Volcanic

Discolored water with increased likelihood of submarine volcanic activity reported near Northern Mariana Islands at 20-25N 145-01E on January 13.

North Pacific Ocean · HYDROPAC 153/24

What this record establishes

Cancelled notice · 2026-08-14 18:10Z

This notice disappeared from the issuing source's in-force list. No explicit recovery or all-clear is established by that removal.

Source and dates
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · US GEOLOGICAL SURVEY 0/24 132346Z JAN 24.. Issued 2024-01-13 23:49Z. First collected 2026-08-17 13:41Z; last seen in collection 2026-08-17 15:50Z. Collection dates record ingestion, not a new incident or a fresh field observation.
Location covered
North Pacific Ocean. The parsed report position is 20.417, 145.017. 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. HYDROPAC 12/242024-01-01 · Cancelled notice
  2. HYDROPAC 153/24 · this notice2024-01-13 · Cancelled notice
  3. NAVAREA XI 322/262026-07-16 · Listed in force
  4. HYDROPAC 2039/262026-07-16 · Listed in force
Compare all 4 notices, changes and original texts →

Current notices and reporting history in the North Pacific Ocean →

issued
2024-01-13 23:49Z
status
Cancelled notice
authority
US GEOLOGICAL SURVEY 0/24 132346Z JAN 24.
issued by
US GEOLOGICAL SURVEY
sea
North Pacific Ocean
position
20.417, 145.017
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:41Z

Original warning text

WESTERN NORTH PACIFIC.
NORTHERN MARIANA ISLANDS.
DNC 12.
DISCOLORED WATER WITH INCREASED LIKELIHOOD
OF SUBMARINE VOLCANIC ACTIVITY REPORTED
IN 20-25.00N 145-01.00E AT 132250Z JAN.

Reading this warning

DNC (Digital Nautical Chart)
A reference to one of the regions of NGA's Digital Nautical Chart, used to tell the reader which charts a warning affects.
Discoloured water
Patches of unusually coloured sea — often a sign of a submarine volcano or of a shoal.
Volcanic activity
An erupting or restless volcano near or under the sea, with a keep-clear radius around it.
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.

All warning terms →

Collected reports in this area · volcanic activity

10 within 180 nm since 1999 · 2 in the last 12 months · 2 listed in force now

99
00
05
10
15
20
25
26

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

Worldwide in the collected sources

12 volcanic activity listed in force · see all

Record snapshot 2026-10-01 19:13Z; source collection times vary.

Volcanic

Submarine eruptions, discoloured water, pumice rafts. All current volcanic activity →

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.