Bottom-pressure water column height, last 4 days. The payload self-escalates from 15-min to 1-min/15-sec sampling when its detection algorithm triggers — escalated samples draw red.
Height anomaly vs 24-h median (tide-scale variability removed).
COASTAL GAUGE — OBSERVED VS TIDE
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1-minute observed water level (white) against the harmonic tide prediction (blue), last 12 h · datum MLLW.
De-tided residual (observed − predicted) — a tsunami arrives as an abrupt oscillation on this trace. This is the trace the warning centers read.