By: Cristen Hemingway Jaynes
Published: July 19, 2023
Edited by Chris McDermott
An aerial view of Crawford Lake as a team consisting of scientists from Carleton University and Brock University gathered sediment layer samples from the lake bottom at the Crawford Lake Conservation Area near Milton, Ontario, Canada on April 12, 2023. PETER POWER / AFP via Getty Images
Following years of discussions by scientists on how and when humans began to significantly alter the planet, Canada’s Crawford Lake has been chosen to mark the beginning of a new geological epoch: the Anthropocene.
The [url=https://e360.yale.edu/digest/anthropocene-epoch-crawford-lake-canada#:~:text=Scientists have selected Crawford Lake,imprint on the geologic record.]International Union of Geological Sciences[/url] had to select one site that symbolized humans’ enormous effect on Earth before the new era could be officially declared, reported Yale Environment 360.
Each year, particles collect on the tranquil, 79-foot-deep lake and settle to the bottom to form strata of sediment that become a record of the environmental conditions of that time, much like tree rings, according to the journal Nature. If the scientists’ choice is approved, a core of sediment from the lake — located in a conservation area in Ontario — will become the “golden spike” to mark the start of the Anthropocene.
“The sediments found at the bottom of Crawford Lake provide an exquisite record of recent environmental change over the last millennia,” said Simon Turner, a researcher at University College London, in a statement. “It is this ability to precisely record and store this information as a geological archive that can be matched to historical global environmental changes which make sites such as Crawford Lake so important.”
Sediments on the lake’s bottom include evidence of Indigenous Peoples, European settlers, ash from the burning of [url=https://www.ecowatch.com/fossil-fuels-explained-ecowatch.html#:~:text=A 2021 study found that,of its sulfur dioxide emissions.]fossil fuels[/url], nitrates from chemical fertilizers, logging and radioactive plutonium-239 from the testing of nuclear weapons, according to Yale E360, Nature and The Guardian.
“[T]here are no burrowing organisms to disturb the sediments, allowing the precise calendar age of sediments to be determined by layer counting, just like tree rings,” Francine McCarthy, a scientist at Brock University in Ontario, told Yale E360.
Other locations in the running for the origin of the golden spike included a Gulf of Mexico coral reef, a Polish peat bog and the Antarctic ice sheet.
In 2016, the Anthropocene Working Group (AWG) decided that humans had had such an impact on the planet that it was time for a new geological epoch, The Guardian reported.
The current geological epoch, the Holocene, began 11,700 years ago, following the last big Ice Age. All of human civilization developed during the Holocene, which was marked by global environmental stability, allowing many plant and animal species to flourish.
If Crawford Lake is approved as the site of the beginning of the Anthropocene, the new geological epoch will officially be declared in August of 2024.
Hallmarks of the Anthropocene include climate change, plastics pollution and devastating impacts on wildlife.
Plutonium isotopes from hydrogen bomb tests have been selected by the AWG as the main marker of the new epoch. The isotopes were spread around the world beginning in 1952, then decreased quickly following the 1963 Nuclear Test Ban Treaty.
“The Anthropocene that starts in the 1950s represents a very rapid change that we have caused to the planet. There’s hope in that respect. The combined impacts of humanity can be changed rapidly for good and for bad. It’s not inevitable that we have to slide into continuing environmental poverty,” said AWG Chair Professor Colin Waters from the University of Leicester, as reported by The Guardian.
THANKS TO: https://www.ecowatch.com/anthropocene-epoch-canada-lake.html