≋≋≋───/////──≋≋≋─────────────≋───────────≋≋≋──/////──≋≋≋── TSUNAMI WARNING BOARD ////// DART NETWORK + USGS TRIGGER FEED ──────≋≋≋──/////──────────────────≋≋≋──/////──≋≋≋──────────

Tsunami Warning Board — Live DART Network

DART buoy wave activity · USGS submarine earthquake triggers · Travel-time simulator · Historical tsunami archive · Auto-refresh every 60s

✓ NO ACTIVE WARNING

Pacific, Indian & Atlantic ocean basins — all clear. This is informational only — always verify with official sources.

Last checked: —

Official tsunami.gov ↗

Active Warnings

All Clear ✓ · check tsunami.gov

DART Network

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/ 39 buoys online

Trigger Quakes 24h

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M6.5+ submarine events

Last Major Event

Tōhoku

2011 · M9.0 · 19,759 dead

Days Since Warning

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since last NOAA Pacific warning

Max Wave Activity

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highest DART buoy reading

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Fetching data...

Live Tsunami Radar — DART + USGS 100%

DART — no data DART <0.5m DART 0.5–1m DART 1–2m DART >2m Historical event Trigger quake Click ocean → travel-time rings

Event Stream ● LIVE

Initializing feeds...

USGS · earthquake.usgs.gov · NDBC · ndbc.noaa.gov · Updates every 60s

≋ Travel-Time Simulator Click any ocean area on the map above to simulate

≋ Click any ocean location on the map to simulate tsunami propagation. Concentric rings show 1h / 2h / 4h / 8h travel-time boundaries at ~500 km/h average speed (simplified). Real NOAA models use bathymetric data.

Free Tsunami Warning Board — DART Buoy Network & USGS Trigger Data

The Tsunami Warning Board is a free, real-time monitoring dashboard that aggregates data from the NOAA DART (Deep-ocean Assessment and Reporting of Tsunamis) buoy network and the USGS Earthquake Hazards Program to give a comprehensive view of current tsunami risk. DART buoys are pressure-sensor platforms anchored to the ocean floor across the Pacific, Atlantic, and Indian Oceans. They detect sea-floor pressure changes caused by passing tsunami waves and transmit data via satellite to warning centers within minutes. This dashboard monitors 39 DART stations for wave activity anomalies and flags any submarine earthquakes (M6.5+, depth <100km) that could potentially generate tsunamis.

The live map uses an equirectangular projection to display all active DART buoys as colored squares — green for calm conditions, yellow for elevated activity, orange for watch-level readings, and red for alert-level anomalies. Historical tsunami events are plotted as red circles scaled by death toll, providing geographic context for where destructive tsunamis have originated. Recent submarine earthquake triggers appear as yellow dots with magnitude labels. Clicking anywhere on the ocean draws concentric travel-time rings at 1, 2, 4, and 8 hour intervals, with arrival estimates for 30 major coastal cities worldwide.

Travel-Time Simulator

The travel-time simulator uses a simplified propagation speed of 500 km/h — a reasonable average for open-ocean tsunamis, which actually travel at depths-dependent speeds of 500–900 km/h in the deep Pacific but slow dramatically to 30–50 km/h in shallow coastal waters. The haversine formula calculates great-circle distances from the click point to each of 30 monitored coastal cities, then divides by 500 km/h to estimate arrival time. This is an educational tool; real NOAA/PTWC forecasts use sophisticated numerical models incorporating full ocean bathymetry. Always follow official guidance from tsunami.gov and local emergency authorities.

No Signup. No Ads. No Install.

This dashboard runs entirely in your browser with no backend, no tracking beyond standard analytics, and no subscription required. It is one of over 90+ free browser tools at jasperbernaers.com. Data is sourced from public USGS and NDBC APIs with no API key required.

Frequently Asked Questions — Tsunami Warning Board

How does tsunami early warning work?

Tsunami early warning is a multi-step process: 1) Seismograph detection — seismic networks detect a large submarine earthquake (typically M7.0+) within seconds. 2) Initial alert — warning centers issue a preliminary advisory based on earthquake magnitude and location alone. 3) DART confirmation — DART buoy pressure sensors detect the actual tsunami wave passing underneath, confirming whether a significant wave was generated. 4) Refined forecast — numerical models calculate wave heights and arrival times for coastal communities. 5) Public warning — sirens, cell alerts, and emergency broadcasts are issued. The DART network is critical because many large earthquakes do not generate destructive tsunamis — DART confirmation reduces false alarms that erode public trust.

What are DART buoys?

DART (Deep-ocean Assessment and Reporting of Tsunamis) buoys are a NOAA system of pressure sensors anchored to the ocean floor in deep water, typically 1,000–6,000 metres depth. The bottom pressure recorder (BPR) detects tiny changes in water column height caused by a passing tsunami wave — even a wave just 1 cm high on the open ocean generates a detectable pressure change. The BPR transmits data acoustically to a surface buoy, which relays it via NOAA's GOES satellite to the Pacific Tsunami Warning Center and West Coast & Alaska Tsunami Warning Center. DART buoys operate in "standard" mode (15-minute intervals) and switch to "event" mode (15-second intervals) when triggered by a seismic event.

Why is the warning board usually showing no active warnings?

Tsunamis capable of widespread destruction are rare events — on average, only 1–2 per decade cause significant casualties. While large submarine earthquakes occur regularly, the vast majority do not generate destructive tsunamis because the seafloor displacement is insufficient, the fault geometry is unfavorable, or the rupture zone is too small. Since 2011, the most recent Pacific-wide warning was issued in 2022 following the Hunga Tonga volcanic eruption. Local warnings are more frequent — the Japan Meteorological Agency issues warnings for the Japanese coast several times per year following nearby earthquakes. The absence of warnings on this board is entirely normal and expected; it reflects the genuine rarity of tsunami events rather than a data gap.

How fast does a tsunami travel?

Tsunami propagation speed depends directly on ocean depth via the shallow-water wave formula: v = √(g × d), where g is gravitational acceleration (9.8 m/s²) and d is water depth. In the deep Pacific (average depth ~4,300m), this gives speeds of approximately 740 km/h — comparable to a commercial jet aircraft. In shallower water (200m depth), speed drops to around 160 km/h. Near shore (10m depth), the wave slows to just 36 km/h but simultaneously amplifies in height through the "shoaling" effect. The simplified 500 km/h used in this simulator represents a rough average for trans-oceanic propagation. Real NOAA models calculate propagation on a fine grid incorporating full bathymetry.

What triggers a tsunami?

The most common tsunami trigger is a submarine earthquake — specifically a megathrust earthquake where one tectonic plate is suddenly thrust upward or downward, displacing the overlying water column. Generally, M7.0+ earthquakes at depths shallower than 100km along subduction zones pose the highest risk. Other triggers include: submarine landslides (which can generate locally devastating waves even from smaller earthquakes — the 1998 Papua New Guinea tsunami was triggered by a landslide); volcanic eruptions (the 2022 Hunga Tonga eruption generated a tsunami detected worldwide); and very rarely, asteroid or meteor impacts (no confirmed examples in recorded history, but modeled as catastrophic). The location of the seafloor displacement matters greatly — vertical fault motion is far more tsunamigenic than horizontal strike-slip motion like along the San Andreas Fault.

How accurate is the travel-time simulator?

The simulator uses a simplified 500 km/h flat average speed and straight-line (great-circle) distance, making it an educational approximation rather than a forecasting tool. Real tsunami travel-time models used by NOAA and the Pacific Tsunami Warning Center (PTWC) account for: variable ocean depth along the propagation path (shallower areas slow the wave); refraction around submarine ridges and seamounts; reflection from coastlines; and dispersion effects. The actual arrival time for a specific location can differ from the simplified estimate by 30–120 minutes depending on the source location and the bathymetric complexity of the propagation path. For any real emergency, follow guidance from tsunami.gov, the Pacific Tsunami Warning Center, and local civil defense authorities.