Earthquake Awareness and Preparedness
Earthquakes occur suddenly without warning at any time of day or night. Although the West Coast has the
greatest seismic activity, the potential for earthquakes exist everywhere in the United States. In the Midwest,
three of the largest historical earthquakes occurred in winter of 1811-1812 within the New Madrid Fault
System in southeastern Missouri. A New Madrid Earthquake has the potential to impact eight states:
Alabama, Arkansas, Illinois, Indiana, Kentucky, Mississippi, Missouri and Tennessee. The Wabash Valley
Seismic Zone along Illinois-Indiana border is another earthquake source in the Midwest that would impact
three states: Illinois, Indiana and Kentucky. Another active area in the Eastern United States is the
Charleston area in South Carolina.
About the Webmaster
The webmaster is a professional engineer with extensive research experiences in many aspects of
structural and earthquake engineering. He earned his Ph.D. degree in earthquake engineering in 1997
from Kobe University, Japan. He survived the January 17th 1995 Kobe Earthquake although the building he
lived in with his family partially collapsed as shown on the earthquake pictures below. Recently, he finished
a two and half years research project at Missouri University of Science and Technology (formerly University
of Missouri, Rolla) on seismic hazard analysis in the New Madrid Seismic Zone and the effect of future
earthquakes on structures and bridges in the Midwest. He published 24 papers (on seismic analysis and
design of buildings, bridges, underground structures, and soil-structure interaction) in refereed journals,
peer-reviewed international conferences and symposiums. The findings of these research activities were
presented in Egypt, Japan, South Korea, Iran, China, France, Canada and the USA.
The descriptions, illustrations, suggestions and recommendations included in this web site are intended to
improve earthquake awareness and preparedness in active seismic zones in the United States and
elsewhere. However, they do not guarantee the safety of an individual or a structure. The webmaster of this
web site does not assume liability for any injury, death, property damage, loss of revenue, or any other effect
of an earthquake.
|Photo 1 - Front View of our Home
|Photo 2 - Back View for our Home
after Kobe Earthquake
|Earthquake Awareness and Preparedness
|Recent Earthquakes and Earthquake News
Recent earthquakes around the globe causing death and building damage are reported including: the
2011 Tohoku Earthquake and Tsunami in Japan, the 2010 Haiti Earthquake, the 2009 L’Aquila Earthquake,
and the 2008 Sichuan Earthquake. Earthquake news reported include: the Loma Prieta earthquake
anniversary, the annual Great California ShakeOut earthquake drill, and the latest fact sheet on the New
That being said, what can you do to protect yourself, your family, your home, your personal
possessions and home contents from future destructive earthquakes? This web site will help you by
providing earthquake information on the following topics:
Natural Hazards affecting your Home Safety
Natural hazards associated with earthquakes that may affect your life and home safety include: soil
amplification, liquefaction, landslides, surface fault rupture, tsunamis, fire hazards, industrial hazardous
materials release, and chemical hazards release from garage or utility room. Factors influencing the
intensity of ground shaking at your home during an earthquake are also discussed.
Earthquake Prediction in the Midwest
General information on earthquake prediction of the New Madrid Fault System in Southeast Missouri is
provided. A New Madrid Earthquake of magnitude 6.0 or larger generated from the New Madrid Fault has a
25-40% chance of occurrence during the next 50 years. Earthquakes magnitudes of 7.0-8.0 similar to any
of the three large earthquakes of winter 1811-1812 have a 7-10% probability of occurrence in the same
time frame. Most buildings in the Midwestern States were not built to withstand earthquake ground
shaking, where earthquake awareness and preparedness have lagged far behind the West Coast.
Consequently, a moderate-to-large New Madrid Earthquake would cause substantial economic loss and
structural damage to buildings in Tennessee, Missouri, Kentucky, and Illinois, especially for unreinforced
masonry construction in Memphis, TN. Of special interest is a comparison of the regions of potential
impact of two earthquakes of similar magnitudes: the 1906 San Francisco Earthquake and the December
16th 1811 New Madrid Earthquake.
Earthquake Prediction in California
General information on earthquake prediction in California is provided. California Earthquakes has a
99.7% probability of having an earthquake magnitude of 6.7 or larger by the year 2032. The southern
segment of San Andreas Fault has the highest probability of generating an earthquake in Southern
California with a 67% chance of striking the Greater Los Angeles Area, while Hayward Fault is the most
likely earthquake source in Northern California with a 63% chance of striking the San Francisco Bay Area.
Larger earthquakes are less likely during same time frame. The probabilities of earthquake magnitudes
7.0, 7.5 and 8.0 are 94%, 46% and 4.5%, respectively. The anticipated economic loss and earthquake
damage from future California earthquakes are discussed. Of special interest in California are tsunami
warning and emergency training.
Recent earthquakes around the globe are reminders for people living in seismic zones to prepare!
Earthquake preparedness requires you to be aware of the proximity of your home to active fault lines and
be knowledgeable on the factors influencing earthquake damage to your home. It also requires a disaster
preparedness plan to ensure home safety through seismic retrofitting the home structure and risk
mitigation of home contents. Earthquake insurance is an effective option in reducing the potential costs of
inevitable future earthquakes. Flood insurance would also be effective for people living near the coast in
Disaster Relief Programs and Your Personal Finance
You may wrongly believe that the United States Government will take care of all your financial
needs if your home is damaged and suffer losses in an earthquake which is not true! In fact, the
federal disaster relief programs are designed to help you get partly back on your feet but not to
replace everything you lose. Therefore, most of the property damage caused by an earthquake will
end up being handled and paid for by you, while still responsible for your existing personal debt
like mortgage, auto loans, and credit card payments.
Earthquake Damage, Construction Materials and Home Safety
Your home which is your biggest financial asset as well as your investments made in home contents and
personal possessions may be at risk when a moderate-to-large earthquake strikes your area. The 1994
Northridge Earthquake and the 1995 Kobe Earthquake that occurred in urban areas demonstrated that
earthquake damage is influenced by construction materials, anchor bolts not effectively connected to the
concrete foundations, unbraced cripple walls of the crawl space, soft story in the first floor due to large
openings without effective bracing, year built, and number of stories. Basic knowledge of the structural
issues of your home and the potential earthquake damage is the first step towards earthquake
preparedness. This would help you decide on seismic retrofitting the structural components of your home
as well as risk mitigation of its nonstructural components and contents, thus reducing the risk to lives and
insuring your home safety.
Seismic Activity at your Home
Seismic activity at your home is due to three main processes: the fault rupture mechanism that initiates
from the hypocenter, the propagation of seismic waves within the earth’s crust, and soil amplification at the
top layers of the earth’s surface. Earthquake hazards and the intensity of ground shaking is a function of
three main factors: the earthquake magnitude, the closest distance from the ruptured fault to your home, as
well as the depth and types of soil materials from the ground surface to the base rock. For instance, soft
soils in San Francisco Bay Area would amplify and prolong the shaking even at great distances from the
ruptured fault, while hard bedrocks do not amplify the shaking. Deep soils in valleys and sedimentary
basins like the Mississippi River Valley and Los Angeles Basin would shake more than bedrock in the hills
as seismic waves are trapped and reverberate. Earthquake hazards can be estimated using the interactive
USGS maps by following a simple approach to help you decide on retrofitting your home..
Your standard home insurance policy does not cover earthquake damage to your home structure,
home contents, or personal possessions. However, it covers other kinds of damage that may
result from earthquakes, such as fire and water damage due to burst gas and water pipes. Your
vehicles are only covered under the comprehensive part of your auto insurance policy. How do you
plan to protect your home and investments made in home contents from the costs of
destructive earthquakes? Earthquake insurance which should include contents insurance is an
option for effectively managing these potential costs. Only 12% of California residents currently
have California earthquake insurance down from 33% in 1996 when the devastating Northridge
Earthquake was still fresh in people's minds! On the other hand, 35% of homes have Missouri
earthquake insurance coverage. Recent earthquakes in Haiti and Japan serve as a wake up calls
that may influence people decision to reconsider buying earthquake insurance.
Emergency Preparedness and Disaster Recovery
What to do before, during, and after an earthquake? Emergency preparedness against natural disasters
such as earthquakes and tsunamis requires purchasing a household emergency kit, survival kits for
household members, and maintaining survival food and emergency drinking water for 2 weeks at all times.
It would also be beneficial to take an emergency training course on first aid and cardiopulmonary
resuscitation before a seismic event hits your area. Participate in earthquake drills in your region or
state-wide events like the annual Great California ShakeOut Earthquake Drill in October. Disaster
management during an earthquake as well as disaster recovery after the earthquake requires you to follow
the specific recommendations of earthquake-related organizations which are discussed in complete
Risk Mitigation of Home Contents
These are simple techniques to secure the contents of your home to the studs of the interior walls
using inexpensive hardware tools and materials found in hardware stores. Items in the garage
shall also be secured to reduce damage to vehicles. Such self-mitigation techniques can be
undertaken by homeowners as they are simple to explain and require no special expertise,
materials or tools to implement. You should mitigate the contents of your home whether you
seismic retrofit it or not, because a study from the University of California in Los Angeles
demonstrated that 55% of the injuries during the 1994 Northridge Earthquake were caused by
falling furniture or objects, while only 1% of injuries were caused by structural damage, and other
injuries were due to people falling or behaving dangerously! The study stated that many of these
injuries could have been prevented through risk mitigation of home contents undertaken before the
earthquake. Water heaters are of special concern and should be braced to the wall studs with two
heavy-gauge metal straps and lag screws near the top and bottom of the tank.
Seismic Retrofitting of Home Structure
You should seismic retrofit the structural system of your home if you live within 30 miles from active
fault lines or within regions highly susceptible to liquefaction. You probably have to retrofit it if you
live within 30-50 miles from major faults, especially if your home is constructed before the 1980’s.
This would ensure the structural integrity of your home to withstand earthquakes with no or little
structural damage which would help in returning your family quickly back to their normal life style.
Seismic retrofitting is costly but may be addressed one step at a time. The best return on the
investment of retrofitting efforts is to initially secure the home foundations followed by bracing the
cripple walls, then bracing or strengthening the walls of the soft story (first floor with large
openings), and finally anchoring the connections of the walls and the masonry chimney to the
structural members of the floors and roof.
Seismic Retrofitting and Risk Mitigation
Observations from recent earthquakes demonstrated that the loss of property, level of structural
damage, time and efforts required for repair and recovery, and cost of repairs, as well as injuries
and damage to contents are significantly reduced in buildings where seismic retrofitting of the
structural system and risk mitigation of the nonstructural components and contents have been
made. Seismic retrofitting measures are expensive and would require hiring a professional
engineer and a building contractor. However, risk mitigation measures are simple enough to be
done by you, where commercial kits are inexpensive and available in hardware stores and online
stores like Amazon. Pros and cons of seismic retrofitting vs. risk mitigation based on recent
earthquake reconnaissance reports are discussed, where a conclusion has been made!