SODA LAKE

WHY IN NEWS?

Phys.org: Scientists have discovered a soda lake which may given rise to life on earth

BACKGROUND

• A soda lakeor alkaline lake is a lake on the strongly alkaline side of neutrality, typically with a pH value between 9 and 12.
• They are characterized by high concentrations of carbonate salts, typically sodium carbonate (and related salt complexes), giving rise to their alkalinity.
• In addition, many soda lakes also contain high concentrations of sodium chloride and other dissolved salts, making them saline or hypersaline lakes as well. High pH and salinity often coincide, because of how soda lakes develop. T
• he resulting hypersaline and highly alkalic soda lakes are considered some of the most extreme aquatic environments on Earth.
• In spite of their apparent inhospitability, soda lakes are often highly productive ecosystems, compared to their (pH-neutral) freshwater counterparts. Gross primary production (photosynthesis) rates above 10 g C m⁻²day⁻¹ (grams of carbon per square meter per day), over 16 times the global average for lakes and streams (6 g C m⁻² day⁻¹), have been measured. 
• This makes them the most productive aquatic environments on Earth.
• An important reason for the high productivity is the virtually unlimited availability of dissolved carbon dioxide.
• Soda lakes occur naturally throughout the world typically in arid and semi-arid areas and in connection to tectonic rifts like the East African Rift Valley