Introduction
On February 6th, 2013, one of the biggest subduction caused earthquakes ever recorded in the Solomon Islands area occurred. The Solomon Islands are located in the South Pacific in the Oceanic region. They lay over the boundary line of the Pacific and Indo-Australian Plates, this particular spot along the boundary is a subduction zone, the Pacific Plate is being forced under the Indo-Australian Plate causing displacement[Fig. 1].
[Fig. 1] Image of plate boundaries.
Solomon Islands and Tectonic Movement
The Solomon Islands are located over the subduction zone of the Indo-Australian Plate and the Pacific Plate. A subduction is caused when a oceanic and a continental plate converge (move towards each other). As they converge the oceanic plate sinks or is pushed under the continental plate because it has a higher density [Fig. 2]. Whereas a continental plate is far
more buoyant and can not sink. Subduction can only occur if one of the plates is a oceanic plate because otherwise neither plate will move under and they will collide and thicken instead.
[Fig. 2] Diagram of the subduction between the two plates.
2013 Earthquake and Tsunami
On February 6th, 2013, a huge amount of seismic activity was recorded when the subduction of the Pacific Plate under the Indo-Australian Plate caused a shallow dipping movement under the fault line. This resulted in an earthquake with a moment magnitude of 8.0 on the Richter Scale and a Tsunami that reached a height of 1.5m before it hit Santa Cruz. The event was preceded by many foreshocks in the area. After the major event there were more than 20 recorded aftershocks, including one measuring at 7.1 on February 8th.
The closest island to the epicentre was Nendo. Its largest city Lata was said to feel the shocks and quake the most.
Although the initial earthquake and its aftershocks were damaging the most alarming prospect was the potential tsunami caused by the earthquake. This was worrying for the citizens as this had occurred only 6 years before in 2007.
[Fig. 3] Image of the Solomon Island Earthquake.
Economic Impacts:
Loss of water and power facilities
Housing ruined
Over 6,000 people are thought to have been made homeless
Crops and livestock lost
Damaged airstrip – trading
Entire villages were wiped out
Many other countries and islands were forced to evacuate
Environmental Impacts
Wiped out plantations and natural habitats
Killed native wildlife
Ruined water quality
Caused pollution [debris]
Social Impacts
At least 13 people are thought to have been killed and many more injured
Relief aids weren’t able to access the island easily due to a damaged airstrip
Food and water ran low at shelters and charities because of the islands isolation
Over 6,000 citizens left homeless on Nendo and Santa Cruz
Loss of livestock and crops – businesses and the people’s livelihood
[Fig.4] The Solomon Islands after the devastating earthquake and tsunami.
Conclusion
The Solomon Islands are situated in the area of the Ring of Fire. This is where 90% of the worlds seismic activity occurs, due to the movement of the tectonic plates that lay in this region of the world. In turn, this increases the potential risk of occurrences such as the ones of 2013 in the Solomon Islands; this means the government and disaster relief agencies should be more prepared and make it easier for medical aid to access the islands and other countries in the region of the Ring of Fire.
[Fig.5] Map showing the Ring of Fire.