ABSTRACT: The Role of Lake Level Dynamics in Lacustrine Stratal Architecture and Sequence Development: Evidence from The Songwe Delta, Lake Malawi, East Africa

AAPG Bulletin ◽  
2001 ◽  
Vol 85 ◽  
Author(s):  
Matthew R. Buoniconti1, Christopher
Keyword(s):  
East Africa ◽  
Lake Level ◽  
Lake Malawi ◽  
Stratal Architecture

Rock varnish record of the African Humid Period in the Lake Turkana basin of East Africa

The Holocene ◽  
2021 ◽  
pp. 095968362110116
Author(s):  
Tanzhuo Liu ◽  
Christopher J Lepre ◽  
Sidney R Hemming ◽  
Wallace S Broecker
Keyword(s):  
East Africa ◽  
Lake Level ◽  
Drainage System ◽  
Early Holocene ◽  
Lake Turkana ◽  
Moisture Condition ◽  
Turkana Basin ◽  
Rock Varnish ◽  
Geomorphic Features ◽  
Humid Period

Rock varnish is a manganiferous dark coating accreted on subaerially exposed rocks in drylands. It often contains a layered microstratigraphy that records past wetness variations. Varnish samples from latest Pleistocene and Holocene geomorphic features in the Lake Turkana basin, East Africa display a regionally replicable microstratigraphy record of Holocene millennial-scale wetness variability and a broad interval of wetter conditions during the African Humid Period (AHP). Three major wet pulses in the varnish record occurred during the generally wet interval of the early Holocene (11.5–8.5 ka) when the lake attained its maximum high stand (MHS) at 455–460 m. A >23 m drop from the MHS occurred between 8.5 and 8 ka. Subsequently two additional wet pulses occurred during the early to middle Holocene (8–5 ka) when the lake occupied its secondary high stand at 445 m. Collectively, these five wet phases represent an extended wet interval coincident with the AHP in the region. One moderate wet phase occurred during the subsequent climatic transition from the humid to arid regime (5–4.3 ka) after the lake level dropped rapidly from 445 m to <405 m. Five minor wet phases took place during the overall arid period of the late Holocene (4.3–0 ka) when the lake level oscillated below 405 m. These findings indicate that the AHP terminated rapidly around 5 ka in the Turkana basin in terms of lake level drop, but the regional shift in relative humidity from the AHP mode to its present-day condition lagged for about 700 years until 4.3 ka, hinting at a gradual phasing out in terms of moisture condition. These findings further suggest that Lake Turkana overflowed intermittently into the Nile drainage system through its topographic sill at 455–460 m during the early Holocene and has become a closed-basin lake thereafter for the past 8 ky.

Lake level change, climate, and the impact of natural events: the role of seismic and volcanic events in the formation of the Lake Patzcuaro Basin, Michoacan, Mexico

2005 ◽  
Vol 135 (1) ◽  
pp. 35-46 ◽  
Author(s):  
I. Israde-Alcántara ◽  
V.H. Garduño-Monroy ◽  
C.T. Fisher ◽  
H.P. Pollard ◽  
M.A. Rodríguez-Pascua
Keyword(s):  
Lake Level ◽  
Lake Level Change ◽  
Level Change ◽  
Volcanic Events ◽  
Lake Patzcuaro Basin ◽  
Change Climate ◽  
The Impact

scholarly journals Lundin Petroleum AB's experience in East Africa: The role of the private sector in conflictprone countries

2010 ◽  
Vol 5 (2) ◽  
Author(s):  
Christine Batruch
Keyword(s):  
Private Sector ◽  
East Africa ◽  
Stakeholder Engagement ◽  
Corporate Responsibility ◽  
Armed Conflict ◽  
Political Issues ◽  
Oil Revenues ◽  
Peace And Development

Lundin Petroleum spent over twelve years exploring for oil in Sudan, Ethiopia, and in Kenya. During this period it was faced with an armed conflict in Sudan, the risk of rebel activity in Ethiopia, and tribal clashes in Kenya. This meant the company had to consider operations in remote countries not only from a geological and commercial perspective, but also to take into account ongoing conflicts. This required considering political issues and developing mechanisms to ensure the sustainability of its operations. To this end it developed a corporate responsibility framework which emphasized stakeholder engagement, seeing oil revenues as potentially acting as a catalyst for peace and development.

scholarly journals Batai and Ngari Viruses: M Segment Reassortment and Association with Severe Febrile Disease Outbreaks in East Africa

2006 ◽  
Vol 80 (11) ◽  
pp. 5627-5630 ◽  
Author(s):  
Thomas Briese ◽  
Brian Bird ◽  
Vishal Kapoor ◽  
Stuart T. Nichol ◽  
W. Ian Lipkin
Keyword(s):  
East Africa ◽  
Disease Outbreaks ◽  
Amino Acid Identity ◽  
Reassortant Virus ◽  
Febrile Disease ◽  
Segment Sequence ◽  
Human Illness ◽  
Batai Virus ◽  
Bunyamwera Virus

ABSTRACT Ngari virus is an orthobunyavirus recently recognized as a reassortant between Bunyamwera virus and an as yet unidentified M segment donor. Analysis of M segment sequences of Batai and Ilesha viruses revealed 95% deduced amino acid identity between Batai virus and Ngari virus. These findings suggest Batai virus as the donor of Ngari virus M segment sequence. Analysis of Batai virus-related African isolates identified UgMP-6830, isolated from mosquitoes in Uganda, as an isolate of Batai virus. KV-141, isolated during a febrile disease outbreak in Sudan, was identified as another isolate of Ngari virus, emphasizing a role of this reassortant virus in severe human illness throughout East Africa.

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