Hidden ‘Paleo Valleys’ Could Help California Survive Droughts
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Photo caption: An irrigation canal separates an almond orchard and a field that lies fallow in May 2021 in the Central Valley region of California. […] Photo credit: Justin Sullivan/Getty Images. Article by Erica Gies. Scientific American –
“Paleo valleys,” carved by ice age rivers and now underground, could provide spaces to recharge California’s depleted groundwater
When glaciers covered the Sierra Nevada mountains several times over the last million years, rivers flowing down the mountains grew more powerful, cutting channels a mile wide and 100 feet deep into what is now California’s Central Valley. When the glaciers receded, high-velocity meltwater surged down the slopes, carrying with it scoured gravel and rock. As the flow slowed along the valley below, the cobble dropped out of the water column, filling the canyons. These “paleo valleys” […]
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