Nepedia
Back to Discover
Advanced Reader
🗺️

Moruroa

geography Maturity 11-13 Next article →

Moruroa is an atoll located in the southern Pacific Ocean.

Moruroa atoll
Moruroa atoll

An atoll is a ring-shaped coral reef that surrounds a central lagoon.

This atoll is part of the Tuamotu Archipelago within French Polynesia. It sits approximately 1,250 kilometres southeast of Tahiti. Administratively, it belongs to the commune of Tureia. This commune also includes the atolls of Fangataufa, Tematangi, and Vanavana. Moruroa is most famous for its history as a site for nuclear testing.

The history of European contact with Moruroa began in the 18th century. Commander Philip Carteret first visited the atoll in 1767. He named the location "Bishop of Osnaburgh Island." In 1792, the British whaler Matilda was wrecked on the atoll. This event led people to call the area "Matilda's Rocks." Later, Frederick William Beechey visited the site in 1826. Early explorers noted that the atoll was not continuously inhabited. While copra workers lived there briefly in the late 19th century and again between 1942 and 1952, there has been no permanent population since those times.

Between 1966 and 1996, France used Moruroa and Fangataufa for extensive nuclear weapon tests.

The French government established the Direction des Centres d'Expérimentations Nucléaires, or DIRCEN, on 21 September 1962. This agency was created to administer the testing operations. Infrastructure construction began in May 1963. To support these operations, the atoll of Hao was used as a base. Hao is located 245 nautical miles northwest of Moruroa. These tests fundamentally changed the environment and the political landscape of the Pacific.

Nuclear testing at Moruroa occurred in two distinct stages. The first stage involved atmospheric nuclear tests. These were explosions conducted in the air or on the surface. Between 1966 and 1974, France conducted 41 atmospheric tests. Scientists used different methods to detonate these devices. Some were placed on barges, while others were air dropped from bombers. Many devices were also suspended from helium-filled balloons. One method involved a device suspended from a balloon, which President Charles de Gaulle observed in person on 10 September 1966.

Due to intense international pressure, France moved to underground testing in 1974. This change followed protests, such as when New Zealand sent two frigates, HMNZS Canterbury and Otago, to the atoll in July 1973. For underground tests, workers drilled deep shafts into the volcanic rocks underlying the atolls. The nuclear devices were then detonated at the bottom of these shafts. However, this method caused significant geological concerns. Scientists observed cracking in the atolls, a phenomenon known as "tired mountain syndrome." This raised fears that radioactive material could escape into the ocean.

One major accident occurred on 25 July 1979 during an underground test. The nuclear device became stuck halfway down an 800-metre shaft. Because it could not reach the bottom, it was detonated at half the usual depth. This explosion triggered a large submarine landslide on the southwest rim of the atoll. A significant portion of the outer slope broke loose. This event caused a tsunami that affected Moruroa and injured workers. The blast also created a crack 2 kilometres long and 40 centimetres wide.

The testing era ended following a period of intense global controversy. In 1995, President Jacques Chirac decided to conduct another series of tests. This decision caused worldwide protests and an embargo on French wine. Riots also occurred throughout Polynesia. The last nuclear test at Moruroa took place on 27 December 1995. The final test in the region occurred on Fangataufa on 27 January 1996. Reports on the total number of explosions vary. Some sources state there were 181 explosions at Moruroa, while some scientists claim 175 total explosions occurred in the Pacific.

Today, Moruroa remains a site of scientific and environmental concern.

Atoll Mururoa - Map
Atoll Mururoa - Map

As of October 2005, visiting the atoll is prohibited due to high radioactive contamination. The area is still guarded by French Forces. A 2012 report indicated that only 11 of the 20 monitoring sensors were functional. This suggests the atoll could potentially collapse without warning. Additionally, researchers continue to study the health consequences of the tests. In 2021, the institute INSERM published a study regarding the health of the general population and former workers in French Polynesia.

693 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (10)
File:Polynésie française collectivity location map.svg
Polynésie française collectivity location map.svg
File:Flag of the Gambier Islands.svg
Flag of the Gambier Islands.svg
File:Flag of Tuamotu Archipelago.svg
Flag of Tuamotu Archipelago.svg
File:Flag of French Polynesia.svg
Flag of French Polynesia.svg
File:Red pog.svg
Red pog.svg
File:Moruroa atoll.JPG
Moruroa atoll.JPG
File:Mururoa lagon.jpg
Mururoa lagon.jpg
File:Mururoa.December.2005.JPG
Mururoa.December.2005.JPG
File:Atoll Mururoa - Map.jpg
Atoll Mururoa - Map.jpg
File:Mururoa lg.jpg
Mururoa lg.jpg
More to explore

🔗 What's this?

Concepts mentioned in this article

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.