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Oldoinyo Lengai Project

Evacuation campain to protect the Masaii tribe living around the volcano.

Oldoinyo Lengai, Tanzania

Masaii family

Masaii families live in close distance to the volcano Oldoinyo Lengai.

The volcano Lengai had big explosive eruptions with fatal effects for the Masaii tribe living close to the volcano. The day will come, where we perhaps see another big eruption and therefore we would like to start an evacuation campain to give aid to the Masaii in case of this. For example see NEWS from end of March 2006!

Lengai Lengai


The strato volcano Oldoinyo Lengai with its altitude of app. 2950 meter is located in the African Rift Valley of Tanzania. The slopes of the volcano are as steep as 50 degrees and in prehistorical times, enormous land slides occured maybe also triggert by explosive eruptions. In historical times, Lengai erupted fluid natron carbonatite in gentle eruptions with explosive intervals by the average of every 30 years. The last noticed events of this explosive eruptions were in 1917 (50 km around the volcano were severely effected), in 1926, in 1940 and 1942 (observed by Richard with VEI 3) and in 1966 (200 km around the volcano were severely effected).



Today many Masaii families live around the volcano and most of the younger generation have certainly forgotten that the holy mountain of the Masaii tribe can cause death and distruction. (June, 6, 2004)
What can we do and what should we do?
First the tanzanian authorities and volcanological institutions need to know about our offer of aid. They should give us support, permission and orders. After this, we could edit a hazard map of the area. A warning system including a live-cam at the top of the volcano could be installed. Local volunteers (like Burra Gadiye) could get involved in the project to take their part. An simple paper with instructions at an emergency case should be handed out to all living around the volcano. A video show could be organized at local villages to show what a volcanic eruption can cause. A conference at the town of Arusha could be one effective thing for any coordination. Transportation for evacuation could be organized, as well as a first aid plan by the tanzanian authorities and the Red Cross.

It's of course not certain, if this project will be finished before the next explosive eruption will start. Anyway, there is no time to loose. We have a brilliant example what an evacuation campain can cause. The clarification by Maurice and Katia Krafft just befor the 1991 Pinatubo eruption safed many lifes.
Belton, Weber, Szczepansky, Szeglat, Donth, Barkemeyer, who know Lengai very well, will take part on this project, as well as Ms. Erika Vye (University of Munich, geophysiks) and the Lengai expert Celia Nyamweru (Canton University, NY).
Prof. Joerg Keller and Jurgis Klaudius (IMPG, Freiburg) take part for the scientific leadership. The GVN and USGS are asked for their statements and support.

How can we start the evacuation campain at Oldoinyo Lengai:

1 A meeting of members to coordinate this project should come first.

1.1 What can we do and what should we do?
1.2 Who is doing what?
1.3 How could a time table look like?

2 First meeting with the authorities and vulcanoloical Inst. to offer our aid with this project.

2.1 No panic concerning a big eruption.
2.2 Our offer of datas (hazard paper) and suggestions concerning what to do.
2.3 Which authorities are responsible.
2.4 Getting an official permit and order to organize some coordinations.

3 Contacting officials and institutions to ask for help and permission.

3.1 Meeting with the Masaii Chief.
3.2 Meeting with Masaii villagers.
3.3 Meeting with the Red Cross and Flying Doctors.
3.4 Meeting with other tansanian aid oraganisations.
3.5 Meeting with the National Park authorities.

4 Second meeting with the authorities to presentate the results of coordination.

4.1 Asking permission to come into action.
4.2 Setting a program of who is doing what in case of emergency.

5 Practical help and work to do.

5.1 Handing out plans and papers to the Masaii Chief and villagers.
5.2 Coordination info forwarding to the Red Cross and Flying docters.
5.3 Coordinating info forward by the National Park authorities and vulcanological Inst.
5.4 Coordinating and handing out papers to other authorities and organisations.
5.5 Setting up some warning systems at Lengai.

Lengai report from May 2008 (Chris Weber and Szeglat):

Only minor ash eruptions were reported by local Masai after the last noteable eruptions on 8 April and 17 April 2008. Some of the evacuated local Masai had returned back to their settlements, but part of the livestock had not returned from evacuation sites yet midd of May 2008. The volcanic fall-out of pyroclastics was still visible around the volcano. Due to a heavy rain period (season) vegetation damage was not as severe, as it could have turned out by this strong explosive eruption period of O. Lengai (BGVN 33:2). Up to around 1000 m altitude the vegetation, mostly "Elefant grass", normal grass and some Akazia trees, were undamaged around the volcano, except for the western sides where severe damage of the vegetation occurred as far as 10 kilometers away from the summit. Some lahars had happened on the north and northeast of the volcano's out runs. The elderly Masai reported, that in compare to their visible observations, the recent eruption period was stronger than the 1966/1967 explosive event.

Summit visit of O. Lengai by Chris Weber and Marc Szeglat, 14 unil 16 May 2008.
The former common trekking route (track) up O. Lengai is not recommended so far, because of rockfall hazards and bad hiking conditions. We used a very steep route on the SE side (named "simba route") of the volcano to climb up. From about 1000 m altitude volcanic ash-layers were clearly visible on the ground, but new grass had already grown since the eruption. At approximately 1500 m on the SE- volcano flank, all vegetation started to be covered (or being destroyed) by volcanic pyroclastics ("ash fall out"). From about 2500 m, additional impacts of volcanic bombs were visible. The volcano's inactive south crater was the location of our camp site. All vegetation was whiped out and volcanic bomb impacts from the last explosive events on April 2008 were quite impressive to study (see picture below).

The active north crater of O. Lengai had a new morphology (see map and cross section). The diameter of the crater from N to S was 300 m and from E to W 283 m. The crater floor was at approx. 2740 m altitude, accordingly 130 m deep seen form the west crater rim. Two vents were located as c1 and c2 inside the crater and obviously not at older hornito locations (marked with Tx in the map). Both vents were dergassing with strong pressure and quite noisy. On 15 May a period of powder ash eruption started until midday (see picture). This happened again on 16 May, unknown which vent was responsible for this. After our descent we visited an abandoned Masai boma on the west side of O. Lengai. The "ash fall" forced the local family Lesele to flee from their home only a few kilometers away form the summit of O. Lengai.

impact crater impact crater
Figures form the left: bomb impacts in the south crater; Marc gives scale.
N crater N crater
Figures form the left: ash eruption at the north crater seen from the summit (2960m); view over the crater towards the east.
north crater Boma and Lengai
Figures form the left: looking inside the north crater (130 m deep); abandon Boma with Lengai in the background
Lengai: map of the crater 5/2008 (C. Weber)

Map of Lengai 2008
Cross section A-B 5/2008 (C. Weber)

Cross section 2008

Lengai reports from Aug 2007 (Chris Weber and others):

Only few effusive eruption periods on Lengai have been reported since end of March 2006 with an overflow to the west far down the slopes and the followed collaps of the central area of the crater. Evidence of lava flows have been given by remote sensing data (MODIS) analyzed by Matthieu Kervyn 20 June 2006. The volcanologist Steven Beresford has noted only some days old lava flows from hornito T37B on 13 June 2006. This activity has been confirmed by locals. Activity with surface lava flows have then returned on 20 June 2007 due to information of the local Lengai observer and guide Burra Ami Gadiye. Through July 2007 many tectonic earthquakes have been reported from the Rift Valley area around Lengai, some with epicenters as close as 20 km and only at 10 km depth. Christoph Weber has visited O. Lengai with an excursion group and noted as well many earthquakes between 18 and 24 August 2007. On midnight between 3 and 4 September 2007 activity has culminated with a very strong and gasrich eruption ("paroxysm"(1)) causing a some kilometer high eruption column and damage to the vegetation on the volcano slopes, documented on a ASTER satellite image on 4 September. Ash fall out of about 1 cm has been reported from the tourist facility Moivaro camp at the shore of Lake Natron. The access to the volcano has been closed for visitors by local authorities.

Visit of O. Lengai by Chris Weber 21 and 23August 2007.
With an excursion group Chris Weber started to climb O.Lengai with some local porters on 21 August early morning. With the knowledge of strong effusive eruptions inside the crater and because of clowdy and foggy conditions that day, the porters (some Masai and some of other tribes) were told not to enter the crater without a volcano guide. But some ignored the warning and crossed the crater by themselves, which caused a terrible accident at around 0800 that day. The local Masaii Pambau (Pemba) (HELP for him in urgently needed - see below!) fell into a running quite deep lava flow, more than 500 degrees celsius hot. Somehow he managed to get out of the lava, but leaving both legs and one arm of him completely burned. Half an hour later Chirs Weber arrived with his group at the crater of O. Lengai. The well equipped group started first aid treatment and organized an effective and immediate rescue down the steep volcano slopes with the help of some tough men such as Burra Ami Gadiye and Othman Swalehe. After treatment in Arusha hospital financed by volcano Expedition Int., the Masai was on the way to recover midd of September, which is some kind of a miracle because of his severe burning injuries.

On 23 August Chris Weber and his group reached the crater of O. Lengai at 0815 again. Rough degassing natroncarbonatitic activity from several central vents took place this day. Lapilli and ash was even carried by the wind outside the crater onto the western climbing track. With very good weather conditions Chris Weber took an overview picure of the crater (see figure 1.) and a view from the the SE to the central area of hornitos (see figure 2.). This eruption period, which started on 20 June, had filled the collapsed central pit area completely with new lava. Some hornitos were grown up again at locations T40C, T52, T58, T57B and new located at T57C and all of those were active with lava degassing and being spitted out. Active lava lakes occurred futher more at the east side of the remaining fragments of the collapsed T49B hornito and at T49 location (see figure 3.). The most violent activity occurred on 23 August at T56 located lava lake with lava fountaining up to 40 m high and lapille thrown out even much higher. Lavaflows mainly to the western crater area accompanyed this activity. From 1200 until 1400 massive lava flows drained ouside the crater via the west overflow as far down the volcano slopes as 1500 m altitude.

Lava temperatur was measured with 516C at a Pahoehoe lava flows in slow motion. Fumarol (F1) temperatures were measured with 82C. Lava samples were taken and will be analysed by Prof. Jörg Keller, IMPG, University of Freiburg, Germany. Most noteable expansions of crater rim overflows are only to the north.

During the night from 3 to 4 September activity on O. Lengai culminated into some kind of "paroxysm"(1) with lapilli and ash eruptions about 3 km high. Due to observation pictures taken from a plane on 5 September, the morphology of the crater and hornitos had not changed dramatically. Satelite pictures showed vast areas of burned vegetation on the south, west and northwest slopes of O. Lengai. The burning at the south was caused by a bush fire which started already before 20 August (eyewitnessed by Chris Weber), while the burnt areas to the west and northwest have been caused by lava flows on the slopes of O. Lengai. This is confirmed by MODIS images for the date of 31 August and 1-2 Septermber 2007, analysed by Matthieu Kervyn. Today it is uncertain, if this "paroxysm"(1) of acitivity and/or the unusual strong seismic activity at the African Rift Valley part may lead to a strong explosive eruption like 1966/1967.

Some of the information are provided by Fred Belton (see listed reports at his website), Celia Nyamweru, Matthieu Kervyn, Jurgis Klaudius and Prof. Joerg Keller.

(1) "paroxysm" definition as unusual strong culmination of an eruption period or notable strong single eruption, not to be missunderstood as an vulcania, plinian or ultra plinian eruption, though it could be one of those as well.

central area from top central area from SE
Figures form the left: crater O. Lengai seen from the summit (2960m), central area of hornitos looking fom SE
central area (c) Marko Schmiedel (c)Marko Schmiedel
Figures form the left (c) Marko Schmiedel: central area of hornitos looking W from a plane, lava from T58C during the night, Feb. 2006.
Lengai reports and NEWS from February 2006:

Christoph Weber arrived with a film team at the crater of O. Lengai 1100 on 02 February. C. Weber took scale of the the tallest hornito T49B with approximately 2890 m altitude (GPS) standing ~60 m above the crater floor at the NW overflow. No recent eruption had accured at T49B, but strong noisy degassing took place sometimes. Just east of T49B the hornito T56B had convecting lava deep inside and some only days old lava flows streched from three different vents at T56B towards the east as far as the E overflow. After the major collaps of T56B in 2004, this hornito (standing at approximately 2875m altitude on 02 Feb.) has nearly grown up again to its former shape and altitude. Also from T58C and the collapsed T58B hornito some days old lava flows were found on the eastern slopes passing the old and weathered T37, T37B and T45. The caldera shaped collapsed T58B had it's flat flour at ~2865m altitude with four active vents inside. Lava convection was close to the surface of T58B and inside the tall T58C.
At 1300 on 02 February a sudden increase of activity took place with two lava fountains at T58B lasting only some seconds. At the same time lava spilled out at all T58B vents, a T58C flank vent to the east and at a T56B vent. A lava flow went from T58B ~50 m towards the east. Lava spatter with lava flows inside T58B and up to ~150m towards the east occurred as well the following 3 days. From 0500 until 0730 on 06 February higher activity occurred with lava outflow at T58C. T58B showed also higher activity level from than on until C. Weber left the crater on 07 February morning.

Lava temperatur was measured with 519C at an Aa lava flow with cooled surface and not in motion any more. Fumarol temperatures were measured as well. During an observation flight on 13 February C. Weber noticed new lava flows from T58B and T56B vents. Crater rim overflow measurements on 2 February 06 indicate no change since last reported in Bulletin v. 30, no. 4 by Fred Belton (width in meter):
NW overflow: 3 February 06 (135m)
E overflow: 3 February 06 (72m)
W overflow: 3 February 06 (20m)
N overflows: 3 February 06 (1m at each of three locations)

central area central area
Figures form the left: central area of hornitos looking NW (person at arrow gives scale), Looking N from the summit at 2960m

Various attachments for others:

Visitors on Lengai:

02 February, Chris Weber and 4 participants (until 07 Feb.) plus 2 german day visitors
03 February, non
04 February, 2 germans camping one night
05 February, 2 dutch, one german day visitors
06 February, 2 russian, 2 german dayvisitors
07 February, non

Lava samples: Taken at 1330 on 02 February from gasrich Pahoehoe flow at T58B shortly after cooling off.
Wind directions (over 5000m altitude) and climat on Lengai 02/2006:

02 February, wind NE, closed high clouds, dry
03 February, wind NE, clear, dry
04 February, wind SE, clear, very hot, dry
05 February, wind NE, some fog at the summit only, dry
06 February, wind NE, clear, dry
07 February, wind SE, clouds from midday on, dry

Measurements of cracks:

CR3, 4,63m -0,01m
CR2, 4,79m -0,01m
CR1, distroyed

ERUPTION-NEWS starting 2006: Villagers flee as volcano erupts

(SOURCE: Guardian (c)ippmedia ,Date: 2006-04-01 10:44:07)
By (c)Adam Ihucha, Arusha
Hundreds of villagers living around Mount Oldonyo Lengai in Ngorongoro District have been forced to flee their homes after the volcano erupted on Thursday, 30th. Eyewitnesses said they heard a rumbling noise before the volcano began discharging ash and lava, prompting local residents to flee the area in their hundreds. District officials estimated that about 3,000 people from Nayobi, Magadini, Engaruka, Malambo, Ngaresero, Gelai Bomba and Kitumbeine villages left their homes within a few hours of the eruption, adding that most of them trekked to villages in neighbouring districts. Ngaresero resident Ibrahim ole Sakay said alarm bells were sounded after smoke was seen coming from the peak of the mountain, adding that people panicked after lava began pouring out of the volcano. 'People had to flee their homes in order to save their lives?it was the only sensible thing to do because a volcano eruption can easily obliterate whole villages and communities,' he said. He added that the eruption destroyed vegetation and polluted water sources, but no casualties were reported. 'Thank God, nobody was injured although smoke is still visible at the top of the mountain,' he said, adding that it was unlikely that those who fled their homes would return while smoke was still bellowing from the peak. Ngorongoro District Commissioner Assey Msangi told The Guardian by telephone that it was not unusual for minor eruptions to occur at the mountain. 'I have not yet received an official report, but eruptions are a common phenomenon at Mount Oldonyo Lengai because they occur almost every year,' he said. Mt Oldonyo Lengai is located in the Rift Valley, about 120 kilometres northwest of Arusha. It is the only volcanic mountain in the world that discharges the highly fluid natrocarbonatite lava that usually contains almost no silicon. Natrocarbonatite lava is also much cooler than other lavas; averaging only about 950 degrees F (510 degrees C) compared to temperatures of over 2,000 degrees F (1,100 degrees C)?for basaltic lavas. At about 370,000 years old, Oldonyo Lengai is the youngest big volcano in this part of the Rift Valley.

Summary: "Paroxysm" late March 2006 (C. Weber) ... so it has cooled down ...!?

(based on information sources from Celia Nyamweru, Fred Belton, and others)
...The eyewitness David Peterson reported to Celia Nyamweru, that a smoke column was visible on 28 March 2006, which propably marks the start of a bigger eruption on Oldoinyo Lengai. This ash column could have been triggered by a violent degassing (lava fountain up to strombolian and explosive eruption) or a mayor collapse of the hornitos T56B and T58B because of flank uplift by lava. Both phenomena occurred during recent years and were described for example by F. Belton (Bulletin v. 30, no. 4) and C. Weber (Bulletin v. 29, no. 2) and may come together in one single event. This type of eruption is not comparable with the last big explosive eruption period of 1966/67.
On 30 March a lava flow on the lower slopes of O. Lengai was observed. Aerial views on O. Lengai indicated that a large lava flow had traveled from T58C (and T58B?) to the southeast and clockwise over the south part of the crater. At the west overflow the lava escaped on the outer flank of O. Lengai running down mainly inside a gorge (deep erosion gully/korongo) until approximately 1000 meters altitude. Some vegetation at the crater rim and along the gully was ignited by this lava, but because of rainy season the fire was not very severe or prolonged. During the first days of April no activity was observed on the outer flanks of O. Lengai. Reports of evacuations of the Maasai communities around O. Lengai during the first days of April were not confirmed, though the Tanzanian government's recommendation to evacuate was reported by the local media (e.g. Guardian, Arusha, by Adam Ihucha, 1 April).
Michael Dalton-Smith flew over O. Lengai on April 4 and reported to F. Belton that fresh looking black lava covered the already grey lava flows from 30 March inside the gully on the western slope. Visitors who climbed Lengai later on reported about a big lava channel, 5 meters wide and 2,5 meters deep, starting from the hornito T58C, following the flow field to the south west and then continuing outside the crater at the west overflow where there was a channel 8 meters wide and 3 meters, probably deepened by thermal erosion. The collapsed hornito area at T56B and T58B measured about 30 meters north to south and 15 meters east to west with an active lava lake inside. The tall hornitos T58C (partly collapsed to the southeast) , T49B and T57B were mostly not affected by the collapse, and as well the west part of T56B remained standing.

Lengai (c) M.Kervyn
Image to the top: GPS crater map provided by Matthieu Kervyn (Univ. of Gent) from 5/2006. More about Lengai studies (fieldtrip) from M. Kervyn at (http://users.ugent.be/~mkervynd/lengai.htm)
Lengai (c) Jean Perrin
Image to the top (c)J. Perrin 2006: view of the crater 5/2006 with the collapsed central area.

LENGAI: Two moderate earthquakes have hit Lengai volcano in Tanzania. The first earthquake measured 5.4 with an epicenter 13 km east of the volcano at 11:42 pm last night (local time). The second earthquake measured 4.7 with an epicenter 20 km west of the volcano at 12:10 am today. Both earthquakes had a shallow focus at depth of 10 km. by John Seach

(FALSE REPORT ?) Thousands flee homes after volcano eruption!
2007-07-19 10:27:27
By Adam Ihucha, Arusha
Thousands of villagers living around Mount Oldonyo Lengai in Ngorongoro District have fled their homes following a volcano eruption triggered by the earth tremors that have recently hit most parts of the northern zone. Sources say more than 1,500 people, mostly Maasai herdsmen from Ngaresero, Orbalal and Nayobi villages, have abandoned their homes following the tremors, whose impact has also been felt in parts of neighbouring Kenya. Ngaresero villager Peter Parkipuny said in a telephone interview: ``We heard roaring sounds before the volcano started discharging ashes and lava.``
``Thank God, nobody was injured although smoke is still visible at the top of the mountain,`` he added, noting that it was highly unlikely that those who fled would return while smoke was still bellowing from the peak. Two earthquakes rated as moderate hit the Oldonyo Lengai (Maasai for `mountain of God`) volcanic mountain at 11:42pm on Sunday and at 12:10am the next day. The first, which measured 5.4 on the Richter scale, had its epicentre 13km east of the volcano. The second measured 4.7 on the Richter scale and had its epicentre 20km west of the volcano, with volcano experts saying both tremors had a shallow focus at the depth of 10km. Yet another tremor, this time measuring 6.0 on the Richter scale, hit about 100km (60 miles) away from this municipality on Tuesday evening. It provoked the world?s only active volcano that spews natrocarbonatite lava.
Arusha Regional Police Commander Basilio Matei has cautioned tour operators against taking tourists around Mount Oldonyo Lengai, citing security reasons. ``Tour agencies should not take their visitors anywhere near or around the mountain because one can never tell when the volcano will erupt again,`` he stated, explaining that many tourists might be interested in witnessing the rare natural phenomenon ``but Tanzania is their host and must take all measures possible to guarantee their safety``. This is the second volcanic eruption to occur in the northern zone since the one in March 2006, which also saw a number of villagers flee their homes for their safety. An estimated 3,000 people fled to safe ground within hours of the eruption, most trekking to villages in neighbouring districts.
Mount Oldonyo Lengai, standing at 3,450 meters above sea level, is the world`s only active sodium carbonite volcano and doubles as the world`s only volcano that emits natrocarbonatite lava. Natrocarbonatite lava usually contains almost no silicon and is much cooler in temperature than other lavas. The highly fluid lava measures 510 degrees Celsius, while basaltic lava that can be as hot as 1,100 degrees Celsius.
SOURCE: Guardian

(From: Palhol, Fabien: an e-mail from my contact in Tanzania this morning)
Apparently, an eruption started on Lengai Monday 16th. The volcano is throwing stones (some people have been injured) and is making a lot of noise and smoke. The government seems to have stopped tour companies to take tourist into this area.
SOURCE: tanzanian travel operator

The news reports from the Guardian looks very (too) similar to the one form April 2006 ?!?. Well, to me and others knowing Lengai, no eruption has been clearly eyewitnessed or reported yet. So a big eruption is still uncertain today.
by Chris Weber
More about Lengai studies (fieldtrip) from Matthieu Kervyn (Univ. of Gent)

CONTINUE with: (http://users.ugent.be/~mkervynd/lengai.htm)

Details of a hazard paper from the IMPG (J. Keller)

CONTINUE with: (the webside is not ready today!)

Sattelite observation (infra-red picture of the area) Univ. of Hawaii

CONTINUE with: (http://modis.higp.hawaii.edu/)

The accident on Lengai in Aug. 2007 (see report above) caused severe burnings of Pambaus legs and one arm. Finaly the legs had to be amputated, which was successful. This treatment (amputation) was a charity by "Friends of Lengai", doctors, Lutheran Hospital, Arusha and Flying Medical Services. The artificial legs was a donation by Jaipur Foot Project (Nairobi). Celia Nyamweru, Cindy Ebinger, Lyle Harrison and others helped which a lot engagement. Even when the amputation was a full charity, some other high medical costs had and have to be balanced.

Financial HELP is still welcome and can be done via VHDL or the blog of Celia:

Pambau Pambau
Images: Pambau with his artificial legs. He is very happy and proud.
Pambau Pambau
Special Thanks:
For the first aid of Monika Seeger, the evacuation team of Burra Ami Gadiye, Othman Swalehe and others.
Directly after the accident in 2007, Chris Weber and the VEI travel group (Anita Wassener, Monika Seeger, Walter Dussler, Gert Diefenbacher, Marcus Daumann) have spend about 600 EURO for evacuation and medical first aid costs.
In October 2008 and 2009, the "Volcano Friends" of Eifel have collected some USD for Pambau.
In September 2010, family and friends of Chris Weber have donated about 1000USD. This has been used to pay the Flying Medical Services bill.
Ms Lyida Lazi has donated 100USD in October 2010.

Links to other related websides:

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