understanding earthquakes: science, monitoring & … earthquakes: science, monitoring &...
TRANSCRIPT
Understanding Earthquakes:
Science, Monitoring & Impacts
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Natural Hazards: Earthquake • Volcanic Eruption • Landslide • Flood • Geomagnetic Storm • Wildfire • Tsunami • Coastal Erosion
NATURAL HAZARDS MISSION AREA SAFRR Project: Science Application for Risk Reduction …
Dr. Erin R. Burkett Geophysicist U. S. Geological Survey Science Application for Risk Reduction (SAFRR) Project
I have nothing to disclose.
Disclosure
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Natural Hazards: Earthquake • Volcanic Eruption • Landslide • Flood • Geomagnetic Storm • Wildfire • Tsunami • Coastal Erosion
SAFRR: Science Application for Risk Reduction
The mission of SAFRR is to innovate the application of hazard science for the safety, security, and economic well-being of the nation.
The SAFRR Project
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Natural Hazards: Earthquake • Volcanic Eruption • Landslide • Flood • Geomagnetic Storm • Wildfire • Tsunami • Coastal Erosion
• Discuss the science of earthquakes and associated risk in Southern California.
• Describe the physical, social, and mental impacts of earthquakes.
• Outline technologies and resources for reducing risk from earthquakes.
Objectives
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Natural Hazards: Earthquake • Volcanic Eruption • Landslide • Flood • Geomagnetic Storm • Wildfire • Tsunami • Coastal Erosion
Origins of Earthquakes: Big Picture Driving Forces
Plate Tectonics: heat escaping earth = convection
= tectonic plate motions
= earthquakes, mountains, volcanoes…
Faults of CA
1857 M7.9
• Pacific plate
moves NW relative to North American plate
• San Andreas Fault: largest but not the only one
~5 cm/yr
1906 M7.8
Earthquake fault rupture generates seismic waves that cause shaking. Seismometers/sensors monitor seismic wave (ground motion) activity.
Earthquake Science & Monitoring
Earthquakes: Monitoring
• Advanced National Seismic System (ANSS) for U.S., ~7000 stations
• CISN: California Integrated Seismic Network (CA region of ANSS), ~450 stations
http://earthquake.usgs.gov/ monitoring/anss/
Earthquake Monitoring Equipment
Seismometer Accelerometer
Battery
Power Control
Data Logger
Telecomm
Sump Pump
Recording Earthquakes
Accelerometer “EpiSensor”
Seismic appliance “Q330”
Seismographs: now electronic; used to be “Drum Recorders”
EEW: Electronics vs. Seismic Waves
Modern seismic networks are fast enough to gather and process earthquake data and send alerts to EEW users before shaking arrives.
Earthquake Early Warning (EEW)
• Mexico - 10,153 dead in Mexico City 1985
• Japan - 6,434 dead in Kobe 1995
• Taiwan - 2,415 dead in Chi Chi 1999
• Turkey - 17,127 dead in Izmit 1999
• China - 87,587 dead in Wenchuan 2008
Why Others Have Early Warning Systems
Why EEW Technology is Useful…
Imagine everyday situations…
Why EEW Technology is Useful…
((( EARTHQUAKE! )))
An earthquake can make everyday situations hazardous…
But if alerted…
Why EEW Technology is Useful…
• USGS Fact Sheet available online
• Search “ShakeAlert Fact Sheet” or see SAFRR webpage
EEW Fact Sheet
• Field geologists analyze a cross-section (trench) of a fault
• Dates of and relationships between layers/ offsets provide evidence of past fault movements
Earthquake Geology & Paleoseismology
Geologic evidence = southern San Andreas quakes every ~100 yrs!
Earthquake Geology & Paleoseismology
• 1857: Fort Tejon quake, M7.9, population ~4,000
• Now more than 16 million in LA area; >22 million in SoCal, …plus complicated infrastructure & internet interdependencies!
Since the last SoCal “Big One”…
ShakeOut Simulation: The next “Big One”
ShakeOut Simulation of Shaking Intensity
The ShakeOut Scenario:
• the future “Big One” made tangible
• lays out possible impacts
• motivates & informs planning, preparedness, and mitigation efforts
• The “Great ShakeOut” earthquake drill/exercise, Drop, Cover, & Hold On, developed as a successful scenario outcome
Scenarios: Disasters Made Real
http://www.shakeout.org
The possible “Big One:” an earthquake on the southernmost San Andreas Fault
•180 mile rupture
•Magnitude 7.8
•100 seconds of fault rupture
•Shaking for over 2 minutes in many places
•SAFRR led a group of scientists, engineers, and others to create a realistic scenario of what could happen.
The ShakeOut Scenario
• Significant injuries (50,000), deaths (1800), damages ($213 billion, 300,000 buildings)
• Transportation: roads impassable due to damage, debris, landslides, fault rupture, gridlock, stranded commuters
• Lifeline disruptions: critical water system damage (no water weeks to months), electricity & gas outages, phone systems overwhelmed
• Fires following earthquake
• Damaging aftershock sequences may occur for decades
Full Report details http://pubs.usgs.gov/of/2008/1150/ Resources: www.shakeout.org
ShakeOut Scenario: Impacts
Liquefaction Christchurch, M6.3 2011
Tsunami: Underwater, Subduction Earthquake
Secondary Earthquake Phenomena
• Tsunamis
• Landslides
• Fires
• Liquefaction
• Aftershocks
• Flooding
1906 San Francisco earthquake-induced fires (Sacramento Street)
2001 El Salvador earthquake-induced landslide
Ph
oto
: Arn
old
Gen
the
• Tsunamis
• Landslides
• Fires
• Liquefaction
• Aftershocks
• Flooding
Ph
oto
: Ed
win
L. H
arp
Secondary Earthquake Phenomena
Gas pipelines break => Fire, explosion
San Bruno explosion (September 2010)
ShakeOut Impacts: Fire Following
Earthquakes => Flooding, supply disruption
NBCNews.com: Water Main Break Floods UCLA Campus
ShakeOut Impacts: Water
FEMA Guidelines for code: 90% probability that the building will not collapse
= 10% Collapse rate in code-compliant stock
Red Tags without Collapse Northridge: about 230 collapses
LA County: 2,290 Red Tags
SF Marina in 1989: 40-50 Red Tags, 4 collapses
Yellow Tags Northridge LA County: 9,445 Yellow Tags
Northridge LA County: 2,290 Red Tags
10 RED TAGS PER COLLAPSE
4 YELLOW TAGS PER RED TAG
Analysis for ShakeOut Scenario courtesy of Keith Porter (UC Boulder, Engineering)
Building Damage & Destruction
Hospitals: The ShakeOut Scenario Supplemental Study http://www.colorado.edu/hazards/shakeout/hospitals.pdf
In the 1994 Northridge quake, several hospitals lost functionality:
- building failure: non-ductile reinforced concrete - equipment failures - power outages; emergency power intermittently lost - water damage from rupture of interior water lines & rooftop tanks - patients evacuated; health care in parking lots - facility closure for months
Impacts to Hospitals
Unrestrained patient records shelves.
Unanchored nurse’s station.
Damaged non-ductile reinforced concrete frame building at St. John’s Hospital, Santa Monica
Environmental Contamination: • Smoke, gases, other combustion products • Releases of raw sewage • Landslides & dusts containing the soil
fungus C. Immitis. • Hazardous chemicals released from
damaged industrial facilities • Toxicants in dusts and debris from
building collapse
Environmental Health Impacts: • Short term increase in heart
attacks, strokes, asthma likely • Gastrointenstinal illnesses, skin
infections • Area not considered endemic for
Valley Fever outbreak (e.g., 1994 Northridge)
• Long term impacts of chemical and toxicant exposures not well studied
Kobe, Japan (1995)
Concepcion, Chile (2010)
Environmental Health Impacts
All railroads and freeways into Los Angeles cross the San Andreas Fault
Transportation Disruption (ShakeOut)
Mental Health Challenges
• Fear of injury or death
• Separation from family; worry during loss of communication
• Horror of witnessing injury/death/damage
• Post-traumatic stress & grief
• Separation-anxiety in children
• Depression
• Loss of trust in safety & security of the world
• …continued during aftershocks
The Risk…
“Research suggests that the long-term emotional consequences of a disaster are related to feelings of powerlessness and lack of control over forces bigger than oneself.”
Earthquake Psychology
Why Earthquakes Incite Fear:
•Unpredictable
•Uncontrollable (powerlessness)
•Dreadedness of outcome
•Not understood (origins or impacts)
e.g., “Risk Perception” –Paul Slovik
Countermeasure:
• EEW; culture of readiness
• Acceptance & understanding:
– We live in earthquake country.
– Damage is controllable
• Death is rare; damage preventable
• Education & awareness
The Risk…
Earthquake Risk
Many do not comprehend risk (fear > risk)
– Skiing accident (1 in 10,000)
– Lightning strike (1 in 83,930)
– Earthquake (~1 in 125,000)
…it’s NOT just about dying
Earthquake Risk
It’s not the earthquake that kills… It’s objects & structures around us that are (preventable) threats.
What risks are we comfortable living
with?
Earthquake Risk Perception
We often ignore risks we cannot see.
Earthquake Risk Perception
Earthquake Risk Perception
Living with earth quakes means: •understanding the science •using technology & engineering •to be prepared for one ANYtime •... by accepting them as part of our culture
• Consider what could happen in a big earthquake and what you can do now to reduce damage and recover quickly.
• Secure Your Space
- Top heavy furniture - Water heaters - TVs & electronics - Vulnerable structures
• Store More Water
- 1 gallon per person per day for at least 3 days and ideally for 2 weeks
• Have a Fire Extinguisher - Everyone must know proper use
• Establish a family or work emergency plan
- Know contacts, where to meet
Whether at home, work, or school
Learn more at: www.DareToPrepare.org
Earthquake Preparedness
The system fails when too many pieces of the system fail. Efforts must prevent the disaster from becoming a catastrophe.
When can an economy recover and when does it falter?
Disaster vs. Catastrophe
City of Los Angeles Mayor’s Report “Resilience By Design,” informed
through USGS collaboration.
•ShakeOut Scenario guided the development of a plan to increase City of LA’s seismic resilience
•Addresses areas of seismic vulnerability:
– Pre-1980 buildings presenting unacceptable risk to lives of residents
• non-ductile reinforced concrete buildings
• Soft-first-story buildings
– Water system infrastructure
• Water for fire fighters
• Seismic resistant pipes
• Protected fault crossings for aqueducts
• Less dependence on imported water
– Communications infrastructure http://www.lamayor.org/earthquake
Science(ShakeOut)-Informed Policy
California aqueduct
• http://www.earthquake.usgs.gov/earthquakes
USGS Earthquake Resources
Accessibility of Earthquake Resources
Consideration of cultural and language barrier issues important in increasing earthquake awareness and preparedness.
Earthquake information available in a number of languages through resources such as:
www.earthquakecountry.org/roots/
• Contact: [email protected] or
• Resources (scenarios, videos, reports):
http://www.usgs.gov/natural_hazards/safrr/
Questions?
Mountains courtesy of Earthquakes