Tales from East Africa" - University of Minnesota

”Tales from East Africa"Tom JohnsonLarge Lakes Observatory, andDepartment of Geological SciencesUniversity of Minnesota Duluthwww.d.umn.edu/llo

Or, the title I suspect you may be thinking:“Yet Another Professor’s Willy Nilly, IrresponsibleExpenditure of Federal Funds in Far-Away Lands”

The Great Lakes of East AfricaTurkanaAlbertEdwardVictoriaTanganyikaMalawi

IPCC (IV) prediction of climate change during the 21 stcentury(average of 21 climate models)

“Africa is one of the most vulnerable continents to climatechange and climate variability, a situation aggravated by--- low adaptive capacity.”Intergovernmental Panel on Climate Change, AR4, 2007

Looking for patterns and connections in the global climate system ----

What role (if any) has climate played in the evolutionof our species?

Cave paintings fromthe Sahara

Tree ringsThe “Paleoclimatologists”Ocean drillingIce cores

Piston coringOn the oceanOn Lake Victoria

Finding the right place to core with seismic reflection profiling

Lake Tanganyika - 1982

R/V Nyanja – 36 ft, 12 tons

Our second night out on Tanganyika ----

A tow into the village ofNyanza Lac, BurundiAdrift and out of fuel

More than 4 km of sediment underlie the major rift lakesLake Tanganyika

Lake Turkana,Kenya - 1984

Looking at Lake Turkana, Kenya to determine the Nile’s pastBlue NileWhiteNileOmo R.Lake Turkana

Fossil diatoms indicate that an abrupt shift from freshwater tosaltwater conditions happened 4300 years agoDryWetJohn Halfman, Ph.D thesis, Duke Univ.

The Old Kingdom of Egypt collapsed 4200 years ago

Exciting new developments ------

TEX86 – A proxy for past temperaturebased on tetraether compounds (GDGTs)from Thaumarchaeamarine Thaumarchaea(

Lake Malawi• >700m deep• 4th deepest lakein the world• ~600km longand average of55km wide• Anoxic below200m

A 25,000 year history of temperature in the African tropicsRecent warming5000 years ago – asurprisingly warm time in thesouthern African tropicsSignificant cooling duringthe ACR and YDSite 2The last glacial maximumPowers et al., 2005

Temperature records from Lake Tanganyikashow recent warming, much like the whole world

Site 2Site 1

LaminatedDiatom silty clayNonlaminatedCalcareous silty clay - usuallybioturbated

A 1.2 million year record of temperature in the Malawi basin

EXISTING UNDERSTANDINGFIGURE 2.3' 9 &=4$8+' "1' +' SHWKG +' Paranthropus boisei' 8,+( $5# ' 1"5( 7' ?. ' G +,. '$( 'SVOV'+%'_ 4753+$'A",B&D'/) "@( '@$%) '+',&=4$8+'"1'+'SHNKG +'# +( 7$?4&'"1'%) &'/+# &'1,"# 'Z&( $( >D'

Hominin evolution extends back some 7 million yearsWe have only begun to recover the record of human evolution!

African Great Lakes in Peril:Lake Malawi example

Lake Malawi has ~1000 species offish: the most of any lake in theworld.99% of these species are endemic tothe lake.Ornamental fish trade serves as animportant source of foreignexchange.Fish provide 75% of the animalprotein intake for the people ofMalawi.

IPCC (IV) prediction of climate change during the 21 stcentury(average of 21 climate models)

--------5000 m 3 water/ha y required forirrigation. If applied to one millionhectares, amounts to 5 km 3 waterper year."Promoting IrrigatedAgriculture in Malawi"

Lake Malawi level from ~1863 to 2011Shire outflow- 15 km3/yNo outflowfrom 1900 to1935- 10 km3/y- 5 km3/yOutflow would stop!

Approximately 95% of Malawi’s electricity is derived from fourhydroelectric dams on the Shire River, which flows out ofLake Malawi

Lake Malawi – the next Aral Sea?

Needs at the systems level approachCLIMATE SYSTEM &DYNAMICSLAKE MALAWI DYNAMICSHYDROLOGICAL ANALYSISLAND COVER/LAND USEHUMAN DIMENSION

The Research Team Co-PIs• Climate - Sharon Nicholson, Florida State Univ.; Bette Otto-Bliesner, NCAR• Hydrology - Assefa Melesse, Florida Intl. Univ.; Eric Wood*, Princeton Univ.• Lake Dynamics - Jay Austin, Stephanie Guildford, Robert Hecky, Thomas Johnson,Joe Werne*, all at Univ. Minnesota Duluth• Human Dimension – Asli Aslan, Tracy Dobson, Anne Ferguson, Craig Harris, SiegSnapp*, Leo Zulu, all at Michigan State Univ.• Ecosystem Services, Economic Tradeoffs – Stephen Polasky*, Univ. MinnesotaTwin CitiesProposal in Review at NSF ---

Unique complexities of the system:• Data poor, underfed region of our planet• Poverty is prevalent• People are particularly vulnerable to thewhims of climate• Expatriate pressure for agriculturedevelopment

January 2012Subsurface moorings in Lake Malawi

My sincere thanks to my friends, colleagues and students inUMD’s Large Lakes Observatory and collaboratinginstitutionsFunding provided over the years by:• The U.S. National Science Foundation• The U.S. National Oceanic and Atmospheric Administration• The University of Minnesota• The Petroleum Research Fund of the American Chemical Society

My sincere gratitude is extended to the OutstandingAdministrators who have ably laundered managed theresearch grants in LLO over the past 17+ years:• Mary Plante• Colleen Denny• Yvonne Chan• Lori JohnsonAnd to the patient and highly professional members ofthe UMD SPA team who have insured that our funnypapers preposterous propositions proposals always areproperly contrived formatted and arrive on time at thefunding agencies:• Jim Loukes• Elizabeth Rumsey• Janice Sakry• Bill Flaherty• Claudia Carranza