Island debris
avalanche, 500 yr old,
viewed from summit of
Augustine volcano
Buried former
coastline, traveled 5
km farther into Cook
Inlet
Generate tsunami
waves that run 5 – 30
m above sea level at
distances of 80 – 100
km
Begét, 2000, Fig. 2
Tsunami at Krakatau, Sunda
Straits, Indonesia




Caldera collapse at
Krakatau on 26
August 1883
Tsunami killed 36,000
people
Travel times (hr) and
maximum wave
heights (m) as
tsunami propagated
along coastlines
Maximum wave
heights varied greatly
depending on coastal
aspect and
morphology
Begét, 2000, Fig. 3
Volcanic triggers of tsunamis

Santorini
 Caldera collapse and pyroclastic flows into sea



Wave height 10 - 50 m
Travel distance 150 – 500 km
Mount St. Helens, 18 May 1980
 Debris avalanche into Spirit Lake caused tsunami



Wave height 260 m
Travel distance 4 km
Lake Nyos, Cameroon
 Exhalative emission of CO2


Wave height 25 - 75 m
Travel distance 5 km
Air shocks

Up to 15-fold amplification of atmospheric
pressure
Blong, 2000, Table 1
Lightning



Cloud-to-ground
lightning from ash
cloud
Strikes related to
quantity of tephra
Electrostatic
charge builds up
from volcanic
particles scraping
against each
other
Blong, 2000, Table 1
Lightning, Volcán Cerro Negro 1971, Nicaragua
Fisher et al., 1997, Fig. 8-1; photo by José
Viramonte
Volcanic gases and aerosols
Water vapor a major component
 SO2 next most important
 Corrosive or reactive: SO2, H2S, HF, HCl
 CO2 in areas of low ground or poor
drainage
 pH of associated rainwater may be 4.0-4.5

Blong, 2000, Table 1
Gases and volcanic lakes


Cold springs degas
below thermally stratified
lakes, allowing
accumulation of gas
Lake Monoun, 15 August
1984
Crater lakes along Cameroon volcanic line:
alkalic volcanoes parallel to Benue rift
 Killed 39 people

Lake Nyos, 21 August
1986
 Killed ~1700 people


Landslides may have
triggered releases
Gas denser than air
 Hugs ground,
asphyxiating life in its
path
M. Barton
Summary--Petrologic synthesis;
Volcanic hazards, I.

Petrologic synthesis
 Broad spectrum of magma compositions on Earth are related to a
multidimensional continuum of Earth processes
 Unlikely that compositions map uniquely against single geologic settings



Hazard, vulnerability, and risk
Risk identification, analysis, reduction, transfer, and education
Volcanic hazards







Lava flows
Ballistic ejecta and tephra falls
Pyroclastic flows and surges and rock/debris avalanches
Catastrophic failure of caldera lakes
Lahars, mudflows, and jökulhlaups
Earthquakes, ground deformation, air shocks, tsunamis, and lightning
Volcanic gases and aerosols
Lecture 24: Volcanic hazards, II:
Eruption response and mitigation

Cultural theories: People as risk takers

Volcanic crisis management
 Individualist
 Egalitarian
 Hierarchist
 Fatalist
 Hermit
 Risk identification
 Risk analysis
 Risk reduction
 Risk transfer
 Risk education

The danger of living inside a paradigm
 Inquiry into breakthroughs
 Volcanic hazards: “What you don’t know you don’t know”
Cultural theories: Categories of
people as risk takers

Individualist
 Optimistic view—building codes have been improved, so risk is
decreased

Egalitarian
 Invokes precautionary principle, presses for urgent action
 Buildings are better but exposure is increasing (e.g., more
people), so better land-use planning needed

Hierarchist
 Everyone knows her/his place
 Things are about right as they are, but more research needed
and more regulation required

Fatalist
 Hopes for best, fears worst
 Whatever risk reduction is done, volcano will get you anyway

Hermit
 What volcano?
Blong, 2000, p. 1216

Questions



What type of
risk taker are
you?
What type of
risk takers are
the
volcanologists
who work on
active
volcanoes?
Possibility for a
disconnect
Individualist
 Optimistic view—building codes
have been improved, so risk is
decreased

Egalitarian
 Invokes precautionary principle,
presses for urgent action
 Buildings are better but exposure is
increasing (e.g., more people), so
better land-use planning needed

Hierarchist
 Everyone knows her/his place
 Things are about right as they are,
but more research needed and
more regulation required

Fatalist
 Hopes for best, fears worst
 Whatever risk reduction is done,
volcano will get you anyway

Hermit
 What volcano?
Stages of risk management
Risk identification
 Risk analysis
 Risk reduction
 Risk transfer
 Risk education

Blong, 2000
Risk analysis

Relative risk indices for volcanoes in Papua New
Guineas for Volcanic Explosivity Index (VEI) = 4
Blong, 2000, Table II
Risk reduction

Lahars
 Lateral dike made of
concrete designed to
protect a town from
lahars from Mayon
volcano, Philippines
Blong, 2000, Fig. 2
Risk reduction

Lahars
 Settling basins made of steel and concrete on slopes of Usu
volcano, Hokkaido, Japan
 Retention ponds designed to impede the passage downstream
of successively smaller boulders and trees
 Principle



Reduce energy of flow
Trap the larger material
Reduce the volume
Blong, 2000, Fig. 3
Risk reduction

Ballistic ejecta
 Reinforced concrete shelter designed to resist impact
of ballistic ejecta, Sakurajima, Kyushu, Japan
Blong, 2000, Fig. 4
Risk education

Lack of knowledge of hazards was an issue
even with USGS scientists and managers
 Kraffts’ “disaster movies” helped

Education of the decision makers and the public
during the monitoring phase was a key issue at
the Nevado del Ruiz disaster
 “Flujos de lodo (mudflow) just didn’t mean a thing to
the people of Armero” --C. Newhall

Confronting the issue for Pinatubo saved lives
 Kraffts’ “disaster movies” helped again
Response and mitigation of lava flows
Fisher et al., 1997, Table 7-1
Mount Etna, Sicily, Italy
Sampling lava at Mt. Etna
Mount Etna
R. Decker
National Geographic, Feb. 2002
Mount Etna, Sicily, Italy



Slow-moving mafic
lava flows
Earthen barriers
slowed lava flows but
generally have not
been successful
Most effective control:
diverting lava flows
near the source, high
on mountain, by
breaching natural lava
levees by excavation
and blasting
 Began with eruption of
1991-1992
 Saved village of
Zafferana Etnea
Fisher et al., 1997, Fig. 7-3; adapted
from Barberi et al., 1993
Mount Etna diversion
Peterson and Tilling, 2000, Fig. 10
Adjustments to risk

Modify the hazard
 Not likely for volcanoes

Modify vulnerability to hazards
 Land use planning
 Build diversions for lahars

Risk transfer--distribute loss to wider community
 Insurance
 Disaster relief
Most common form of adjustment made: Do
nothing
Blong, 2000, p. 1216
“What you don’t know you don’t
know”

The danger of living inside a paradigm
False sense of familiarity
Decisions seriously affected by “What you
don’t know you don’t know”
Corollary: The Law of Unintended
Consequences
Mount Unzen, 3 June 1991


French volcanologists Maurice
and Katia Krafft, American
volcanologist Harry Glicken, and
40 Japanese journalists were
killed during emplacement of a
pyroclastic flow
What they knew
 Unzen produces small, though
remarkably numerous (>5000),
pyroclastic flows from Plinian
column collapse
 Steep valleys on the volcano’s
flanks channelize the pyroclastic
flows
 Adjacent ridges provide tempting
perches to view small pyroclastic
flows
Fisher et al., 1997, Fig. 5-4
Pyroclastic flow from dome
collapse at Mount Unzen

What they didn’t know
 The flow could be larger in volume than earlier ones
Fisher et al., 1997,
Fig. 5-5B
Pyroclastic flow from dome
collapse at Mount Unzen

What killed them
 The flow was large enough to permit separation of glowing cloud
from underlying glowing avalanche
 The cloud climbed the ridge, engulfing their viewpoint
Fisher et al.,
1997, Fig. 5-5A
The volcanologist and the public

The balancing act
Sounding the alarm to save lives
The cost of false alarms

False alarms
Considerable monetary costs of evacuation,
work loss, etc.
May cause people not to act the next time an
alarm is sounded
Nevado del Ruiz, Columbia

Prediction of possible types of emplacement modes
during imminent eruption
Schmincke, 2004, Fig. 13.14
Nevado del Ruiz, Columbia

Actual results of eruption, 13 Nov 1985
 Very minor tephra fallout fan
 Deadly lahars in lower reaches of Río Guali Río Lagunillas
Schmincke, 2004, Fig. 13.14
Lessons from the Armero catastrophe,
Nevado del Ruiz, Columbia

On the whole, the government acted responsibly
 But was not willing to bear the economic or political costs of early
evacuation or a false alarm

Science accurately foresaw the hazards
 But was insufficiently precise to render reliable warning of the crucial
event at the last possible minute

Crucial event occurred two days before the Armero emergencymanagement plan was to be critically examined and improved
 Thus bureaucratic delays to progress of emergency management over
previous year also contributed to the catastrophic outcome
Voight, 1990
Fisher et al., 1997, Fig. 6-3
Pinatubo
Maps, at similar scales, of
Prediction (made on 23
May 1991)
Actual eruption (15 June
1991)
Schmincke, 2004, Fig. 13.29
Special problem: Large eruptions

Managing risks from low probability – high
impact events
 Great difficulty in predicting
 Notoriously difficult for people to deal with rationally—
before and after the latest (rare) event


Analogies with fatalities at industrial accidents
Compare the public and the government dealing
with the 9/11 terrorist attack
 Before and after
A lesson from Mount St. Helens

Great maps of distribution of eruptive
products of last 4500 yr, and good
knowledge of its 40,000 yr history
Experts correctly predicted the ash
distribution, the mudflows, the floods, and the
pyroclastic flows

But the experts couldn’t imagine a debris
avalanche collapsing the mountain or the
lateral blasts
Mount St. Helens lesson, cont’d

The eruption involved a debris avalanche,
followed about a minute later by a directed blast
 Neither previously was a widely recognized volcanic
process
 The avalanche and directed blasts of the 18 May
1980 eruption were far more destructive than the
pyroclastic flows and lahars, which had been most
feared

Scientists expected a clear warning of
impending eruption, from leveling data, seismic
monitoring, etc.
 None was recognized at the time

Only 2 of the 57 fatalities occurred within the
“red zone” of hazard maps
Question

What about the next voluminous silicic,
caldera-forming pyroclastic eruption?
Something akin to an eruption that led to
deposition of the Bishop Tuff and collapse of
the Long Valley caldera (or Yellowstone, etc.)
There is no historical precedent for an
eruption as voluminous and explosive—
nothing even close to it
Magnitude of
the problem

Comparison of
tephra volumes
 Note logarithmic
scale
Simkin and Siebert, 2000, Fig. 6
Mount St. Helens vs. Yellowstone
For comparison, dispersal of ash
from 18 May 1980 eruption of
Mount St. Helens
Measurable ash fallout from three
eruptions from Yellowstone since 2.2
Ma covered more than half of US
Cas and Wright, 1987, Fig. 5.8; after
Sarna-Wojcicki et al., 1981
Fisher et al., 1997, Fig. 5-10
Question

What is it that we “don’t know we don’t
know” about silicic, caldera-forming
pyroclastic eruptions?
Question

What do you do—if anything—if you are
concerned about what you don’t know you
don’t know?
Breaking the cycle
“What you don’t know you don’t know”
could be something regarding volcanic
hazards
or
 It could be that you are looking for a
scientific breakthrough in another area
(even something personal, rather than
technical)

Consider engaging in an inquiry


Act as if, or pretending that, you really don’t know
anything
Purposefully approach the problem from an
entirely different point of view
 Like an outsider would, like—or perhaps not like—a
technically trained person from another field would
approach it (a botanist, an astrophysicist)


Work from first principles to see what might be
possible
Be creative
 Brainstorm about what might be possible, i.e., possible
scenarios
 Effectively engage others creatively—in groups
Possible benefits
Geologists have an easier time seeing what
they’re looking for, rather than something they
don’t expect

Create hypotheses, then test them against
evidence that you never thought to look for
before

Intentional breakthrough discovery vs.
serendipitous discovery
Summary

Cultural theories: People as risk takers

Volcanic crisis management
 Individualists, egalitarians, hierarchists, fatalists, and
hermits
 Respond differently; require different strategies to engage
 Risk identification (volcanologists)
 Risk analysis (engineers and scientists)
 Risk reduction (government: building codes, land use
planning, physical diversions)
 Risk transfer (policy makers, insurers)
 Risk education (public servants and others)
Most common form of risk adjustment made: Nothing

The danger of living inside a paradigm

Next time: Volcanism and mineral deposits, I.
 Volcanic hazards: “What you don’t know you don’t know”
 Inquiries may lead to breakthroughs