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NEHRP-USGS Interactive Maps

I created these Interactive Maps for the updated 2023 NSHM-CONUS ground-motion values -- including our proposed uniform risk target of 1.5% probability of collapse in 50yr. These maps include the full MPRS, as well as the ASCE 7-22 MCER values for comparison.
The maps are highly interactive and informative. Let me know if you're interested in having me generate serverless interactive maps that meet your company needs!

I have created these interactive maps to provide a detailed qualitative evaluation and comparison of the ground-motion values computed using the 2023 National Seismic Hazard Model (NSHM) when compared to the current ASCE-7 MCE_R values. These maps offer a quantitative evaluation of proposals that are working their way through BSSC PUC (Provisions Update Committee) and ASCE 7 committees.

These maps are for informational purposes only.

NOTE: The DATA used in these maps has been generated by Dr. Sanaz Rezaeian and Dr. Nico Luco of the USGS in 2025, supported by the Engineering and Risk Project and the National Seismic Hazard Modeling Project team members. These yet unpublished data are provisional and have been provided to serve the profession through these maps.

🔍 What You Can Visualize

1. 50-Year Probability of Collapse (PoC) for ASCE 7-22 MCE_R

  • Available for two site classes (BC, D) and four periods (0.2s, 1.0s, 2.0s, 5.0s).

2. ASCE 7-22 MCE_R PSA

  • Risk-Targeted (1.0% in 50yr PoC) Deterministically capped MCE_R, based on NSHM-2018.

3. NSHM-2023 PSA

  • Risk-targeted PSA with:

    • 1.5% in 50-year PoC

    • 1.0% in 50-year PoC

  • Deterministic 84th percentile PSA, based on 1.0% in 50-year PoC PSHA.

4. Ratio of NSHM-2023 PSA to ASCE 7-22 MCE_R PSA

  • Choose to load only ratio values or both ratio and PSA values.

  • ⚠ Important: Filter out cases where very small numerators create misleadingly large ratios.

5. Ratio of NSHM-2023 PSA to NSHM-2023 PSA

  • Same source model, different risk targets!

  • Use this to quantify the effect of different risk targets.

  • ⚠ Important: Filter out cases where very small numerators create misleadingly large ratios.

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⚠ System Performance Considerations

These maps contain large datasets and advanced features, which may exceed your system’s capabilities. For best performance:

  • Focus on smaller regions instead of the entire dataset.

  • Use filtering tools to manage data size.

🔎 Note: All terms are defined according to ASCE 7 standards.

⚡ Interactive Features

✅ Toggle map layers
✅ Add custom markers
✅ Filter data dynamically
✅ Hover for detailed location info
✅ Click on a location to view more data (e.g., MPRS values)

© 2020 by Silvia Mazzoni, Silvia's Brainery, Santa Monica, CA

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