Erosion i believe is the answer
Volcanic soil has a lot of minerals that plants take in as nutrients.
GPS, Glonass are the most popular
A. Human Activity
"According to the National Climate Assessment, human influences are the number one cause of global warming, especially the carbon pollution we cause by burning fossil fuels and the pollution-capturing we prevent by destroying forests. The carbon dioxide, methane, soot, and other pollutants we release into the atmosphere act like a blanket, trapping the sun's heat and causing the planet to warm. Evidence shows that 2000 to 2009 was hotter than any other decade in at least the past 1,300 years<span>. This warming is altering the earth's climate system, including its land, atmosphere, oceans, and ice, in far-reaching ways."
https://www.nrdc.org/stories/are-effects-global-warming-really-bad
Hope this helps!</span>
Ice was produced using radiation effect by setting out shallow terra cotta rays with just small amount of water. At night when the temperatures were cool while humidity is low the water used to freeze in the morning.the ice formed was collected and stored in caverns
