---
title: "Active tsunami messages (NOAA/NWS Tsunami Warning Centers)"
method: GET
path: "/api/v2/hazards/tsunami"
tags: ["Disasters & Hazards"]
---

# Active tsunami messages (NOAA/NWS Tsunami Warning Centers)

`GET /api/v2/hazards/tsunami`

Currently-active tsunami CAP 1.2 messages retransmitted from the NOAA/NWS Tsunami Warning Centers (NTWC Palmer AK + PTWC Honolulu HI). CAP-native: severity/certainty/urgency are read verbatim from the source (severity.derivation='native'), and the full CAP block is exposed. Gated to status=Actual, non-Cancel, non-expired messages; an empty result means no active message is published. Sugra retransmits and does not issue warnings.

## Query parameters

- `min_lat` number, nullable — Bounding-box south edge (on the source epicenter).
- `max_lat` number, nullable — Bounding-box north edge.
- `min_lon` number, nullable — Bounding-box west edge.
- `max_lon` number, nullable — Bounding-box east edge.
- `limit` integer — Maximum messages returned (most recently updated first).

## Response `200`

Successful Response

- EnvelopeTsunamiFeed
  - `data` TsunamiFeed, required
    - `query` TsunamiQuery, required
      - `min_lat` number, nullable
      - `max_lat` number, nullable
      - `min_lon` number, nullable
      - `max_lon` number, nullable
      - `limit` integer, required
    - `total_matched` integer, required — Active tsunami messages matching the filters BEFORE the limit.
    - `count` integer, required
    - `events` TsunamiEvent[], required
      - `schema_version` string, required
      - `event_id` string, required
      - `event_type` string, required
      - `source_event_time` string, nullable
      - `updated_time` string, nullable
      - `geometry` HazardGeometry, required
        - `lat` number, nullable — Latitude, decimal degrees (WGS84). Null if the source omitted a location.
        - `lon` number, nullable — Longitude, decimal degrees (WGS84).
        - `depth_km` number, nullable — Hypocentre depth, kilometres.
      - `area` object, nullable — null - the native CAP area (circle / UGC zones) is in cap.info.area.
      - `place` string, nullable
      - `metrics` TsunamiMetrics, required
        - `preliminary_magnitude` string, nullable
        - `magnitude_type` string, nullable
        - `origin_time` string, nullable — Earthquake origin time, ISO 8601 UTC.
        - `depth_km` number, nullable
        - `epicenter` string, nullable
        - `vtec` string, nullable
        - `msg_type` string, nullable — CAP msgType: Alert | Update | Cancel.
        - `cap_event` string, nullable — CAP event tier: Tsunami Warning | Watch | Advisory | Information.
      - `severity` HazardSeverity, required — CAP-aligned severity block (OASIS Common Alerting Protocol vocabulary).
        - `severity` string, required — CAP severity: Extreme | Severe | Moderate | Minor | Unknown.
        - `certainty` string, required — CAP certainty. Earthquakes are Observed (the event happened).
        - `urgency` string, required — CAP urgency. Earthquakes are Past (an observed event, not a forward alert).
        - `derivation` string — 'native' (read verbatim from a CAP-native source) or 'sugra-computed' (derived by Sugra - carries no sovereign brand-shield).
      - `cap` object, nullable — The native CAP 1.2 block (identifier/status/msgType/info/area/...). Populated - this is a CAP-native source.
      - `source` HazardEventSource, required
        - `institution` string, required
        - `tier` string, required — Sovereign (S) - named publicly.
        - `event_url` string, nullable — Upstream event page for full detail.
      - `disclaimer` string, required
    - `attribution` HazardAttributionSet, required
      - `sources` HazardSourceAttribution[] — Every sovereign source that contributed events.
        - `registry_key` string, required
        - `source_name` string, required
        - `licence` string, required
        - `citation` string, required
        - `disclaimer` string, required
      - `effective_reexport` string, required — Most-restrictive re-export verdict across the sources.
    - `disclaimer` string, required
    - `upstream` object
  - `meta` SugraMeta, required — Metadata attached to every /api/v1/* response envelope.
    - `endpoint` string, required — Requested endpoint path.
    - `data_time` string, required — ISO 8601 UTC timestamp of the source data, not of the request.
    - `response_time` string, required — ISO 8601 UTC timestamp when this response was produced.
    - `provider` string, required — API name and version.
    - `source` string, nullable — Identifier of the primary upstream source used for this response.
    - `attribution` string, nullable — Human-readable attribution mandated by an upstream source (e.g. a securities regulator or self-regulatory organization). Present only on responses whose source requires the owner and source to be clearly identified. Do not remove or alter it when using the response.
    - `fallback_used` boolean, nullable — True when the primary source failed and a fallback produced the data.
    - `fallback_chain` string[], nullable — Ordered list of sources attempted, in the order they were tried.
    - `cached` boolean, nullable — True when this response was served from the internal cache.
    - `stale` boolean, nullable — True when the cached response was returned after the upstream rate-limited or errored. Clients can use this to detect degraded data.

## Other responses

- `401` — Missing or invalid `x-api-key` header.
- `422` — Validation Error
- `429` — Daily rate limit exceeded. Check `X-RateLimit-Reset` for the next window.
- `503` — Upstream source is temporarily unavailable. Retry after a short delay.

---

[API](https://skmtc.net/sugra/apis/sugra-api.md) · [All operations](https://skmtc.net/sugra/apis/sugra-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/sugra/sugra-api/versions/dcf7427e6897/schema)