List of earthquakes in Vanuatu

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Earthquakes in Vanuatu are frequent and are sometimes accompanied by tsunami, though these events are not often destructive. The archipelago, which was formerly known as New Hebrides, lies atop a complex and active plate boundary in the southwestern Pacific Ocean.

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Overall, the population in this region resides in structures that are highly vulnerable to earthquake shaking, though some resistant structures exist. Most buildings in Vanuatu are constructed with lumber. [1]

Tectonic setting

The primary tectonic feature of the 1,200 km (750 mi) island chain is the New Hebrides Trench, the convergent boundary between the Australian and Pacific plates. Along the Wadati–Benioff zone, earthquake activity has been observed as shallow, intermediate, and deep-focus events at depths of up to 700 km (430 mi). Volcanic activity is also present along this north-northwest trending and northeast-dipping subduction zone. [2]

While much of the island arc experiences intermediate-depth earthquakes along a Wadati–Benioff zone that dips steeply at 70°, the area adjacent to the d'Entrecasteaux Ridge does not. There is a corresponding gap in seismicity that occurs below 50 km (31 mi) where it enters the subduction zone from the west. According to the NUVEL-1 global relative plate motion model, convergence is occurring at roughly 8 cm (3.1 in) per year. The uncertainty, which also affects the Tonga arc, is due to the influence of spreading at the North Fiji Basin. Of the 58 M7 or greater events that occurred between 1909 and 2001, few were studied. [3]

Earthquakes

DateRegion Mag. MMI DeathsInjuriesCommentsRef
2024-12-17 Efate 7.3 Mw IX14265Severe damage [4]
2023-01-08 Espiritu Santo 7.0 Mw VIIMajor damage [5] [6]
2018-12-16 Ambrym 5.5 Mw VISeveral houses destroyed [7] [8]
2018-08-21 Pentecost 6.5 Mw VII1Minor damage [9]
2010-12-25 Tafea 7.3 Mw V4Minor damage/tsunami [10] [11]
2010-08-10 Shefa 7.3 Mw VIIBuildings damaged/Power outages [12] [13]
2009-10-07 Torba 7.4 Mw VIII
2009-10-07 Torba 7.8 Mw VIITsunami
2009-10-07 Torba 7.7 Mw IX
2009-06-03 Efate 6.3 Mw VI4Landslides [14]
2009-05-29 Efate 5.7 Mw VI10Landslides / damage [15]
2007-08-01 Sanma 7.2 Mw VII1Many buildings damaged [16] [17]
2002-11-28 Torba 5.9 Mw VII3Landslides / damage [18]
2002-01-03 Efate 7.2 Mw XSeveralRockslides / damage [19]
1999-11-26 Ambrym 7.4 Mw VIII5–1040–100Landslides / damage / five killed by tsunami
1999-08-22 Ambrym 6.6 Mw IX [20] Foreshock / landslides [21]
1997-04-21 Santa Cruz Islands 7.7 Mw VIISome damage / tsunami [22]
1992-10-11 Tanna 7.4 Mw VIII [23]
1990-07-27 Espiritu Santo 7.2 mb VII2Moderate damage [24]
1973-12-29 Espiritu Santo 7.2 Ms VIIIModerate damage
1973-12-29 Espiritu Santo 7.5 Ms VIIIModerate damage NGDC 1972
1971-10-27 Tutuba 6.8 Mw VI1SomeSevere damage [25]
1965-08-11 Malakula 7.6 Mw IXModerate damage / tsunami NGDC 1972
1910-11-10 Malakula 7.3 Mw VIModerate damage / tsunami NGDC 1972
1909-07-08Moderate damage / tsunami NGDC 1972
Note: The inclusion criteria for adding events are based on WikiProject Earthquakes' notability guideline that was developed for stand alone articles. The principles described also apply to lists. In summary, only damaging, injurious, or deadly events should be recorded.

See also

Related Research Articles

<span class="mw-page-title-main">Convergent boundary</span> Region of active deformation between colliding tectonic plates

A convergent boundary is an area on Earth where two or more lithospheric plates collide. One plate eventually slides beneath the other, a process known as subduction. The subduction zone can be defined by a plane where many earthquakes occur, called the Wadati–Benioff zone. These collisions happen on scales of millions to tens of millions of years and can lead to volcanism, earthquakes, orogenesis, destruction of lithosphere, and deformation. Convergent boundaries occur between oceanic-oceanic lithosphere, oceanic-continental lithosphere, and continental-continental lithosphere. The geologic features related to convergent boundaries vary depending on crust types.

<span class="mw-page-title-main">Wadati–Benioff zone</span> Planar zone of seismicity corresponding with the down-going slab

A Wadati–Benioff zone is a planar zone of seismicity corresponding with the down-going slab in a subduction zone. Differential motion along the zone produces numerous earthquakes, the foci of which may be as deep as about 670 km (420 mi). The term was named for the two seismologists, Hugo Benioff of the California Institute of Technology and Kiyoo Wadati of the Japan Meteorological Agency, who independently discovered the zones.

<span class="mw-page-title-main">Deep-focus earthquake</span>

A deep-focus earthquake in seismology is an earthquake with a hypocenter depth exceeding 300 km. They occur almost exclusively at convergent boundaries in association with subducted oceanic lithosphere. They occur along a dipping tabular zone beneath the subduction zone known as the Wadati–Benioff zone.

The 1980 Honduras earthquake struck just offshore Honduras on August 9 at 05:45 UTC. Two people were killed and many injured.

The 1999 Ambrym earthquake occurred on November 27 at 00:21:17 local time with a moment magnitude of 7.4 and a maximum Mercalli intensity of VII. The back arc thrust event occurred within the Vanuatu archipelago, just to the south of the volcanic island of Ambrym. Vanuatu, which was previously known as New Hebrides, is subject to volcanic and earthquake activity because it lies on an active and destructive plate boundary called the New Hebrides Subduction Zone. While the National Geophysical Data Center classified the total damage as moderate, a destructive local tsunami did result in some deaths, with at least five killed and up to 100 injured.

The 2018 Fiji earthquakes occurred on August 19, at 00:19:40 UTC and on September 6 15:49 UTC. The epicenters were located close to the Fijian island Lakeba, and around 270 km from the small town of Levuka on Ovalau. The first earthquake registered a magnitude of Mww  8.2, and is the largest earthquake of 2018. It had a focal depth of 600 km, making it the second largest earthquake ever recorded at a depth greater than 300 km; a tie with the 1994 Bolivia earthquake, and behind the 2013 Okhotsk Sea earthquake. The initial earthquake was caused by a normal fault below the South Pacific Ocean. A Mww  7.9 event struck the islands again on September 6 at a depth of 670 km; this earthquake was a mainshock of its own. Both earthquakes may be considered a doublet event.

The 2021 Kermadec Islands earthquakes were a series of earthquakes with magnitudes of 8.1 and 7.4 that occurred at 19:28:31 UTC on 4 March 2021. The epicentres were located southeast of Raoul Island in the Kermadec Islands, part of the New Zealand outlying islands. The main magnitude 8.1 earthquake was preceded by a magnitude 7.4 foreshock and followed by a magnitude 6.1 aftershock. A separate, unrelated magnitude 7.3 earthquake occurred off the coast of the North Island of New Zealand, approximately 900 km to the south, several hours before the main quakes. More than a dozen aftershocks exceeded magnitude 6.

The 2021 Loyalty Islands earthquake was a 7.7 magnitude earthquake that struck offshore between Vanuatu and New Caledonia on February 11, 2021, at 00:19 local time. It is the 4th largest earthquake of 2021.

<span class="mw-page-title-main">2002 Port Vila earthquake</span>

The 2002 Port Vila earthquake occurred in the early dawn of 3 January 2002, 4:22 a.m. local time (UTC+11) northwest of Port Vila, the capital of Vanuatu. It had a magnitude of 7.2 Mw and a maximum intensity of X (Extreme) west of the island on the Modified Mercalli intensity scale. There are no exact estimates on the number of injured individuals, but the majority of accounts say there were "several" amounts of injured civilians. the event also caused a minor tsunami of about 0.4–0.8 m just 11 minutes after the quake.

<span class="mw-page-title-main">New Hebrides Trench</span> Oceanic trench in the southern Pacific Ocean

The New Hebrides Trench is an oceanic trench which is over 7.1 km (4.4 mi) deep in the Southern Pacific Ocean. It lies to the northeast of New Caledonia and the Loyalty Islands, to the southwest of Vanuatu, east of Australia, and south of Papua New Guinea and the Solomon Islands. The trench was formed as a result of a subduction zone. The Australian plate is being subducted under the New Hebrides plate causing volcanism which produced the Vanuatu archipelago.

The Vanuatu subduction zone is currently one of the most active subduction zones on Earth, producing great earthquakes, with potential for tsunami hazard to all coastlines of the Pacific Ocean. There are active volcanoes associated with arc volcanism.

<span class="mw-page-title-main">2024 Port Vila earthquake</span> Earthquake in Vanuatu

At 12:47:26 VUT on 17 December 2024, a Mw7.3 earthquake struck Port Vila, the capital of Vanuatu. At least 14 people died while 265 others were injured. Extensive damage occurred in Port Vila and surrounding areas. The earthquake also generated a 25 cm (10 in) tsunami.

References

  1. ↑ "PAGER". United States Geological Survey.
  2. ↑ Yeats, R. (2012), Active Faults of the World, Cambridge University Press, p. 478, ISBN   978-0521190855
  3. ↑ Frolich, C. (2006). Deep Earthquakes. Cambridge University Press. pp. 399–401. ISBN   978-0805836523.
  4. ↑ "M 7.3 – 30 km W of Port-Vila, Vanuatu". United States Geological Survey. 17 December 2024.
  5. ↑ "M 7.0 – 23 km WNW of Port-Olry, Vanuatu". United States Geological Survey. 8 January 2023.
  6. ↑ "Se registra terremoto de magnitud 7.0 en Vanuatu; no se reportaron víctimas" [7.0 magnitude earthquake recorded in Vanuatu; no casualties were reported]. El Mañana (in Spanish). 8 January 2023.
  7. ↑ "M 5.5 – 82 km ESE of Lakatoro, Vanuatu". United States Geological Survey. Retrieved 2018-12-27.
  8. ↑ "Vanuatu eruption sparks series of quakes". Radio New Zealand. 2018-12-18. Retrieved 2018-12-27.
  9. ↑ "M 6.5 – 78 km E of Lakatoro, Vanuatu". United States Geological Survey. Retrieved 2018-08-21.
  10. ↑ "M 7.3 – 141 km W of Isangel, Vanuatu". United States Geological Survey. 25 December 2010.
  11. ↑ "Tsunami Event: Vanuatu". National Geophysical Data Center.
  12. ↑ "M 7.3 – 33 km NW of Port-Vila, Vanuatu". United States Geological Survey. Retrieved 2022-04-05.
  13. ↑ "Earthquake panics Vanuatu residents". The Sydney Morning Herald . 2010-08-04. Retrieved 2022-04-05.
  14. ↑ "M6.3 – Vanuatu". United States Geological Survey.
  15. ↑ "M5.7 – Vanuatu". United States Geological Survey.
  16. ↑ "M 7.2 – 56 km E of Luganville, Vanuatu". United States Geological Survey. Retrieved 2022-03-02.
  17. ↑ "Powerful earthquake damages Luganville on Vanuatu island of Santo". Radio New Zealand. 2007-08-02. Retrieved 2022-03-01. A police officer was injured during the 7.2 magnitude quake as he tried to leave police headquarters and many residents fled their homes when it struck at about 4am local time.
  18. ↑ "M5.9 – Vanuatu". United States Geological Survey.
  19. ↑ "M7.2 – Vanuatu". United States Geological Survey.
  20. ↑ "PAGER" (PDF). United States Geological Survey. 2 March 2023. Retrieved 3 April 2023.
  21. ↑ "M6.6 – Vanuatu". United States Geological Survey. Retrieved September 18, 2016.
  22. ↑ "M7.7 – Santa Cruz Islands". United States Geological Survey.
  23. ↑ "M 7.4 – 47 km NW of Isangel, Vanuatu". United States Geological Survey.
  24. ↑ "M7.2 – Vanuatu". United States Geological Survey.
  25. ↑ "M6.8 – Vanuatu". United States Geological Survey.

Sources

Further reading

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