Spatially Varying Tidal Planes For Tsunami Hazard Modeling

Northern Australia's tidal variation, from 1.4 m at Lady Elliot Island to over 5.4 m near St Lawrence, complicates tsunami hazard assessments. This dataset presents a technique to model tsunamis with a spatially varying Highest Astronomical Tide, demonstrated in the Gladstone region using nested grids with 10 m resolution. The work was presented at the 2025 Australasian Coasts & Ports Conference and hosted by the Australian Ocean Data Network.

Use Cases

• Model tsunami inundation extent using spatially varying Highest Astronomical Tide (HAT) values across a region.
• Compare tsunami scenarios at different HAT levels, such as at Lady Elliot Island, South Trees, and Rosslyn Bay.
• Conduct probabilistic tsunami hazard assessments leveraging earthquake source zones and offshore scenarios from the 2018 Australian Probabilistic Tsunami Hazard Assessment.
• Refine tsunami evacuation plans by identifying inundation zones derived from hydrodynamic models instead of heuristics.

Strengths

• Demonstrates method across a significant tidal range, from 1.4 m to over 5.4 m.
• Uses nested computational grids with resolution down to 10 m to resolve inundation.
• Method validated via comparison with scenarios at different HAT levels at three distinct sites.

Limitations

• Primary data format is a PDF, limiting direct machine-readability and analysis.
• Case study is focused on the Gladstone region, limiting geographic generalizability.
• Specific row counts, simulation parameters, and raw data volumes are not provided.

Provenance

Source

Australian Ocean Data Network

Collection Method

Hydrodynamic tsunami simulation using nested grids and a proposed tidal adjustment technique.

Time Range

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Freshness

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Geography

Gladstone region and northern Australian coast (e.g., Lady Elliot Island, St Lawrence, Queensland)