EPS 20 Final lec 17-24

FEMA NATIONAL PREPAREDNESS REPORT, 2019 (Sara K. McBride)

"Attempts to enhance levels of preparedness among individual households, communities, and various organizations which lie outside the emergency management profession's immediate sphere of control have shown little to no sign of improvement. Preparedness campaigns such as Ready.gov, America's PrepareAthon, and National Preparedness Month, all aimed at individual households and communities, have not produced the desired results... Past efforts to apply top-down or one-size-fits-all solutions have too often ended in disappointment."

Loma Prieta

- 1989 -EQ on the SA fault -$7 Billion in damage -Worst case scenario -Major EQ 7.1 Collapse: Section on land fill over soft mud (red dash) • No collapse: Section on stronger sand and gravel (red line) Damaged Areas: San Francisco Marina District, Oakland, Santa Cruz Marina District built on waterlogged landfill and many structures were soft story so massive damage due to liquefaction Epicenter under loma prieta mountain

UCB campus

1. Continuous process of evaluation and improvement First assessments started in 1975• $250 million spent retrofitting 18 buildings by mid-1990s SAFER project started in 1997• $1 billion spent retrofitting dozens of buildings 2. Current initiative started in 2017 • New assessment of all buildings using current state of knowledge • All problematic building issues (rated V or less) resolved by 2030 Phase 1 & 2 assessments complete: 114 buildings Phases 3: 505 buildings - to be completed June 2020??? Expected to have ~135 Berkeley buildings rated V, VI or VII: - retrofit, replaced or vacated by 2030 Campus Tour Stop 1 Residence Halls Non-ductile concrete high rise Constructed in 1960 Retrofitted with steel concentrically braced frames in the 1990s New "infill" housing constructed in 2005 Engineered for their location using internal unbonded braces Stop 1 Dinning facilities Original facility constructed in 1960 along with the surrounding high rise accommodation (right) Determined to be a very vulnerable so were demolished Crossroads dining facility constructed in 2002 Designed for continued operation after an earthquake to serve the Cal and surrounding communities Uses unbonded braces and shatter resistant glass Stop 2 Berkeley Art Museum Non-ductile concrete with vertical walls supporting cantilever galleries Constructed in 1970 Bold and innovative at the time The same structural elements that make the building innovative also compromise the structural integrity stepped configuration, cantilever tree walls, expansive skylight entrance, window walls on lower level The cost of a retrofit is the same as a new building Minimal retrofit now in place, funding for a new building being sort The theater moved out Stop 3 PFAT/Hearst Annex Constructed in 1999 New (temporary) home to the Pacific Film Archive Theater The 1997 analysis of the Berkeley Art Museum indicated that it was not safe enough for a busy theater The Hearst Annex provides "surge" housing for those displaced by the retrofit program Stop 3 Barrows Hall Non-ductile concrete frame Constructed in 1964 Retrofit completed 2001 cost $20 mill Original design emphasized vertical columns with generous opening on the ground floor: a floating superstructure Such designs often lack the shear walls necessary to withstand lateral ground motions during an earthquake The solution was to jacket the ends of the buildings to increase the strength and stiffness of the building Stop 4 Latimer & Hildebrand Non-ductile concrete Constructed from 1960 to 1966 Same architect but different structural engineers: Latimer: Henry Degenkolb - world renowned earthquake engineer Hildebrand: T. Lin - recognized for edgy, bold designs Both required a seismic retrofit following the 1997 review • The series of earthquakes (Alaska 1964, Caracas 1967, San Fernando 1971) significantly improved understanding of building performance in earthquakes resulting in substantial changes in building codes • Substantial changes to codes were also made following the Northridge 1994 and Kobe 1995 earthquakes Stop 4 Latimer Hall Non-ductile concrete Constructed in 1963 Retrofit completed 2001 Retrofit was entirely external • added to outer column of concrete to vertical box columns and concrete beams on odd floors • added to shear walls on east and west sides Stop 4 Hildebrand Hall Non-ductile concrete, shear wall around elevators only: soft story and floating superstructure Constructed in 1966 Retrofit completed 2001 • added shear walls on east and west sides • added unbonded braces on north and south • attachment of vertical concrete facing improved Stop 5 Hearst Memorial Mining First building designed by John Galen Howard, the first campus architect who designed much of the campus' "classical core" Unreinforced masonry with granite cladding Completed in 1907 Retrofit completed 2002; cost $80 mill Base isolation (developed at UC Berkeley) used to decouple the building from ground shaking: minimized the changes to this architecturally important building 134 base isolators Stop 5 Stanley Hall Original Stanley Hall • constructed 1950 of non-ductile concrete • demolished in 2001 as retrofit more expensive than a new building New Stanley is steel moment frame with unbonded braces Modes of building failure, What is the common factor? Soil failure/liquefaction Narrow-base structures Bending/weak structures Partial wall collapse

1933 Long Beach earthquake

1. Houses "tossed" off foundations-- most common 2. School buildings collapsed 230 school buildings: destroyed, major damage, or unsafe to occupy Recognized the failure of unreinforced masonry bearing walls 1933 Field Act banned unreinforced masonry construction for new schools

Probabilistic ground shaking

1. Take the predicted ground shaking for each earthquake 2. Take the probability of each earthquake 3. Calculate the probability that ground shaking will exceed some level Intensity of ground shaking that has a 50% probability of being exceeded within the next 30 years Probabilistic ground shaking Engineering version Spectral acceleration at 1.0 sec in %g 2 1 g = 9.81 m/s scale goes up to 2.5g! with 2% probability of exceedance in 50 years During a 50 year lifetime of a building there is a 2% chance of stronger shaking International building standards call for a maximum of 1% collapse probability in 50 years

Lessons from Research: risk and crisis communication (Sara K. McBride)

1. The Public is not lazy, apathetic or uneducated. The one general "public" does not exist; publics do. People are busy. Differing publics have different priorities and today, you are probably not on this list... 2. SEEING THE PUBLIC AS ONE MASSIVE GROUP there are groups and you approach them differently 3. Most publics do not respond to numbers alone. This is not a matter of getting the numbers right and simply tell "them" the numbers. contextualize and tell a story 4. Comparing risks and showing them that they've accepted similar risks in the past is shown to be ineffective 5. Fear campaigns are rarely successful. Think short term gains (the diet phenomena) Without positive suggestions on ways improve circumstances, these campaigns are largely ignored anger from the publics towards the fear inducing agency. not sustainable produces anger and mistrust 6. Communicate the risk, not just the hazard. Give different publics immediate actions they can take to improve their future situation. 7. Not addressing realistic concerns from people. 8. Why do scientists struggle to communicate? Science as a culture ●Unique language, terms, and concepts ●Specific channels used that are only accessed by scientists (conferences, journal articles) ●Can create isolation; echo chambers ●Base their communication on impressing colleagues rather than interacting with people. peer review focus 9. Keeping people "out" ●What this looks like: ●-Controlling information ●-Purposely not inviting challenging groups to conversations ●-Not acknowledging other people's point of view ●-Determining priorities based solely on your own perspective MULTIDICIPLINARY SOLUTIONS We need a sustained culture of resilience and preparedness Summing up ●There are many, many barriers to people not preparing (a few mentioned here). ●This is about culture, which is broader than booklets, pamphlets, websites, or tweets. ●Inclusive approaches are key to more preparedness activities. ●We need all kinds of people to help us do better.

Why did many concrete columns fail in Northridge EQ?

Concrete is good with compression, but bad with tension, so add steal which is good with tension in shearing reinforcement

Are shallow or deep earthquakes felt further away?

Deep earthquakes

Iben Browning

EQ Charlatan who predicted EQ in Missouri in 1990 but it never happened

EQ and pandemics

Earthquakes can Cause Disease Outbreaks - Pandemics Increase Earthquake Vulnerability - Earthquakes Impact Response to Pandemics Haiti bad conditions in Sanitation caused by earthquakes Vulnerability to disease increases pandemics increase boner ability to earthquake preparedness the coronavirus response and earthquakes are contrasting methods Risk of pandemics(COVID19) the hazard is pathogens opportunity and transmission we can control by social distancing reproductivity= duration x opportunity ( how many people you have come into contact with) x susceptibility( are you likely to get sick) x transmit ability( how easily does it get transmitted/ how) the goal is to have less than one R

Faults with highest hazard in Bay Area

Hayward (26%) South San Andreas (21%) South Calaveras (26%)

Risk

Hazard x Vulnerability decrease by decreasing vulnerability risk estimate- probability of reaching intensities

US approach

Takes an "All-Hazards" Approach • In 2006, President George W. Bush signed the Pandemic and AllHazards Preparedness Act • In 2019, Congress passed The Pandemic and All-Hazards Preparedness and Advancing Innovation Act (PAHPAI), which aims to improve the nation's preparedness and response to both natural and deliberate man-made threats • The law centralizes federal responsibilities and requires statebased accountability for response to earthquakes and tsunamis, hurricanes, flooding wildfires, terrorism-related events, and disease outbreaks

Why are EQ forecasts set for 30 years?

That is the average length of a home mortgage--helps people determine need for EQ insurance, safety of their home

How Do Scientists Calculate Earthquake Probability?

The Global Positioning System (GPS) and other land surveyingand geologic techniques have allowed scientists to make more accurate measure- ments of how the current plate motions— totaling 1.6 inches per year across the San Francisco Bay region—distribute stress onto these individual faults. Balancing plate motions with the slip during large earthquakes and slow creep on faults allows scientists to calculate average rates of earth- quake occurrence over periods of hundreds to thousands of years. A trench excavated across the Hayward Fault in Fremont revealed evidence of 12 large earthquakes over the past 1,900 years. The time interval between these earthquakes ranged from about 100 to 210 years. Historical records indicate that the most recent large earthquake on this fault occurred in 1868. The rate of large earthquakes in the San Fran- cisco Bay region was high in the late 1800s but dropped abruptly after the 1906 San Francisco earthquake on the San Andreas Fault. Scientists believe that the post-1906 earthquake rate decreased because the large amount of slip along the San Andreas Fault in 1906 temporarily reduced the stress onmany of the faults in the region. However, the ongoing motion of the tectonic plates began rebuilding stresses after the 1906 event, and earthquakes larger than magni- tude 5.5 resumed during the second half of the 20th century. Future large, damaging earthquakes in the San Francisco Bay region, similar in size to the 1989 Loma Prieta and 1906 San Francisco earthquakes, may or may not be accompanied by the level of earth- quake activity observed in the late 1800s.

the blind zone

The region close to the epicenter where telemetry and processing delays prevent warning Network latency Goal:• >90% stations operating • data latency <1 sec Data packetization and telemetry median:6.5 sec ElarmS-RT latency: Seismometer to warning (on ElarmS computers) median: 11.8 sec

Surface Rupture

The surface expression of the slip at depth that produced the earthquake. Provides info on length, slip distribution, rupture complexity, structure of the endpoints (used in fault scaling relations) Recognition of rupture geomorphology and structure that can be seen while fresh and may encountered in paleoseismic trenches

blind thrust faults

They are a lurking danger of unknown dimensions, as the region around Los Angeles has experienced more than once.When seismologists checked their geologic maps, they could not find any fault in this area, hence the epicentral region was marked low risk on the hazard maps. Intensive studies after the quake revealed that the area is underlain by the Puente Hills thrust system, which nobody knew about before. may have been a clearly visible and active fault ten thousand years ago

building code policy

1920s: Building codes initiated in the US • 1923: Great Kanto earthquake lead to efforts in Japan • 1925: City of Santa Barbara introduced code including consideration of horizontal forces• 1928: first Uniform Building Code included recommendation for earthquake resistant designs 1933 Field Act banned unreinforced masonry construction for new schools-- not retrofitting 1939 Garrison Act applied Field Act standards to existing schools, not just new schools 1967 Greene Act set deadlines for schools to be inspected and retrofitted/replaced if needed Initial building code were based on observed damage in quakes Today, we measure shaking and feed into designs, particularly for bigger structures

Awareness and planning make a difference

2004 M9.1 Sumatra earthquake and tsunami ~300,000 people exposed ~230,000 dead in tsunami Little awareness No warnings People went to the beach to watch VS 2011 M9.1 Tohoku earthquake and tsunami ~300,000 people exposed ~16,000 dead in tsunami Sea walls and barriers Warning system Public education and drills

SF Eq probabilities 2016

62% probability of magnitude 6.7 or greater by 2032 Smaller earthquakes: 80% probability of M 6.0 to M 6.6 earthquake by 2032 ...and we had the 2015 M6.0 Napa quake ...the 2016 report 72% chance (up from 62%) of one or more M ≥ 6.7 earthquakes by 2043 33% chance (up from 27%) on the Hayward-Rodgers Creek Fault 22% chance (up from 21%) on the San Andreas Fault Earthquake probabilities ...the 2008 report Statewide: 99% chance of M ≥ 6.7 San Francisco region: 63% chance of M ≥ 6.7 Los Angeles region: 67% chance of M ≥ 6.7 Annual losses in California: $2.2 bill Average annual losses across CA due to building damage only $104 Average annual losses per capita due to building damage only

Earthquake Outlook for the San Francisco Bay Region 2014-2043

72% probability of one or more M ≥ 6.7 earthquakes from 2014 to 2043 in the San Francisco Bay Region Timeline of magnitude 5.5 and greater earthquakes in the San Francisco Bay region 1850-2014. In the 50 years prior to 1906, there were 13 earthquakes with a magnitude between 6 and 7, but only 6 earthquakes of similar magnitude inthe 110 years since 1906. The rate of large earthquakes is expected to increase from this low level as tectonic platemovements continue to increase the stress on the faults in the region The faults in the region with the highest estimated probability of generat- ing damaging earthquakes between 2014 and 2043 are the Hayward, Rodgers Creek, Calaveras, and San Andreas Faults. In this 30-year period, the probability of an earth- quake of magnitude 6.7 or larger occurring is 22 percent along the San Andreas Fault and 33 percent for the Hayward or Rodgers Creek Faults. Individual sections of these faults have lower probabilities for large earthquakes to occur

Statewide chance of M>6.7 in next 30 years

99%

When was EEW first suggested?

After Hayward Quake in 1868 Suggested again by Tom Heaton in 1985

Components of an Earthquake early warning system

Algorithms-- How to detect? What area to warn? Accuracy: false/missed? How fast Seismic network--How many sensors? How to send data? How fast? Users--Who? What action? How fast? - use education Alerting--How? How fast? How accessible Process of discovery How quickly can we detect and characterize an earthquake? Is the available warning time useful? For what? Who should/will fund a warning system? What will it cost? How do we educate people to use the system?

Areas of highest seismic hazard in US?

Along San Andreas Fault New Madrid Seismic Zone

aftershocks

Always smaller aftershocks, expect • 1 quake one mag unit smaller • 10 quakes two mag units smaller • 100 quakes three mag units smaller, etc... But, can also lead to a larger "mainshock" • 1 in 20 California earthquakes are followed by a larger quake

Probability/Likelihood in EQ science

Based on best available knowledge, like plate movement, prior EQs in area, stress field, geologic setting

how Earthquake Early Warning works

Basic principle: Detect an earthquake as soon as the rupture starts, in order to give a notice to infrastructure/population located further away. (EEW): local and regional versions local is a single detector regional is a system of seismic networks and complex algorithms p-wave detected by closest seismograph --> informing public only works if there is a dense network need multiple sources to determine the location and fault mechanism -Possible because body waves travel faster than surface waves, which are responsible for most of the damage. -Necessitates a good instrumental coverage. -Location and magnitude have to be precise enough.-No false alarms. EEW Algorithms--Process to generate alert 1. Earthquake nucleates underground 2. P-wave detected by closest stations P-wave arrival times => location P-wave amplitude (and frequency)=> magnitude 3. Alert generated For any user location: Time till shaking and shaking intensity can be estimated Most systems rely on the fact that an earthquake comes in two parts: a fast- moving, sudden jolt and a slower-mov- ing wave that causes the great majority of the damage A network of seismometers can quick- ly identify the earthquake's epicenter, improve predictions ofthe earthquake's magnitude and reduce the incidence of false alarms. Origins of Earthquake early warning San Francisco - 1868 First proposed earthquake early warning system J.D. Cooper • Detectors outside the city • Use telegraph wires • Earthquake bell • Automated • Will work for distant shocks

Global Seismic Networks: history and purpose

Began being used during nuclear era to monitor test ban treaties Now also used in dense arrays in order to determine hazard in specific areas for retrofitting needs of buildings

possible precursory stages

Build-up of elastic strain Dilatancy (the phenomenon exhibited by some fluids, sols, and gels in which they become more viscous or solid under pressure) and development of Crocs influx of water and unstable deformation in Fault Zone- causes foreshocks sometimes sudden drop in stress followed by aftershocks

Prediction is ______ Forecasting is ______

Certainty Odds, chances, probability

Communication Defined (Sara K. McBride)

Communication is a transactional process in which people generate meaning through the exchange of verbal and non-verbal messages in specific contexts, influenced by individual and societal forces and embedded in culture (Alberts, Nakayama, & Martin, 2007, p. 21). It can be both an art (creative/critical discourse) and a science (social sciences). Communication is the "umbrella" term for public relations, media relations, marketing and associated sub-disciplines. Related terms in emergency management are "public education" (campaigns to educate the public about risk and emergency preparedness) and "public information" (communication in times of crisis).

Recording earthquake shaking using buildings

Initial building code were based on observed damage in quakes Today, we measure shaking and feed into designs, particularly for bigger structures Transamerica building • completed 1972• 49 stories - 260 m high • accelerometers record motion Loma Prieta earthquake • 100 km away• shook for >1 minute• top swayed > 30 cm 1984, M6.2 Morgan Hill earthquake • 20 km from West Valley College• Center of Gymnasium roof swayed more than expected Resulted in changes to the Uniform Building Code (in 1991) ...this type of roof now has to be less flexible in new buildings ...but, existing buildings do not have to be modified

probabilistic hazard assessment

It is a standard method to quantify hazards used in civil engineering and in the insurance industry.

Japan: Early warning systems

Jan 1995: Kobe earthquake - 6,000 dead • 1800 seismic stations installed Feb 2004: JMA begins testing Aug 2005: Successful warning: Sendai, Miyagi • M7.2 earthquake • 140 schools/agencies • warnings up to 16 sec Oct 2007: Nationwide public warning system launched

Which country has the most advanced EEW system?

Japan, initiated in 1995 following Kobe EQ Began operation in 2007 nationwide

2014 South Napa Earthquake

M6.0 West Napa Fault Epicenter in American Canyon Rupture Length 18-25 cm Unreinforced masonry buildings continued to experience damage An unreinforced masonry building retrofitted with steel-braced frames that performed well during the earthquake with no signs of any structural or nonstructural damage Single family homes2014 South Napa earthquake Wood frame buildings with cripple walls experienced partial collapse 1933 Long Beach earthquake Homes "tossed" off foundations

CLASS GOALS

Make you more aware of earthquakes • Make you more knowledgeable about earthquakes • Make you more prepared for the next big earthquake to inform future leaders of our society about the various hazards associated with earthquakes, and to provide the necessary information for you to make intelligent decisions about earthquake mitigation options Your charge make a difference...start small, go big, be an earthquake-responsible citizen

masonry buildings

Masonry bricks and mortar are brittle: they crack and collapse still breaking in 2019 Expect collapse, fallen walls/facing, bricks falling into street • Problem recognized in 1933 Long Beach earthquake

Mexico City: Seismic Alert System

Mexico City: Bowl of jello 300 km from subduction zone But, city built on lake bed 1985 M8.0 Michoacan earthquake > 5,000 dead in the city "Front detection" 300 km • Developed in 1989 in the wake of the 1985 Michoacan earthquake • 15 stations along coast • Station data transmitted to central processing in Mexico City • Warning issued when two stations indicate an event greater than M 5 ~300 km allows 60+ sec warning M7.3 Guerrero earthquake September 14, 1995 • event successfully detected and an alert issued • 72 sec warning • no real damage in Mexico City

Which country had first EEW system in the world?

Mexico, called SASMEX, built following 1985 EQ

Does CA have EEW?

My shake goal: 4 million users by 2020 people want it 87.6%

CISN Network--how many stations?

Over 3,000 stations California Integrated Seismic Network

What we need for EQ prediction

Prediction: To be useful, we have to exactly pinpoint: Where When How strong(magnitude) No false alarms No missed EQ affects all facets of life These are scientifically very stringent and challenging requirements We need at least one measurable precursor, which consistently occurs before each large EQ seismic gaps help determine where it is more likely

Hog Lake Paleoseismic Site: San Jacinto Fault Zone

Quasi-periodic earthquake occurrence

SF earthquake scenarios

San Andreas: Repeat of 1906 4.7% probability in 30 years San Andreas: Peninsula Segment 4.4% probability in 30 years San Andreas: South Segment 2.6% probability in 30 years Hayward: North + South Segments 8.5% probability in 30 years 21% probability of any rupture on Hayward North (that's us!) in 30 years

Why is predicting earthquakes so hard?

Scientific process 1. Observation of a physical process è measurements 2. Development of physical theory è predict outcomes Earthquake rupture-What observations are needed? 1. Location of faults ...all faults 2. Stress on fault ...every patch 3. Physical properties of fault surface ...every patch What theory is needed? 1. Criteria for slip to start - nucleation point 2. Process of rupture propagation across fault 3. Criteria for slip to stop at a point determining magnitude 1. Basic observations are so hard The faults are buried kilometers beneath the surface Fault surfaces are very heterogeneous Faults are massive undulating surfaces below below ground the ground is not flat, creep, different structures, locked pattern 2. Earthquake rupture is a critical failure process-- need to better understand nucleation, propogation, rupture etc • Constant build-up of stress • Fault patches failing, i.e. slipping, all the time Most failures stay small, some become big Analogy:Avalanche on a pile of sand-- cannot predict sliding systems Earthquake swarm on faults in eastern California complex system-- unpredictable bc of all the variables

stress shadow

Seismicity rate dropped after 1906 up to 1906 there are many EQs but after the 1906 EQ there are only a few The important lesson here is that for most of this century, central California has been experiencing a seismically quiet period caused by stress relaxation after 1906. The region may slowly be recovering from this "stress shadow" to a more normal state of seismicity as the tectonic plates continue to move, and the stresses on the major faults recover to the values that they had in 1905.

Little earthquakes are good, right, because they bleed off some of the stress so that the 'Big One' isn't so bad?

Smaller earthquakes do not decrease the stress of a large earthquake because for every 10 magnitude 5 earthquakes there are 100 magnitude four earthquakes and 1000 magnitude three earthquakes.

Soft story buildings

Structurally weak first stories, e.g. apartments with carports collapse risk in moderate earthquakes car garage that is unenforced Expect partial collapse• Problem recognized: 1989 Loma Prieta, 1994 Northridge Berkeley Soft Story Program - enacted Jan 2014 • Mandatory retrofit of soft-story buildings with 5 or more dwellings • Apply for retrofit building permit by Dec 31st, 2016• Work must be completed within 2 years

probability of an earthquake

This can be calculated from the average recurrence interval, variability (ie.,± 75 years) called the coefficient of variation, and the amount of time (elapsed time) since the most recent large earthquake The magnitude and recurrence are used to calculate ground motions, from a single fault or an ensemble of faults, for building codes and critical facilities. EQ Cycles present is key to past geologic processes and natural laws now operating to modify the Earth's crust have acted in the same regular manner and with essentially the same intensity throughout geologic time, and that past geologic events can be explained by phenomena and forces observable today

EQ forecasting

Time-dependent, short-term forecasting considering earthquake clustering and possible precursors Probabilistic assessment of EQ occurrence Only estimate of location and magnitude not when hazard estimate based on identification of faults info about the average slip rates where the segment is in the cycle We can use the long-term processes to estimate the probability of earthquakes and their hazard A return period, also known as a recurrence interval or repeat interval, is an average time or an estimated average time between events The concept behind Earthquake forecasting is Elastic Rebound 1. Displacement across the San Andreas in the 50 years prior to 1906 was 3.2 m 2. Max displacement during 1906 was 6.5 m 3. When do we expect the next event? 6.5/3.2 x 50 = 100 year Assumptions: everything is constant • The rate of plate motion i.e. strain across the fault • The physical properties of the fault We can use the long-term processes to estimate the probability of earthquakes...this is earthquake forecasting Earthquake odds - a balancing act Plate tectonics: • Loads the faults- rate of load accumulation through GPS or long term slip rates • Measure using GPS Slip on the faults: • Creep - from GPS • Earthquakes - need past events recurrence interval, trenching, probability of shaking, location estimate, Each possible earthquake must be identified • 7 faults • 18 fault segments • 35 rupture scenarios

Communication (as a research discipline) (Sara K. McBride)

Transdisciplinary: multi research disciplines combined with knowledge of practitioners

What can EEW be used for?

Trigger actions, Protect oneself, Being ready for shaking Reducing Falling hazards 1. Personal Safety (duck cover and hold on) 2. Automated Control (shutting off gas valves, slowing down train cars, etc) 3. Situation Awareness (rerouting critical infrastructure, powering up generators at hospitals, initiating emergency response)

EQ Charlatans

Try to make money off of predictions Iben Browning Luke Thomas David Nabhan

Purposes of Forensic Seismology

Understand building collapses Understand mine collapses for legal arguments Meteors Rock falls Costa Concordia shipwreck Nuclear test ban treaties

Uses of Forensic Seismology

Understanding 9/11 and the blasts, how the buildings collapsed in order to build better buildings in future Enforcing nuclear test ban treaty Legal work--why did a mine collapse

Examples of Retrofitting on Campus

University Hall X bracing Hearst Mining base isolator and moat wall Wurster Hall base isolators

2019 Ridgecrest Earthquakes

Unreinforced masonry buildings continued to experience damage

How good are our estimates?

Very difficult to test our forecasts do not know how they will interact with other faults But when we translate earthquake hazard into shaking hazard, it means the whole Bay Area should be built for strong shaking Japan: Since 1979 earthquakes causing 10 or more fatalities have not occurred in regions forecast to have high hazard

Performance levels

WE WANT • Immediate Occupancy • Negligible structural damage Life safety maintained Essential systems operational Minor overall damage CURRENT Damage Control Slight structural damage Life safety attainable Essential systems repairable Moderate overall damage

Seismic Hazard Estimates

We can make estimates of this based on observations and understanding of real fault ruptures that include the length and endpoints might look like, and amount of slip on the fault. These values, plus how deep the fault extends into the crust, determine the magnitude. We're also interested in the probability of an earthquake rupture on a fault. This can be calculated from the average recurrence interval (ie., every 250 years), variability (ie.,± 75 years) called the coefficient of variation, and the amount of time (elapsed time) since the most recent large earthquake. The magnitude and recurrence are used to calculate ground motions, from a single fault or an ensemble of faults, for building codes and critical facilities.

Earthquake prediction theories

We want a silver bullet An observable that we can make before every earthquake Proposed candidates • Foreshocks, seismic swarms • Change in velocity of seismic waves • Ground uplift • Radon gas • Electrical conductivity • Animal behavior Some of these have been observed before an earthquake But none have been observed before all (big) earthquakes...or even before many earthquakes P-velocity variations cracks form reducing seismic velocity But... Need exact location of the earthquake to measure this change in velocity...no convincing observations of changes in velocity radon gas may be released from bedrock prior to earthquakes Ground uplift and tilt Nigata 1964 Gradual ground elevation and subsidence over decades Sudden subsidence near future epicenter in the year prior The 1964 earthquake But... The data is now suspect Ground uplift and tilt The Palmdale Bulge (Apparent) rapid uplift in the region of Palmdale starting in the 1960 Maximum of 35cm Was this a precursor for an earthquake? No earthquake occurred. Signal turned out to be data error Electrical conductivity Lab experiments show that water saturated granite changes resistivity just before fracturing But... How do we measure electrical signals in the ground? There are too many man-made signals Animal behavior no conclusive evidence

EQ Cycles

What Goes In Plate boundary stress Must Come Out Fault slip: Earthquake ruptures Creep

Hazard

What nature presents to us speed of tectonic movement, location of faults, locked or aseismic creep, quality of soil constant - unable to be changed The single most important cause for damage to structures and harm to people during a temblor is the shaking of the ground. • Shaking intensity, size of tsunami, landslides 2 Components of Seismic Hazard PGA (peak ground acceleration) /Strength of EQ/Soil Conditions Probability Seismologists actually use the peak ground acceleration (PGA) expected in an earthquake as a measure of the seismic hazard. The larger the expected PGA is, the larger is the seismic hazard. The ground acceleration is usually compared to a standard acceleration, which in our case is the average gravitational acceleration at the surface of the Earth. Like in the case of PGA the seismic hazard also increases when the expected peak ground velocity (PGV) gets larger. earthquake engineers have spent countless hours trying to generate ground motion prediction equations to properly quantify the seismic hazard.Such calculations become even more complicated, the strength of the ground shaking is very strongly influenced by the type of rock or soil on which structures or buildings are constructed. In general, harder bedrock shakes less severely than softer, non-consolidated sediments do. Another element which can amplify the seismic hazard is the actual topography of an earthquake prone region. The seismic waves can trigger whole basins filled with soft sediments to shake in resonance, further increasing the severity of the shaking. Near mountain tops or ridges the seismic waves can be focused by being reflected off steep slopes. This process can also result in a higher thanexpected peak ground acceleration. And finally, sediments saturated with water pose an additional seismic hazard. When shaken hard by seismic waves such ground can liquify and loose all its mechanical strength needed to support the foundation of buildings and structure

Vulnerability

What we put in nature's way quality of construction, personal preparedness- can reduce turns hazard into risk • Population density and exposure • Construction quality of buildings and structures • Personal preparedness "Earthquakes don't kill people, buildings do" The risk we face depends on what we put in the way of the hazard. We reduce risk by reducing our vulnerability. Step 1: Identify, understand, quantify the hazard Step 2: Identify, understand, quantify the vulnerability Step 3: Reduce the vulnerability and risk to acceptable levels Strategies include 1. Estimating earthquake probabilities 2. Estimating fault slip and shaking levels 3. Designing buildings to withstand slip and shaking 4. Insurance to cover the cost of recovery 5. Public policy to encourage/enforce risk mitigation 6. Rapid/short-term warning and response systems Our goal when Living with earthquakes is to reduce the risk to acceptable levels

Single family homes

Wood framed homes are good placesto be in an earthquake Wood beams are ductile: they can bend and absorb earthquake motions without breaking Pre-1979 homes may need to be bolted and braced to attach wood frame to the foundation. Expect cripple wall collapse and homes knocked off foundations • Problem recognized: 1933 Long Beach, 1989 Loma Prieta, 1994 Northridge, 2011 South Napa... But, is your home pre-1979? then "bolt and brace" sales tax by retrofit Home knocked off foundation in 1994 Northridge earthquake Wood framed home with weak cripple wall resting on foundation cripple walls break and buckle

foreshocks

Yes, increased seismicity can lead to more seismicity We can't tell foreshocks are foreshocks until it's too late examples: successes and fails Success: Haicheng, China, February 1975 • predicted an imminent earthquake, evacuation ordered • nine hours later a large earthquake struck destroying many homes but there was little loss of life Failure: false alarm Kwangtung provice, August 1976 • predicted an imminent earthquake, evacuation ordered • people slept in tents for nearly 2 month - no earthquake Failure: missed alarm Tangshan, July 1976 • no immediate precursors, no evacuation • more then 250,000 people died - one of the deadliest earthquakes

dams

attract EQs

myshake

berkeley made Early warning delivery, detailed image information reported by users, preparedness and safety tips, real time earthquake information around the globe. Alert message Must be simple and provide action Alert delivery Geotargeted Smartphone push notifications how fast? how reliable? Earthquake detection Sensor network • seismic networks • smartphones(Uses accelerometer in cell phone) instead of waiting for a sensor • internet of things Alert delivery Broadcast network geotargeted alerts virtuous circle: scientific discovery, hazard reduction, user application, citizen science History of ShakeAlert Got funding in 2006 to test algorithms 2008 begins to implement end-to-end system 2011 complete system operational Phase 3 2014 West Coast Network prototype Being tested by Google, UCB, BART

Building codes

building codes decrease our vulnerabilities but they have to be developed through experience... Building codes: regulations governing design, construction, alteration and maintenance of structures They specify minimum requirements to safeguard health, safety and welfare of building occupants Building codes exist for all aspects of building design Obtaining a building permit is about ensuring that these standards are met developed through experience Building codes are essential to ensure safe buildings But we have to learn from past mistakes, and they are not usually retroactive. You want to live and work in post 1980 building. Earthquakes cause horizontal forces, while building design mostly focuses on vertical forces

Non-ductile concrete buildings

collapse risk in moderate earthquakes Brittle behavior in joints and columns Limited amount of reinforcing steel Affects buildings constructed prior to late-1970s when 1976 code was adopted Expect collapse, partial collapse, debris in street• Problem recognized: 1985 Mexico City, 1994 Northridge, 1995 Kobe, 2011 Christchurch... Non-ductile Concrete Retrofit Program • enacted October 2015• construction permit prior to 1977 • affects 1,400 buildings in LA • mandatory retrofit (or demolish) • 3 years to submit plan • 10 years to obtain permit • 25 year to complete work Column failure $12 billion highway bridge earthquake strengthening program Retrofit: Steel casing around existing columns New columns: Continuous steel spirals

fault cluster

irregular cycles interaction with other faults can produce stress shadow

Mitigation is the answer

moved from prediction to mitigation (building codes, hazard elements, understand probabilities) To become more resilient, we must enact effective mitigation strategies ...the Engineering ...the Public Policy ...the Sociology

what can we predict?

once an earthquake has nucleated, i.e. started, we can predict ground shaking

UC Berkeley

over the years, spent more than $1 billion to address our buildings' seismic deficiencies Our current initiative is the product of revisions to the UC Seismic Policy that were adopted in 2017 every building with significant seismic performance deficienci es be retrofitted, replaced or vacated no later than the year 2030. As per the Regents' policy, the effort to assess and rate every building on each of the 10 UC campuses was launched in 2018 and relies on a phased approach and schedule: Phase 1: Completed no later than Dec. 31, 2018 Phase 2: Completed no later than June 30, 2019 Phase 3: Completed no later than June 30, 2020 The University's proven, proactive approach to seismic safety dates back to 1975, when the UC system developed its first formal systemwide seismic safety policy and initiated efforts to assess and improve the seismic safety of its infrastructure. Since then, there have been 37 major earthquakes in California (magnitude 5.1 or above), with not a single injury or fatality on any of the UC campuses. By the mid-1990s, 18 buildings on the Berkeley campus had been identified and were retrofitted at a cost of approximately $250 million. Then, in 1997, Berkeley launched its second, more comprehensive seismic safety program called SAFER — Seismic Action Plan for Facilities Enhancement. SAFER provided the Berkeley campus with an up-to-date, comprehensive analysis of structural seismic safety performance of over 250 campus buildings. We have, to date, spent more than $1 billion addressing seismic deficiencies as identified by the SAFER program across more than 1 million square feet of space in dozens of buildings — work that continues to this day.

Inside the Fault: Trenching

place time of eq and magnitude find the distribution of eq in history - paleoseismology Trenches can be:NarrowDeep Intimidating Dangerous Exciting Informative Multiple lines of evidence for surface ruptures in multiple trenches Development of a long record requires an excepNonal site with excellent preservaNon of strata and abundant dateable material, such as peat and seeds

Denali

success story Alaska r strike slip 1000km wide 2002 m7.9 330+km slip The vulnerability seems extremely high in a very small area near the Richardson Highway, a mere 75 km from the epicenter of this quake. There the Trans-Alaska oil pipeline crosses the fault. The existence of the Denali Fault and thecorresponding high seismic hazard had been known for decadesbefore the pipeline was built in the 1970's. While for most of itslength of 1300 km the pipeline rests on a support of stilts andsteel cross bars, engineers used a different design for the 600 m wide corridor, where the pipeline crosses the fault zone. There itrests on teflon shoes, which can move on concrete slider beamsset directly into the ground. This approach allowsthe ground to shift during an earthquake by up to Slider beam length ~8 m whileminimizing the shear forces acting on the pipes themselves,because they can freely slide on their teflon bases. the ground underthe pipeline slipped by more than 4 m. significantly reduced the vulnerability of thepipeline and thereby decreased the seismic risk This example shows that we can do a lot to reduce the vulnerability of buildings, structures and, in fact, ourselves as a response to an earthquake hazard. It is intuitively clear that the seismic hazard is higher in areas, where strong earthquakes occur in short regular intervals of several decades.

fault segment

used to estimate earthquake hazard and shaking divide faults into portions on the historic slips large earthquakes are larger segments

fault system

whole plate boundary system

WHY DID PEOPLE SEEM RELUCTANT? (Sara K. McBride)

● Children ● Busy working ● Did not take it seriously ● Did not want to ● Disability (adult) ● Uncertainty ● Did not believe in the technique ● Confused instructions ● Embarrassment ● Anxiety ● Inappropriate location ● High body mass EXPLORING EMBARRASSMENT ● SOCIAL EMOTION ● CAN BE PART OF SOCIAL NORMING AND MILLING PROCESS ● CAN BE ADDRESSED BY: HUMOR, VISUAL AIDS, MESSAGING ● MORE FREQUENT DRILLS ● NORMALIZING BEHAVIOUR HELPING CARETAKERS OF CHILDREN -INJURY DATA (Northridge etc...) -Messaging around: protective yourself first, then children. -Explore options in terms of messaging, imagery, and trainings LIMITATIONS -OBSERVER BIAS AND INTERPRETATION -HAWTHORNE EFFECT -LACK OF INDIVIDUAL IDENTIFIERS -ACCOUNTING FOR CULTURAL NORMS -TRAUMA FROM RECENT EARTHQUAKES Overall, we could improve messaging to be more inclusive of different needs.