- #1
What Causes Rivers and Lakes to Appear Green in Glaciated Upland Regions?
In summary, the conversation discusses the color of lakes and rivers in glaciated regions, specifically mentioning a green color due to sediment on the bed of the lake. The conversation also mentions specific locations, such as Lake Louise in Canada and the Andes in Argentina and New Zealand, where glacial lakes have a turquoise color due to "rock flour." The conversation also mentions the use of false color in satellite images to display information outside of the visible spectrum, cautioning against making assumptions about the real color of objects in such images.
- #2
Nereid
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Where is this?
It may be http://www.vec.ca/english/4/lake_louise.cfm .
It may be http://www.vec.ca/english/4/lake_louise.cfm .
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- #3
EIRE2003
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This photograph is taken of the Andes in Argentina.
- #4
Nereid
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New Zealand also has turquoise glacial lakes, with "rock flour" ascribed as the cause.EIRE2003 said:
In this image, of some lakes in the Andes, the rock flour is said to cause the lakes to be 'light blue'.
Seems to be variations on a theme.
- #5
tyroman
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To EIRE2003
Care must be taken when making assumptions about satellite images, particularly when the words "false color" appear in the caption...
Sensors on landsat type surveyors often detect and record electromagnetic signals which are outside the visible spectrum. To display this information visually in a photograph, scientists assign a false color (in the visible spectrum) to wavelengths otherwise invisible to the human eye. Thus, the color of something in a satellite photo is not necessarily its real color...
Care must be taken when making assumptions about satellite images, particularly when the words "false color" appear in the caption...
Sensors on landsat type surveyors often detect and record electromagnetic signals which are outside the visible spectrum. To display this information visually in a photograph, scientists assign a false color (in the visible spectrum) to wavelengths otherwise invisible to the human eye. Thus, the color of something in a satellite photo is not necessarily its real color...
- #6
EIRE2003
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Yes i know that but this is not a satellite photo this photo was taken from the ISS. There is no false colour it is a natural.
1. Why is the river or lake a green color?
The green color in a river or lake is typically caused by the presence of algae and other aquatic plants. These plants contain chlorophyll which gives them a green color and can cause the water to appear green as well.
2. Is the green color in the river or lake harmful?
In most cases, the green color in a river or lake is caused by harmless algae or plants. However, some types of algae can produce toxins that can be harmful to humans and wildlife if ingested or exposed to in large quantities.
3. How does the green color affect the ecosystem of the river or lake?
The presence of green algae and plants in a river or lake can have both positive and negative effects on the ecosystem. On one hand, they provide food and habitat for certain aquatic species. On the other hand, excessive growth of algae can deplete oxygen levels in the water and harm other species.
4. What can be done to prevent or reduce the green color in rivers and lakes?
One way to prevent or reduce the green color in rivers and lakes is to reduce the amount of nutrients, such as nitrogen and phosphorus, that enter the water. This can be done through proper waste management and reducing the use of fertilizers. Additionally, controlling the population of certain aquatic species, such as geese, can also help reduce the amount of nutrients in the water.
5. Can the green color in rivers and lakes be an indicator of pollution?
In some cases, green colored water in a river or lake can be an indicator of pollution. This is because excessive nutrients from human activities, such as agricultural runoff or sewage discharge, can cause an overgrowth of algae. However, not all green colored water is necessarily a sign of pollution, as some types of algae are natural and harmless to the ecosystem.
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