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
New Hebrides, officially the New Hebrides Condominium (french: link=no, Condominium des Nouvelles-Hébrides, "Condominium of the New Hebrides") and named after the Hebrides Scottish archipelago, was the colonial name for the island group ...
, 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
Lumber is wood that has been processed into dimensional lumber, including beams and planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, wi ...
.
Tectonic setting
The primary tectonic feature of the island chain is the
New Hebrides Trench, the
convergent boundary of the
Australian
Australian(s) may refer to:
Australia
* Australia, a country
* Australians, citizens of the Commonwealth of Australia
** European Australians
** Anglo-Celtic Australians, Australians descended principally from British colonists
** Aboriginal A ...
and
Pacific Plates. Along the
Wadati–Benioff zone
A Wadati–Benioff zone (also Benioff–Wadati zone or Benioff zone or Benioff seismic zone) is a planar zone of seismicity corresponding with the down-going slab in a subduction zone. Differential motion along the zone produces numerous earthq ...
, earthquake activity has been observed as shallow, intermediate, and
deep-focus events at depths of up to . Volcanic activity is also present along this north-northwest trending and northeast-
dipping oceanic trench
Oceanic trenches are prominent long, narrow topographic depressions of the ocean floor. They are typically wide and below the level of the surrounding oceanic floor, but can be thousands of kilometers in length. There are about of oceanic tren ...
.
While much of the
island arc
Island arcs are long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries. Most island arcs originate on oceanic crust and have resulted from the descent of the lithosphere into the mantle alon ...
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 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 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.
Earthquakes
See also
*
List of tectonic plate interactions
Tectonic plate interactions are classified into three basic types:
* Divergent boundaries are areas where plates move away from each other, forming either mid-ocean ridges or rift valleys. These are also known as constructive boundaries.
...
*
List of volcanoes in Vanuatu
References
Sources
*
External links
Predicting Earthquake Hazard in VanuatuSolomon & Vanuatu Islands—Earthquakes & Tectonic Setting
– IRIS Consortium
IRIS (Incorporated Research Institutions for Seismology) is a university research consortium dedicated to exploring the Earth's interior through the collection and distribution of seismographic data. IRIS programs contribute to scholarly research, ...
{{DEFAULTSORT:List of earthquakes in Vanuatu
Vanuatu
Vanuatu ( or ; ), officially the Republic of Vanuatu (french: link=no, République de Vanuatu; bi, Ripablik blong Vanuatu), is an island country located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of no ...
Earthquakes
Earthquakes in Vanuatu