on October 18. According to the laborious satellite imagery, in the period 2000-2009 Canada has lost 6.7 thousand miles? (1,2%) surface area (only in the country of 1.3 million lakes).
It’s weird. It was predicted that the lake will grow, not shrink.
The reduction in Arctic lakes has been seen before, but only in the most southern part of the Arctic, where warming is melting the permafrost and allows water to escape into the soil. A new study
It’s amazing though, because during the study period, the Northern region has received more rain.
The lakes are mainly replenished by seasonal snowmelt. Theoretically, the temperature rise in the region should lead to a decrease of the snow cover and to encourage growth in lakes. Another factor can be a delicate balance between rainfall and evaporation: the higher the temperature and the stronger the wind, the greater the evaporation. As for the mentioned permafrost — while there is no evidence that in Canada it massively melts.
Water loss can affect the amount of greenhouse gases emitted by the ecosystem of the region. When the lake dried, exposed sedimentary rocks start to give carbon dioxide. At the same time, stagnant water emit methane, and therefore the drying of the marshes are able to reduce the levels of this greenhouse gas.
The study is published in the journal
Based on the materials
Canada dry lake: ecologists in disbelief
on October 19. Dotted with spots of lakes landscape of Canada gave environmentalists a nasty surprise. According to satellite imagery 1.3 million lakes, the country has lost 1.2 percent (6700 sq km) of water surface in the period from 2000 to 2009. All that scientists know about what is happening in the region’s natural processes, implies an increase of the total area of lakes, but not the reduction.
Whatever the reason, the loss of water can have a negative impact on the local ecosystem and to complicate people’s lives. Migratory water birds, aquatic flora and fauna living on the lakes indigenous tribes — all of them may be in danger, if the drainage continues. \»Ten years is enough to assume that this trend of climate change,\» says the Director of the International Arctic studies center in Fairbanks Larry Hinzman.
Previously, the drying of the lakes was observed only in the southern Arctic, where warming has melted the permafrost and water left in the soil. But the latest study, conducted by researchers from the University of Maryland, talks about strange trend: decreasing the area of the Northern lakes, while the South remains intact.
Reduction lakes all the more surprising that during the whole study period in the region of precipitation above the average. It was possible to expect the increase of water level in the lakes, but this has not happened.
There are other factors that would lead to the opposite results than those found in the study. So, most of the water in the lake system comes as a result of snowmelt. However, the melting of snow as a result of increasing crenelate temperature did not raise the water level. Also not noted increased evaporation of water and no signs of melting permafrost in the Far North.
The reduction in the area of lakes may affect the amount of greenhouse gases emitted into the atmosphere, the researchers said. Drained areas of the bottom can release large amounts of carbon dioxide. But standing lake water emit methane, which is more active greenhouse gas. Scientists still find it difficult to answer, will increase greenhouse activity in this region when drying lakes or not.