Speakers: Cynthia Gardner, Research Geologist, U.S. Geological Survey  Carolyn Dreidger, Hydrologist/Outreach Coordinator ; The 18 May 1980 eruption of Mount St. Helens awoke the Pacific Northwest to the reality that Cascade volcanoes erupt with significant consequences to communities downstream and downwind. What will you need to know when your community‟s backyard volcano showed signs of unrest? Do you know how you will be alerted? What kind of information you will receive? What hazards may confront you and for how long? At what point will you be required to make decisions? What are the sources of uncertainty during volcanic unrest and eruption? This session is intended as a dialogue between volcano scientists and emergency managers, infrastructure managers, and the business community. Scientists will present basic information about Cascade volcanoes, the hazards they pose, timescales of eruptive unrest and activity, the USGS alert-level system, and uncertainties in forecasting eruptive events.

1. 2011 Partners in Preparedness Conference2011 Partners in Preparedness Conference
10 things you need to know about the10 things you need to know about the
l i b k dl i b k dvolcano in your backyardvolcano in your backyard
Cynthia Gardner and Carolyn Driedger
U.S. Geological Survey, Cascades Volcano Observatory
26 April 2011

2. Course Outline
1 Your volcano will erupt again1. Your volcano will erupt again
2. You will get warning (monitoring, messages)
3. The warnings will not be black and white, i.e, there is a
l t f t i t i d li ith l i ti itlot of uncertainty in dealing with volcanic activity
4. Emergency managers will need to make decisions and
take actions long before outcomes are known
5. The types of hazards are known - IAVCEI video
6. Near-source hazards can develop rapidly - evacuation
prior to an event will be necessary (issues about long-prior to an event will be necessary (issues about long
term evacuation; funding for closures, etc.)

3. Course outline (cont.)
7. Lahars (volcanic mudflows) follow river valleys that start on
volcanoes - affects may last long after eruption is overvolcanoes affects may last long after eruption is over
8 Tephra (volcanic ash) moves in the direction and at the speed
of the wind - it will take time to get downwind
9 Th l l t t t b th l th t9. The volcano closest to you may not be the one only one that
affects you
10. Volcanic eruptions can last for days to years and do not have
to be large to be disruptive
Bringing it home to your communityBringing it home to your community
Scenario
Do you have questions that you want answered in this course?Do you have questions that you want answered in this course?

4. Your volcano will erupt again
Subduction is the process behind many hazards in the PNW
1
Subduction is the process behind many hazards in the PNW
• Subduction earthquakes >>> volcanic earthquakes
• Volcanic eruptions are rarely triggered by a subduction eqs

5. Your volcano will erupt again
C d l h l lif d t hi t iCascade volcanoes have long life spans and recent histories

6. Your volcano will erupt againp g
Not all volcanic eruptions occur at the big volcanoes
By Jason Brewer, 1977

7. You will be warned2
Volcanoes often give days to months of warning
As magma moves to the surface:As magma moves to the surface: Surface
deformation
•• It breaks a pathwayIt breaks a pathway
•• It releases gasesIt releases gases
•• The chamber or conduit mayThe chamber or conduit mayThe chamber or conduit mayThe chamber or conduit may
increase or decrease in volumeincrease or decrease in volume
These processes result in effectsThese processes result in effects
that we can measure:that we can measure:
•• EarthquakesEarthquakes
•• Emission of magmatic gasesEmission of magmatic gasesEmission of magmatic gases,Emission of magmatic gases,
principally COprincipally CO22 and S gasesand S gases
•• Ground deformationGround deformation
Input of
magma
Input of
magma

8. You will be warned
M it i i ti l t l d t ti f t tiMonitoring is essential to early detection of unrest, eruption
and hazardous events

9. USGS mandate is to provide warningp g
USGS alertUSGS alert--level system focuses on the state of the volcano with anlevel system focuses on the state of the volcano with an
emphasis on ash for the aviation communityemphasis on ash for the aviation community
TERM COLOR DESCRIPTIONDESCRIPTION
Alert level Aviation Color Code
Volcano is in normal non-eruptive state
Volcano is exhibiting signs of elevated unrest
GREEN
YELLOWElevated unrest above known
NORMAL
ADVISORY
Typical background, non-eruptive state
Volcano is exhibiting signs of elevated unrest
above known background levels
Volcano is exhibiting heightened/escalating
unrest with increased potential of eruption
OR ti d ith
YELLOW
ORANGE
Elevated unrest above known
background activity
Heightened/escalating unrest with increased
potential for eruptive activity. timeframe
variable OR minor eruption underway
ADVISORY
WATCH
OR, eruption underway with no or
minor ash emissions
Eruption is forecasted to be imminent with
significant emission of ash into the
atmosphere likely OR,RED
variable, OR, minor eruption underway
that poses limited hazards
Highly hazardous eruption underway
or imminentWARNING p y
Eruption is underway with significant ash
into the atmosphere
or imminent

10. You will be warned
Know your communication links
C ll DCall Downs
ex. Mount St. Helens
C ll d d hCall downs are used when
changing alert-levels, to
update officials about a
significant change insignificant change in
activity, or when eruptive
activity ceases
How do you fit into
this call down?

11. You will be warned
Know all of your sources of information and how youKnow all of your sources of information and how you
will be informed
Scientific information:Scientific information:
• USGS and PNSN for
volcanic activity
•USGS for warning - Alert•USGS for warning - Alert
Level System
• USGS and NWS for ash fall
and lahar warningsand lahar warnings
Response Information
• NIMS/ Unified Command
Websites: http://volcanoes.usgs.gov
S/ U ed Co a d
• Interagency response plans
Public information
• Media
• Social media

12. Alert Level Change - Normal to Advisory
Probably most difficult step for scientists
Diffic lt to pinpoint hen something is o t of the ordinar• Difficult to pinpoint when something is out of the ordinary
• Likely to bring intense media scrutiny
• Joint Information Center likely needed
• Responders should start reviewing plans
• Conference calls
• No promise of that an eruption will occurNo promise of that an eruption will occur

13. Warnings will not be B&W3
Scientists cannot directly measure the magma system
Like weather systems uncertainty
Surface
deformation Like weather systems, uncertainty
about outcome (size, style, timing,
eruption/no eruption, vent area) is
high
deformation
high
Unlike weather systems, we don’t
yet have physics-based models to
Everything we want to know is
forecast outcome
beneath ground and we don’t
yet have instruments to directly
measure what it is that we
o ld like to kno
Input of
magma would like to knowmagma

14. Warnings will not be B&WWarnings will not be B&W
All Cascade volcanoes show a range in eruptive size and style
The 1980s eruption was about 5 times larger
than the 2004 to 2008 eruption; largest MSH
event about 6 to 8 times larger than the 1980-
86 event.

15. Warnings will not be B&WWarnings will not be B&W
Vent location determines what areas will be affected

16. Warnings will not be B&W
V l i t ll l t l th th t lV l i t ll l t l th th t lVolcanic unrest generally lasts longer than other naturalVolcanic unrest generally lasts longer than other natural
hazardshazards
Event DurationWarningHazardous
Event Weeks to
months
Days Days Weeks to
months
Months to
years
Flood
Hurricane
y
Earthquake/
tsunami
Hurricane
Wildfire
Eruption
Wildfire
Hazardous events can occur during unrestHazardous events can occur during unrest

17. EMs will need to make decisions longEMs will need to make decisions long
before outcomes are knownbefore outcomes are known
5
“Decision window”
before outcomes are knownbefore outcomes are known
for public officials
Shape, character,
arameters
p , ,
duration very irregular
Build-up suggests
eruption is likely
nitoringpa
eruption is likely
Cannot guarantee that
eruption will not occur
sityofmon
e up o o occu
Intens
Time

18. EMs will need to make decisions long
before outcomes are known
Eruption1
before outcomes are knowns
Decision
window for
Eruption1 Eruption 3
arameters
public
officials
onitoringpansityofmo
Back to
sleepBack to
sleep2 4
Inten
Time

19. Decision making across cultures
Scientists and public officials who understand eachScientists and public officials who understand each
other’s culture beforehand, will likely work well together
Scientists
Public officials
We all want to succeed, we all need to succeed

20. Volcano hazards
N t thi ill ff t t
5
Not everything will affect you at once
•• Proximal areas ( ≤15 mi) subjectProximal areas ( ≤15 mi) subject
t lti l l th l h dt lti l l th l h d i tto multiple lethal hazards:to multiple lethal hazards: minutes
to tens of minutes
•• Intermediate areas (> 15 <100)Intermediate areas (> 15 <100)
Lahars, tephra fall and floods affectLahars, tephra fall and floods affect
river valleys:river valleys: tens of minutes to
hours
•• Distal hazards (>100 mi)Distal hazards (>100 mi) -- TephraTephra
fall affects areas downwind:fall affects areas downwind:
hour(s) to days( ) y
•• Excess sediment in watershedsExcess sediment in watersheds
reduces flood capacity:reduces flood capacity: week(s) to
decadesdecades

21. Volcano Hazards
IAVCEI videoIAVCEI video
International Association for
Volcanology and Chemistry of theVolcanology and Chemistry of the
Earth’s Interior

22. Volcano hazards
N t thi ill ff t tNot everything will affect you at once
•• Proximal areas ( ≤15 mi) subjectProximal areas ( ≤15 mi) subject
t lti l l th l h dt lti l l th l h d i tto multiple lethal hazards:to multiple lethal hazards: minutes
to tens of minutes
•• Intermediate areas (> 15 <100)Intermediate areas (> 15 <100)
Lahars, tephra fall and floods affectLahars, tephra fall and floods affect
river valleys:river valleys: tens of minutes to
hours
•• Distal hazards (>100 mi)Distal hazards (>100 mi) -- TephraTephra
fall affects areas downwind:fall affects areas downwind:
hour(s) to days( ) y
•• Excess sediment in watershedsExcess sediment in watersheds
reduces flood capacity:reduces flood capacity: week(s) to
decadesdecades

23. Proximal hazards
6
Near source hazards can develop rapidly
30 i t l i ti30 minutes or less warning time
too short to detect the activity,
give warning and take action
Officials have difficult decisions:
• Limiting access
• Road closures
• Evacuations
• Alternate escape routes
• Warning system
• Securing the closed area• Securing the closed area
• Recovery issues
Big questions -- duration,g quest o s du at o ,
resources and resiliency

24. Lahar hazards
L h i ll th t t t th l
7
Lahars occur in valleys that start on the volcano;
generally not all valleys affected
Know which rivers start on your
lvolcano
Ask scientists where the most
likely vent area will be and what
rivers it might affect
Have a plan to deal with
reservoirs on potentially
ff t d iaffected rivers

25. Lahar hazardsLahar hazards
Hazards can persist long after an eruption is over

26. Lahar hazardsa a a a ds
Hazards can persist long after an eruption is over
Bridge crossing immediately
affected by the eruption;
months latermonths later
Some communities in the
Philippines were not affected untilPhilippines were not affected until
years to a decade after the eruption

27. Tephra (ash) hazards
8
Tephra (ash) hazards
Tephra moves in the direction(s) of and at the speed(s) of the wind
How far downwind are you? In what direction?

28. Tephra (ash) hazardsep a (as ) a a ds
Tephra affects aviation, which may impede recovery efforts
• ~2000 flights over the Cascades daily
• Ash can reach cruise altitudes in a matter
of minutes
How would reduced aviation affect your recovery?

29. Tephra (ash) hazards
M i 1980Many more resources since 1980
http://volcanoes.usgs.gov/ash/

30. A distal volcano may affect you the most
Tephra (ash) can affect communities far from sourceTephra (ash) can affect communities far from sourceTephra (ash) can affect communities far from sourceTephra (ash) can affect communities far from source
9

31. Eruption duration10
Volcanic events can last for weeks, months, decadesVolcanic events can last for weeks, months, decades
Event DurationWarningHazardous
Event Weeks to
months
Days Days Weeks to
months
Months to
years
Flood
Hurricane
y
Earthquake/
tsunami
Hurricane
Wildfire
Eruption
Wildfire

32. Eruption durationEruption duration
Your volcano may be above or below average
Mount St. Helens, WA: 1980-86
Mount St. Helens: 2004-08
Kasatochi, AK 2008: 20 hours
Okmok, AK 2008: 3 weeks
Redoubt, AK: 1989-1990; 5 months
C t P k AK 1992 3 5 th
A d ti <6
Crater Peak, AK: 1992, 3.5 months
Unzen Volcano, Japan: 1991-1994
Sourfriere Hills, Volcano, Montserrat:
Average duration <6 mos
, ,
1995 - present
Santa Maria Voclano, Guatemala:
1923 - present

33. Small eruptions can be disruptive
Even small explosive eruptions have had world-wide affects
E-15 eruption was small, but affected
millions in Europe
Lightning often
occurs during ash
eruptions; can affecteruptions; can affect
nearby power and
communications
Re-suspension of ash affected Icelandic communities
for months afterwards

34. Small eruptions can be destructivep
Hot rocks interacting with snow and ice can generate large lahars
23 000 l l t th i li h23,000 people lost their lives hours
after a small eruption at Nevado del
Ruiz, Colombia in 1985
Above: Nevado del Ruiz
Right: The town of Amero
after the about 1 month after
the catastropic er ption onthe catastropic eruption on
13 November 1985

35. Bringing it home to your community
• Get to know the hazards in
your communityyour community
• Know the interagency
response plan for your
community
• Know what materials are
available for training yourg y
CERT team
• Include volcanoes in your
multi hazard trainingmulti-hazard training
• Know how to inform your
community (learn, inquire,
plan)

36. Bringing it home to your community
K h t h d ff tKnow what hazards affect your area
• Are you affected by lahars?
• Do you have a regional lava flow
hazard?
• Are you directly or indirectly affected
by volcanic events?
H ld h ff t• How could ash affect your recovery
plans/ability to help a neighboring
jurisdiction?

37. Bringing it home to your community
F ili i lf ith th h d d th thFamiliarize yourself with the hazards and the ways they
could affect your community
http://volcanoes.usgs.gov/publications
/assessments.php

38. Bringing it home to your community
F ili i lf ith ’ l dFamiliarize yourself with your agency’s response plan, and
your role in unified command
At the JIC - MSH crisis October 2004

39. Bringing it home to your communityg g y y
Add volcano preparations to your CERT multi-hazard
training materialsg

40. Bringing it home to your communityBringing it home to your community
Messages USGS gives to the public
• Learn—Become knowledgeable about volcano
issues. Learn whether you live, work or go to
school in a volcano hazard zone.
• Inquire---Ask public officials how they advise you
to respondto respond.
• Plan---For how you and your family will respond
in the event of any natural disaster.in the event of any natural disaster.

41. The goal of planning is to prevent
natural processes from becomingnatural processes from becoming
human disasters
Cascades Volcano ObservatoryCascades Volcano Observatoryy
360-993-8973
www.vulcan.usgs.gov
y
360-993-8973
www.vulcan.usgs.gov

42. Scenario - Mount HoodScenario Mount Hood

43. What’s at risk - Mount Hood
• Community of Government Camp at base of volcano; other communities
within 30 minutes of being affected by lahars
• Hwys 26 and 35. Hwy 26, major route to central Oregon with over 8200
vehicles passing by Government Camp daily.
•• Major air traffic route into Portland, flying at altitudes <25k; over 600Major air traffic route into Portland, flying at altitudes 25k; over 600
commercial flights/day = ~120,000 people/day; ~1700 tons/day air cargo;
30th largest airport in the U.S.
• Bull Run watershed major water supply to Portland; some pipes still• Bull Run watershed, major water supply to Portland; some pipes still
exposed in lahar hazard zone
•• Four ski areas; summer training grounds for US Ski Team. Prime
backcountry recreational area.
• Iconic Timberline Lodge on flank of volcano; major tourist destination
Potential to affect Col mbia Ri er ater a barging fish ater q alit• Potential to affect Columbia River waterway: barging, fish, water quality

44. Hazard zones - Mount HoodHazard zones Mount Hood

45. Mount Hood eruptive stylep y
•Few sustained explosive events (>1Few sustained explosive events ( 1
hour)
• Lava flow or lava dome growth and
collapse collapses difficult tocollapse - collapses difficult to
predict
•Dome collapse results in hot rock
interacting with snow and ice to
produce lahars
• Dome collapse results in ashp
clouds lofting to altitudes of 15,000
to 30,000 feet and drifting downwind
(normally eastward)

46. How are you being affected?How are you being affected?
How are you getting information?y g g
What information do you want?
What actions are you taking? Unified Command/JIC?
?How are your resources holding up?
How are you getting information out?y g g
What questions are you getting from your community?
From the media?From the media?

47. Notes or Action Items

48. Notes or Action Items

49. Mount Hood scenario: Days 1-14Mount Hood scenario: Days 1 14
• Day 1: USGS detects eq swarm; nothing unusual mentions swarm in weekly update
• Day 3: Swarm continues; USGS releases Information Statement noting
continued activity; picked up by some local media
• Day 6 (Saturday night): Three mid-M3 eqs and 5 high M2 eqs rock volcano; felty ( y g ) q g q
at TL and Govt. Camp; USGS changes Alert Level to Advisory early Sunday a.m.
• Day 7: Poor weather, can’t see volcano; media calls increase considerably:
eqs continuing mostly M1s and 2s but at higher rateq g y g
• Day 9: Weather clears; detection of minor CO2 and H2S; no obvious changes at
volcano, but eqs continue as do media inquiries
• Day 10: Several more M3 eqs; mid-day under clear skys, steam and ash
emission; higher gas output; USGS raises alert level to Watch; USFS closes
down mountain
• Day 14: First steam and ash emission to 25 000 ft ; last 10 minutes and• Day 14: First steam and ash emission to 25,000 ft.; last 10 minutes and
drifts eastwards; vents located north of Devil’s kitchen area

50. Mount Hood scenario: Days 14-28Mount Hood scenario: Days 14 28
• Day 14: First steam and ash emission to 25,000 ft.; last 10 minutes and drifts
eastwards; vents located north of Devil’s kitchen area;
• Day 15: Another steam and ash emission to 20,000 ft lasting 25 minutes,
moving westward; instrument placed on Crater Rock to look at movement: gas
output increases; media and tourists flocking to areap g
• Day 16-19: Poor weather and intense rain; instrument suggests movement of
Crater Rock, but no confirmation due to weather; two more explosion signals;
small lahar generated in White and ZigZag rivers
• Day 20: Good weather; Gas output increased 2 fold since last measurement, with
notable SO2; USGS indicates unrest increasing, but does not change alert level;
lahars appear related to rain, not volcanic activity
• Days 21-28: Good weather continues; gas measurements up, but steam and
ash explosions cease; eqs continuing at moderate levels; public interest high;
minor movement of Crater Rock

51. How are you being affected?
No declaration - will you be able to maintain vigilance?
What information do you need to make decisions?
Are any areas closed?Are any areas closed?
What pressures may be pushing back at you?

52. Mount Hood scenario: Days 28-49
• Days 21-28: Good weather continues; gas measurements up, but steam and ash
explosions cease; eqs continuing at moderate levels; public interest high; minor
movement of Crater Rockmovement of Crater Rock
• Day 32, July 4th weekend: New seismic signal appears, USGS believes
eruption imminent, raises alert level to highest level (Warning)
• Day 35: No eruption has occurred, USGS decreases alert level back to intense
unrest (Watch)
•Day 40, late evening: size of eqs decreasing, but rate increasing; glow seen iny g q g g g
Devil’s Kitchen area; Alert level raised to Warning
• Day 41: Lava dome extrusion begins. Later in day, explosion destroys growing
dome and sends ash to 35,000 feet drifting westward; small lahar generateddo e a d se ds as to 35,000 eet d t g est a d; s a a a ge e ated
down White River
• Day 49: Lava dome growth continues, grows rapidly, major failure in mid-day
sends lahar down White and Sandy River: on White reaches confluence withsends lahar down White and Sandy River: on White reaches confluence with
Deschutes, on Sandy reaches town of Sandy, 20 feet thick in Welches…

53. Friday, 29 August (3 years later)
A small dome collapse yesterday was 200th
collapse since the eruption began; ash cloudp p g
reached 25k feet, ash drifting westward;
Portland received light dusting
Alert Level has been downgraded to
Watch/Warning from Warning/Red as there is
no longer any collapse activity
Gas, seismicity still well above background
In the past 3 years ago, > 90 ft of sediment has been deposited in former
location of Timberline Lodge and in headwaters of Sandy River; river has
aggraded over 45 ft in reach near Welches; air traffic has been disrupted for
parts to all of 115 days out of past 1095 days since eruption beganparts to all of 115 days out of past 1095 days since eruption began

54. Notes or Action Items

55. Get to know the hazards in your community
Mo nt BakerMount Baker

56. Get to know the hazards in your community
Glacier PeakGlacier Peak

57. Get to know the hazards in your community
Mount RainierMount Rainier

58. Get to know the hazards in your community
Mount AdamsMount Adams

59. Get to know the hazards in your community
Mount St HelensMount St. Helens

60. Get to know the hazards in your community
Mount HoodMount Hood