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.

Contents

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 of 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 oceanic trench. [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 intrudes into 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
2023-01-08 Espiritu Santo 7.0 Mw VIIMajor damage [4] [5]
2018-12-16 Ambrym 5.5 Mw VISeveral houses destroyed [6] [7]
2018-08-21 Pentecost 6.5 Mw VII1Minor damage [8]
2010-12-25 Tafea 7.3 Mw V4Minor damage/tsunami [9] [10]
2010-08-10 Shefa 7.3 Mw VIIBuildings damaged/Power outages [11] [12]
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 [13]
2009-05-29 Efate 5.7 Mw VI10Landslides / damage [14]
2007-08-01 Sanma 7.2 Mw VII1Many buildings damaged [15] [16]
2002-11-28 Torba 5.9 Mw VII3Landslides / damage [17]
2002-01-03 Efate 7.2 Mw XSeveralRockslides / damage [18]
1999-11-26 Ambrym 7.4 Mw VIII5–1040–100Landslides / damage / five killed by tsunami
1999-08-22 Ambrym 6.6 Mw IX [19] Foreshock / landslides [20]
1997-04-21 Santa Cruz Islands 7.7 Mw VIISome damage / tsunami [21]
1992-10-11 Tanna 7.4 Mw VIII [22]
1990-07-27 Espiritu Santo 7.2 mb VII2Moderate damage [23]
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 [24]
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">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.

In seismology, the depth of focus or focal depth is the depth at which an earthquake occurs. Earthquakes occurring at a depth of less than 70 km (43 mi) are classified as shallow-focus earthquakes, while those with a focal depth between 70 km (43 mi) and 300 km (190 mi) are commonly termed mid-focus or intermediate-depth earthquakes. In subduction zones, where older and colder oceanic crust sinks under another tectonic plate, deep-focus earthquakes may occur at much greater depths in the mantle, ranging from 300 km (190 mi) up to 700 km (430 mi).

<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 2013 Balochistan earthquakes took place in late September in southwestern Pakistan. The mainshock had a moment magnitude of 7.7 and a maximum Mercalli intensity of IX (Violent). At least 825 people were killed and hundreds more were injured. On 28 September, a M6.8 aftershock occurred to the north at a depth of 14.8 kilometres, killing at least 22 people.

The 1999 Ambrym earthquake occurred on November 26 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.

<span class="mw-page-title-main">2016 Chiloé earthquake</span> Earthquake in Chile

The 2016 Chiloé earthquake with a magnitude of Mww 7.6 struck 225 kilometres (140 mi) south-west of Puerto Montt in southern Chile at 11:22 local time, 25 December. The earthquake triggered a tsunami warning on coasts located up to 1,000 kilometres (620 mi) from the quake's epicentre, generating massive evacuation across the Greater Chiloé Island, after advice from the Chilean government. Although there was damage in some parts of the island, the government reported no casualties.

<span class="mw-page-title-main">2016 Solomon Islands earthquakes</span> Seismic events

On 9 December 2016 at 4:38 a.m. local time, the Solomon Islands region was rocked by an Mww 7.8 earthquake, centered 30 km off San Cristobal Island, about 61 km southwest of Kirakira, the capital of Makira-Ulawa Province. Initially registering magnitude 8.0, later downgraded to 7.8, the temblor prompted tsunami warnings that kept countries surrounding the Coral, Tasman and Solomon Sea on high alert, but was later cancelled. A large aftershock of magnitude 6.9 occurred shortly afterwards. This earthquake was largely felt, waking many residents who later ran to high ground for fears of a potential tsunami. The earthquake killed a child and affected some 34,000 people in Makira, South Malaita and Guadalcanal Island where many had lost their homes or had no access to basic needs. Earthquakes are common in this region, with little or no fatalities. This earthquake is tied with three other magnitude 7.8 earthquakes for the second largest earthquake of 2016. On 17 December, the Solomon Islands would be rattled again by a 7.9 magnitude earthquake, this time 54 km east of Taron, Papua New Guinea.

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. An 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.

<span class="mw-page-title-main">2013 Craig, Alaska earthquake</span> Earthquake in Alaska and British Columbia

The 2013 Craig, Alaska earthquake struck on January 5, at 12:58 am (UTC–7) near the city of Craig and Hydaburg, on Prince of Wales Island. The Mw 7.5 earthquake came nearly three months after an Mw  7.8 quake struck Haida Gwaii on October 28, in 2012. The quake prompted a regional tsunami warning to British Columbia and Alaska, but it was later cancelled. Due to the remote location of the quake, there were no reports of casualties or damage.

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.

References

  1. ↑ "PAGER". earthquake.usgs.gov.
  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 7.0 - 23 km WNW of Port-Olry, Vanuatu". United States Geological Survey. 8 January 2023.
  5. ↑ "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).
  6. ↑ "M 5.5 - 82 km ESE of Lakatoro, Vanuatu". earthquake.usgs.gov. Retrieved 2018-12-27.
  7. ↑ "Vanuatu eruption sparks series of quakes". Radio New Zealand. 2018-12-18. Retrieved 2018-12-27.
  8. ↑ "M 6.5 - 78km E of Lakatoro, Vanuatu". earthquake.usgs.gov. Retrieved 2018-08-21.
  9. ↑ "M 7.3 - 141 km W of Isangel, Vanuatu". earthquake.usgs.gov. 25 December 2010.
  10. ↑ "Tsunami Event: Vanuatu". National Geophysical Data Center .
  11. ↑ "M 7.3 - 33 km NW of Port-Vila, Vanuatu". earthquake.usgs.gov. Retrieved 2022-04-05.
  12. ↑ "Earthquake panics Vanuatu residents". The Sydney Morning Herald . 2010-08-04. Retrieved 2022-04-05.
  13. ↑ USGS. "M6.3 - Vanuatu". United States Geological Survey.
  14. ↑ USGS. "M5.7 - Vanuatu". United States Geological Survey.
  15. ↑ "M 7.2 - 56 km E of Luganville, Vanuatu". earthquake.usgs.gov. Retrieved 2022-03-02.
  16. ↑ "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.
  17. ↑ USGS. "M5.9 - Vanuatu". United States Geological Survey.
  18. ↑ USGS. "M7.2 - Vanuatu". United States Geological Survey.
  19. ↑ USGS (2 March 2023). "PAGER" (PDF). Retrieved 3 April 2023.
  20. ↑ "M6.6 - Vanuatu". United States Geological Survey . Retrieved September 18, 2016.
  21. ↑ USGS. "M7.7 - Santa Cruz Islands". United States Geological Survey.
  22. ↑ "M 7.4 - 47 km NW of Isangel, Vanuatu". earthquake.usgs.gov.
  23. ↑ USGS. "M7.2 - Vanuatu". United States Geological Survey.
  24. ↑ USGS. "M6.8 - Vanuatu". United States Geological Survey.

Sources

Further reading

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