Are Alaskan rivers turning rusty because of climate change?
Transparent and clean rivers in Alaska are turning into rusty streams. Scientists are working to find the cause of this phenomenon. The orange hue of the water, visible from space, is indeed alarming.
The once crystal-clear water in numerous Alaskan rivers and streams is gradually changing. The water is becoming increasingly murky, with a rusty color. It is suspected that these changes are due to substances being released into the water during the thawing of permafrost.
A team of scientists from the United States Geological Survey, University of California, Davis, and other research centers has studied this phenomenon. They analyzed rivers in Alaska that have started to change color. This involves previously extremely clear water bodies suddenly becoming murky and taking on a vivid rusty color.
As part of the research, scientists collected water samples from 75 different locations spread over an area the size of Texas.
- The more we flew around, we started noticing more and more orange rivers and streams. There are certain sites that look almost like a milky orange juice, said one of the scientists, Jon O’Donnell, author of the study described in the magazine "Communications Earth & Environment".
There are concerns that these changes could signal water contamination with toxins harmful to both nature and humans. Additionally, murky water can hinder fish migration to spawning grounds. Dr. O’Donnell noticed this problem when he visited one of the rivers in 2018. However, an analysis of satellite images revealed that water discoloration has occurred since 2008.
The researcher emphasizes that the river discoloration is so significant that it is noticeable from space. Therefore, the changes are notable.
The orange water resembles that which flows out of mines, but there are no mines in the research area. Therefore, scientists hypothesize that the color change in the water is due to the permafrost thawing caused by climate change. Minerals released from the thawing permafrost alter the water's color.
Analysis of water samples showed that acidity and concentrations of metals such as iron, zinc, nickel, copper, and even highly toxic cadmium have dramatically increased in discolored rivers. The highest concentration is of iron, which is responsible for the change in water color. According to the scientists, these changes are spreading gradually, from small streams to large rivers. The area where these changes are observed is constantly expanding.
To better understand what is happening, scientists plan to conduct further studies. Researchers intend to conduct more investigations to clarify the causes of this phenomenon.
