Discolored water with submarine volcanic activity reported in 20-25.20N 145-01.80E at 270127Z jan
North Pacific Ocean · HYDROPAC 306/23
What this record establishes
Archived notice · 2023-07-18 01:41Z
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) · US GEOLOGICAL SURVEY 0/23 272353Z JAN 23.. Issued 2023-01-28 00:02Z. 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
- North Pacific Ocean. The parsed report position is 20.420, 145.030. 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
- Cancel HYDROPAC 306/23 and this msglater cancellation notice
Current notices and reporting history in the North Pacific Ocean →
- issued
- 2023-01-28 00:02Z
- status
- Archived notice
- authority
- US GEOLOGICAL SURVEY 0/23 272353Z JAN 23.
- issued by
- US GEOLOGICAL SURVEY
- sea
- North Pacific Ocean
- position
- 20.420, 145.030
- source
- NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z
Original warning text
WESTERN NORTH PACIFIC. NORTHERN MARIANA ISLANDS. DNC 12. DISCOLORED WATER WITH SUBMARINE VOLCANIC ACTIVITY REPORTED IN 20-25.20N 145-01.80E AT 270127Z 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.
Collected reports in this area · volcanic activity
10 within 180 nm since 1999 · 2 in the last 12 months · 2 listed in force now
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.
- Discolored water with increased likelihood of submarine volcanic activity reported in vicinity 20-26.00N…2026-07-16
- Discoloured water reported in vicinity of 20-26.0N 145-01.0E at 160013Z jul2026-07-16
- Discolored water with increased likelihood of submarine volcanic activity reported in 20-25.00N 145-01.00E…2024-01-13
- Discolored water with submarine volcanic activity reported in 20-25.2N 145-01.8E at 012230Z jan2024-01-01
- Cancel HYDROPAC 1304/142014-05-06
- Mariana Islands2014-05-05
Month of issue in the collected archive
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 2026-09-25 00:01Z; 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.