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.
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]
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]
| Date | Region | Mag. | MMI | Deaths | Injuries | Comments | Ref |
|---|---|---|---|---|---|---|---|
| 2024-12-17 | Efate | 7.3 Mw | IX | 14 | 265 | Severe damage | [4] |
| 2023-01-08 | Espiritu Santo | 7.0 Mw | VII | Major damage | [5] [6] | ||
| 2018-12-16 | Ambrym | 5.5 Mw | VI | Several houses destroyed | [7] [8] | ||
| 2018-08-21 | Pentecost | 6.5 Mw | VII | 1 | Minor damage | [9] | |
| 2010-12-25 | Tafea | 7.3 Mw | V | 4 | Minor damage / tsunami | [10] [11] | |
| 2010-08-10 | Shefa | 7.3 Mw | VII | Buildings damaged / power outages | [12] [13] | ||
| 2009-10-07 | Torba | 7.4 Mw | VIII | ||||
| 2009-10-07 | Torba | 7.8 Mw | VII | Tsunami | |||
| 2009-10-07 | Torba | 7.7 Mw | IX | ||||
| 2009-06-03 | Efate | 6.3 Mw | VI | 4 | Landslides | [14] | |
| 2009-05-29 | Efate | 5.7 Mw | VI | 10 | Landslides / damage | [15] | |
| 2007-08-01 | Sanma | 7.2 Mw | VII | 1 | Many buildings damaged | [16] [17] | |
| 2002-11-28 | Torba | 5.9 Mw | VII | 3 | Landslides / damage | [18] | |
| 2002-01-03 | Efate | 7.2 Mw | X | Several | Rockslides / damage | [19] | |
| 1999-11-26 | Ambrym | 7.4 Mw | VIII | 5–10 | 40–100 | Landslides / 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 | VII | Some damage / tsunami | [22] | ||
| 1992-10-11 | Tanna | 7.4 Mw | VIII | [23] | |||
| 1990-07-27 | Espiritu Santo | 7.2 mb | VII | 2 | Moderate damage | [24] | |
| 1973-12-29 | Espiritu Santo | 7.2 Ms | VIII | Moderate damage | |||
| 1973-12-29 | Espiritu Santo | 7.5 Ms | VIII | Moderate damage | NGDC 1972 | ||
| 1971-10-27 | Tutuba | 6.8 Mw | VI | 1 | Some | Severe damage | [25] |
| 1965-08-11 | Malakula | 7.6 Mw | IX | Moderate damage / tsunami | NGDC 1972 | ||
| 1910-11-10 | Malakula | 7.3 Mw | VI | Moderate damage / tsunami | NGDC 1972 | ||
| 1909-07-08 | Moderate damage / tsunami | NGDC 1972 | |||||
| 1878-01-10 | |||||||
| 1875-03-22 | royalty islands | ||||||
| 1863-08-17 | 7.5 | [26] | |||||
| 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. | |||||||
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.
Sources