STATEMENT OF

DR. DAVID APPLEGATE

U.S. GEOLOGICAL SURVEY

U.S. DEPARTMENT OF THE INTERIOR

BEFORE THE

COMMITTEE ON HOMELAND SECURITY AND GOVERNMENT AFFAIRS

AD HOC SUBCOMMITTEE ON STATE, LOCAL, AND PRIVATE SECTOR PREPAREDNESS AND
INTEGRATION

UNITED STATES SENATE

DECEMBER 4, 2007

Mr. Chairman and Members of the Subcommittee, thank you for the
opportunity to testify at this hearing on the impacts that a major
earthquake in the New Madrid seismic zone would have on the Nation and
what can be done to prepare for and mitigate those impacts. My testimony
will focus on the role of the USGS and our coordination with other
Federal agencies, particularly FEMA; will address differences between
the New Madrid seismic zone and other active faults around the country;
and will provide an overview of USGS work in monitoring and notification
of seismic activity.

From today's perspective, the three large earthquakes that struck the
lower Mississippi Valley in the winter of 1811 and 1812 seem quite
distant in time -- but infrequent events nevertheless represent very
real risks. If the New Madrid earthquakes of 1811-1812 were to recur
today, significant damage to buildings, transportation, and critical
infrastructure would occur in at least eight states, resulting in loss
of life and economic disruption. While earthquakes are inevitable, their
consequences on our built environment are not, and there is much that we
can do as a Nation to improve our resilience to these and other natural
hazards.

At the U.S. Geological Survey (USGS), we strive to deliver the
information and tools that emergency managers, public officials and
citizens need to prevent natural hazards from becoming disasters. The
USGS has the lead Federal responsibility under the Stafford Act (P.L.
93-288) to provide notification -- including forecasts and warnings
where possible -- for earthquakes, volcanoes and landslides. The USGS is
a partner in the congressionally established National Earthquake Hazards
Reduction Program (NEHRP) along with the Federal Emergency Management
Agency (FEMA), the National Institute of Standards and Technology (the
lead agency), and the National Science Foundation (NSF). In
collaboration with these Federal partners plus state and local
governments and universities, USGS reports on earthquake size, location,
and shaking intensity; develops regional and national hazard assessment
maps and related products; supports targeted research to improve these
products; and builds public awareness of earthquake hazards. Along with
our NEHRP partners, USGS is committed to translating research results
into actions that can reduce earthquake losses.

**Why Are There Earthquakes in the Central United States?**

Most earthquakes occur where the brittle plates that form the Earth's
crust and uppermost mantle interact, either pressing together, pulling
apart, or sliding by one another. Such is the case with California's San
Andreas Fault, where the plate that underlies the Pacific Ocean is
sliding past the North American plate, and with the subduction zones off
the Pacific Northwest and Alaska, where plate collision is forcing
oceanic crust to slide beneath North America, generating giant
earthquakes and active volcanic chains.

But earthquakes also occur far from present-day tectonic plate
boundaries as the stresses from those plate interactions are translated
into the more stable interiors. Such intraplate earthquakes in the
central and eastern United States are less frequent than earthquakes in
California or Alaska, but the hazard they pose is by some measures
equally significant. The older, colder crust in the central and eastern
United States allows earthquake waves to travel much farther and thereby
affect much larger areas than earthquakes of comparable size in the
west. That is the case with the New Madrid seismic zone, which stretches
from just west of Memphis, Tennessee, up into southern Illinois. Another
geologic factor increasing the hazard from New Madrid earthquakes is
that earthquake waves tend to be amplified by the soft soils of the
Mississippi Valley, adding to the intensity of shaking experienced by
communities there.

All these factors came into play during a two-month period in 1811 and
1812 when three earthquakes with moment magnitudes estimated at between
7.5 and 8.0 had a profound effect on the region and were felt as far
away as the eastern seaboard. Thousands of aftershocks followed and
continued for decades. Although few people lived in the region at the
time, the effects on the landscape remain clear nearly two centuries
later. These effects include sand blows, formed when strong shaking from
a large earthquake caused wet, loose sand deposits to lose cohesion and
-- acting like a liquid -- erupt onto the ground surface through
overlying silt and clay layers. Studies of such sand blows show that
similar sequences of major earthquakes have happened at least twice
before, in about 1450 A.D. and 900 A.D.

Based on geologic research on the paleoseismic record of past
earthquakes, the USGS estimates that there is a 7 to 10 percent chance
of a New Madrid earthquake the size of those in 1811-12 occurring in the
next 50 years. However, the occurrence of even a moderate-sized
earthquake located in close proximity to urban centers such as Memphis
or St. Louis could be locally devastating. The last magnitude-6
earthquake struck near Charleston, Missouri, in 1895. The chance of such
an earthquake occurring in the New Madrid region in the next 50 years is
25 to 40 percent.

These probabilities are derived from the USGS National Seismic Hazard
Maps, which are developed from geologic information about faults,
evidence of prehistoric earthquakes, instrumental and historical
earthquake catalogs generated by seismic monitoring, and ground
deformation measurements. The National Seismic Hazard Maps are used to
estimate probabilities of large earthquakes and the ground shaking to be
expected if those earthquakes occur.

An important facet of the NEHRP partnership is the cooperation between
the USGS and FEMA to incorporate these seismic hazard maps into model
building codes. These USGS maps are the basis for seismic design maps in
the International Building Code and the International Residential Code,
which have been adopted in almost all states. The newest version of
these maps has recently been delivered to the Building Seismic Safety
Council for incorporation into the next generation of model building
codes. Seismic hazard maps are also used in the design of bridges, dams,
and other critical facilities; for loss estimation studies; and to set
premiums for earthquake insurance.

The USGS has recently begun developing higher-resolution maps and other
products that focus on the most vulnerable urban areas. In the central
and eastern United States, these include Memphis, St. Louis, and
Evansville, Indiana, which is in the Wabash Valley seismic zone along
the southern border of Illinois and Indiana. Such maps require detailed
mapping of surficial geology and knowledge of sub-surface geology in
order to incorporate the local effects into estimates of shaking. They
are useful for prioritizing retrofitting of unreinforced masonry
buildings, initial seismic design of structures, and urban planning.
Urban hazard mapping in the central United States involves a number of
state and university partners including St. Louis University, the
Illinois State Geological Survey, the Missouri Department of Natural
Resources, the Kentucky Geological Survey, the University of Missouri at
Rolla, the University of Memphis, and the Indiana Geological Survey.

**Delivering Rapid Information for Emergency Response**

Just as knowing where earthquakes occur can lead to building codes that
save lives through a more resilient built environment, knowing where
shaking is most intense immediately after an earthquake also can save
lives by providing emergency responders with the situational awareness
they need to concentrate their efforts where they matter most.

For that reason, the USGS and our partners have been building the
Advanced National Seismic System (ANSS) to modernize the Nation's
seismic monitoring infrastructure and provide, within minutes,
information about strong shaking and probable damage. The ANSS consists
of a national backbone network, regional networks, a 24/7-staffed
National Earthquake Information Center, and ground- and structure-based
instruments concentrated in high-hazard urban areas. Currently about 15
percent deployed, the ANSS has already greatly improved information
available for emergency responders, engineering performance studies, and
long-term earthquake hazard assessments.

The USGS provides rapid reports of potentially damaging earthquakes to
the National Command Center; the White House; the Departments of
Defense, Homeland Security (including FEMA), Transportation, Energy, and
the Interior; State and local emergency managers; numerous public and
private infrastructure management centers (for example railroads and
pipelines); the news media, and the public. These earthquake
notifications are delivered as e‑mails and text messages to over 100,000
users. A suite of information products are available through the USGS
Earthquake Hazards Program website, which receives an average of two
million hits per day. For undersea earthquakes, USGS also provides
near-real-time seismic data to the National Oceanic and Atmospheric
Administration tsunami warning centers, supporting their monitoring and
notification mission.

In the central United States, earthquake monitoring is accomplished
cooperatively by the USGS, the Center for Earthquake Research and
Information at the University of Memphis, St. Louis University, and the
University of Kentucky. The ANSS Mid-America Region includes the New
Madrid and Wabash Valley seismic zones, as well as ANSS urban
strong-motion monitoring targets of Memphis, St. Louis, and Evansville.
There currently are 200 real-time seismic stations in the central United
States., only 70 of which meet modern standards. Over 500 seismic
stations are planned for the central United States. These regional
networks process approximately 200 earthquakes for the New Madrid
seismic zone annually. The ANSS Mid-America Region also encompasses the
East Tennessee and South Carolina seismic zones that pose a threat to
Alabama, Georgia, South Carolina, North Carolina, Virginia, West
Virginia, Kentucky, and Tennessee. In these areas, roughly 40 stations
are processed in real-time to provide information on about 70
earthquakes annually.

Within five minutes after a potentially damaging earthquake in the
central United States, notifications are sent to local, state, and
Federal emergency management officials and others with the epicenter and
preliminary magnitude of the earthquake. Within 20 minutes, an initial
ShakeMap is released showing areas of expected higher ground shaking for
use in emergency response, utilities, business recovery, and public
awareness. Within 60 minutes after the earthquake, seismograms have been
analyzed to determine the geometry of the fault, and an improved
ShakeMap is released. With ANSS only partially deployed, these ShakeMaps
are primarily model-based rather than data-based, due to the sparse and
heterogeneous station coverage in the region. As additional sensors are
installed, these maps will improve in resolution and accuracy.

Three months ago, the USGS began delivering a new product, known as
Prompt Assessment of Global Earthquakes for Response (PAGER), which
provides rapid estimates of population exposure to shaking in the same
timeframe as ShakeMap. The PAGER system overlays the estimated shaking
intensity with a global population database to estimate population
impact. This gives emergency responders and aid agencies a rapid
estimate of the extent of the likely response required. Such information
is particularly valuable in cases where communications may be down.
Domestically, PAGER complements the rapid loss estimates that are
generated using FEMA's HAZUS software in conjunction with USGS
ShakeMaps.

**Using Scenarios to Better Understand What is at Risk**

The actions we as a society take before hazardous events strike are even
more important than how we respond in the aftermath of a natural
disaster. In addition to the geologic factors that raise the hazard from
intraplate earthquakes, an important reason why central U.S. earthquakes
can be particularly devastating is that the impacted communities are
less prepared than their west coast counterparts. Most of the buildings
and infrastructure were built without consideration of seismic shaking,
in large part because it has been so long since the last damaging
earthquakes in the region. In the New Madrid seismic zone, the challenge
to strengthen or replace the many vulnerable structures is compounded by
the large numbers of jurisdictions that would be affected by a large
earthquake.

Scenarios are a tool that can help make such hazards more real by
detailing the likely consequences of a repeat New Madrid earthquake
sequence on today's society, where the hundreds of settlers in 1811-12
have been replaced by millions of residents in cities, towns, and farms
across the region as well as a complicated, interconnected
infrastructure that serves not only the local population but the Nation
as a whole. The information in a scenario can be used to reduce the
vulnerability of lifelines, retrofit critical structures, improve
monitoring systems, plan emergency response, and educate our citizens.

Scenarios are being used by FEMA and others to carry out more realistic
preparedness exercises. This year's Spills of National Significance
(SONS) exercise, which used a New Madrid earthquake scenario developed
by the USGS and partners as its trigger for testing spill response, and
FEMA's upcoming catastrophic planning exercise based on a New Madrid
earthquake, should improve preparedness in the region.

The impacts of an earthquake of magnitude of 7.5 or greater in the New
Madrid seismic zone are daunting, starting with significant structural
damage to buildings in Arkansas, Mississippi, Alabama, Tennessee,
Kentucky, Indiana, Illinois, and Missouri. Lifelines crossing the
region, including highways, bridges, and oil and gas pipelines leading
to the northeastern United States., would be severely damaged,
particularly in the Mississippi Valley. If the earthquakes were to occur
when the Ohio and Mississippi Rivers were high, loss of levees would be
likely, along with flooding of low-lying communities. The City of
Memphis, with over one million people in its metropolitan area, would be
the most affected urban center. Memphis has an aging infrastructure, and
many of its large buildings, including unreinforced schools and fire and
police stations, are particularly fragile when subjected to severe
ground shaking. Very few buildings were built using modern building
codes that have some provision for seismic-resistant design.

Earthquake hazards involve more than just seismic shaking. The 1811 and
1812 earthquakes caused landslides along the bluffs from Mississippi to
Kentucky. Today a repeat event could be expected to produce similar
effects in downtown Memphis. At least one highway and one railroad
bridge crossing the Mississippi River are unlikely to survive a major
New Madrid earthquake, and many old overpasses would likely collapse. A
significant hazard in the New Madrid region is a type of ground failure
called liquefaction, which in 1811 and 1812 affected a region from south
of Memphis to St. Louis. Liquefaction causes soil to flow and form deep
cracks that may make roadways in the Mississippi Valley of Arkansas and
Missouri (such as I-55) impassible. Liquefaction can cause flooding of
fields and roads with water, sand, and mud, disrupting agriculture for
an extended period of time. Liquefaction and failure of levees and
riverbanks could make the Mississippi River unnavigable for many weeks.
Although Memphis is likely to be the focus of major damage in the
region, St. Louis, Little Rock and many small and medium-sized cities
would also sustain damage.

One characteristic of New Madrid earthquakes is particularly noteworthy.
Geologic evidence suggests that the sequence of three large earthquakes
in a two-month period in 1811 and 1812 is characteristic of the region.
This means that during recovery efforts, subsequent earthquakes as
strong as the first shock, rather than just weaker aftershocks, must be
considered when deciding where to feed and shelter people and when to
start rebuilding.

Much more detailed scenarios are being developed for the forthcoming
catastrophic planning exercise being undertaken by FEMA in conjunction
with the Mid-America Earthquake Center headquartered at the University
of Illinois at Urbana-Champaign as well as by the Earthquake Engineering
Research Institute (EERI). This scenario will be similar to the one that
EERI produced for a major earthquake striking Seattle.

**Building Public Awareness**

The citizens of this region will bear the brunt of a future New Madrid
earthquake. They need to be educated on the likely consequences of
earthquakes, how to recognize a safe building, the importance of
retrofitting and how to respond safely. In particular, there is a need
to educate people on how to better secure the contents of their homes
and workplaces. Damage to contents caused \$12 billion of the \$40
billion in losses in the 1994 Northridge earthquake that struck southern
California.

Through the Central U.S. Earthquake Consortium, the USGS and FEMA are
working with state emergency management agencies, departments of
transportation, and geological surveys to provide information that they
can use in their planning and public education efforts. Activities
include developing shaking scenarios for state and local exercises,
sponsoring field trips for state and local officials and the business
community, and holding local earthquake town hall meetings and other
public forums throughout the region. Additional efforts include
participating in earthquake awareness week activities, maintaining a
Public Earthquake Resource Center at the USGS office at the University
of Memphis Center for Earthquake Research and Information, and preparing
and distributing educational and informational materials.

**Scientific Questions Remain**

An integrated picture of what will happen in a future New Madrid seismic
zone earthquake \-- from rupture on the fault to shaking and damage of
buildings and infrastructure \-- requires research on all aspects of the
earthquake process. Such research may include: mapping the near-surface
geology in the urban region; determining the location and geometry of
all hazardous faults; measuring the seismic wave speed across the range
of near-surface materials; and deploying ANSS sensors in the ground to
quantify the way earthquake waves travel in the region and in key
engineered structures to better predict how they will respond to severe
shaking. These results would provide a more complete picture of where
mitigation would do the most good and would better support emergency
response. Scientific analysis reduces uncertainty, and further
engineering evaluation will help reveal the actual level of
vulnerability in our built environment and help prioritize retrofitting.
A few of the research questions that the USGS and its NEHRP partners are
pursuing include:

-   What is the full extent of the New Madrid seismic zone? We are
    searching for additional geologic evidence, using seismic and
    geophysical exploration methods to identify active fault systems.

-   Are there other areas in mid-America besides the New Madrid zone
    that can produce large earthquakes? How often do they occur? We know
    that the Wabash Valley seismic zone has magnitude 6.5 or greater
    earthquakes with about a 4,000-year recurrence. The search continues
    for geological and geophysical evidence that can reduce uncertainty
    with regard to the timing of prehistoric earthquakes and active
    fault systems.

-   Can we identify areas of high hazard using GPS measurements of
    ground deformation? In contrast to plate boundaries like
    California's San Andreas fault, where the rate of major earthquakes
    is predictable based on measured deformation, large earthquakes in
    the New Madrid region seem to happen much more frequently than
    predicted from GPS measurements of ground deformation. The USGS and
    NSF are supporting research and monitoring activities to better
    constrain these ground-deformation rates and better understand the
    process that leads to earthquake rupture in this intraplate setting.

-   What level of ground shaking can we expect from future large
    earthquakes? Data from an expanded ANSS will improve ShakeMap and
    urban hazard maps. Additional work is needed to measure and map the
    properties of soils that amplify ground shaking.

-   What information is most needed by local officials to promote and
    prioritize mitigation actions, and by emergency managers to best
    respond when an earthquake strikes?

**Conclusion**

While there is still much that we do not know about the earthquake
hazard in the heartland, we could significantly improve the resilience
of our society and economy through greater preparedness and targeted
mitigation. In the future, earthquake monitoring and long-term data and
information collection activities will continue to be crucial for
decisionmakers seeking to ensure public safety.

Mr. Chairman, this concludes my remarks. I will be pleased to answer any
questions you may have.