![]() Cedar boughs lined the auger hole in a Wendat ceremony prior to drilling. This lake may be far removed from human activity, but it is never disconnected. As a marker, the glass creatures signal the overall global acidification of earth, as this carbon-laden air continues to dissolve into our freshwater systems. Since preindustrial times atmospheric carbon has risen from 278 parts per million to almost 421 this year -and it’s still rising exponentially. ![]() 0009 gigatons per year of atmospheric carbon in 1950, 5.3 and in 2017, 36.1 gigatons. Taken together, the chrysophyte layers -borne of a species sensitive to different temperatures, salinities, and pHs -tell a story. Though you can wend your way around it through cedar and maple trees in fifteen minutes, the lake plunges seventy-seven feet deep into the earth, and like a natural test tube, has collected layers of sediment year after year. It was formed millennia ago when a massive glacier sheared off the top of a limestone sinkhole within the Niagara escarpment. These seasonal layers, or varves, of dark and bright, have stacked one on top of the other in this way undisturbed for over a thousand years.Ĭrawford Lake is very small and very deep. The following year, when the water warms again, chalky white calcite precipitates out from the surrounding rock into a bright layer of summer sediment. As the temperatures plunge, they die and settle at the bottom of the lake in a dark, organic layer in the sediment. These chrysophytes, a type of freshwater algae, bloom near the surface in the summer, constructing exquisite shells of latticed silica around their soft, single-celled bodies. Others, like greenhouse gasses, plastics, and biomass loss, continue to rise with dire consequences.įollow the search for the golden spike here to learn more about each site as the science continues to unfold.Ĭrawford Lake, Ontario (Andrea Arrogante/Conservation Halton) Crawford Lake, Canada Material: ChrysophytesĭEEP IN THE WINTER FREEZE of Ontario, Canada, tiny glass creatures-delicate as snowflakes-fall through the watery depths of Crawford Lake. Some of these signals in the rock, like plutonium, sulfur, and DDT have been largely curbed through hard work and local, national, and international restrictions. Though mid-century plutonium has emerged as the frontrunner for the new epoch’s golden spike, a tidal wave of other signals are also coupled with its rise. ![]() We yet have agency to drive which direction we go.” “Earth will never go back to Holocene levels, but what we don’t know,” he says, “is where it’s going to settle out. “When the Earth System goes from a previous state to a new state,” explains Anthony Barnosky of Stanford University and the Anthropocene Working Group, “what happens in the transition is a lot of bouncing back and forth between something resembling what’s going to be the new state, and what looks a little more like the old state-really wide fluctuations. It must represent an environmental shift so intense that the entire planet crosses a threshold into a completely new biogeochemical paradigm. Like the meteorite dust that heralded the demise of the dinosaurs at the end of the Cretaceous, the golden spike is a signal in the strata that must be global and synchronous. In 2019, a review began of eleven main sites around the world in search of a “golden spike” indicating this massive shift in the Earth System. ![]() ALARMED BY FAST-GROWING SCARS of climate change, extinction rates, and ocean acidification, geologists from the International Commission on Stratigraphy-tasked with defining the official Geological Time Scale and known for their glacially-paced analyses-have begun to examine evidence that we have entered a new geological epoch called the Anthropocene. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |