BOSTON--(BUSINESS WIRE)-- Catastrophe risk modeling firm AIR Worldwide Corporation (AIR) announced the availability of an update to its probabilistic earthquake risk model for the United States. The model is used by insurers, reinsurers, corporations and government agencies to assess and manage earthquake risk in the U.S.

Over the past several years, there has been substantial new research to better assess seismic hazard and the response of structures to earthquake-induced ground motion, said Dr. Jayanta Guin, senior vice president of research and modeling at AIR Worldwide. AIR is committed to incorporating the most advanced science and engineering in our models.

Highlights of the enhanced model include:

• An updated view of seismic hazard in the U.S. that is consistent with the 2008 U.S. Geological Survey (USGS) National Seismic Hazard Maps
• An updated approach to estimating earthquake-induced ground motion based on the Next Generation of Ground-Motion Attenuation Models (NGA) project
• Updated damage functions based on extensive analysis of damage and claims data and sophisticated three-dimensional engineering analyses performed by AIR engineers and other researchers

The USGS recently updated the National Seismic Hazard Maps by incorporating new seismic, geologic, and geodetic information on earthquake rates and associated ground shaking. Producing the update involved interactions with hundreds of scientists and engineers, including AIR researchers, at regional and topical workshops. The AIR model is consistent with the USGS update, which represents the best available science on U.S. earthquake hazard.


The AIR model also incorporates the newly developed Next Generation of Ground Motion Attenuation Models (NGA) equations, which are used for predicting ground motion generated by earthquakes. The NGA equations were the result of a five year multidisciplinary research program coordinated by the Pacific Earthquake Engineering Research Center (PEER) in partnership with the U.S. Geological Survey (USGS) and the Southern California Earthquake Center (SCEC). The resulting NGA equations incorporate significantly more ground motion data and data of better quality, particularly at close proximities to high magnitude earthquakes, and provide a more robust method for estimating ground motion.

The damage functions in the model were updated based on engineering analysis, a thorough understanding of building codes, the results of published studies, and analysis of detailed claims and damage data. The breadth and depth of recent USGS changes have prompted AIR engineers to re-examine existing claims and damage data, not only with respect to the 1994 Northridge, California earthquake, but also for more recent events such as Nisqually (2001) and San Simeon (2003). This re-examination has led to an even deeper understanding of vulnerabilities of structures to earthquakes.

The enhanced methodology used in the development of AIR's damage functions is the same as that recently adopted by major research universities, the Applied Technology Council, FEMA and PEER. Certain applications of the methodology used by AIR engineers have been funded by the USGS. The damage functions of the model have been peer reviewed by Stanford University Professor Greg Deierlein, Director of the John A. Blume Earthquake Engineering Center and Deputy Director for Research of the Pacific Earthquake Engineering Research (PEER) Center, and Dr. Charles Kircher, Principal at Charles Kircher & Associates and a key developer of HAZUS.

The methodology used by AIR to develop its damage functions is well conceived and consistent with established practice, stated Drs. Kircher and Deierlein in their peer-review.

AIR has gone beyond the USGS by employing state or local maps that have more detailed geologic information at high spatial resolution, and explicitly modeling ground motion effects for major basins in California, Washington, and Nevada. While the overall impact of the inclusion of basin effects is relatively small for most buildings, it has implications for tall buildings located on deep basins: the deeper the basin, the more vulnerable the building.

Additionally, the AIR model takes into account the spatial correlation of ground motion parameters. Ground motion generated by an earthquake can produce spatial patterns in which pockets of ground motion are either higher or lower than predicted by attenuation equations. These pockets may be very large and encompass an entire metropolitan area. Therefore, spatial correlation can have a significant impact on modeled losses in cases where the larger/smaller-than-expected ground motion pocket occurs in a densely populated area.


Each of the enhancements implemented in the new AIR U.S. Earthquake Model represents the most advanced science that the wider scientific and engineering communities have to offer, commented Dr. Guin. The Version 11.0 update to AIR's Earthquake Model for the U.S. represents the culmination of more than two years of research and development to provide the most robust and scientifically advanced U.S. earthquake model available.

The updated AIR Earthquake Model for the U.S. is available in Version 11.0 of AIR's CLASIC/2â„¢, CATRADER® and CATStation® catastrophe risk modeling applications.

About AIR Worldwide Corporation

AIR Worldwide Corporation (AIR) is the scientific leader and most respected provider of risk modeling software and consulting services. AIR founded the catastrophe modeling industry in 1987 and today models the risk from natural catastrophes and terrorism in more than 50 countries. More than 400 insurance, reinsurance, financial, corporate and government clients rely on AIR software and services for catastrophe risk management, insurance-linked securities, detailed site-specific wind and seismic engineering analyses, agricultural risk management, and property replacement cost valuation. AIR is a member of the ISO family of companies and is headquartered in Boston with additional offices in North America, Europe and Asia. For more information, please visit www.air-worldwide.com.

AIR Worldwide

Kevin Long, 617-267-6645

klong@air-worldwide.com

Source: AIR Worldwide Corporation