Lahar Travel Time — lahar-watch

Lahar Travel Time Calculator

Model warning windows for downstream communities based on drainage, scenario, and lahar volume · Based on USGS lahar inundation models

1 — Select Drainage

2 — Scenario / Trigger

3 — Estimated Volume

Volume 0.5 km³

            0.01 km³ (small)4 km³ (Osceola-scale)
          

Reference Events

Electron Mudflow (~1507) — ~0.1 km³ · west flank collapse · no eruption

Osceola Mudflow (~5,600 BP) — ~3.8 km³ · reached Commencement Bay

Mt St Helens 1980 — ~0.5 km³ debris avalanche

Detection → Alert

Sensor detect: ~10s · EOC alert: ~30s · Sirens: ~2 min

Puyallup River — Warning Timeline Eruption scenario

            T+0 — Lahar initiates
            T+3h 00m — Puget Lowlands
          

Warning Windows by Community