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United States · Stratovolcano

Ahyi

Type
Stratovolcano
Elevation
55m (submarine)
Last eruption
2026
Ahyi
Photo: Submarine Ring of Fire 2006 Exploration, NOAA Vents Program · Public domain · Wikimedia Commons
Type
Stratovolcano
Country
United States
Region
Northwestern Pacific / Mariana Volcanic Arc
Elevation
55m (submarine)
Coordinates
20.437, 145.030
Last eruption
2026
Tectonic setting
Subduction zone / Crustal thickness unknown
Landform
Composite
Major rock type
Andesite / Basaltic andesite
Geological summary

Ahyi seamount is a large conical submarine volcano ~18 km SE of the island of Farallon de Pajaros in the northern Marianas. Water discoloration has been observed there, and in 1979 the crew of a fishing boat felt shocks over the summit area, followed by upwelling of sulfur-bearing water. On 24-25 April 2001 an explosive eruption was detected seismically by a station on Rangiroa Atoll, Tuamotu Archipelago. The event was well constrained (+/- 15 km) at a location near the southern base of Ahyi. An eruption in April-May 2014 was detected by NOAA divers, hydroacoustic sensors, and seismic stations.

Eruption history

13 recordedGlossary
Summary (VEI over time)
Click a bar to see individual eruptions · Use arrow keys to move between bars, Enter to open
1934~1943 · 1 eruptions · max VEI 11961~1970 · 2 eruptions · max VEI 01970~1980 · 1 eruptions · max VEI 01980~1989 · 1 eruptions · max VEI 01989~1998 · 2 eruptions · max VEI 01998~2007 · 1 eruptions · max VEI 02007~2016 · 1 eruptions · max VEI 22016~2025 · 4 eruptions · max VEI 119341952198019982016

Detailed timeline

  1. 2025VEI 0Observed
    2025-10-20 – 2026-01-09
  2. 2024VEI 0Observed
    2024-01-01 – 2024-03-27
  3. 2024VEI 0Observed
    2024-08-05 – 2025-05-28
  4. 2022VEI 1Observed
    2022-11-18 – 2023-06-11
  5. 2014VEI 2Observed
    2014-04-24 – 2014-05-17
    Summit crater and SE slope
  6. 2001VEI 0Observed
    2001-04-24 – 2001-04-25
    S of Ahyi (20.34 N, 145.02 E)
  7. 1994VEI 0Observed
    1994-04-23 – end unknown
  8. 1989VEI 0Observed
    1989-09-21 – 1989-12-27
    SW of Ahyi (~20.3 N, 144.9 E)
  9. 1985VEI 0Observed
    1985-08-02 – 1985-09-05
    SW of Ahyi
  10. 1979VEI 0Observed
    1979-11-15 – 1979-11-15
    Near the Ahyi summit
  11. 1969VEI 0Observed
    1969-03-11 – 1969-03-13
    S of Ahyi (20.24 N, 145.02 E)
  12. 1967VEI 0Observed
    1967-03-27 – 1967-04-10
    SW of Farallon de Pájaros
  13. 1934VEI 1Observed
    1934-07-15 – end unknown
    Vicinity of Farallon de Pájaros

Nearby volcanoes

External links

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