Marc Szeglat

Oldoinyo Lengai: The holy mountain of the Masai (1996 until 2004)

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Author Chris Weber

The 2nd part of Chris Weber’s Ol Doinyo Lengai report describes what happened at the volcano in Tanzania, between the years 1996-2004.

Report on Lengai 17 August 1996

Ol Doinyo LengaiChristoph Weber climbed Lengai on 17 August and he observed a lava fountain up to 3-m-high on T37. During his entire time of visit lava still poured out. Beside activity at T37, Weber saw some quite fresh black Aa and Pahoehoe lava flows on the crater floor. He estimated the thickness of the fresh flows as typically 20-30 cm. Fresh flows were easy to distinguish because they may change from black to grayish white as they cool within days. They were often stacked, particularly on flow field F37, the one most active at that time, forming a composite of new flow material about a meter thick overall. Because of the rough irregular surfaces on some flows, their contacts with successive flows often contained considerable void space. Many of the flows were tube-fed, the tubes typically being 10- to 150-m long.

Report on Lengai 6 August 1998

Observation of the crater from 6 August 1998, 0800 until 7 August 0800 by Chris Weber. On 6 August at 0800 an eruption started at hornito T37N1. This hornito has a platform about 5 m above the surrounding area while it is highest peak at the northern flank is about 8 m high. A little splatter cone had build up on this platform where foaming white to pale grey carbonatite lava splashed out and fed short lava flows with a few meters length down the west-slope of T37N1. Most of the lava went into older lava tubes west of this hornito. The vasiculation of the gas rich lava was high. The activity stopped around 1100 with a 4 m drop of the lava level in T37N1.

On the same day at 1400 lava splashed out of two openings close to it is peak of hornito T48. The black degassed very liquid lava fed little lava flows reaching 8 m of length down the east-slope. The activity stopped shortly after 1600.

On 7 August at 0408 a loud explosion blew of the top and northside of hornito T49 after several earthquakes during the night. The earthquakes seamed to have shallow and deeper hypocenter in the volcano. Rocks of this hornito up to 1 m3 were thrown or rolled a few meters to the north by this explosion. Right after the explosion a lava fountain (fire curtain) approximately 15 m high continued until 0413 with a loud turbojet-noise. Pahoehoe lava with little viscosity (1-5 Pa s) which splashed down north of the hornito traveled fast to the north and west.. The 10-20 cm thin flow stopped moving shortly after the end of the eruption. The amount of erupted lava was about 70-100 m3. Lava pearls up to 4 mm diameter and fine ash were transported at least over 200 m by the wind in northwest direction. The fountain had a dark red glow. The hornito lost less than one meter of the 6 m elevation., whish it had before the explosion.

At 0615 on 7 August hornito T44 started activity for an unknown time. Black liquid lava splashed out of it is 6 m high peak and splattered on the flanks of the cone. No lava flow was observed until 0815.

T40 degassed with mild turbojet-noise. The lowest point [ X ] of the crater-rim over the crater-floor in northwest was 20 cm.

 

Report on Lengai 3 until 11 Oktober 2000

Eruptive activity: On 3rd Oct. from 1200 until 1350 hours spattering occurred in the saddle between T49 and T49B out of a small vent. Two little lava flows were observed at the northern and southern flank of T49 during that time. At 1350 the west side of T49B collapsed and released out of an approximately 6 m wide and 5 m high gap a sudden flash flood of lava. Parts of the collapsed wall of T49B were washed towards the west as big blocks. Within a few seconds the flow had reached halfway between the cone and the NW Overflow. After 5 minutes the flow had reached its final extent about 40 m short of the NW Overflow (See map of flows: Flow 4A). The lava flow was up to 5 centimeter thick and later Aa flows were several decimeters thick.

Until 8th Oct. lava spattering and many small lava flows (formed from overflowing the vent, as spatter fed flows or emitted from small new vents and fissures) had nearly closed the gap in the west wall of cone T49B. Only close to the top of T49B spattering occurred on the evening of 8th Oct. On the morning of 9th Oct. at 1035 hours nearly the same west flank of new lava collapsed in the same manner as on 3rd Oct., leaving a 7 m wide and 7 m high gap. Lava went in a flash flood within seconds towards the NW and stopped just 10 m before the NW Overflow. The flow covered the Flow 4A and is shown in the flow map as Flow 4B.

During the afternoon of 9th Oct. T48 had strong degassing and for only 10 minutes ejection of tear-drop lapilli occured. After this event T48 went quiet for the rest of our visit. Right after sunset of 9th Oct. at 1810 hours a crack opened at the SSW base of T49C with a sudden noisy gas jet followed by a 10 minutes spraying of lava droplets and sperical lapilli up to approximately 10 m high. A small lava flows (Flow 4C) were emitted too and moved NW. From there on until our descent on 11th October no flows were observed, meanwhile the lava lake inside T49B was still in motion and heavily splashing and degassing.

Accident: Jürgis steped into a little lava flow in October 2000.

In the evening Oct. 3rd, 2000 small lava flows were to be seen again at Hornito T49, so that I called the geologist of the IMPG team, Jürgis Klaudius, who was already resting in his tent, to have a look. He was curious and to hurry up, he put on his sneakers instead of his mountain boots, and jumped out of the tent. We went to the lava flow in the dark and then a scream from Jürgis followed. He briefly had stepped into a 20 cm high lava flow at a temperature of about 500 degrees, which was flowing across a flat terrain and just looking black in the dusk. All light plastic and gorotex parts of his sport shoe were burned, the leather parts and the sole were left as a framework.
The consequences were quite fatal. Despite my good first aid and quick treatment of the burned injuries, Jürgis had to be evacuated from the mountain after two more days with his infected foot on 6th August. Since an attempted air rescue by heli failed because of non capacity, only the rescue down the steep mountain slope remained. In the steep upper part, over 45 degree, Jürgis had to slide down on his butt with his injured foot forward wrapped into bandage. This was painful and distroyed his trousers. In the middle of the way down, two of us gave him a support and when it got flatter, the four of us rescuers shouldered the tired man piggyback changing every 10 minutes one after another. For this descent we needed about 8 hours instead 4 hours or so.

Following, Jürgis, me and driver Mike had an 8 hour drive through the night into hospital in Arusha. Next morning I had already rebooked the flight from Jürgis towards Germany and then Mike and I started our journey back to the Lengai, where I made the ascent with a load of 30 kg luggage early in the following morning. Later on when Jürgis had returned to Germany a succesfull skin transplantation took place. Luckily everything went fine again without immobility consequences.

 

Report on Lengai 18 until 22 Oktober 2002

By the arrival 18th June the fresh looking and still black lava flows were visible from T49B on a length of 120 meters towards western directions. From T46 black lava flows streched towards NW, W, SW, and South on a length of 20 to 80 meters. The hornito T37B was covered with still black lava and propably had erupted recently. The flanks of T48 as far as to T44 were covered with black lava lapilli also propably from recent activity. The diameter of the T49 base (eruption center) increased strongly compared to august 2001.

A new eruptioncenter was clearly visible half way between T46 and the West overflow an could be numbered as T54. The eruption site of T54 was an open lava pond with an overflow of about 40 meters towards the west. Black lava had covered older lava flows who had left the crater on his west side in Febuary 2002. A lava lake bubeling deep inside T48 was clearly heard during the days of our observation. The fumarolic activity and its temperature (> 125°C) increased also from summer 2001 until summer 2002. Three recognizable relativly deep released single vibrations occured during our visit

Activity and small lava flows were observed from T49B. On 18th June lava spattering from the top of T49B went on in intervals of intensitiy from 14:00 until 19:00 hours. The maximum height of the lava fountains of was arround 3 meters. A litle lava flow went from the top towards the norh east for about 50 meters. During the day of 19th June spattering occurred with a duration everedge of 30 minutes followed by one and a half our breaks of now activity until 04:15 hours in the afternoon. No more activity outside hornito T49B and other hornitos was observed until 22nd June. On 22nd June arround 10 m3 collapsed from the wall below the summit of T49B into the crater.

 

Report on Lengai 10 until 14 February 2004

On 10 February 2004, Chris Weber and others visited Lengai for 5 days. The summit of the tallest hornito in the center area of the active crater at Oldoinyo Lengai was at approximately 2886 m altitude (GPS), standing about 33 m above the surrounding crater floor to the north. This tallest hornito at the T49 location (T56B) was not active anymore, while T48B (T58B) had a lava lake deep inside it’s hornito, clearly indicated by noises and tremor. The activity had changed to the common effusive and lava lake activity. This occured at the old T49 eruption center, also indicated by the activity of T49B during observation and an active new vent (numbered T49G by C. Weber) at the north flank of T49 (T56B), about half way up from its base to the north side.

This new activity propably caused two collapses (depression) in the north flank of T49 (T56B), already visible since January 2004 (first described by B. Donth). The T49G vent, hosted at the upper collaps, had a steady degassing lava lake with many overflows during the visit of C. Weber. Lava penetrated the lower collaps at T49 and lava flows reached as far as to the NW overflow. On 12 and 13 February T49B spattered lava for some hours, feeding lava flows to the west (T51), finally escaped into a lava tube system. The lava temperature very close to the lava lake was measured at 588°C. Aa lava flows not in motion anymore at flat terrain were measured between 480°C and 500°C.


References

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography.

Bell K, Dawson J B, 1995. Nd and Sr isotope systematics of the active carbonatite volcano, Ol Doinyo Lengai. In: Bell K, Keller J (eds), Carbonatite Volcanism, Oldoinyo Lengai and the Petrogenesis of Natrocarbonatites, Berlin: Springer-Verlag, p. 100-112.

Dawson J B, 1962. The geology of Oldoinyo Lengai. Bull Volcanol, 24: 349-387.

Dawson J B, Keller J, Nyamweru C, 1995. Historic and recent eruptive activity of Oldoinyo Lengai. In: Bell K, Keller J (eds), Carbonatite Volcanism, Oldoinyo Lengai and the Petrogenesis of Natrocarbonatites, Berlin: Springer-Verlag, p. 4-22.

Global Volcanism Program (GVP), 1996. Bulletin of Global Volcanism Network (BGVN), Smithsonian Institution

Pacaya volcano continues to erupt volcanic ash

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Guatemala’s Pacaya is also located in close proximity to the capital: here, it is only a good 25 km as the crow flies to the center of Guatemala City. Accordingly, even moderate eruptions of the volcano often affect the capital and disrupt air traffic. Also in the last 24 hours Pacaya was active and produced volcanic ash. It rose to a height of 4000 meters. The ash drifted up to 25 km in a southwesterly direction. Ash precipitation occurred in the communities of El Rodeo and El Patrocinio. Volcanic bombs dispersed up to 500 m around McKenney crater. The lava flow on the southern flank is 1000 m long. From its front, block avalanches are coming down.

Pinatubo: Seismicity increased

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Pinatubo in the Philippines is seismically unsettled. Yesterday PHILVOLCS detected 25 volcanotectonic earthquakes at the volcano on Luzon. The previous day, there were 8 tremors. The alert status is at “1.” It is interesting that at the beginning of the phase with increased seismicity, it was stated that the tremors were tectonic in nature. Apparently, the activity has shifted. It is also interesting that the capital Manila is encircled by the two volcanoes: while the Taal caldera is located 70 km south of Manila, Pinatubo is located 100 km northwest of the capital. Large eruptions could have a correspondingly strong impact on the metropolis, depending on the wind direction.

Sangay: Ash cloud detected

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Let’s start not in alphabetical order, but with the apparently strongest eruption of the last 24 hours. This was delivered by the Ecuadorian volcano Sangay. According to VAAC, volcanic ash rose to an altitude of 12800 m and dispersed to the northwest. A smaller ash cloud rose to 6700 m and moved in the opposite direction to the southeast. Speculatively, the higher ash cloud was explosively produced and the smaller eruption cloud originated from a pyroclastic flow that descended on the southern flank of the volcano. Due to the permanent cloud cover, visual observations of the event are rare. What does exist, however, are reports that the sky darkened over the towns of Riobamba and Chambo. In addition, there were showers of ash. People showed concern. The volcanologists of IGEPN are also concerned: they fear that continued rains could trigger lahars.

Etna Paroxysm No 12

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The 12th consecutive paroxysm on Etna began this morning. Activity began to increase significantly around 7:30 am. Already half an hour later, a lava flow began to emerge from the New Southeast Crater. In the meantime, the paroxysm has reached its peak.

You can see from the broad tremor base that the paroxysm was increasing comparatively slowly and has now been going on for quite a long time. It looks like it peaked at 10:30 CET (9:30 UCT). The tremor amplitude has risen even a bit higher than during the last paroxysms. Once again, the eruption takes place in unusually good weather. There is almost no wind and the eruption cloud rises vertically. VAAC Toulouse detects volcanic ash at 10,400 m altitude. On a thermalcam, one can see the lava flow that has descended far into the Valle del Bove. Obviously, however, there is only the lava flow in the eastern direction, no lava seems to be on the way in the south.

Taal: Alert level raised

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PHILVOLCS has been reporting for several weeks an increase in seismicity under the large Caldera volcano on Luzon, which caused a stir with an eruption only last January. In addition to numerous volcanotectonic earthquakes, volcanic tremors also increased significantly recently. The total number of volcanic tremor events has risen to 866 since the increased activity began on February 13. The volcanic tremors have increased seismic energy compared to previously recorded episodes and have ranged from 3 to seventeen 17 minute durations. In addition, the other parameters that indicate magma is moving at shallow depths are beginning to change: the acidity of Crater Lake increased, rising (or falling) from pH 2.79 to pH 1.59. The water is becoming more acidic because of increased volcanic gases rising. The water temperature increased to 74.6 degrees. Slight bottom deformation was detected using InSAR imagery. Concomitant changes in microgravity were recorded. New measurements have detected positive microgravity changes throughout the Taal caldera, consistent with density changes due to magma migration, magma degassing, and hydrothermal activity. All of these parameters are of concern and the alert status has been raised to “yellow.” Evacuations have not yet been initiated. Authorities remind that Volcano Island is a permanent exclusion zone. The photo shows the volcano during last year eruption.

Iceland earthquake M 5,0

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Iceland’s Reykjanes Peninsula experienced a new earthquake with a magnitude of 5. According to IMO, the earthquake was detected at 02:02. The epicenter was located about 3 km west-south-west of Fagradalsfjall. Already at 0:22 a short tremor phase was registered. It lasted 20 minutes and can be seen on the graph by the fact that also the frequency bands 0.5-1 Hz and 1-2 Hz deflected. This was followed by a general increase in seismicity, at the peak of which the M 5.0 earthquake occurred. Interestingly, the EMSC located this earthquake on the northern coast of the Reykjanes Peninsula, in the immediate vicinity of the national capital. The EMSC gives a magnitude of 5.2.

Pacaya: Eruption in Progress

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Unlike Etna, Pacaya did not take long to erupt and has been delighting with a fancy lava fountain for hours. INSIVUMEH reports glowing tephra rising up to 700 m above crater level. An ash cloud is rising up to 4500 m above sea level and drifting towards the southwest and west. In the communities downwind, ash and lapilli are raining and there is even a warning that blocks will fall. Likewise, there is a warning that lava flows may be formed, or that existing lava flows may increase. So it remains exciting at the volcano. It is noteworthy that there is a new livecam from CONRED, which is currently transmitting a livestream (see below).

Oldoinyo Lengai: Chris first adventure in Aug. 1996

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Author Chris Weber

The small town of Arusha (1200 m) in Tanzania was the starting point. From Arusha I took a public bus to the village of MtoWa Mbu about 100 km northwest, even partly paved. The next day journey was not so easy to get organized. So, I went to the village pub for a beer and a couple of darts games. My search for tranport got public and before dinner, I had arranged a lift. The next morning I got up with the first light and went out on the street of the village as agreed. After waiting for over an hour – I had forgotten to set the clock to “Tanzanian” time – a guy came running along and pointed to a scrap-looking Toyota pickup truck that was loaded with many goods. Well, ok. From MtoWaMbu we turned north on a bumpy dusty road and followed it to the Masai village of Selela and further on to Engaruka. Changing passengers jumped on and off, all finding uncomfortable space on the loading. This was an important service for the villages along the route to get goods and transportation.

Behind Engaruka there was no more settlement and more and more wild animals like zebras, giraffes and antelopes appeared in the open gras plains. The Toyota got stuck more and more often in the deep dust. When the driver tried to get it out, the engine of the old car increasingly failed by overheating. The rift shoulder rose steeply to the left and the stratovolcanoes Kitumbeine, Karimassi and Gelai (2942 m) could be seen to the north. In the evening after countless breakdowns, we – driver, assistant and I – gave up reaching our final destination, also because orientation was very difficult in the dark. The driver allowed us to approve a few beers, because we had no food at all. After that we fell asleep easily, lying peacefully on a tarp under the starsky, despite of scorpions, poisonous snakes and lions. We had at least reached the eastern slopes of Oldoinyo Lengai. The next morning the dust swallowing and shaking came to an end after 24 hours on the 150 km stage. Near Lake Natron (610 m) was the small Masai settlement Engarosero, where I got unloaded from the Toyota together with four live chickens, 2.5 crates of beer, many crates of Coca Cola, all kinds of plastic goods and equipment. I was welcome by the Siningo family in a simple campsite near to the village.

The ascent of Ol Doinyo Lengai on August 17, 1996

I got ready to set off for the summit of Lengai in the morning with a 25 kg backpack including 6 liters of water and a lot of useless equipment. The Masai told me, that it was customary to take a guide up the mountain. Well, I smiled and declined with many thanks, because I thought the mountain, which had been described in some literature as unclimable, was relatively easy in terms of commonly mountaineering experience. The Masai laughed and let me go.

The temperature was still pleasantly fresh in the morning, but that changed brutally around noon. In a dry river canyon I found a place in the shade – luckily without cobras and scorpions – to rest and save water. After the midday heat, I continued to climb through sticky annoyingly high grass and came across car tire tracks at approximately 1300 m. Great, but sadly I didn’t have a car. From there, the stratovolcano Lengai rose noticeably steeper on an increasingly narrow mountain ridge. Meanwhile deep canyons, that had been washed out by the rare rain in the relatively soft rock of the volcano, occured to the right and left hand side.

Night was falling, but thanks to the full moon, I was able to continue climbing without a headlamp. Despite the relative coolness of the night I was quite thirsty and sweated a lot, which was due to the steep upper volcanic flank of over 45 degrees. Then finally I reached the 2830 m high crater rim at the west side. But my enthusiasm didn’t last long, because seconds later , I found myself 2 meters deeper in a mountain crevasse that I had overlooked in the dark. Fortunately, apart from bleeding scratches on the legs, the fall went off lightly.

After this incident, I was able to enjoy the activity spectacle in the crater of Lengai for the first time. The moon had set, but in the large crater – from a size of a sports stadium – were clearly visible half a dozen of hornitos, or tall hills. The lava of the crater looked like white snow, with only a few black spots in between and suddenly, I saw a faint shimmer of red in a black lava flow. Liquid lava, only some hundred degrees hot. The source of it became evident as lava boiling and bubbling more and more violently behind a small lava dam. It hissed, gurgled and cracked softly but also somehow frightening. I climbed very carefully into the crater and approached the fluctuating activity at dawn. After exploring and taking a few photos, I used the cool morning for the descent, which didn’t take long but seemed endlessly long without water through the dry and increasingly hot savannah. In the camp, I reported about my success and the activity of Lengai, which was taken with respect by those people who came across.

 

Abstract

The Oldoinyo Lengai is located in the East African Gregory Rift in Tanzania at 2,751 latitude south and 35,902 longitude east. The current height of the stratovolcano is 2960 m.

Its mountain base is located in the bottem of Rift Valley at approx. 600 m altitude, with a western connection to the over 2000 m high valley shoulder. The steep volcano slopes run into Lake Natron in the north, which extends to the border with Kenya and further on.

The age of the Lengai is about 370,000 years, so far behind the last major folding phase of this part of the East African Rift 1.2 million years ago, in which several carbonatitic volcanoes were formed.

The older part of the Lengai is the dorment south crater. It erupted yellow tuffs 370,000 to 150,000 years ago. The young and still active part is the north crater. It initially ejected black tuff until around 1,250 years ago. Then the eruptiones of natron-carbonatitic lava began, which has filled the crater with mostly high viscose lava flows. For the Masai tribe living arround the volcano, Lengai is sacred mountain and the seat of their creator Engai.

G. Fischer was probably the first European to penetrate this volcano in 1883, which is located in what is now Tanzania. The first scientific report on the crater and its special lava was provided by F. Jäger in 1904. Reck made the first photographic report in 1914. From then on, several expeditions visited the Lengai, although it was not the frequently climbed volcanoes in the 19th century due to its remoteness and difficult access.

Eruption Datas Oldoinyo Lengai

The first dated major explosion of the previous century occurred in 1917. Ashes (tephra) were thrown nearly 50 km into the surrounding area and lava flows reached the base of the volcano. This eruption was numbered with the Vulkan Explosiv Index (VEI) 3.

In 1923 A. Barns observed night glow over the crater and in 1926 another explosive eruption occurred, also observed by Richard in 1940 and 1942 – for weeks, ash clouds rose over the volcano after violent explosions (VEI 3).

On August 9, 1966, what is probably the most serious explosion in historical times occurred. An ash (tephra) cloud rose over 4,000 meters into the sky and ash fell 200 km away. There were no major explosions between 1967 and 1983.

Since 1983 until today, many effusive and smaller ash (tephra) eruptions, only interrupted by a longer rest period from 1993 to 1994, have almost filled the crater. From 1999 the overflow of lava began until another very explosive phase occurred in 2007/2008. Since then, the over 130 m deep crater that was left, has been backfilled again with effusive lava.

Petrography of Ol Doinyo Lengai

Soda carbonatitic (alkali carbonatitic) minerals: Nyerereite (Na0.82K0.18) 2Ca (CO3) 2 and Gregoryite (Na0.78K0.05) Ca0.17 (CO3). This non-silicate magma is a mixture with sodium-calcium-carbonate. The inclusion of bubbles is caused by a high proportion of dissolved CO2. The temperature of the melt is relatively cold at around 600 ° C from an igneous point of view. This temperature is just enough to cause a red glow at night. The viscosity of the melt is 1-5 Pa s (basalt has approx. 100-1000 Pascal sec., Water 0.01 Pa s) and reaches flow speeds with a slight gradient of 10 km / h.

 

 

Location Date Temperature (°C)
T40 lava lake 28 August 1999 529
Pahoehoe flow in a tube near T40 1 September 1999 519
Aa flow still in motion at flat terrains (60 cm thick) 1 September 1999 516
Pahoehoe flow in a tube near T49B 3 October 2000 507
Aa flow still in slow motion at flat terrain (25 cm thick) 3 October 2000 496
Pahoehoe flow in a tube near T49G 11 February 2004 588
Pahoehoe flow in a tube near T49B 12 February 2004 579
Aa flow not in motion anymore at flat terrain (15 cm thick) 13 February 2004 490
Pahoehoe flow in slow motion (10 cm thick) flat terrain 26 June 2004 560
Pahoehoe flow (15 cm thick) in motion inside a Levée 03 February 2005 561
Aa flow not in motion anymore at flat terrain (15 cm thick) 03 February 2005 520
Aa flow not in motion anymore at flat terrain (10 cm thick) 06 February 2006 519
Pahoehoe flows (20-50 cm thick) in slow motion 23 August 2007 516

Table 1. Lava temperature measured by a digital thermometer (TM 914C with a stab feeler standard K-Type). The instrument was used in the 0-1200 Celsius mode. Calibration was by the Delta-T ethod: values are +/- 6°C in the 0-750°C range, with at least 4 different measurements at one spot. These temperatures compare well with the range of the first temperature determinations on natrocarbonatites of 491-544°C by Krafft & Keller June 1988 (Science vol. 245, 1989), although occasionally higher temperatures up to 588°C have been obtained in the eantime.” Courtesy of Christoph Weber.

References

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography.

Bell K, Dawson J B, 1995. Nd and Sr isotope systematics of the active carbonatite volcano, Ol Doinyo Lengai. In: Bell K, Keller J (eds), Carbonatite Volcanism, Oldoinyo Lengai and the Petrogenesis of Natrocarbonatites, Berlin: Springer-Verlag, p. 100-112.

Dawson J B, 1962. The geology of Oldoinyo Lengai. Bull Volcanol, 24: 349-387.

Dawson J B, Keller J, Nyamweru C, 1995. Historic and recent eruptive activity of Oldoinyo Lengai. In: Bell K, Keller J (eds), Carbonatite Volcanism, Oldoinyo Lengai and the Petrogenesis of Natrocarbonatites, Berlin: Springer-Verlag, p. 4-22.

Global Volcanism Program (GVP), 1996. Bulletin of Global Volcanism Network (BGVN), Smithsonian Institution

Sinabung: Seismicity high

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At the Sinabung on Sumatra the situation comes to a head: here the seismicity increased enormously in the last days and not only debris avalanches were registered, but above all earthquakes with low frequencies. They indicate massive magma rise. Yesterday, a good 560 of these quakes were recorded. In the first 6 hours of today, there were already 239 quakes. In addition, 112 signals testified to debris avalanches. The dome is growing and the situation is becoming more and more critical!