- Kathleen Scavone
- Posted On
The Living Landscape: Getting to the core of the matter
LAKE COUNTY, Calif. – What if our ancient and sprawling lake could talk?
The stories it would tell would originate in the Early Pleistocene, around 500,000 years ago.
In a sense, our ancient lake is talking to us today thanks to core samples that were taken from beneath the lake in the spring of 2012.
Then, a team of scientists from the University of California, Berkeley commenced drilling the sediments beneath the lake from their floating sediment core drilling rig.
Situated in the center of the Upper Arm of the lake, they extracted 3-inch diameter cores in order to answer a myriad questions about the lake.
For example, what were prehistoric conditions like back then on the lake? Which species of insect and plant life proliferated then? And, even more important, how has global warming affected Clear Lake and its environs?
UC Berkeley biologists hope that these core samples will aid them in predicting how life on our planet today will adapt throughout current and future environmental issues.
The answers may help state and local governments with plans and policies in these uncertain times.
UC Berkeley project leader, Cindy Looy, assistant professor of integrative biology, states on her website, “We are reconstructing the past to better forecast the future, because we need to know what's coming in order to adequately prepare for it.”
Looy's team of UC Berkeley faculty includes experts such as ecologists, climate modeling experts, paleontologists, pollen experts and botanists.
They are looking at our lake's core for charcoal, freshwater organisms and pollen spanning back 130,000 years, well before the human population of the vicinity.
Methods utilized by the experts include the analysis of the aforementioned matter by observing the 400-foot cores every centimeter, or every 10 years, which will give them readings of the lake's nutrient levels, temperature and oxygen content that all correlate to lake levels as well as rainfall.
Previous United States Geological Survey core samples were read every meter, making the UC Berkeley observations 100 times better with regards to time resolution.
The series of pictures into the past will reveal how the area transformed itself throughout natural global warming occurrences.
The UC Berkeley mud core samples from the lake prove that there were once forests much like Cobb Mountain's. Then, when the ice sheets receded the area became oak-dominated.
Our lake is considered by scientists to be unique, since it has endured when most other lakes outside the tropics were wiped out by glaciers.
Through the science of limnology, as the science of inland water is named, lakes around the globe are arrayed from oligotrophic to eutrophic, meaning “undernourished” and “well-nourished,” respectively.
Lakes like Lake Tahoe that are deep and cold are nearly sterile or oligotrophic, while lakes such as ours that are shallow and warm are considered eutrophic.
Eutrophic lakes support a thriving plant population with its rich nutrients, such as nitrogen, phosphorus and iron.
All of these plants give sustenance to fish, worms, shellfish and crustaceans such as crayfish, which then feed the astonishing array of avian species like grebes, egrets, wood ducks, coots, eagles, osprey and more, along with the thriving mammal populations of river otters, mink, raccoons, etc.
Learning about our lake is thrilling and ongoing.
Here in our bioregion the “book of nature” constantly reveals its hidden aspect under volcanic rocks, along the shoreline, and now beneath the depths of the oldest lake in North America.
Kathleen Scavone, M.A., is a retired educator, potter, freelance writer and author of “Anderson Marsh State Historic Park: A Walking History, Prehistory, Flora, and Fauna Tour of a California State Park” and “Native Americans of Lake County.”