kalff 2002
DESCRIPTION
Kalff 2002. Kalff 2002. Fig. 16-2 (Kalff 2002). Wetzel 2001. Payne (1986). Payne (1986). Depth (m). Chemical stratification in Lake Tanganyika and Malawi (Hecky et al . 1996). Depth (m). Chemical stratification in Lake Victoria 1961 – 1990 (Hecky et al . 1996). - PowerPoint PPT PresentationTRANSCRIPT
Kalff 2002
Kalff 2002
Fig. 16-2 (Kalff 2002)
Wetzel 2001
Payne (1986)
Payne (1986)
Chemical stratification in Lake Tanganyika and Malawi (Hecky et al. 1996)
Dep
th (m
)
Chemical stratification in Lake Victoria 1961 – 1990 (Hecky et al. 1996)
Dep
th (m
)
Concentration-depth profile of chlorophyll a in Lake Victoria 1961 -1990(from Hecky 1993)
Attempts to tame a killer lake
Betsy Bodamer
Lake Nyos
General Info• Volcanic Crater Lake• Formed ~400+ years ago• Surface area = 1.58 km2 • Max depth = 210 m• Chemocline ≈50 m• Volume = 179,400,000 m3
• rainfall = 2.5 m/yr • Inflow
– 0-50 m: rainfall & streams– 50-210 m: soda springs
• CO2 rich water
• Outflow– Natural dam/spillway
The 1986 Disaster• ~80 million m3 of CO2 released from
Lake Nyos• Killed ~1800 people and thousands
of animals. • Cause = rapid overturn
• Volcanic or limnetic? Or both?
Degassing Lake Nyos
• 2001: full fledge degassing column was successfully assembled, installed and primed. – continuous– 50 m fountain
• Spray = 90% CO2 and 10% water.
• 50,000 STP m3/day
Trends across latitude in some important characteristics of freshwater systems[Lewis 1987]