Mount OlDoinyo Lengai Trekking

  1. Home
  2. »
  3. Service
  4. »
  5. Mount OlDoinyo Lengai Trekking

Mount OlDoinyo Lengai Trekking Overview

Ol Doinyo Lengai volcano, altitude of 2960 meters (9711 feet), is a unique and extremely fascinating volcano that towers above the East African Rift Valley in Northern Tanzania, just south of Lake Natron. It is the only volcano in the world that sometimes erupts natrocarbonatite lava, a highly fluid lava that contains almost no silicon.

Natrocarbonatite lava is also much cooler than other lavas, being only about 950 degrees F (510 degrees C) compared to temperatures over 2000 degrees F (~1100 degrees C) for basaltic lavas. Natrocarbonatite is the most fluid lava in the world. Lava with a low gas content can flow like a whitewater stream, and actually has a viscosity near that of water.

Natrocarbonatite lava glows orange at night but is not nearly as bright as silicon-based lavas since it is not as hot. During the day it is not incandescent; most flows look like very fluid black oil, or brown foam, depending on the gas content. In the past, some visitors to the crater believed they were seeing mudflows. Most newly solidified lava is black and contains crystals that sparkle brightly in the sun.

There are also sometimes small flows known as “squeeze-ups” that are light gray when they flow and harden. Contact with moisture rapidly turns natrocarbonatite lava white because of chemical reactions that occur when the lava absorbs water.

Eventually, the water absorption process turns lava flows into a soft brown powder. During dry weather the whitening of flows happens over a period of a few days to a couple of weeks, depending on the thickness of the flow. In rainy weather, the lava surface turns white immediately.

In parts of the crater that have been inactive for several months, the ground is light brown/white and so soft that one sinks into it when walking.

Ol Doinyo Lengai also has phases of explosive activity during which the composition of the lava may contain much more silicate material, reducing its viscosity. In this type of eruption, there is no fluid lava and activity takes the form of ash eruptions accompanied by the ejection of blocks and bombs.

However, the initial phases of an explosive eruption may include strong lava fountains. The two most recent explosive eruptions occurred during 1966-1967 and 2007-2008.

Since the mid 1980s, lava flows, and to a much lesser extent, explosive eruptions, have been witnessed by many observers of Ol Doinyo Lengai. Natrocarbonatite lava eruptions are usually centered in one or more small cones that have been formed on the crater floor by previous eruptions of lava.

These eruptions have typically taken the form of open lava pools or lakes that may or may not be overflowing, lava flows issuing from holes or cracks inside or near the base of the cones, or lava splashes or fountains from the summit vents of the cones.

The activity is not well understood but is thought to be a function of the plumbing of the crater, the level of the lava within the plumbing, and the gas content of the lava. No one knows what causes the lava to flow out at any particular time or how the various vents in the crater are interconnected.

Mineralogists would like to understand how the lava evolves under the surface and why it has its unusual chemical composition, but that also is unknown, although there are several theories. Finally, no one has any idea why the pattern of frequent small lava flows gave way to explosive activity at the end of August 2007 and how that may have been related to earthquakes in the region during the previous two months.

Eruption of T58C on July 15, 2004

Mount OlDoinyo Lengai Climb Itinerary – 3 Days 2 Nights

  • Arrival in Arusha, Tanzania

    You will be picked up from Kilimanjaro International Airport and transferred to your accommodations in Arusha town. During the short drive (approximately one hour) your driver/guide will brief you on your Kilimanjaro climb. Today you will spend your time at your leisure and relax for your upcoming exciting adventure.
    Accommodation Masailand Hotel, bed and breakfast

  • Day 1: Arusha to Lake Natron

    Depart Arusha city at 7.00 am and drive to Ngaresero village (Lake Natron) with packed lunch. This is about 5 to 6 hours driving. Dinner and overnight at Giraffe eco camp.

  • Day 2: Lake Natron - OlDoinyo Lengai Trekking

    At very early morning 1:00 a.m. drive to the base of the Ol’doinyo Lengai mountain to start the climb. Reach at the summit during sunrise and spend sometime there before coming down to the base of the mountain.

    From there clients will be transferred by jeep to Giraffe eco camp for shower and rest. Dinner and overnight at Giraffe eco camp.

  • Day 3: Lake Natron - Arusha city

    Morning have breakfast then drive back to Arusha city. This depends on the itinerary.

  • Day 4: Onward Journey

    After a much needed night’s rest, we will bid you goodbye. If you have arranged airport transfers with us or Zanzibar trip, we will collect you in the morning for your onward journey.

    Meals included: Breakfast

Request a free quote for this Adventure

– All accommodations per itinerary
– All meals per itinerary
– All tours and entrance fees per itinerary
– All transportation and transfers per itinerary
– National Park gate fees
– Transport from/to the park gate
– Camping fees
– Certified, experienced, English-speaking guides
– Salaries for all crew members
– Rescue fees (as required by the national park)
– Tents, foam sleeping pads, cooking equipment, and eating utensils
– Oximeters
– Emergency Oxygen (2L canister)

– International and domestic flights
– Meals not listed
– Beverages and alcohol
– Tips for guides, drivers, hotel staff
– Optional tours
– Single room supplement
– Personal expenses (visas, airport taxes, Internet, etc.)
– Tips for guides, porters, and cooks (budget $400-550/person)
– Sleeping bags and personal gear $45 for a single tent
– Low season discount in April/May


Tanzania Safari on Picture