January 2009: Tom Casadevall of the U.S. Geological Survey related details of a visit to Tanzania to study the impact of future eruptions on Tanzania's tourism industry.  Results of their field work was reported directly to President Jakaya Kikwete.  Links to a detailed report of the survey will be posted here when available. There is a short article available here.

January 2009: Thomas Holden of Nature Discovery reported on a climb via the SE route, which terminates at the south crater rim. He reports that during the previous nine months, ten different groups attempted to climb by the SE route but none of them reached the summit due to the route's difficulty.  The SE route becomes even steeper than the NW Pearly Gates route and is covered by a hard crust.  During his January climb, an ice axe was used to cut steps in the crust.  There was no report about the summit activity level. Thomas also stated in a mid-March email that two more groups that attempted the SE route during the past two months turned back near the top due to the difficulty of the route, in spite of further attempts to improve the footing by cutting steps. The NW route (Pearly Gates) is much easier but exposes climbers to danger from eruptions since the rim of the active crater is directly above them.

February 2009: Dr. Anatoly Zaitsev reports: "Between the 12th and the 22nd of  February 2009 a group from St. Petersburg, Russia (A.N. Zaitsev, S.V. Petrov, T.A. Golovina and E.O. Zaitseva) and Tuebingen, Germany (G. Markl and T. Wenzel) visited several sites in Tanzania, including Oldoinyo Lengai volcano. During our visit Oldoinyo Lengai did not show any signs of explosive activity and we did not observe emission of ash or gases from the northern crater. The summit of Oldoinyo Lengai was reached at 8.30 (German group) and 9.00 am (Russian group) on the 18th of February after four and a half hours of climbing using the traditional western path. We stayed for five hours at the summit and walked around the deep pit of the active crater (western, southern and eastern parts) and inside the depression between the southern rims of a new and old craters. Three hornitos (wide cones) were observed deep in the crater floor. One hornito, with broken upper part, was permanently active during our visit. Inside the hornito there was “bubbling” lava and several times it erupted black natrocarbonatite spatter."

March 2009: Stefan Lübben climbed Lengai on March 14 and reports: "I have been on the summit together with a guide and a porter at the 14.03.2009. We have taken the way through the Pearly Gate and have had no stronger problems on the way. At the summit we have been in the clouds, it was realy wet and there was a strong wind. We could smell the sulphur but there was nothing to hear from the vulcano. I think the vulcano was completely quiet." 

Photo courtesy Stefan Lübben

Clearly seen here are several active or recently active vents. Photo courtesy  Stefan Lübben

April 2009: Alexander Daneel sent photos from a flight over the crater on April 7, 2009.  The photos clearly show the small lava cones deep inside the crater that were seen to be active by Hervé Loubieres and Françoise Vignes on Sept 1, 2008.  These photos suggest that there has no recent activity from the cones and they do not appear to have significantly incerased in size since Sept 1, 2008.

Looking SE across the crater Of Lengai. Photo courtesy Alexander Daneel.

View of the small lava cones on the floor of the pit crater. A crater rim collapse area is visible at the lower left.  Photo courtesy Alexander Daneel

April 2009: Ben Wilhelmi flew over Lengai around April 25 and forwarded several photos, some of which appear below.

This view toward the SE shows another view of a recent collapse of the crater rim. Photo courtesy Ben Wilhelmi

Photo courtesy Ben Wilhelmi

Closeup of the pit crater floor showing numerous vents and extensive spatter cone formation. These features have probably formed over the previous 4-5 months. Photo courtesy Ben Wilhelmi

June-August 2009: A few reports received during the summer, including ones documenting visits in August by Thomas Holden, in July by David Gregson, and in June by Tobias Fischer, indicate that Lengai continues to produce small effusive eruptions within the pit crater.  Thomas Holden reported that on his climb in late August (exact date unknown) he saw active lava flows. Tobias Fischer witnessed flows and a small lava lake ~5m in diameter in June.  David Gregson did not see significant activity but heard sounds of activity at depth. Although the activity appears to have returned to the typical eruptions of fluid natrocarbonatite lava for which Lengai is so well known, no samples of the new flows have been obtained for analysis due to their inaccessability deep inside the pit crater.  It is not known how similar the new lava is in composition to the lavas produced prior to the 2007-2008 eruption.

A convecting lava lake on the floor of Lengai's pit crater in June 2009. Photo courtesy Tobias Fischer

An eruption of lava below the east wall of the pit crater in late August. Photo courtesy Thomas Holden

Oct 2009: Tony van Marken and his team climbed on Oct 1. He reported: "We did not see moving lava – but it was making a rumbling noise – like the rapids in a big river. We did not walk the whole way around – just from r – l – anti-clockwise.  A dangerous place – you slip and you are gone."  Tony's climb is documented in his expedition blog.  He included a lot of detail and it is a good resource for anyone planning to climb Lengai.

Oct 2009: Schalk Boshoff of South Africa emailed me to report: " Willem Daffue and myself climbed Lengai with guide John on 20 October 2009.  Unfortunately we had rain when we reached Pearly Gates by 04:00 AM, where we spent 2 hours to wait until first light.  When we got to the top by 06:30 the cloud was so thick one could only see about 10m ahead.  The wind was blowing severely and it was very cold with rain.  We walked around the crater rim for about 90 degrees and could hear the vents blowing below, as well as bubbling sounds, but could not see a thing!"