Unpublished photos of the planet’s most unusual volcano

activity ExplosiveExplosive of the volcano Ol Doinyo LengkaiOl Doinyo Lengkai, nicknamed “Mountain of the Gods”, is almost permanent, as evidenced by the thermal signals frequently seen inside the crater of the summit in satellite images of the sector. But the temperature of this particular volcano – A carbonate – At around 500°C, thermal signals are very weak compared to typical volcanic eruptions, preventing accurate assessment and monitoring of activity. It is necessary to rely on very rare direct observations because VolcanoVolcano is in the right place desertdesert And its climb is unconvincing, even if the promised views are worth the detour…

A gradually filling ditch

A paroxysmal eruption in 2007–2008 created a crater 300 meters in diameter with a steep central part. the groundthe ground Rated as 120 meters deep. After this event, Excellent function The edges of these steep walls were quickly resumed, and already the crater had raised the ground about twenty meters. Today, it sits about 2,800 meters above sea level, about 70 meters below the rim of the crater and appears to have risen a little more than five meters a year…if this activity continues, that’s why. Between 1998 and 2007, we would have had to wait at least two decades for the crater to complete and fill up again!

Unlike last year’s trip, no recent major volcanic flows were observed. Active craters were still in a central position, some in the same position as the previous year, but they were difficult to identify conescones Volcanoes are fragile morphologymorphology Very variable…

Thanks to Sylvain Sermet, manager of the agency 80 days journey Allowing me to use these photos for free and thus beautifully illustrate this article. He still has places Stay at Lenkai from 7th to 17th June 2024.

The planet’s most unusual volcanic discovery

With its vertical sides and volcanic silhouette, it sits in the middle of the Tanzanian savannah, not far from Lake Natron. According to the Maasai, a semi-nomadic tribe living in this part of Africa, the god who created the volcano resides where he gave it its name. Magnificent landscape, mystical place, even volcanic interest like the Maasai Gods Mountain! Because this volcano emits carbonates and lavas in the world ColorColor Black when inside ConnectingConnecting It turns white as it cools…

The article Ludovic LeducLudovic LeducPublished on April 13, 2023

The volcano is in the middle of the East African Rift, which runs across Africa for at least 5,000 kilometers, from Afar to Mozambique. This is splitsplit Over time, it was the result of an extensive process that split the African continent in two. This allows for partial fusion CodeCode At this level, but at a much lower rate, it forms alkaline-rich magmas (SodiumSodium And PotassiumPotassium significant).

The rise of this magma Earth’s crustEarth’s crust A later process towards volcanism would be relevant SeparationSeparation Two liquidsliquids Magmatic, magmas can be distinguished by their composition SiliconSilicon. The first is silicate, like most terrestrial magmas and nepheline in nature. This forms the deep reservoir of the volcano.

But from this magma, a second fluid is extracted because it does not mix with the first fluid. variationvariation Density rises in the volcanic building and forms a A shallow reservoir. This magma is very special because it contains less than 20% silicon (compared to more than 40% for all other magmas). EarthEarth) and very rich CalciumCalciumSodium and Potassium: It is carbonate in nature.

Two types of explosions

This shallow reservoir feeds the near-permanent activity of this volcano, a unique activity on our planet! In fact, Ol Doinyo Lengaï is the only terrestrial volcano that emits this type of volcano! Now, these lavas are quite surprising: they are a Exceptional fluidity, black to dark brown color When they merge and At a temperature of about 500°C Only — 800 to 1,200°C for “classic” magmas! In addition, they work very quicklyAtmosphereAtmosphere And, within hours, The MineralsMinerals Carbonates spoil and whiten…

If these carbonatites make up the uniqueness of this volcano, they make up only about 5%. VolVol Of the volcano, the rest is associated with the magma of the Nephilim! The latter is associated with violent eruptions that usually recreate a crater at the top of the volcano. Thus before 2007, the summit crater was filled, completely filled with carbonatites released over the previous four decades, and the crater overflowed.

Enthusiasts can get as close as possible to these amazing lava flows! But from September 2007 there was a violent eruption, with a paroxysm in February 2007 that produced a 15 kilometer high ash plume! During this eruption a crater 300 to 350 meters in diameter was formed instead of the platform … Later, after the violent eruptions of 1917, 1940-1941 and 1966-1967, carbonatic activity resumed and began. To fill this deep hole…

A black and white crater is now visible

Since 2008, eruptive activity has been observed sporadically through satellite imagery through photographs of some curious individuals climbing the volcano or faint flashes. We can see that the floor of the crater is gradually rising so that the activity is now visible in good condition… Thus in June 2022, Sylvain Cermet And his clients observed five to seven active vents at the bottom of the crater aligned in a west-northwest/east-southeast direction. The function of each of them varies. Here, projections reached a height of a few meters, forming relatively upright cones several meters high. There, it flows at the bottom of the crater. At its center, the base of the ancient and crumbling cone sheltered small bubbling lakes…a contrasted scene according to the craters, so, day and night, but for three days they stayed. On top of the volcano. Sylvain Sermet is going there next June: Could the volcano have formed?

Thanks to Sylvain Sermet, manager of the agency 80 days journey Allowing me to use these photos for free and thus beautifully illustrate this article. He still has places Stay in Lengai next June.

Lengai’s performance in the video. © Sylvain Sermet, 80 Days of Travel