Study 04 Tsunami vs Storm Surge Results

Study 04 — Results (PARTIAL corpus seal)

Status: PARTIAL_CORPUS_SEAL 2026-08-20T20:10:00Z — not the full multi-gauge Form. Single-gauge integer-mm onset vs sealed chart minutes for two tsunami positives + Sandy adversary; Tonga water-branch VOID until pressure channel pulled.

Charter: Study 04 · Ledger: corpus/study-04/study04_ledger.json

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Frozen integers (this partial seal)

Symbol	Value
T_exc_min_mm	500
T_lag_tol_min	45
Chart Pago (Samoa)	57 min
Chart Nawiliwili (Tohoku)	456 min
Onset	first sample |level − first-hour median| ≥ 500 mm
Quantization	CO-OPS meters decimal-string → integer mm

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Grades

Gauge / window	Class	lag_min	chart_min	onset_mm	Verdict
Pago Pago 2009-09-29 (Samoa M8.1)	tsunami	24	57	−1255	WIN
Nawiliwili 2011-03-11 (Tohoku M9.1)	tsunami	446	456	+608	WIN
The Battery 2012-10-29/31 (Sandy)	adversary	—	—	−503	WIN (no seismic origin clock)
Port San Luis 2022-01-15 (Tonga)	dual	−111	780	+510	VOID_NEED_PRESSURE

Summary: tsunami 2/2 WIN · adversary 1/1 WIN · Tonga VOID.

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Still OPEN for full LAW FROZEN

• Multi-gauge coherence (≥3 azimuthal quadrants)
• Full corpus rows (Kuril, Maule, Chignik, Noto, …)
• Tonga Lamb branch with co-timed air_pressure
• Detide via CO-OPS predictions product (this seal used first-hour median)
• Standing trigger on next M≥7.5 subsea event

Partial seal is a finding, not a rename of the full Form. Full Form freezes only when the OPEN list closes.