A Sunken Kingdom Re-emerges
BORTH, WALES — There is a poem
children in Wales learn about the sunken kingdom of Cantre’r Gwaelod,
swallowed by the sea and drowned forever after. On a quiet night, legend
has it, one can hear the kingdom’s church bells ringing.
When
the sea swallowed part of Britain’s western coastline this year and
then spat it out again, leaving homes and livelihoods destroyed but also
a dense forest of prehistoric tree stumps more exposed than ever, it
was as if one had caught a faint glimpse of that Welsh Atlantis.
The
submerged forest of Borth is not new. First flooded some 5,000 years
ago by rising sea levels after the last ice age, it has been there as
long as locals remember, coming and going with the tides and
occasionally disappearing under the sand for years on end. But the floods and storms
that battered Britain earlier this year radically changed the way
archaeologists interpret the landscape: A quarter-mile-long saltwater
channel cutting through the trees, revealed by erosion for the first
time, provided a trove of clues to where human life may have been
concentrated and where its traces may yet be found.
“We used to think of this as just as an impenetrable forest — actually this was a complex human environment,” said Martin Bates,
a geoarchaeologist at the University of Wales Trinity St. David, who
oversees the excavation work in Borth on a beach he played on as a
toddler. “The floods have opened our eyes as to what’s really out
there.”
Scanning
the army of ghostly spikes protruding from the sand here one recent
morning, Dr. Bates said it was as if nature were making a point: The
recent torrential rains, linked by a growing number of climatologists to
human-induced climate change, have provided an ancient laboratory to study how humans coped with catastrophic climate change in the past.
Indeed,
across Britain, two consecutive years of exceptional winter weather
have left in their wake some equally exceptional discoveries: from unexploded wartime bombs
and Victorian shipwrecks to archaeological finds that are nearly a
million years old. Scientists have barely kept up. Last winter was the wettest on record, according to the Met Office, the national weather service.
Dog walkers and amateur archaeologists are being sought
in ever-greater numbers to help record new sites. In some areas hit
especially hard by erosion, locals are equipped with cameras that log
digital images with geocoordinates so the artifacts they find on beach
walks can be added to national databases.
“Archaeologists can’t be everywhere, but locals can,” said Erin Kavanagh, Dr. Bates’s partner and a fellow archaeologist.
Nicholas Ashton, the curator of Paleolithic and Mesolithic collections at the British Museum,
has been organizing “fossil road shows” in which he invites civilians
to bring in any potential archaeological finds and have them identified.
(One man recently showed up with a six-inch-long hippo tusk and a
well-preserved ax, both found locally and both more than half a million
years old.)
Having
those extra eyes on the ground can make all the difference in coastal
areas, Dr. Ashton said, for what the sea reveals, it tends to reclaim
almost as soon. He learned this lesson firsthand.
In
May 2013, shortly after the first set of storms, Dr. Ashton
commissioned Dr. Bates, an old university friend, to work on Britain’s
east coast in Norfolk. The beach near Happisburgh (pronounced
hays-boro), a longstanding archaeological site, had suffered severe
erosion. Dr. Ashton, an expert in early humans, wanted a geophysical
survey to map any channels or rivers that might lie beneath about 30
feet of sediment. Some of these channels, he reckoned, might contain
evidence of early humans because sources of freshwater would have been
natural gathering spots.
It
was on their second visit, on May 10, that Dr. Bates noticed some
indentions on the otherwise flat horizons of the laminated silts
recently laid bare on the beach. The humps and bumps looked familiar. He
told Dr. Ashton: “They’re just like the human footprints in Borth.”
Footprints
of humans and animals in Borth had been dated to about 6,000 years ago.
The site in Happisburgh was 900,000 years old, a time when mammoths and
hippos still roamed in these parts. No human bones or prints that old
had ever been found in Britain.
Could this be possible?
A
frantic race against time began. Every day, the shape of the prints
would blur a little more as the coming tide eroded the contours of
heels, toes and arches. A team led by Sarah Duffy
from the University of York arrived to apply a technique called
multi-image photogrammetry, taking about 150 digital photographs of the
surface area containing the prints and feeding it into a program that
created a three-dimensional model. By the time another team had come to
do some laser scanning, it was too late: The prints were barely visible.
Panicked, scientists lifted from the site a 130-pound block of sediment with one faint print on top, to have it analyzed at the National Oceanography Center.
It is the only remaining physical evidence of the footprints: Before
the month was out, all traces of them had vanished. It was a powerful
reminder of both the resilience and the fragility of human life.
“What had been preserved for nearly one million years was taken back by the sea in the space of 10 days,” Dr. Ashton said.
Initially
skeptical, he said he knew the footprints were real when Dr. Duffy’s
computer images landed in his inbox sometime last June. “I thought,
bloody hell, we are dealing with something quite extraordinary here,” he
said.
The footprints, the oldest known outside Africa, probably belonged to a family group of Homo antecessor, a cousin of Homo erectus that possibly became extinct when Homo heidelbergensis
from Africa settled in Britain about 500,000 years ago, he said. Using
foot-length-to-stature ratios, scientists estimate that the male was
perhaps 5 feet 9 inches tall, and the smallest child a little less than
37 inches.
Little is known about this early human species. Fossil skeletons
in Atapuerca, Spain, from around the same time suggest that they walked
upright and looked much like modern humans, though their brains were
smaller. If they had language, it was primitive. Living at the tail end
of an interglacial era, as winters were growing colder, they may have
had functional body hair. So far, there is no evidence that they used
clothes, shelter, fire or tools more complex than simple stone flakes...
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