Earthquake Hazard
Hayward fault and Richmond
Sierra Boyd
Christina Valen
“California is all that it is cracked up to be”
Suresh Raman
Intros
Suresh Raman
MS, Electrical Engineering
Software Professional for 30 years
MyShake Team Lead, BSL
Sierra Boyd
PhD, Earth and Planetary Science
Research Data Analyst, BSL
Christina Valen
MS, Computational Science
Data Analyst, BSL
Quick facts – notable earthquakes in CA
• 1906
• 1989
• 1994
M7.9 San Francisco (widespread fires)
M6.9 Loma Prieta (freeway span collapse)
M6.7 Northridge (most expensive earthquake in the US)
7 earthquakes in California greater than M6.7 since the 1994 Northridge earthquake (30+ years ago) Measures of an Earthquake
Shaking Intensity and Magnitude
• Shaking Intensity, aka the Modified Mercalli Intensity (MMI), is a measure of the shaking caused by an
earthquake (it is what you feel)
• It is a subjective measure, not based on instrument readings (although instrument readings can supplement it)
• It will vary with distance and soil characteristics
• It is from 1 to 10, with 3 being mild and 6 being strong
For the Hayward fault
Area of slippage is 110km * 8km
Length of slip is 2m
(all calculations in dyne-cm)
Mw = (2/3) * log10(3 * 1011 * 110 * 8 * 2 * 1012) – 10.7 M7.1
Earthquake
Measure -
Magnitude
• Magnitude is a measure of the size of the earthquake, specifically, the amount of energy released.
• No longer called the Richter scale
• It is now called just the magnitude scale (or “moment” magnitude scale) • It is from 1 to 10 (sort of), Northridge 1994 was M6.7 Mw = (2/3) * log10(rigidity of rock * area of contact * length of slip) – 10.7 For the 2004 Indian Ocean Earthquake (and Tsunami)
Rigidity is 3 * 10
11 dyne/cm2
Area of slippage is 1100km * 120km
Length of slip is 10m
(all calculations in dyne-cm)
Mw = (2/3) * log10(3 * 1011 * 1100 * 120 * 10 * 1012) – 10.7 M9.03
Mount Tambora, 1815
Yellowstone Caldera
What
event is
this, at
M2.3?
Predicted Shaking due to an Earthquake of a given
Magnitude (ie Ground Motion Prediction)
Shaking (MMI) = function of Magnitude(M), Distance(D), Site conditions
For eg (Davidson-Wald, 2007, simplified):
• MMI = c1 + c2(M-6) + c3(M-6)^2 + c4*log(D)+c5(D)+c6(MlogD) Using the simplified equation and the constants from Davidson-Wald:
• A M7 earthquake at 10km (6mi) distance would cause MMI 8 shaking.
Hayward fault major history
• Last notable earthquake was a M5.8 near Berkeley in 1870. • Previous M7 earthquake on the Hayward fault was in 1868, originated in Fremont and ruptured north till Berkeley. It had 6 ft of horizontal slip. • Last six major earthquakes occurred at intervals of 95 to 183 years, with an average interval of about 150 years.
• We are currently at 157 years!
Uniform California Earthquake Rupture Forecast
(UCERF version 3)
● By the Working Group on California Earthquake Probabilities ● Endorsed by USGS, Southern California Earthquake Center (SCEC), California Geological Survey (CGS)
UCERF3 Fault Model
● Using 350 fault sections
● 250,000 fault scenarios
● Incl. multi-fault rupture
scenarios
● One of the fundamental
physical quantities being
evaluated in the models is the
amount of “moment”(energy)
locked/released due to
various slip scenarios.
The warmer colors (ie, towards red)
represent higher fault slip rates
UCERF3 rupture
probabilities for
earthquake >= M6.7
before 2044
Fault Name Probability
Southern San Andreas 53%
Northern San Andreas 33%
Calaveras 25%
Hayward 15%
Hayward-Rodgers Creek 32%
Richmond Hazard Map by
Metropolitan Transport and Assoc. of Bay Area
Govts. (aka MT/ABAG)
https://mtc.maps.arcgis.com/apps/webappviewer/index.html?id=4 a6f3f1259df42eab29b35dfcd086fc8
This map shows a composite shaking hazard for the Bay Area based on the probability of many different possible earthquakes. The shaking level shown on the map has a 10% chance of being exceeded over the next 50 years.
Shaking Hazard Map
Liquefaction susceptibility
Thank You!
Questions?
Suresh Raman
Sierra Boyd
Christina Valen
Road Network
250k nodes, 550k edges (OSM)
7 million people
13 people/road segment
Water Network
100k joints, 100k pipes (EBMUD)
1.4 million customers
14 people/pipe segment
System of Systems
“The benefit of infrastructure is diffused…”
“How do we show the value?”
Interdependency - Alameda Case Study
2 Bassman T.J., Zsarnóczay A., Saw J., Wang S., Deierlein G.G., “High-Fidelity Testbed Development for Regional Risk Assessment in Alameda, California”, 12th NCEE, 2022 Transportation & Water Infrastructure
Inventory Generation Tools Ground Shaking and Permanent Deformation 3 4
We Can Expect Scenes Like This
The sooner and the
better organized
we are, the less
time and expense
it will take for
recovery.
Why Use Radios
After an
Earthquake?
• Radios may be the only
option to communicate in
your neighborhood and to
call out for help.
• Neighbors can
help first responders
by using hand-held
radios to report
victims and hazards,
and help save lives
Richmond Emergency
Communication (EMCOMM)
Radio Operators train, drill and
practice regularly.
Communication is Key
Richmond CERTs
(Community Emergency Response Teams)
train for immediate response.
CERTs and EMCOMM Radio Operators are trained in the
Incident Command System (ICS).
Richmond neighborhoods have Incident Command Posts (ICPs)
Richmond Communication / Incident Command Post Structure ICPs report Emergencies to the City EOC
Emergency
Operations
Center
Neighborhood
ICP
Damage
Assessment
Medical Team Fire
Team
SAR
Team
Ham
Radio
Ham
Radio
FRS
Radio FRS
Radio
GMRS Radio
Neighborhood
ICP
ICPs also communicate with each other.
Neighborhood Field Teams send messages to their ICP
EMCOMM begins and ends in the Field.
The Incident
Command Post
Communication
structure in
Richmond will
be used after
the earthquake
for recovery,
but…
To respond effectively
community volunteers
need support
• Caches of Supplies within
reach
• Emergency Response and
ICP Training for more
citizens
Richmond Needs
More Neighborhood
Incident Command
Posts
• Neighbors helping
neighbors
• Training and using a
common structure
and language
• Communicating
when situations
cannot be handled
Thank you and
Remember
• The sooner and the better
organized we are, the less
time and expense it will
take for recovery.
The Power of
Neighbor-to-Neighbor
(N2N)
Rocky Saunders
West Contra Costa Fire Safe Council
Neighbors are First Responders
• Neighbors helping neighbors is the first response action in any emergency or disaster event.
• N2N assistance within the first hour of an event (aka the “Golden Hour”) has the highest potential return for first aid and community response like evacuation.
• N2N is a force-multiplier leveraging fire, law enforcement, and emergency medical responses.
1 N2N is an Investment Our Citizenry
• Investment in N2N is a leveraged investment in your citizenry. • N2N benefits includes:
• Delivering Disaster Response: first-aid, coordinated evacuations, effective neighborhood response including evacuations, if necessary • Building community awareness
• Creating an informed citizenry
• Summary: N2N is a force-multiplier that can leverage emergency response. It is an investment in Richmond’s citizenry.
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