Melting in the Andes: Good bye glaciers


From the shade of an adobe house overlooking Peru's Santa River, Jimmy Melgarejo squints at the dual peaks of Mount Huascarán looming against a cloudless sky. “The snow keeps getting farther away,” says Melgarejo, a farmer worried about his livelihood. “It's moving up, little by little. When the snow disappears, there will be no water.” Throughout the Andes, millions of people voice the same concern as they watch climate change eat away at the mountain chain's icy mantle. But although everyone fears a water shortage, they do not know how quickly it will come or how severe it will be. An interdisciplinary team of scientists is now trying to provide some answers through a US$1-million project funded by the US National Science Foundation. The crew, which pulls together hydrologists, geochemists, geographers and historians, mainly from the United States and Canada, is tracking the fate of glacial meltwater as it runs from the mountains down to the ocean. Their goal is to develop models to forecast water flow and its effects on residents downstream. […] “You can think of glaciers as hydrological Prozac — they smooth out the highs and lows,” says Jeffrey McKenzie, a hydrogeologist at McGill University... Without the glaciers, downstream water users will have to adapt to greater variability between the wet and dry seasons… McKenzie, who is studying the interaction between surface water and groundwater, explains that many lakes and rivers in the Cordillera Blanca are naturally acidic because glaciers grind over rocks rich in sulphate, which gets dissolved into the meltwater…

Read more at Nature