Description

The goal of seismic-hazard analysis (SHA) is to state the probability that some Intensity Measure Type (any measure of earthquake shaking found to correlate with damage) will exceed a specified level at a site over a particular time span (e.g., the lifetime of a building). The two main model components needed for SHA are an Earthquake Rupture Forecast (ERF), which gives the probability of all possible fault-rupture events over the time span of interest, and an Intensity-Measure Relationship (IMR), which gives the exceedance probability at a site given the occurrence of an arbitrary fault-rupture event.

There is consensus that significant improvements in SHA will require a more physics-based approach to modeling. This applies to forecasting both where and when faults will rupture (an ERF), as well as predicting the consequent ground shaking and exceedance probabilities (an IMR). Unfortunately there is no consensus on how to construct more physics-based models, which explains, in part, why our national seismic hazard maps are based on both a time-independent ERF (where each event is completely independent of all others) and empirically-based IRMs. This lack of consensus means that we will need to accommodate alternative models, and in fact, proper SHA requires that all viable models be included in the analysis (to adequately represent “epistemic” uncertainties). To reach this very challenging goal of accommodating multiple, perhaps physics-based models, we clearly need a computational infrastructure for SHA that enables both users and modelers to “plug in” without creating additional demands on their time or abilities.

The SCEC SHA focus group has two major activities aimed at improving SHA: RELM (to develop alternative, physics-based ERFs), and OpenSHA (a community modeling environment for SHA). Both of these activities are detailed below. There are also related efforts in the Ground Motions focus group and the Implementation Interface. These include the “NGA” project to develop empirically-based IMRs (know as attenuation relationships) and waveform modeling efforts that could someday form the basis of more accurate, physics-based IMRs. Please see the reports from those focus groups for details.

Leader: Ned Field
Co-leader: David Jackson

2006 Overview

2006 SCEC Request for Proposals

2005 Overview

2005 Workshops and Activities

SCEC-Funded projects related to Seismic Hazard Analysis in 2005

2005 SCEC Request for Proposals

2004 Overview

Annual Report for Seismic Hazard Analysis

2004 Workshops and Activities

SCEC-Funded projects related to Seismic Hazard Analysis in 2004

2004 SCEC Request for Proposals

2003 Overview

2003 SCEC Request for Proposals