Quakes

Earthquake with magnitude of 7.4 occurred in vicinity 54-30.00N 160-48.00W at 160648Z jul

Gulf of Alaska · NAVAREA XII 441/23

What this record establishes

Archived notice · 2023-07-16 07:55Z

This notice comes from the historical archive. Its archived status does not establish when or how the reported situation ended.

Source and dates
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · NTWC 0/23 160723Z JUL 23.. Issued 2023-07-16 07:32Z. First collected 2026-08-17 13:38Z; last seen in collection 2026-08-17 15:46Z. Collection dates record ingestion, not a new incident or a fresh field observation.
Location covered
Gulf of Alaska. The parsed report position is 55.739, -159.101. It is a position in the source message, not a live location. Check the original wording for limits and qualifications.

Related notices and cancellation links

These reports were linked by category and sea, with positions within 30 nautical miles and issue dates within 30 days of another report's recorded in-force span. Links can extend through other members, so the full group can cover a larger area or period. Proximity does not confirm that they describe one incident.

  1. USGS-US7000KG302023-07-16 · Cancelled notice
  2. USGS-US7000KG312023-07-16 · Cancelled notice
  3. NAVAREA XII 440/232023-07-16 · Archived notice
  4. NAVAREA XII 441/23 · this notice2023-07-16 · Archived notice
  5. NAVAREA XII 442/232023-07-16 · Archived notice
  6. NAVAREA XII 443/232023-07-16 · Archived notice
Compare all 7 notices, changes and original texts →

Current notices and reporting history in the Gulf of Alaska →

issued
2023-07-16 07:32Z
status
Archived notice
authority
NTWC 0/23 160723Z JUL 23.
NAVAREA
NAVAREA XII
issued by
NTWC
sea
Gulf of Alaska
position
55.739, -159.101
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

GULF OF ALASKA.
NORTH PACIFIC.
ALASKA.
1. EARTHQUAKE WITH MAGNITUDE OF 7.4
   OCCURRED IN VICINITY 54-30.00N 160-48.00W
   AT 160648Z JUL. TSUNAMI WAVES ARE POSSIBLE
   WHICH COULD CAUSE DAMAGE TO THE
   SURROUNDING COASTS.
2. TSUNAMI ACTIVITY IS FORECASTED TO START AT
   THE FOLLOWING TIMES:
   A. SAND POINT 55-20.19N 160-29.60W AT 0810Z.
   B. KODIAK 57-54.58N 152-23.69W AT 0835Z.
   C. COLD BAY 55-12.55N 162-42.85W AT 0935Z.
3. TSUNAMI WAVE HEIGHTS CANNOT BE PREDICTED
   AND MAY BE A SERIES OF WAVES WHICH COULD BE
   DANGEROUS FOR SEVERAL HOURS AFTER THE
   INITIAL WAVE ARRIVAL.
4. CANCEL NAVAREA XII 440/23.

Reading this warning

Position (degrees and minutes)
How warnings write positions: degrees, a hyphen, then minutes, with N/S and E/W — 49-40.8N 003-43.8W.
Date-time group (DTG)
A compact UTC timestamp — day, hour and minute followed by Z — such as 201500Z for the 20th at 15:00 UTC.
Cancellation reference
A line that cancels an earlier warning by its number, such as CANCEL HYDROLANT 1085/12.
NAVAREA
One of the 21 ocean areas of the World-Wide Navigational Warning Service, each with a coordinator that broadcasts long-range warnings.

All warning terms →

Collected reports in this area · earthquake & tsunami bulletins

72 within 180 nm since 1997 · 0 in the last 12 months · 0 listed in force now

97
00
05
10
15
20
25

Counts include repeat notices about the same situation. NGA archive coverage ends 2024-05; live collection began 2026-08-17. The period between them is incomplete. An empty year is not evidence that no hazards occurred.

Month of issue in the collected archive

J
F
M
A
M
J
J
A
S
O
N
D

All available years combined. Uneven collection and repeat bulletins affect these counts; this chart does not measure the seasonality or probability of incidents.

Nearby notices listed in force · within 120 nm

No other collected notice is currently listed in force within this radius. This does not establish safe conditions.

Worldwide in the collected sources

2 earthquake & tsunami bulletins listed in force · see all

Record snapshot 2026-10-03 07:52Z; source collection times vary.

Quakes

Undersea earthquakes of magnitude 5.5 and above (USGS) and the tsunami bulletins NAVAREA coordinators relay. All current earthquake & tsunami bulletins →

Not for navigation. This is a re-rendering of an official navigational warning for awareness; mariners must use official NAVAREA broadcasts and their national MSI service.