The Applied Technology Council (ATC) is pleased to announce the scheduling of the 2nd ATC-35 Workshop on National Earthquake Ground-Motion Mapping for Thursday and Friday, May 10-11, 2001, in San Francisco at the Radisson Miyako Hotel. The Workshop is being convened by ATC and the U.S. Geological Survey (USGS). Like the first ATC-35 National Earthquake Ground Motion Mapping Workshop held in Los Angeles, this Workshop will provide a multidisciplinary examination of key scientific and design-related issues that affect the preparation of the second round of national ground-motion maps by the USGS and their possible modification and usage in recommended seismic design provisions and codes for buildings, bridges and other facilities. The Workshop will also provide input for USGS on new map-related products desired by map users.

Following is a preliminary list of topics to be addressed at the Workshop:

A. Scientific Issues for Models for Probabilistic National Ground-Motion Mapping and Effects on Ground-Motion Hazard

• Should near-fault directivity be modeled in mapping?
• Should time-dependent earthquake probabilities be modeled in mapping?
• Which ground-motion attenuation relationships should be used in mapping?
• How should uncertainty in seismic source models and attenuation models be incorporated in the mapping and shown in the results?

B. Issues for Design Maps

• How often should maps be updated?
• What should be the degree of detail in design maps? Should contours or zones be used?
• Should deterministic bounds be incorporated in design maps? Where? How should they be determined?
• What should be the role of the USGS in preparing design maps?

C. Map Products and New Directions

• What new products and capabilities related to ground motion mapping do users want?

The Workshop is open to the profession at large, though space and participation may be limited. Registration will be accepted on a first-come, first-serve basis. The Workshop registration fee is $150 ($120 for ATC subscribers) and includes the cost of workshop luncheons and refreshments. A late fee of $25 will be imposed on registrations postmarked after May 1, 2001.

Persons wishing to participate in the Workshop should contact the Applied Technology Council:

555 Twin Dolphin Drive, Suite 550, Redwood City, California 94065 Phone:650/595-1542 Fax: 650/593-2320 e-mail: atc@atcouncil.org. web: www.atcouncil.org