China’s coal mine accidents rise amid push for higher production

Reuters | February 24, 2023 | 

Coal miner in Xingtai, China. (Image courtesy of Wikimedia Commons.)

A deadly coal mining collapse in China this week is one of a growing number of industry accidents over the last year, government statistics show, coinciding with Beijing’s recent push for higher production to improve energy security.


At least six people were killed and 47 others are still missing two days after the dramatic collapse of an open pit coal mine in China’s northern region of Inner Mongolia, its No. 2 coal producing province.

The reasons for the collapse are still not known, and the mine owner could not be reached by Reuters.

The National Mine Safety Administration (NMSA) did not immediately respond to a request for comment on the accident.

But it comes after NMSA statistics released this month showed the number of accidents at coal mines almost doubled in 2022 compared to 2021 and the death toll reached a six-year high of 245, just after China called for higher coal output.

Already the world’s biggest coal producer and consumer, China increased its coal output last year by 9% to a record 4.5 billion tonnes, with the country urging miners to ramp up production after a nationwide power shortage in late 2021 led to a quadrupling of domestic prices.

Soaring global coal prices and energy supply disruption in the wake of Russia’s invasion of Ukraine also prompted Beijing to improve its energy security.

Though its mines are known to be among the deadliest in the world, accidents and deaths had been falling steadily in the decade to 2021 after China shut down excess mining capacity, reduced coal burning and strengthened safety checks.

In 2022, however, there were 168 accidents of varying degrees of severity, data from the NMSA shows, surging from 91 the year before.

In a review of the 2021 accidents, the NMSA said some coal mines were putting more emphasis on profits than safety.

“They ignored safety requirements and rushed to meet the production targets… and even violated operations regulations to run over their designed capacity,” the regulator added.

The open-pit mine that collapsed this week had been closed for three years until April 2021, state media reported. It reopened just as coal prices soared, reaching record levels later that year.

Local mine safety regulators ordered coal mines in Inner Mongolia to carry out safety checks after the accident this week.
Digging deeper

China amended its criminal law in 2021 to include punishments of managers at mines involved in accidents due to over-production.

But the NMSA also said in late 2021 that it would not engage in blind punitive production suspensions at coal mines and would instead send inspectors to help rectify problems and resume output.

With the depletion of shallow coal resources in China, coal miners are also being forced to dig deeper, posing bigger safety risks, according to experts.

“China is mining at a rate of 10 to 25 metres (33 to 82 feet) deeper each year, leaving miners facing more complicated scientific and technical problems,” Yuan Liang, a coal mining professor at Anhui University of Science and Technology, said in a research paper published in January.

China last year approved some 260 million tonnes of new mining capacity and reopened scores of mothballed mines.

Coal production is expected to further increase this year as more newly-approved mines begin operations. Shanxi and Inner Mongolia, China’s top two mining hubs by production, have vowed to lift output up by at least 5% and 2% this year, respectively.

“Improving mining safety is like pushing a boulder up a hill and involves many hurdles,” the NMSA said in a statement last month. “We will have to ensure both supply and safety.”

(By Muyu Xu and Beijing newsroom; Editing by Dominique Patton and Jamie Freed)

Death toll rises after coal mine collapses in northern China

Bloomberg News | February 23, 2023 | 

Coal mine in Hailar, Inner Mongolia, China. 

(Reference image by Herry Lawford, Wikimedia Commons)

The collapse of a coal mine in northern China has claimed four lives with 49 people still missing, state broadcaster CCTV reported Thursday.


Police are investigating the cause of the disaster at the open pit operation in Inner Mongolia and have detained people suspected for being responsible, CCTV said. Six people have been rescued so far after Wednesday’s collapse, in what could prove to be the deadliest mining accident in China in years.

Sun Shaocheng, the top official in the autonomous region, said regulators will roll out safety inspections across all mines in China’s second-biggest coal hub in a bid to prevent other accidents, according to a statement. Officials from the central government’s Ministry of Emergency Management have also joined the on-site rescue effort.

The severity of the incident prompted a response from President Xi Jinping, who called on Wednesday for an all-out rescue effort and probe into its causes. The accident has landed at a sensitive time on the political calendar, with the annual National People’s Congress set to begin in the capital on March 5, and safety checks may well be extended to other mining regions. China is by far the world’s biggest producer and consumer of coal.

Mining coal in China remains a dangerous business that all-too regularly causes fatalities. A spate of deadly accidents at mines in 2021 led to a nationwide safety campaign that disrupted operations and curbed the supply of China’s mainstay fuel, contributing to power crunches that crippled the economy.

The provinces of Shanxi and Shaanxi, China’s other big mining hubs, have launched safety inspections at their mines in the wake of the disaster, according to a note from Citic Futures Co. That may slow production in the first quarter, but the impact is likely to be limited as Beijing continues to prioritize producing enough coal to fuel its economic rebound, Citic said.

Chinese nickel workers file complaint to Indonesia’s rights body over work conditions

Reuters | February 24, 2023 | 

Tsingshan mine at Indonesia’s Morowali Industrial Park (IMIP)

 Nickel Mines Ltd

Three Chinese workers at an Indonesian nickel industrial complex on Sulawesi island have filed a complaint with the country’s human rights commission over poor workplace conditions, the law firm representing them said on Friday.


The workers at PT Indonesia Morowali Industrial Park (IMIP) in Central Sulawesi province said they “endured a lot of physical, psychological, financial damages to their reputation as human beings”, according to a statement from the law firm.

Indonesia has pushed to realise its ambitions to develop the central Sulawesi area into a regional electric vehicle battery hub due to its rich nickel reserves.

More than a dozen deals worth over $15 billion have been signed with global manufacturers including Hyundai, LG and Foxconn in just three years. Chinese companies are another major investor in the region.

But the industry is not without its problems. Last month, a riot broke out in the same province at a nickel smelter owned by China’s Jiangsu Delong Nickel Industry, killing two people, including a Chinese national.

AMAR Law Firm & Public Interest Law Office said IMIP workers experienced poor workplace conditions including a lack of proper safety and respiratory gear, working long hours without breaks, and pay cuts.

Passports belonging to Chinese nationals were also withheld and there was a ban on unionising, the statement said.

Airlangga Julio from the law firm said the three Chinese workers who signed the complaint experienced such treatment between 2020 and 2022.

Uli Parulian Sihombing of the National Commission for Human Rights said the body, which has no punitive powers, is studying the complaint from the IMIP workers.

The workers urged the commission to “look into, probe, monitor” the “rights violations at the IMIP area, whether they be migrant workers or Indonesian workers.”

IMIP did not immediately respond to a request for comment.

The park, which counts China’s nickel company Tsingshan Holding Group as a prominent partner, employs about 100,000 people and spans 2,000 hectares with an airport, mineral processing plants, a port and a hotel for high-level visitors.

(By Stanley Widianto; Editing by Kanupriya Kapoor and Martin Petty)

Nickel shows Indonesia how to escape the middle income trap

The value of Indonesia’s nickel exports surged tenfold in five years after it forced buyers to set up refineries in the country.

Bloomberg News | February 24, 2023 | 

PT. Tiran Indonesia Site Lameruru, North Konawe, Southeast Sulawesi

The value of Indonesia’s nickel exports surged tenfold in five years after it forced buyers to set up refineries in the country. Now Southeast Asia’s biggest economy plans to use that blueprint to catapult the nation into the ranks of higher-income economies by processing everything from copper to fish.


The goal is to double per-capita GDP to $10,000 by 2045, which would bring Indonesia close to the World Bank’s high-income threshold. At the same time, the shift would create new centers of growth outside Java, its richest and most populated island.

“We’re using nickel as the prototype,” said Investment Minister Bahlil Lahadalia. “It’s silly. We have the raw materials, but we sell it to be refined overseas then we import it back. Where did we leave our brain?”

President Joko Widodo points to the economic models of Taiwan and South Korea, two of only handful of nations that managed to escape the so-called middle-income trap by building manufacturing and raising productivity. For decades, Indonesia has relied on exports of raw commodities — an economic strategy prone to the so-called resources curse, where mineral rich nations suck in investment in mining during boom times, but suffer when commodities prices tumble.

The new roadmap to more onshore processing will begin with oil and gas this year, then fisheries. Down the line, Indonesia will only export refined palm oil, coconut products, timber, seaweed and even salt. The government estimates the drive could pull in $545 billion of investment — about half the country’s current nominal GDP.

“We used to sell the Indonesia story by the numbers: 280 million people, thousands of islands, and so on. That’s promoting history, not investment,” Lahadalia said. “Now we tell them: ‘What industry do you want? Here’s what you can make and here’s where you can do it.’”

The investment ministry publishes a menu of projects that investors can choose from, complete with the expected rate of return, breakeven timeline and state incentives available. It includes, for example, a 49.8 billion rupiah ($3.3 million) cocoa bean factory in Central Sulawesi offering a 22% return, or a $1.13 billion copper refinery in East Java with a 16% expected return.

There are signs the policy could work. The country charted its largest-ever trade surplus last year, with investments rising 44% to a record $80 billion, underpinned by nickel and copper that are mainly found on islands outside Java.

In North Maluku, investments in nickel refining expanded the province’s economy by 29% last year.

“Companies have mined nickel there for decades, but it’s only now that we see this massive growth,” said Lahadalia. “With growth, comes jobs. People don’t have to go to Java anymore to look for good jobs.”

In West Papua, one of the country’s poorest provinces, factories are being built to turn natural gas into methanol, urea and ammonia to be used as fertilizers. And throughout the archipelago, plants are being set up to process and package tuna and shrimp ready for consumers, rather than shipping the catches to facilities in Thailand or Vietnam.

Still, Indonesia’s nickel windfall was partly a result of a sudden surge in global demand from factors including the ramp-up of battery production for electric vehicles and a notorious short-squeeze on the London Metals Exchange that gave Indonesia a strong bargaining position to force miners to build smelters. There are also questions over how the government will turn the billions of dollars in smelter investments into wider investment in technology and high-skilled jobs that would boost overall productivity.

There are also legal risks. The World Trade Organization recently ruled in favor of the European Union’s protest against the ban on nickel ore exports. Jokowi has vowed to appeal the ruling and refused to change his policy.

And while Indonesia so far has relied on export bans to force companies to build local downstream facilities, the government has said it wants now to take a softer approach, gradually removing incentives for less-refined goods. For nickel, that means no more tax holidays for smelters that put out products with less than 40% nickel content as the government pushes for at least 70%-80%.

“But we won’t wait,” Lahadalia said. “If we say the industry needs to be ready before we stop exports, it would take too long and we would get the same old excuses.”

For copper giant Freeport-McMoRan Inc., whose local unit has been mining one of the world’s largest deposits of copper and gold since the 1970s, exports of concentrates will stop at the end of this year, when a new smelter needs to be up and running, he added.

Lahadalia is confident the downstreaming strategy won’t be derailed by elections in February next year, when Jokowi must step down after the end of his second term. The shift is already locked into the economy as smelters and factories are already being built, he said.

“Besides, anyone who reverses this would be laughed at,” he said. “We’re halfway there. Why would we go back?”

(By Eko Listiyorini and Norman Harsono)

GEMOLOGY
Gemfields reports updated ‘G-Factor for Natural Resources’ figures

Staff Writer | February 24, 2023 | 

Ruby from Gemfields.

In 2021 Gemfields announced the ‘G-Factor for Natural Resources’, a measure promoting greater transparency around the level of natural resource wealth shared with the governments of host countries.


Gemfields on Friday announced updated figures to the end of December 2022 and invited governance bodies, mining organisations, industry observers and host governments to adopt the G-Factor for Natural Resources to improve transparency when it comes to the share of natural resource wealth paid to a host country’s government.

The G-Factor for Natural Resources is intended to be an uncomplicated indicator of the percentage of a natural resource company’s revenue that is paid to the host country government in primary and direct taxes, plus – where the host government is a shareholder – dividends.

The GFactor for Natural Resources takes its name from the “g’s” in “government”, “governance” and “good practice”.

“Given the evolution of resource nationalism on the one hand, and increasing strategic competition by companies and states for access to resources on the other, it seems to us that a practical measure allowing more direct comparison of the sharing of natural resource wealth would assist greatly in identifying responsible custodians of host nations’ resources,” Gemfields CEO Sean Gilbertson said in a media statement.

“We hope the G-Factor for Natural Resources will be voluntarily adopted by other companies, insisted upon by host governments and incorporated into projects such as EITI,” he said.

Gemfield’s updated G-Factor numbers are here.

First Quantum halts copper processing in Panama as dispute spirals
Cecilia Jamasmie | February 23, 2023 | 3:45 am News Latin America Copper

Cobre Panama mine is First Quantum Minerals’ largest copper operation. (Image courtesy of Cobre Panama.)

Canada’s First Quantum Minerals (TSX: FM) said on Thursday it had halted ore processing operations at its giant Cobre Panama copper mine, in the latest escalation of a dispute with Panama’s government over tax and royalty payments.


Negotiations between the Toronto-based miner and the country’s government over a new contract for the mine turned sour in December, when the President announced a plan to halt the operation.

The move, unusual among Latin American countries, came after the First Quantum missed a deadline to sign the new contract because it didn’t agree with the some of its terms.

Talks have continued since and, at times, they seemed to progress. Earlier this month, Panama’s maritime authority ordered First Quantum’s local unit Minera Panama to suspend loading operations at a major port, effectively blocking all exports from the mine.

The company was then asked to produce a third-party assessment confirming its scales have been properly balanced.

The miner, which said it submitted the proof on February 3, warned it would have to shut down the massive operation by mid-February because of limited storage capacity.

First Quantum has now begun a partial demobilization of its workforce of over 8,000 employees and contractors, it said on Thursday. It noted it expects the impact to increase significantly in the coming weeks if concentrate shipments do not resume.

In addition to workforce reductions, the mine has ceased purchasing supplies and services that are equivalent to $20 million in weekly revenues to more than 2,000 Panamanian companies.

“Panama has continuously demonstrated its commitment to hold talks based on good faith and trust,” the country’s Ministry of Commerce and Industries said in an emailed statement. “However, Minera Panama has demonstrated the opposite, as they have not honored their word and refuse to sign the agreement with the previously accepted terms, instead engaging in delay tactics that have lengthened the process for more than a year.”

The Cobre Panama mine’s union had called its members on Wednesday to strike against the halting of operations, arguing it would negatively impact workers.

Top copper mine

First Quantum is one of the world’s top copper miners and Canada’s largest producer of the metal. It churned out 816,000 tonnes of copper in 2021, its highest ever, thanks mainly to record output at Cobre Panama.

The Cobre Panama mine complex, located about 120 km west of Panama City and 20 km from the Atlantic coast, contributes 3.5% of the Central American country’s gross domestic product, according to government figures.

The asset is estimated to hold 3.1 billion tonnes in proven and probable reserves and at full capacity can produce more than 300,000 tonnes of copper per year, or about 1.5% of global production of the metal.

Anglo American takes $1.7bn writedown on British fertilizer mine
Cecilia Jamasmie | February 23, 2023 | 

Woodsmith is the UK’s biggest mining project in decades. (Image: Sirius Metals.)

Anglo American (LON:AAL) said Thursday it would take a $1.7 billion charge due higher costs and delays at its Woodsmith fertilizer project, which is being built beneath the North Yorks Moors national park in England.


The company, which acquired Woodsmith two years ago with the acquisition of British junior Sirius Minerals said it now expects first product from the mine in 2027.

By then, Anglo American would have spent about $1 billion a year on top of the $1.35 billion it has already invested developing the world’s largest known deposit of polyhalite fertilizer, totalling $6.1 billion.

Woodsmith’s previous owner estimated the project required about $3.3 billion for completion, with first production slated for 2024. Sirius had spent $1.4 billion on the project when Anglo American took over.

The mine, with an estimate productive life of more than 50 years, could become one of the world’s largest in terms of the amount of resources extracted. Woodsmith will generate an initial 13 million tonnes per year of polyhalite, a multi-nutrient fertilizer, containing four of the six key elements needed for plant growth — potassium, sulphur, magnesium and calcium.

Anglo American believes the mine could achieve such output levels in the early 2030s if demand for its product is sufficient.

“Be in no doubt that we are setting Woodsmith up to generate significant cashflows for many, many decades, we’ll be building it out now until 2027,” CEO Executive Duncan Wanblad said in a statement.

While polyhalite is a new product to the fertilizer market, Wanblad said the company was modelling the project economics on a price of $190 per tonne, versus more than $300 per tonne for similar products on the market.
Profit down 47%

The writedown, flagged in December by chief financial officer Stephen Pearce is part of Anglo’s year-end 2022 results.

The global miner posted a full-year net profit of $4.51 billion, 47% less than $8.56 billion it earned in 2021.
It attributed the results to inflationary pressure, higher energy prices and lower production volumes for the results, which lifted production costs even as commodity prices fell.

Full-year revenues fell 15% to $35.12 billion from $41.55 billion in the previous year, below the company-provided consensus of $36.88 billion.

Anglo American kept its 2023 copper production guidance unchanged at between 840,000 and 930,000 tonnes.

Cleantech startup aims to transform mine waste into a ‘climate solution’

Amanda Stutt | February 24, 2023 | 

Arca technology at work on a mine site. Image from Arca.

The clean energy transition is one of the biggest buzz-phrases in the industry, as miners race to reach decarbonisation goals.


A recently rebranded company, Arca, spun out of Carbin Minerals, which started in 2018 at the University of British Columbia (UBC) has discovered that certain types of mine tailings can remove carbon from the atmosphere more quickly than anyone previously thought. And that ultramafic rock can capture and store gigatonnes of CO2.

The company was named last year as one of Canada’s most investable cleantech ventures, and won a $1 million award from XPRIZE and the Musk Foundation in a carbon removal competition. Arca is already collaborating with 11 mining companies and pre-sold over C$1 million worth of carbon dioxide removal credits.

“We work with rocks that are naturally reactive – they aren’t reactive when they’re in the ground, they become reactive when they’re mined, but we have a portfolio of technologies that makes sure that we capitalize on the huge reactive capacity of those materials, once they end up as mined waste,” UBC Professor of Geological Sciences and co-founder and Head of Science at Arca Greg Dipple told MINING.com.

Dipple noted the mineral content of the host rock is key, and that the technology works in ultramafic rocks, which are rich in magnesium silicate.

Arca’s technology accelerates carbon mineralization, the transformation of atmospheric CO2 into stable carbonate materials and it partners with producers of critical metals to transform their mine waste into industrial-scale direct air capture and storage facilities.
Massive “carbon sink”

“After decades of fundamental scientific research, in the lab and in the field, we have discovered new ways to transform mine waste into a massive carbon sink,” Dipple said. “Our mineral activation technology significantly accelerates the natural process of carbon mineralization, transforming mine waste into a valuable new resource and climate solution.”

UBC professor of Geological Sciences and Arca Head of Science Greg Dipple. 

Dipple said the process captures carbon dioxide directly from the air above the mine and it stores it in mineral form where it is stable over geologic time.

“It’s a permanent, dense form of storage of carbon that ultimately ends up under the landscape upon mine closure,” he said. “When the mines are closed and the landscape is restored, all that carbon is stored in the subsurface permanently from the perspective of our lifetimes, stored on geologic timescales.”

It operates on a scale that can be on par with energy use within existing mines.

“We look at the way that mines are being transformed now to deploy renewable electricity and decarbonize their haul feet,” he said. “In the context of those technologies, our technologies will allow operating mines to get rid of the last 10-20% of their emissions that are hard to abate and go beyond that, such that a mine that’s designed with renewable energy and [a] decarbonized haul fleet.”

“A nickel mine, for example, could operate so that achieving a net negative carbon impact – so it will actually be a source of carbon renewal from the atmosphere while providing zero carbon metals for the energy transition.”

Arca CEO Paul Needham pointed out the clean energy transition presents a challenge and a paradox.

“On the one hand, the world will need 10-20 times more nickel and other critical metals to successfully transition to clean energy,” Needham said in a statement. “On the other hand, modern mining processes are carbon intensive. We resolve that paradox by providing a pathway to carbon-negative mining.”

Dipple said this is being proven during baseline studies at operating mines.

“One of the mines we’ve worked at, a large nickel mine in Australia is doing 40,000 tonnes per year we accelerate that three to four times with our technologies, and we can go beyond that,” he said. “If that mine were to reduce its emissions through 100% deployment of renewable for its electricity generation and if it decarbonized its haul fleet, it would already be carbon negative.”

Dipple noted that there is a disconnect between the public perception of mining as a dirty, polluting industry and the reality of the state of the future of mining.

“I think it’s one of the major issues facing the mining sector – facing society at large, because if we don’t provide the metals that we need for the clean energy transition – it’s simply not going to happen,” he said.

Human height remained unchanged for 2,000 years in Milan, finds study

by Justin Jackson , Phys.org

Boxplot visualization of the data according to sex and historical period. 

Credit: Scientific Reports (2023). DOI: 10.1038/s41598-023-28406-5

A study covering 2,000 years of male and female adult statures in Milan, Italy, has been published in the journal Scientific Reports, illustrating a stable environmental influence on height.

Human height depends on an interplay between genetics and environmental factors like fetal health, childhood nutrition, disease exposures, as well as environmental epigenetic factors that can reach back generations. While genetics alone may determine how tall a person could become, the environment they are born into plays a significant role in how much of that genetic growth potential is realized.

Typically when we look around the world, we see that as health and nutrition have become more reliable since the industrial revolution, humans have reached increasingly greater heights.

In past studies, population stature has been linked to environmental factors. Human height dramatically reduced during the switch from hunter-gatherers to more agricultural societies. If you used historically accurate stature to make a movie about the Trojan war, you would need to hire male actors under 169 cm (approximately 5'6''). Human height has been slowly increasing since then, occasionally being shown to wax and wane with times of sustained prosperity, wars, famines, climate change, and exposure to plague.

In the study, researchers from the Università degli Studi di Milano, analyzed 549 skeletal remains from 13 different sites, all within Milan. The remains all came from necropolises dedicated to the less wealthy classes of Milanese society. They were assigned to one of five historical periods: Roman Era (first–fifth centuries AD), Early Middle Ages (sixth–tenth centuries AD), Late Middle Ages (eleventh–fifteenth centuries AD), Modern Era (sixteenth–eighteenth centuries AD) and Contemporary Era (nineteenth–twentieth centuries AD).

About 100 individuals were assessed for each era, split between male and female. Stature was estimated, mostly using femur bones, according to a well-established forensic regression formula. Individual female heights ranged from 143.5 to 177.6 cm, with a mean of 157.8 cm (about 5'2''). Males ranged from 152.0 to 195.4 cm, with a mean of 168.5 cm (5'6''). There was no significant change in average heights when comparing the historical periods.

By focusing their study on a single geographic location with similar urban and socioeconomic characteristics, researchers were able to remove biases that might arise in studies of multiple populations with distinct environmental influences. With such a homogenous environment, external forces on population height, like wars, plagues, or climate, should have been obvious.

Surprisingly, there were no significant fluctuations seen in the statures. Suggesting to the study authors that city life in Milan has provided a stable environment for thousands of years, even for its lowest-income inhabitants.

More information: Lucie Biehler-Gomez et al, The diachronic trend of female and male stature in Milan over 2000 years, Scientific Reports (2023). DOI: 10.1038/s41598-023-28406-5

Journal information: Scientific Reports 

© 2023 Science X NetworkA study of genetic contributions to changes in prehistoric human stature

Study of Yellow River flooding over past 1,000 years shows human activities made flooding worse

Airborne imagery showing the abandoned Yellow River in the northwest of Xuzhou, China.

The river has been confined to a levee-lined channel perched some 10 m above the

 surrounding floodplain while discharging to the Yellow Sea during 1128-1855 CE. 

Note the relict earth dyke constructed in the Ming Dynasty (1368-1644 CE) and the

 breaching section located at the sharp bend resulting from a levee failure in 1851 CE, 

which gave rise to a floodway (the Dasha River) running northeastward and discharging to

 the Shaoyang Lake. Credit: Nan Ding

A team of geologists, paleontologists and environmental scientists from Jiangsu Normal University and the Chinese Academy of Science, working with a colleague from Coastal Carolina University, has found that human attempts to keep the Yellow River in China from flooding over the past 1,000 years only made things worse.

In their paper published in the journal Science Advances, the group describes studying river sediments and historical records to learn more about the impact on the river by locals living in the area over the past millennium.

The Yellow River, the second-longest river in China, has played an important role in the history of that country. For thousands of years, people living near the river have used its fertile soil to grow food. But the population also had to contend with occasional flooding, which ruined crops and likely led to starvation for some. Over time, many of the locals began lining parts of the river with mud banks, hoping to keep the river from spilling out and onto crop lands. But such efforts, it turns out, tended to make things worse.

To learn more about the impact of mud-banking and other attempts to prevent flooding, such as channeling, the research team visited several sites along the river and collected sediment samples. They also collected flood records created over time by people living there. By analyzing both sources together, the group was able to create a detailed history of river flooding going back 1,000 years.

The researchers found that prior to humans altering the environment, the Yellow River tended to flood approximately four times every century. But just 6,000 years after humans established farming in the area, the river was flooding 10 times as often.

Aerial videography showing the levee-lined Yellow River perched around 10 m above the surrounding floodplain in the northwest of Xuzhou, China, during 1128-1855 CE. Credit: Nan Ding

The researchers found that adding mudbanks next to the river led to an increase in sediment deposits, which lifted the river and made it overflow during heavy rains. They note that such flooding has finally been reduced in the modern era by removing mudbanks and increasing natural vegetation along the river, which helps to reduce the flow of soil into the river during the rainy season.

More information: Shi-Yong Yu et al, Human disturbances dominated the unprecedentedly high frequency of Yellow River flood over the last millennium, Science Advances (2023). DOI: 10.1126/sciadv.adf8576

Journal information: Science Advances 

© 2023 Science X Network

Historic flooding predicted along Arkansas River

Deadly waves: Researchers document the evolution of plague over hundreds of years in medieval Denmark

by McMaster University

Remains from the Lindegården excavation site at Ribe Cathedral (Denmark) dated between the 9th and 19th centuries. Credit: Museum of Southwest Jutland

Scientists who study the origins and evolution of the plague have examined hundreds of ancient human teeth from Denmark, seeking to address longstanding questions about its arrival, persistence and spread within Scandinavia.

In the first longitudinal study of its kind, focusing on a single region for 800 years (between 1000 and 1800AD), researchers reconstructed Yersinia pestis genomes, the bacterium responsible for the plague, and showed that it was reintroduced into the Danish population from other parts of Europe again and again, perhaps via human movement, with devastating effects.

The historical samples were taken from nearly 300 individuals located at 13 different archaeological sites throughout the country.

"We know that plague outbreaks across Europe continued in waves for approximately 500 years, but very little about its spread throughout Denmark is documented in historical archives," says Ravneet Sidhu, one of the study's lead authors and a graduate student at McMaster's Ancient DNA Center, where the analysis was conducted.

The McMaster researchers, working with a team of historians and bioarchaeologists in Denmark and Manitoba, performed an in-depth examination of the relatedness and differences between the different strains of plague that were present in Denmark during this time.

Co-lead author Ravneet Sidhu examines an ancient tooth at McMaster’s Ancient DNA Centre. Credit: Matt Clarke, McMaster University

They reconstructed and sequenced the genomes of Y. pestis, using fragments teased from ancient teeth, which can preserve traces of blood-borne infection for centuries. They compared the plague genomes to one another and to their modern-day relatives.

Researchers found positive plague samples in 13 individuals who had lived and died over a period of three centuries.

Nine of those samples provided enough genetic information to draw evolutionary conclusions about the plague's persistence in Denmark. The results create a picture of urban and rural populations hammered by relentless waves of plague.

"The high frequency of Y. pestis reintroduction to Danish communities is consistent with the assumption that most deaths in the period were due to newly introduced pathogens. This association between pathogen introduction and mortality illuminates essential aspects of the demographic evolution, not only in Denmark but across the whole European continent," says Jesper L. Boldsen, the skeletal collection curator and paleodemographer at ADBOU, University of Southern Denmark.

The analysis, reported today (Feb. 24) in the journal Current Biology, revealed that the Danish Y. pestis sequences were interspersed with medieval and early modern strains from other European countries, including the Baltic region and Russia, rather than coming from a single domestic cluster that re-emerged from natural reservoirs over the centuries.

Remains from the Lindegården excavation site at Ribe Cathedral dated between the 9th 

and 19th centuries. Credit: Museum of Southwest Jutland

"The evidence for plague in Denmark, both historical and archaeological, has been far more sparse than in some other regions, such as England and Italy. This study identified plague for the first time from medieval Denmark, therefore enabling us to connect the experience in Denmark to disease patterns elsewhere," said Julia Gamble a co-author on the study and assistant professor of anthropology at the University of Manitoba.

In striking detail, researchers describe the earliest known appearance of Y. pestis in Denmark in the town of Ribe dating back to 1333 during the Black Death, its appearance in rural areas such Tirup—where there is no surviving historical evidence—and its disappearance by 1649.

Most places it hit in Denmark were port cities, but one of the last outbreaks struck a small rural site in the center of the country with no access to water, suggesting importation via land.

Plague is a disease of rodents, but clearly the results suggest human-facilitated movement of plague, either via rodents traveling with humans or via other vectors on them, such as lice.

"The results reveal new connections between past and present experiences of plague, and add to our understanding of the distribution, patterns and virulence of re-emerging diseases," says Hendrik Poinar, senior author of the paper, director of the McMaster Ancient DNA Center and an investigator with the Michael G. DeGroote Institute for Infectious Disease Research.

"We can use this study and the methods we employed for the study of future pandemics," he says.

More information: Hendrik N. Poinar, Emergence, Continuity and Evolution of Yersinia pestis throughout Medieval Denmark, Current Biology (2023). DOI: 10.1016/j.cub.2023.01.064. www.cell.com/current-biology/f … 0960-9822(23)00133-1

Journal information: Current Biology 

Provided by McMaster University 

Researchers cover thousands of years in a quest to understand the elusive origins of the Black Death