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Ta'u

Photo of this volcano
  • United States
  • Samoan Hotspot Volcano Group
  • Shield | Shield
  • Unknown - Evidence Credible
  • Country
  • Volcanic Province
  • Landform | Volc Type
  • Last Known Eruption
  • 14.23°S
  • 169.454°W

  • 931 m
    3054 ft

  • 244001
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Weekly Report: 28 September-4 October 2022 Citation IconCite this Report

HVO lowered the Volcano Alert Level for Ta’u to Normal (the lowest level on a four-level scale) and the Aviation Color Code to Green (the lowest level on a four-color scale) on 3 October, noting that seismic activity had dramatically decreased and maintained low levels over the past few weeks. Analysis of data from one seismometer that had recorded earthquakes during 2005-2009 suggested that a rate of five detected earthquakes per day was characteristic of long-term background seismicity; the current earthquakes rates were at background levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Weekly Reports - Index


2022: August | September


28 September-4 October 2022 Citation IconCite this Report

HVO lowered the Volcano Alert Level for Ta’u to Normal (the lowest level on a four-level scale) and the Aviation Color Code to Green (the lowest level on a four-color scale) on 3 October, noting that seismic activity had dramatically decreased and maintained low levels over the past few weeks. Analysis of data from one seismometer that had recorded earthquakes during 2005-2009 suggested that a rate of five detected earthquakes per day was characteristic of long-term background seismicity; the current earthquakes rates were at background levels.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


31 August-6 September 2022 Citation IconCite this Report

HVO reported that an earthquake swarm around Ta’u, in the Manu'a Islands of American Samoa, continued during 30 August-6 September. Less than 30 earthquakes per day were large enough to be felt by residents and many more earthquakes undetectable by humans were also recorded; no earthquakes were reportedly felt during 5-6 September. The data suggested that the earthquakes were consistently occurring in an area about 5-15 km off the N shore of the island, at depths of 10-15 km below the surface. There was no change in the frequency or size of earthquakes and the position of the swarm remained unchanged. USGS staff installed GPS equipment during 4-6 September. The Volcano Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


24 August-30 August 2022 Citation IconCite this Report

HVO reported that an earthquake swarm in the Manu'a Islands of American Samoa continued to be felt by residents of Ta'u Island and Ofu-Olosega islands during 24-30 August. Three advanced seismometers were installed beginning the second week of August, one on Ofu Island and two on Ta'u, and by 26 August the data indicated that the source of the activity was related to Ta'u Island. Around 30 earthquakes per hour were recorded each day. At 2033 on 23 August an earthquake widely felt by residents of the Manu'a islands and Tutuila Island was characterized as producing light-to-moderate shaking (a maximum Intensity of V on the Modified Mercalli Intensity Scale); the estimated M 3-3.5 event was the largest recorded since the new instruments were installed. The largest earthquakes recorded during 25-26 August had estimated magnitudes between 3 and 4 and were felt by residents of Manu'a. An estimated M 2.8 event was strongly felt at 0932 on 27 August. Numerous events were felt during 27-28 August, but none were reported during 28-30 August. Booming noises had been reported and investigated for weeks; scientists confirmed that they were related to the earthquakes, noting that the sound waves generated by some earthquakes could produce sounds audible to humans. No signs of ground cracking, landslides, rockfalls, or other activity that could have caused the sounds were seen. The Volcano Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


17 August-23 August 2022 Citation IconCite this Report

HVO reported that an earthquake swarm in the Manu’a Islands of American Samoa continued to be recorded and felt by residents of Ta’u Island and Ofu-Olosega. About 20 earthquakes per hour were recorded by four microseismometers distributed on Tutuila, Ta’u, and Ofu-Olosega Islands. The largest events were estimated to be between magnitudes 2 and 3; most events are too small to be felt. Analysis of the seismic data indicated that the earthquakes were occurring beneath or around the Manu’a Islands, likely closer to Ta’u rather than Ofu-Olosega, though the exact locations, depths, and magnitudes were unknown. The number, size, and frequency of earthquakes recorded by instruments and being felt by people and on both islands indicated that seismicity was above background levels; HVO changed the Volcano Alert Level to Advisory and the Aviation Color Code to Yellow for both volcanoes. Earthquakes continued to be recorded at around the same rate during 20-22 August. Two additional seismometers were installed on Ta’u during 22-23 August.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


10 August-16 August 2022 Citation IconCite this Report

HVO reported that earthquakes were felt by residents of the Manu'a group of islands in American Samoa beginning on 26 July. Residents of Ofu and Olosega islands began reporting earthquakes on 10 August. Experts from HVO, Pago Pago National Weather Service Office (NWS), National Oceanic and Atmospheric Administration (NOAA) Pacific Tsunami Warning Center, NOAA-IOC (NOAA-Intergovernmental Oceanographic Commission), International Tsunami Information Center, and USGS National Earthquake Information Center have been working together to respond to the unrest. USGS scientists arrived on the islands and installed two microseismometers, one in Fiti'uta village on Ta'u island on 13 August and the other in Olosega village on 14 August. The instruments began recording about 20 earthquakes per hour. The largest earthquakes, including the felt events, were estimated to be between magnitudes 2 and 3; most of the events were too small to be felt. The exact location and depth of these earthquakes was unknown, due to limited earthquake monitoring equipment, though the data suggested that the events were beneath the Manu'a Islands, likely closer to Ta'u island rather than Ofu-Olosega, and were probably not related to the recently active Vailulu'u seamount. HVO noted that American Samoa’s volcanoes were monitored remotely by satellites and a distant seismic station in Apia, Samoa; the lack of ground-based monitoring stations does not allow for advanced warning of new activity. Both the Volcano Alert Level and Aviation Color Code were categorized as Unassigned due to the lack of a volcano-monitoring network.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)


The Global Volcanism Program has no Bulletin Reports available for Ta'u.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Eruptive History

The Global Volcanism Program is not aware of any Holocene eruptions from Ta'u. If this volcano has had large eruptions (VEI >= 4) prior to 10,000 years ago, information might be found on the Ta'u page in the LaMEVE (Large Magnitude Explosive Volcanic Eruptions) database, a part of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).

Deformation History

There is no Deformation History data available for Ta'u.

Emission History

There is no Emissions History data available for Ta'u.

GVP Map Holdings

The Global Volcanism Program has no maps available for Ta'u.

Smithsonian Sample Collections Database

There are no samples for Ta'u in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites