Statement of Dr. Lucile M. Jones, Scientist-in-Charge, Southern California, U.S. Geological Survey, U.S. Department of the Interior
before the Committee on Transportation and Infrastructure, Subcommittee on Economic Development, Public Buildings, and Emergency Management, U.S. House of Representatives
February 23, 2006
Mr. Chairman and Members of the Subcommittee, thank you for this opportunity to discuss the likelihood and potential effects of a worst case, catastrophic earthquake in the Los Angeles area.
The United States is subject to a variety of natural hazards including earthquakes, tsunamis, landslides, flooding, volcanic eruption, hurricanes, and wildfires. These hazards can result in considerable human suffering and billions of dollars in property and economic losses. The occurrence of these hazardous events is inevitable; however, the extent of damage and loss of life can be reduced. Accurate, scientifically based geologic hazards assessments and real-time warning systems that define the nature and degree of risk or potential damage are the foundation for preventive planning; social, economic, and engineering adaptations; and more effective post-event emergency response that are essential to hazard mitigation. At the U.S. Geological Survey (USGS), we strive to deliver the information and tools that emergency managers, public officials and the public 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 National Earthquake Hazard Reduction Program (NEHRP), working with the Federal Emergency Management Agency (FEMA), National Institute of Standards and Technology, National Science Foundation, and state and local government.
The USGS Earthquake Hazards Program provides the scientific information and knowledge necessary to reduce deaths, injuries, and economic losses from earthquakes by providing timely notifications of earthquake locations, size, and potential damage; regional and national assessments of earthquake hazards; and increased understanding of the cause of earthquakes and their effects. National and regional scale seismic hazard maps depict earthquake shaking hazards and are used for creating and updating the seismic design provisions of building codes used in the United States.
Of all natural hazards facing the United States, earthquakes have the greatest potential for inflicting casualties, damage, and economic loss. Although damaging earthquakes are infrequent, their consequences can be immense.
Describing a single worst case catastrophic earthquake event limits a full understanding of the earthquake risk. Southern California is home to more than 300 faults capable of producing damaging earthquakes, more than any other metropolitan area in the United States. To illustrate the range of possibilities, two events are described here: a magnitude 8 event on the San Andreas fault, and a smaller, magnitude 7 to 7.5 event on a thrust fault near downtown Los Angeles. The geologic record tells us that both events are inevitable; the only question is: when will the events occur?
A magnitude 7 to 7.5 earthquake on the Puente Hills, Santa Monica, or Hollywood faults in the Los Angeles basin will produce the greatest damage to buildings because the event would occur in an area near many older structures. A model from a FEMA study of expected losses from a Puente Hills fault earthquake predicts a loss of 18,000 lives, 300,000 displaced persons in need of housing, and financial losses of a quarter trillion dollars.
Because there are several large faults in the Los Angeles basin, one event of this type occurs every 500-1000 years. Smaller earthquakes on these faults such as the 6.7 magnitude 1994 Northridge earthquake will happen an average of more than twice per century. The Northridge earthquake resulted in 57 dead and $40 billion in losses. Earthquakes in the range of 7.0 - 7.5 will damage a large number of buildings in Los Angeles and displace hundreds of thousands of people from their homes. Severe business disruption would continue for months following the event.
A different type of disaster will be caused by the great magnitude 8 earthquake on the San Andreas fault that repeats every one to two hundred years. Earthquakes this large involve movement of 20 or more feet along at least 250 miles of the fault. Thus, every structure crossing the fault, including freeways, pipelines, power lines, and railways will be pulled apart by the fault. This would lead to significant disruption to the distribution system for necessities such as water, power, and food. Repairs to infrastructure could take months.
East of Los Angeles, the San Andreas fault dangerously traverses rapidly growing areas of the Inland Empire (San Bernardino-Riverside). In a great earthquake (magnitude 8.0 or greater) along the San Andreas fault, northern Los Angeles County and the Palm Springs area will likely be the hardest hit. Because there is a greater density of older structures in these areas, many buildings will completely collapse, potentially killing thousands. All southern California communities will be subjected to some level of damage; aid for emergency response will have to come from much farther away and will take much longer to arrive.
The level of damage in Los Angeles will likely be higher than current models predict. Existing building codes have been designed largely based on the ground shaking generated by moderate earthquakes. A recent California Institute of Technology study concluded that the energy produced in a magnitude 8 earthquake on the San Andreas fault could cause one or more high-rise buildings in downtown Los Angeles to collapse.
Just as the collapse of the levees in New Orleans turned a disaster into a catastrophe, the secondary effects of an earthquake can also be more calamitous than the earthquake event itself. Any of the major earthquakes that will strike the Southern California region could trigger a range of secondary effects depending upon the exact fault, weakened infrastructure nearby, and the weather. The potential secondary effects include:
Our actions before the earthquake strikes will help to determine the losses during the event. Science can tell us the likely consequences of an earthquake and we can use that information to change the outcome. The USGS along with our partners in Federal, State, and local governments and academia have identified steps toward mitigating the earthquake hazard in southern California.
Southern California has one of the Nation's highest potentials for extreme, catastrophic losses from several natural hazards such as earthquakes, tsunamis, fires, landslides, and floods. Estimates of expected losses from these hazards in the eight counties of southern California exceed $3 billion per year. These numbers are expected to increase as the present population of 20 million grows at more than 10 percent per year. Recognizing this risk, the Administration has proposed an Integrated Multi-Hazards Demonstration Project in southern California as part of the President's FY07 budget request to Congress. The project would demonstrate how integrating information and products about multiple hazards improves the usefulness of this information in reducing loss of life and property from natural hazards. The Integrated Multi-Hazards Demonstration Project initiative brings the unique research and systems capabilities of USGS to bear on complex issues surrounding natural hazards events, especially those that are interrelated such as earthquakes and tsunamis. The development of integrated databases and the enhancement of information technology systems to track multiple hazards will facilitate more rapid communication and response to the user community. The USGS will work with local planners, emergency managers, and first responders to develop products and tools such as integrated hazard maps and planning scenarios and decision tools to improve communication of USGS science to communities at risk.
Natural hazard events during the past year underscore the need for timely, relevant scientific information. Our efforts in hazards monitoring and long-term data and information collection from past and present hazard events is not simply a scientific research endeavor - - it is a matter of public safety.
Mr. Chairman, thank you for the opportunity to appear before you today. I am happy to answer any questions that you and Members of the Subcommittee may have.