Natural disasters in Samoa: past and future risks
Western Samoa is an increasingly popular tourist destination. Every year more and more people come to the islands to relax on the wonderful beaches and admire the beautiful nature. They should find out in advance what kind of natural disasters or catastrophes they may encounter. A natural disaster always comes unexpectedly, but knowing its potential can help you prepare for it.
Climatic characteristics of Samoa
The relatively small archipelago, which according to various sources includes from 10 to 16 islands, is located in the central Pacific Ocean, about halfway between New Zealand and Hawaii.
They are volcanic islands whose topography is mostly mountainous. The central parts of the largest islands, Utopu and Savai’i, are covered with gorges and valleys covered with dense forests. The shores of the archipelago are formed by high and steep cliffs with a narrow strip of beaches. The beaches are often cut off from the open ocean by a wall of coral reefs.
The archipelago is located on the Pacific tectonic plate, near its contact with the Indo-Australian platform. Earthquakes and related cataclysms are therefore very likely to occur.
Samoa is characterised by a tropical climate divided into two seasons. From November to April, the islands are hit by frequent tropical seasons that bring high rainfall and severe storms. From May to October, the archipelago enjoys a relatively calm dry season. The difference in average winter and summer temperatures is insignificant, it does not exceed 1 degree. In summer, it is about +30 degrees, in winter it is only +29 degrees.
Most of the area of the islands is covered with dense forests. The animal world is poor, but there are a lot of birds.
Potentially dangerous factors that can cause a natural disaster include:
- Seismic activity. Collisions of two tectonic platforms threaten strong earthquakes and tsunamis.
- The long length of the coastline. Almost all settlements are located near the coast and can be hit by storms, floods, tsunamis.
- Volcanism. The islands are volcanic in nature, there are many traces of past eruptions. There is a danger of a new eruption.
- Seasonal hurricanes and storms. The archipelago is located in the zone of tropical cyclones, there is a danger of strong storms and hurricanes.
- Heavy rains. May cause short-term floods and overflows of mountain rivers.
The importance of studying the history of natural disasters
The history of natural disasters is important information to learn before travelling to your chosen country. Knowing the potential dangers that may be awaiting you will not only help you choose the right place, but also the time and season of the year when the threat of being at the epicentre of a natural disaster will be minimal.
For example, knowing that the tropical cyclone season, when strong storms are most common, starts in October and lasts until April, you can choose a different time to travel to Samoa.
From this article, you will learn a chronology of natural disasters that have occurred in Samoa in the past.
Earthquakes and tsunamis
According to scientists’ calculations, the Indo-Australian lithospheric plate is slowly moving north-eastwards, colliding with the Pacific plate. Their interaction can cause strong earthquakes, which has happened many times in the past. And since the epicentre of local earthquakes is almost always underwater, they inevitably lead to tsunamis. Here is a list of the largest earthquakes and tsunamis that have occurred in the immediate vicinity of the archipelago.
26 June 1917
The strongest earthquake on the archipelago occurred in the afternoon. The strength of the tremors exceeded 8 points. The epicentre of the earthquake was located to the south-west of the islands underwater. Therefore, the tremors, which were felt in Apia for several minutes, caused a minimum of destruction compared to the subsequent tsunami impact. The wave was up to 12 metres high. It washed away many houses and bridges, but no death toll was recorded.
29 September 2009
A strong earthquake struck off the islands of Tonga. Its magnitude was 8.1. The tremors themselves were practically not felt in Samoa, but the consequences of the tsunami impact were catastrophic.
The islands of American Samoa were especially badly affected, but in the West tsunami reached 6 metres. Waves penetrated deep into the territory for several kilometres, demolishing houses, cars, wiping out entire villages.
Authorities began a hasty evacuation, taking people from Apia and villages to the mountains, but casualties could not be avoided. Many were caught by the tsunami right on the beach and their fate was dire. About 200 people died as a result of the disaster. The damage from the catastrophe was estimated at 147 billion dollars.
Samoa’s islands of volcanic origin. Currently, there are no active volcanoes, but everything can change in the blink of an eye. Everywhere on the islands of the archipelago we find traces of past eruptions, whether they are grottoes dug into granite by molten lava or fields formed by erupting mass flows.
According to volcanologists, the last eruption on the island of Savai’i was in 1911 and was not of great intensity. Before that, eruptions on the islands occurred in 1866 and shortly before our era. And really catastrophic cataclysms date back to the Cretaceous period.
However, the volcanic activity of the region remains high. And if there are no active volcanoes above the water, they exist at the bottom of the ocean. Thus, in the east of the archipelago, which is part of American Samoa, there is an underwater volcano Vailulu. Its top lies at a depth of over 500 metres, and there is increased volcanic activity there.
Storms and hurricanes
The tropical cyclone season in Samoa begins in November and lasts until mid-April. This is when the islands are hit by the wet south-west monsoon, which brings heavy rainfall and often forms into cyclonic eddies. Below, we have compiled a list of the most destructive cyclones to hit Samoa in the last 50 years.
6-9 January 1989, Cyclone Gina
Originating in southern French Polynesia, Cyclone Gina quickly reached Category 1 status. Wind speeds reached 85 kilometres per hour. It ravaged Samoa, ripping out palm trees and demolishing lighthouses. Even the capital Apia was affected. No casualties were reported, but damage from the storm was estimated at $5 million.
25-27 January 1998, Cyclone Tui
This cyclone was weaker than the previous one, with winds not exceeding 75 kilometres per hour. However, it also caused significant damage to agriculture and settlements in the archipelago. Damage from the passage of Tui totalled $1 million.
11-15 December 2012, Cyclone Evan
Hurricane-force wind gusts of up to 114 kilometres per hour paralysed the country’s capital and the international airport. Winds ripped out palm trees and tore roofs off houses. Power supply was disrupted and a sewage treatment plant was destroyed. A state of emergency was declared in the country, but casualties could not be avoided. Three people died, and the total damage exceeded $500 million. It was one of the strongest cyclones in the history of Samoa.
24 April 2016, Cyclone Amos
The island authorities prepared for this cyclone in advance, as it was expected that wind speeds could exceed 170 kilometres per hour. However, in reality, Amos was weaker, with wind speeds not exceeding 120 kilometres per hour. Nevertheless, the heavy rainfall caused road damage and more than 70 per cent of the country’s population was left without light. The island of Savaii was the most affected.
8-9 February 2018, Cyclone Gita
Gita caused the most damage in the islands of Tonga, but did not spare Samoa. Torrential rains dumped up to 320 millimetres of rain on the east coast of Upolu, rivers overflowed their banks and flooded homes, and many roads became impassable due to landslides. About 300 people were forced to evacuate. Wind gusts reached 100 kilometres per hour. No casualties were reported, but the total damage exceeded $10 million.
Floods and fires
The mountainous terrain and few settlements make floods not too dangerous for natives and tourists. If mountain rivers do overflow after a cyclonic downpour, they do not last long. Much more dangerous for coastal settlements, storm surge, which occurs in very strong winds.
Forest fires are not relevant for Samoa. The humid tropical climate is not conducive to spontaneous combustion, and the small population levels the threat of deliberate arson. No significant forest fires have been recorded in Samoa in recent years.
The greatest threat to tourists holidaying in Samoa is the seasonal tropical cyclones that bring strong, gusty winds and rain to the archipelago. Almost every year there are powerful cyclones, which turn into a real disaster for Samoa.
Earthquake and volcanic hazards also remain a concern for the archipelago. Dormant volcanoes can wake up at any moment, and tectonic activity at the lithospheric plate boundary can result in a major earthquake. The same cataclysms can threaten the archipelago with devastating tsunamis.
However, this does not mean that Samoa is a dangerous place, and you should not go there on holiday. These islands are a real tropical paradise, with a marvellous climate and amazing nature. In fact, the risk of being in the epicentre of a truly devastating cataclysm is no higher here than anywhere else on the planet.
The best time to travel to Samoa is from May to September. At this time the season of tropical cyclones ends, the amount of precipitation decreases significantly, and sunny days become more. At the same time, the south-eastern trade winds slightly reduce the air temperature, making it more comfortable.