Underneath the seawater in Japan’s Beppu Narrows lie layers of apparently average residue and muck that recount the narrative of how people have generally adjusted to their general surroundings.
The site is among those being considered for assignment as a “brilliant spike”, an area that offers proof of another geographical age characterized by our species: the Anthropocene.
Scientists have debated for years over whether the Holocene epoch that began 11,700 years ago has truly been replaced by a new period defined by human impact on the Earth, and the path to agreeing on the new era has been long and contentious.
Choosing a location that clearly documents how we have altered our environment—from contaminating it with plutonium from nuclear tests to littering it with microplastics—has been central to their discussions.
Twelve locations have been suggested for the golden spike, including a Polish peatland, an Australian coral reef, and the basin-like Beppu bay in Oita, western Japan.
For nearly a decade, Michinobu Kuwae, an associate professor at the Ehime Center for Marine Environmental Studies, has studied the region.
He started by looking into how climate change affected fish populations. Layers of fish scales that were deposited in the sediment of the bay provided clues about the past.
Given the numerous “anthropogenic fingerprints, including manmade chemicals and radionuclides, layered in the bay’s sediment,” he only recently began to consider the location as a potential golden spike.
The layers permit researchers to pinpoint “the exact date and level of an Anthropocene-Holocene limit,” he told AFP.
“There are the most different anthropogenic markers.”
Yusuke Yokoyama, a professor at the Atmosphere and Ocean Research Institute at the University of Tokyo who has examined core samples from the site, explained that the site’s flawless preservation is the result of a number of distinct characteristics.
The sound floor plunges down rapidly from the coastline, making a bowl that traps material in the water section and “sort of makes a miso soup,” he told AFP.
Water can stream in; however, it just moves back out at the surface, and an absence of oxygen implies there are no creatures upsetting the silt or disturbing stores.
On July 11, the location of the “golden spike” of the Anthropocene will be revealed.
A “warning bell” for humanity.
“It’s like Baumkuchen, the cake, or a stack of pancakes, and you can count those pancakes to get the exact age,” he added.
A number of requirements must be met for a location to be considered a golden spike, including providing evidence of at least the last century and specific “anthropogenic signals” such as the use of nuclear weapons, the alteration of ecosystems, and industrialization.
Additionally, it must provide a comprehensive archive of the time period covered as well as markers that enable researchers to determine which layer represents which year.
Coral is viewed by some as a decent up-and-comer since it fills in layers like a tree trunk and retains components disintegrated in water, including marks from atomic testing.
However, it can’t catch materials that don’t disintegrate in water, such as microplastics.
The residue of Beppu Straight, conversely, catches everything from farming compost run-off to stores from noteworthy floods kept in true documentation, as well as fish scales and plastics.
The most convincing element, notwithstanding, as per Kuwae and Yokoyama, are the marks from a progression of atomic bomb tests done across the Pacific from 1946 to 1963.
The tests delivered barometric radiation that was noticeable universally, yet additionally caused direct marks in places near the testing locales.
Yokoyama stated, “We can detect both.”
“Since Beppu Inlet is found downstream, we can recognize the specific marks of specific tests.”
Core samples taken from Beppu Bay revealed plutonium peaks that were consistent with the results of individual nuclear tests and coral samples taken from Ishigaki, a nearby city.
Beppu Bay and the other potential locations are anticipated to continue to be significant resources for comprehending human impact on the Earth, whichever site is selected as a golden spike.
Furthermore, Kuwae trusts that an authority assignment of the Anthropocene will be a “cautioning chime” for humankind.
He stated, “The global environment is deteriorating rapidly, including global warming.”
“We will be in a state where the first protected earth, when lost, can at this point not be recuperated.”
