Environmental impact of bottled water up to 3,500 times higher than tap water

A new study compares the health and environmental impacts of individual water consumption choices in Barcelona

Peer-Reviewed Publication

BARCELONA INSTITUTE FOR GLOBAL HEALTH (ISGLOBAL)

What is the best option for individual water consumption if we take into account both health and environmental impacts? The answer to that question, according to a new study led by the Barcelona Institute for Global Health ( ISGlobal), a centre supported by the "la Caixa" Foundation, is that, at least in the city of Barcelona, tap water is the option that offers more overall benefits.

The consumption of bottled water has been increasing sharply in the last years on a global scale. According to previous research, this trend can be partly explained by subjective factors like risk perception, taste, odour, lack of trust in public tap water quality and marketing by bottled water companies. This new study, published inScience of the Total Environment, was aimed at providing objective data about three different water consumption choices: bottled water, tap water and filtered tap water. This scientific work has been carried out in collaboration with the Group of Environmental Engineering and Microbiology ( GEMMA) of the Universitat Politècnica de Catalunya·BarcelonaTech (UPC).

Environmental and health impacts are usually assessed separately due to the different methodologies applied and resulting outcomes. Environmental impacts can be estimated with a methodology called Life Cycle Assessment (LCA), while the consequences in human health are estimated with an approach called Health Impact Assessment (HIA). This study has tried to overcome this methodological barrier for the first time by combining LCA and HIA in the same analysis.

Since tap water quality might differ between cities or countries, the research team focused in the city of Barcelona, due to the robustness of available data. The Life Cycle Assessment was conducted using a specific software and a method called ReCiPe, which allowed researchers to estimate the damage to ecosystems and to resource availability as well as indirect impacts in human health derived from the production process of bottled and tap water. The Health Impact Assessment used data on water consumption patterns and on levels of chemical compounds in water supply from the Barcelona Public Health Agency.

Results showed that if the whole population of Barcelona decided to shift to bottled water, the production required would take a toll of1.43 species lost per year and cost of 83.9 million USD per year due to extraction of raw materials. This is approximately1,400 times more impact in ecosystems and 3,500 times higher cost of resource extraction compared to the scenario where the whole population would shift to tap water.

“Tap water quality has increased substantially in Barcelona since the incorporation of advanced treatments over the last years. However, this considerable improvement has not been mirrored by an increase in tap water consumption, which suggests that water consumption could be motivated by subjective factors other than quality ”, says Cristina Villanueva, ISGlobal researcher and first author of the study.

“One of this subjective factors is the perceived presence of chemical compounds in tap water. While it is true that tap water may contain trihalomethanes (THM) derived from the disinfection process and that THMs are associated with bladder cancer, our study shows that due to the high quality of the tap water in Barcelona, the risk for health is small, especially when we take into account the overall impacts of bottled water”, adds Cristina Villanueva.

In this sense, the results estimate that a complete shift to tap water would increase the overall number of years of life lost in the city of Barcelona to 309 (which equals approximately on average 2 hours of lost life expectancy if borne equally by all residents of Barcelona). Adding domestic filtration to tap water would reduce that risk considerably , lowering the total number of years of life lost to 36.

“Our results show that considering both the environmental and the health effects, tap water is a better option than bottled water, because bottled water generates a wider range of impacts”, says Cathryn Tonne, ISGlobal researcher and last author of the study. “The use of domestic filters, in addition to improving the taste and odour of tap water, can reduce substantially THMs levels in some cases. For this reason, filtered tap water is a good alternative. Even though we didn’t have enough data to measure its environmental impact fully, we know it is much lower than that of bottled water”, she adds. However, the authors acknowledge that domestic filtering devices require an adequate maintenance for a proper performance and to avoid microbial proliferation.

###

Reference

Cristina M. Villanueva, Marianna Garfí, Carles Milà, Sergio Olmos, Ivet Ferrer, Cathryn Tonne, Health and environmental impacts of drinking water choices in Barcelona, Spain: A modelling study, Science of The Total Environment, Volume 795, 2021, 148884, https://doi.org/10.1016/j.scitotenv.2021.148884

---

DOI

10.1016/j.scitotenv.2021.148884

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Health and environmental impacts of drinking water choices in Barcelona

 

Exploring blood types of Neanderthal and Denisovan individuals

Ancient blood types contribute new evidence for the origins, history, and demise of archaic humans

Peer-Reviewed Publication

PLOS

 

IMAGE: ERYTHROID BLOOD GROUP DISTRIBUTION FROM DENISOVA AND NEANDERTHAL ARCHAIC GENOMES. BRANCHING MATCHES NUCLEAR DNA TREE TOPOLOGY [43]. BLUE, NEANDERTHAL LINEAGE; RED, DENISOVAN LINEAGE. MADE WITH NATURAL EARTH. FREE VECTOR AND RASTER MAP DATA @ NATURALEARTHDATA.COM. view more 

CREDIT: CONDEMI ET AL, 2021, PLOS ONE (CC-BY 4.0, HTTPS://CREATIVECOMMONS.ORG/LICENSES/BY/4.0/)

An analysis of the blood types of one Denisovan and three Neanderthal individuals has uncovered new clues to the evolutionary history, health, and vulnerabilities of their populations. Silvana Condemi of the Centre National de la Research Scientifique (CNRS) and colleagues at Aix-Marseille University, France, present hese findings in the open-access journal PLOS ONE on July 28, 2021.

Neanderthals and Denisovans were ancient humans who lived across Eurasia, from Western Europe to Siberia, from about 300,000 to 40,000 years ago. Previous research efforts have produced full-genome DNA sequences for 15 of these ancient individuals, greatly enhancing understanding of their species. However, despite being encoded in DNA, these ancient individuals' blood types have received little attention.

In the new study, Condemi and colleagues investigated the previously sequenced genomes of one Denisovan and three Neanderthal individuals (ranging from 100,000 to 40,000 years ago)in order to determine their blood types and analyze the implications. While 43 different systems exist for assigning blood types, the researchers focused on seven systems that are often used in medical settings for blood transfusions.

This analysis of the four individuals' blood types revealed new information about their species. For instance, the ancient individuals had blood type alleles--different versions of the same gene--in combinations that are consistent with the idea that Neanderthals and Denisovans originated in Africa.

In addition, a distinct genetic link between the Neanderthal blood types and the blood types of an Aboriginal Australian and an indigenous Papuan suggests the possibility of mating between Neanderthals and modern humans before modern humans migrated to Southeast Asia.

The Neanderthal individuals also had blood type alleles associated with increased vulnerability to diseases affecting fetuses and newborns, as well as reduced variability of many alleles compared to modern humans. This pattern is in line with existing evidence that links low genetic diversity and low reproductive success with the eventual demise of Neanderthals.

Overall, these findings highlight the relevance of blood types in understanding humans' evolutionary history.

The authors add: "This work identifies the blood group systems in Neandertals and Denisovans in order to better understand their evolutionary history and to consolidate hypotheses concerning their dispersal in Eurasia and interbreeding with early Homo sapiens.

The results of the Groups system analysis of Neandertals and Denisovans confirm their African origin as well as the weakness in their fertility and susceptibility to virus infection leading to a high infant mortality rate."

###

Citation: Condemi S, Mazières S, Faux P, Costedoat C, Ruiz-Linares A, Bailly P, et al. (2021) Blood groups of Neandertals and Denisova decrypted. PLoS ONE 16(7): e0254175. https://doi.org/10.1371/journal.pone.0254175

Funding: The author(s) received no specific funding for this work.

Competing Interests: The authors have declared that no competing interests exist.

In your coverage please use this URL to provide access to the freely available article in PLOS ONE: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0254175

---

JOURNAL

PLoS ONE

DOI

10.1371/journal.pone.0254175

Disclaimer: AAAS and EurekAlert! are

 

Bronze Age cemetery reveals history of a high-status woman and her twins

And migration patterns within her Vatya community

Peer-Reviewed Publication

PLOS

 

IMAGE: LEFT: BONE ASSEMBLAGE FROM BURIAL N. 241A (ADULT FEMALE INDIVIDUAL). RIGHT: BONES ATTRIBUTABLE TO BOTH FOETUSES (N. 241B AND 241C). view more 

CREDIT: CAVAZZUTI ET AL, 2021, PLOS ONE (CC-BY 4.0, HTTPS://CREATIVECOMMONS.ORG/LICENSES/BY/4.0/)

Ancient urn graves contain a wealth of information about a high-ranking woman and her Bronze Age Vatya community, according to a study published July 28, 2021 in the open-access journal PLOS ONE by Claudio Cavazzuti from the University of Bologna, Italy, and Durham University, UK, and colleagues.

People of the Vatya culture that flourished during the Hungarian Early and Middle Bronze Ages (approximately 2200-1450 BCE) customarily cremated the deceased--making the human remains difficult to analyze from a bioarchaeological perspective. In this study, the authors used new osteological sampling strategies to learn more about the people buried in the urnfield cemetery at Szigetszentmiklós-Ürgehegy, one of the largest Middle Bronze Age urn cemeteries in Central Hungary.

Cavazzuti and colleagues analyzed human tissues from 29 graves (three whole burials, or inhumations, and 26 urn cremations) and applied strontium isotope comparison techniques to test if sampled individuals were local to the geographic area. For the majority of sampled graves, each contained the remains of a single individual and simple grave goods made of ceramic or bronze; however, gravesite 241 was of special interest: this grave contained an urn with the cremated remains of an adult woman and two fetuses, buried alongside prestigious grave goods including a golden hair-ring, a bronze neck-ring, and two bone hairpin ornaments.

Though the three inhumed individuals were poorly preserved, the authors were able to confirm these had been adults, though they couldn't determine the sex. Of the 26 cremated individuals, seven appeared to be adult males, 11 adult females, and two appeared to be adults whose sex couldn't be determined. They also identified children's remains: two individuals likely 5-10 years of age, and four individuals ranging from 2-5 years of age--the youngest present aside from the twin fetuses buried with the adult woman in grave 241, which were approximately 28-32 gestational weeks of age. The authors believe the woman in grave 241 may have died due to complications bearing or birthing these twins. Her remains indicate she was 25 to 35 years old at her time of death and the remains were especially carefully collected post-cremation, as her grave exhibited a bone weight 50 percent higher than the average sampled grave. The strontium analysis also revealed she was likely born elsewhere and moved to Szigetszentmiklós in early adolescence, between the ages of 8-13. One other adult woman also appeared non-local to Szigetszentmiklós, with the adult women in general featuring a more varied strontium isotope composition than the adult men, whose isotopes were concentrated in an especially small range--even narrower than those of the children analyzed in the study.

The authors note their findings at the Szigetszentmiklós urnfield reinforce evidence that women, especially of high rank, commonly married outside their immediate group in Bronze Age Central Europe--and confirm the informative potential of strontium isotope analyses even for cremated remains.

The authors add: "Thanks to a wide spectrum of new bioarchaeological methods, techniques and sampling strategies, it is now possible to reconstruct the life-histories of cremated people of the Bronze Age. In this case, the authors investigate the movements and the tragic events of a high-status woman's life, settled along the Danube 4000 years ago, in the territory of modern-day Hungary."

CAPTION

Grave goods from burial n. 241: 1. Bronze neck-ring (Ösenring); 2. Gold hair-ring (Noppenring); 3. Bone pins/needles (Knochennadeln).

CREDIT

Cavazzuti et al, 2021, PLOS ONE (CC-BY 4.0, https://creativecommons.org/licenses/by/4.0/)

Press-only preview: https://plos.io/2V37UyH

Contact: Dr. Claudio Cavazzuti, claudio.cavazzuti3@unibo.it, Ph.: +39 3389095308

Image Captions: 1) Left: Bone assemblage from burial n. 241a (adult female individual). Right: Bones attributable to both foetuses (n. 241b and 241c). 2) Grave goods from burial n. 241: 1. Bronze neck-ring (Ösenring); 2. Gold hair-ring (Noppenring); 3. Bone pins/needles (Knochennadeln).

Image Credit: Cavazzuti et al, 2021, PLOS ONE (CC-BY 4.0, https://creativecommons.org/licenses/by/4.0/)

Citation: Cavazzuti C, Hajdu T, Lugli F, Sperduti A, Vicze M, Horváth A, et al. (2021) Human mobility in a Bronze Age Vatya 'urnfield' and the life history of a high-status woman. PLoS ONE 16(7): e0254360. https://doi.org/10.1371/journal.pone.0254360

Funding: This paper was supported by the Guest Researcher Fellowship granted by the Hungarian Academy of Sciences; by the Momentum Mobility research project hosted by the Institute of Archaeology, Research Centre for the Humanities, Hungarian Academy of Sciences Centre of Excellence (Principal Investigator: Viktória Kiss) and by the grant from Hungarian Research, Development and Innovation Office, project number: FK128013 (Principal Investigator: Hajdu Tamás). The 14C measurements, conducted by the Atomki Laboratory, Debrecen were supported by the European Union and the State of Hungary, co-financed by the European Regional Development Fund in the project of GINOP-2.3.2-15-2016-00009 'ICER'.

Competing Interests: The authors have declared that no competing interests exist.

In your coverage please use this URL to provide access to the freely available article in PLOS ONE: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0254360

---

JOURNAL

PLoS ONE

DOI

10.1371/journal.pone.0254360

 

Global warming may lead to more variable hydroclimate

Peer-Reviewed Publication

CHINESE ACADEMY OF SCIENCES HEADQUARTERS

Global wet regions will not only receive more rainfall, but also experience temporally more varied rainfall events under global warming, according to researchers from the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences (CAS) and the UK Meteorological (Met) Office.

Their study was published in Science Advances on July 28.

From drinking water to hydroelectric energy, the amount of rainfall we receive, and when we receive it, has a significant impact on society and the environment. Rainfall variability is tightly associated with the occurrence of droughts and floods.

Using the Met Office's state-of-the-art climate model simulations and projections, scientists found that in a future warming world, climatologically wet regions will not only get wetter but also more variable, with greater differences between wet and dry conditions.

The increase in rainfall variability, on the whole, is projected to be larger than the increase in average rainfall, with the global mean increase in rainfall variability more than twice as large as the increase in mean rainfall (in a percentage sense).

"As climate warms, climatologically wet regions will generally get wetter and dry regions get drier. Such a global pattern of mean rainfall change is often described as 'wet-get-wetter'. By analogy, the global pattern of rainfall variability change features a 'wet-get-more variable' paradigm," said ZHOU Tianjun, corresponding author of the study.

ZHOU is a senior scientist at IAP and the CAS Center for Excellence in Tibetan Plateau Earth Sciences of CAS. He is also a professor at the University of Chinese Academy of Sciences.

Physically, while warming-induced atmospheric moistening acts to enhance rainfall variability worldwide, regional patterns of change in rainfall variability are dominated by change in circulation variability. "This highlights the importance of improving our understanding of future circulation changes, which is also an important source of uncertainty in climate change projections," said ZHANG Wenxia, lead author of the study.

"The amplified rainfall variability manifests the fact that global warming is making our climate more uneven--more extreme in both wet and dry conditions, with wider and probably more rapid transitions between them," added ZHANG. The resulting wider swings from one extreme to another will challenge the existing climate resilience of infrastructures, human society and ecosystems.

By simultaneously taking into account changes in the mean state and variability of precipitation, the research provides a new perspective for interpreting future precipitation change regimes. Around two-thirds of land will face a "wetter and more variable" hydroclimate, while the remaining land regions are projected to become "drier but more variable" or "drier and less variable."

"This classification of different precipitation change regimes is valuable for regional adaptation planning," said Kalli Furtado, Expert Scientist at the Met Office and second author of the study. "For most regions, the increasing rainfall variability, which could translate into impacts on crop yields and river flows, makes climate change adaptation more difficult."

###

The study was supported by the National Natural Science Foundation of China, the China Postdoctoral Science Foundation, the International Partnership Program of the Chinese Academy of Sciences, and the UK-China Research Innovation Partnership Fund.

---

JOURNAL

Journal of Mathematical Sciences Advances and Applications

DOI

10.1126/sciadv.abf8021

 

‘Less than 1% probability’ that Earth’s energy imbalance increase occurred naturally, say Princeton and GFDL scientists

Earth's energy balance sheet is in the red, leading to higher temperatures, rising sea levels, floods, droughts, more powerful blizzards and hurricanes, and deadlier extreme events.

Peer-Reviewed Publication

PRINCETON UNIVERSITY

 

IMAGE: SHIV PRIYAM RAGHURAMAN, A GRADUATE STUDENT IN ATMOSPHERIC AND OCEANIC SCIENCES AT PRINCETON, REPORTS IN TODAY’S ISSUE OF NATURE COMMUNICATIONS THAT EARTH’S 'ENERGY IMBALANCE' IS GROWING, AND THERE IS LESS THAN 1% PROBABILITY THAT THIS TREND CAN BE EXPLAINED BY NATURAL VARIATIONS IN THE CLIMATE SYSTEM. PUT ANOTHER WAY, THERE'S A GREATER THAN 99% PROBABILITY THAT OUR PLANET'S RISING TEMPERATURES ARE CAUSED BY HUMAN ACTIVITY. view more 

CREDIT: MORGAN KELLY, HIGH MEADOWS ENVIRONMENTAL INSTITUTE

Sunlight in, reflected and emitted energy out. That’s the fundamental energy balance sheet for our planet. If Earth’s clouds, oceans, ice caps and land surfaces send as much energy back up to space as the sun shines down on us, then our planet maintains equilibrium.

But for decades, that system has been out of balance. Sunlight continues to pour in, and Earth isn’t releasing enough, either as reflected solar radiation or as emitted infrared radiation. The extra heat trapped around our globe — some 90% of which is stored in the ocean — adds energy to worldwide climate systems and manifests in many ways: higher temperatures, rising sea levels, floods, droughts, more powerful blizzards and hurricanes, and deadlier extreme events.

While climate scientists have warned for a half-century that this was the inevitable result of adding too much carbon dioxide to the atmosphere, so-called climate deniers have continued to suggest that the observed changes might be a fluke — just natural variation.

“Until now, scientists have believed that because of the short observational record, we can’t deduce if the increase in the imbalance is due to humans or climatic ‘noise,’” said Shiv Priyam Raghuraman, a graduate student in atmospheric and oceanic sciences (AOS) at Princeton. “Our study shows that even with the given observational record, it is almost impossible to have such a large increase in the imbalance just by Earth doing its own oscillations and variations.”

He and his co-authors used satellite observations from 2001 to 2020 and found that Earth’s “energy imbalance” is growing. Raghuraman worked with David Paynter of the Geophysical Fluid Dynamics Laboratory (GFDL), a NOAA-funded national laboratory located on Princeton’s Forrestal Campus, and V. “Ram” Ramaswamy, director of GFDL and a lecturer with the rank of professor in geosciences and AOS at Princeton University. Their paper appears today in Nature Communications.

“It is exceptionally unlikely — less than 1% probability — that this trend can be explained by natural variations in the climate system,” said Raghuraman.

So what has caused the growing energy imbalance?

“We always think, ‘Increasing greenhouse gases means trapping more infrared heat’ — the classic greenhouse effect becomes larger,” said Raghuraman. “This is correct, but the flip side is that the resulting warmer planet now also radiates more infrared heat away to space, so the greenhouse gas heating impact is cancelled. Instead, much of the imbalance increase comes from the fact that we are receiving the same amount of sunlight but reflecting back less, because increased greenhouse gases cause cloud cover changes, less aerosols in the air to reflect sunlight — that is, cleaner air over the U.S. and Europe — and sea-ice decreases.” (Bright white sea ice reflects much more sunlight than sea water, so as sea ice melts, Earth is becoming less reflective.)

In addition, the Princeton and GFDL researchers noted that oceans store 90% of this excess heat. Because of this close relationship between the growing energy imbalance and ocean heating, the Earth’s energy imbalance has important connections to marine health, sea-level rise and the warming of the global climate system. The researchers hope that tracking the historical trends in this energy imbalance and understanding its components will improve the models of future climate change that drive policymaking and mitigation efforts.

“The satellite record provides clear evidence of a human-influenced climate system,” they said. “Knowing that human activity is responsible for the acceleration of planetary heat uptake implies the need for significant policy and societal action to reduce anthropogenic greenhouse gas emissions to curb further increases in Earth’s energy imbalance.”

###

“Anthropogenic forcing and response yield observed positive trend in Earth’s energy imbalance,” by Shiv Priyam Raghuraman, David Paynter and V. Ramaswamy, appears in the current issue of Nature Communications (DOI: 10.1038/s41467-021-24544-4). The research was supported by the National Oceanic and Atmospheric Administration, the Future Investigators in NASA Earth and Space Science and Technology (award 80NSSC19K1372), the High Meadows Environmental Institute at Princeton University, and the Mary and Randall Hack ’69 Research Fund.

---

JOURNAL

Nature Communications

DOI

10.1038/s41467-021-24544-4

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Anthropogenic forcing and response yield observed positive trend in Earth’s energy imbalance

ARTICLE PUBLICATION DATE

28-Jul-2021

 

Giant friction experiment at Kīlauea volcano

Stanford scientists test friction laws in the collapsing crater of an erupting volcano

Peer-Reviewed Publication

STANFORD UNIVERSITY

On April 30, 2018, on the eastern flank of Hawaii’s Kīlauea volcano, lava suddenly drained from a crater that had been spewing lava for more than three decades. Then the floor of the crater, named Pu’u’ō’ō, dropped out.

Within 48 hours, the lava lake at Kīlauea’s summit 12 miles northwest of Pu’u’ō’ō began to fall as magma drained into the volcano’s plumbing. Soon, new cracks opened 12 miles east of Pu’u’ō’ō and molten lava spurted out, crept over roads, burned trees and torched power poles.

Over three months, Kīlauea spat out enough lava to fill 320,000 Olympic-sized swimming pools, destroyed more than 700 homes and displaced thousands of people. The summit landscape itself was transformed as its crater collapsed by as much as 1,500 feet throughout the summer in a way that scientists are only beginning to understand.

“In the entire 60 years of modern geophysical instrumentation of volcanoes, we’ve had only half a dozen caldera collapses,” said Stanford University geophysicist Paul Segall, lead author of a new study in Proceedings of the National Academy of Sciences that helps explain how these events unfold and finds evidence confirming the reigning scientific paradigm for how friction works on earthquake faults.

The results may help to inform future hazard assessments and mitigation efforts around volcanic eruptions. “Improving our understanding of the physics governing caldera collapses will help us to better understand the conditions under which collapses are possible and forecast the evolution of a collapse sequence once it begins,” said co-author Kyle Anderson, PhD ’12, a geophysicist with the U.S. Geological Survey who was part of the team working on-site at Kīlauea during the 2018 eruption.

The nature of friction

A key factor controlling the collapse of volcanic calderas – and the rupture of earthquake faults around the world – is friction. It’s ubiquitous in nature and our everyday lives, coming into play any time two surfaces move relative to each other. But interactions between surfaces are so complex that, despite centuries of study, scientists still don’t completely understand how friction behaves in different situations. “It’s not something that we can entirely predict using only equations. We also need data from experiments,” Segall said.

Scientists seeking to understand the role of friction in earthquakes usually run these experiments in labs using rock slabs barely larger than a door and often closer to the size of a deck of cards. “One of the big challenges in earthquake science has been to take these friction laws and the values that were found in the laboratory, and apply them to, say, the San Andreas Fault, because it’s such an enormous jump in scale,” said Segall, the Cecil H. and Ida M. Green Professor of Geophysics at Stanford’s School of Earth, Energy & Environmental Sciences (Stanford Earth).

In the new study, published July 23, Segall and Anderson examine the slipping and sticking of Kīlauea volcano’s collapse block – a chunk of crust five miles around and half a mile deep – to characterize friction at a much larger scale. “We set out to develop a mathematical model of that collapse, highly simplified, but using modern understanding of friction,” Segall said.

Kīlauea’s collapse

Kīlauea’s caldera collapsed not in one smooth descent, but rather like a sticky piston. Roughly every day and a half, the collapse block dropped by nearly eight feet in a matter of seconds, then stopped. That’s because as magma in the chamber below the caldera surged out to fissures in Kīlauea’s lower eastern flank, it took away support for the overlying rock. “Eventually, the pressure becomes low enough that the floor falls in and it starts collapsing, like a sinkhole,” Segall said.

By the time the 2018 Kīlauea eruption ended, the volcano’s piston-like collapse events repeated 62 times – with each one triggering an earthquake and every move tracked down to the millimeter every five seconds by an array of 20 global positioning system (GPS) instruments. During the first few dozen collapse events, the geometry of the rock surfaces changed, but they held stable for the final 30 halting descents.

The new research shows that for this type of eruption, when the eruptive vent is at a lower elevation, it leads to a bigger drop in pressure below the caldera block – which then makes it more likely that a collapse event will start. Once collapse initiates, the weight of the massive caldera block maintains pressure on the magma, forcing it to the eruption site. “If not for the collapse, the eruption would have undoubtedly ended much sooner,” Segall said.

Evolving friction

Segall and Anderson’s analysis of the trove of data from Kīlauea’s caldera collapse confirms that, even at the vast scale of this volcano, the ways different rock surfaces slip and slide past one another or stick at different speeds and pressures over time are very similar to what scientists have found in small-scale laboratory experiments.

Specifically, the new results provide an upper bound for an important factor in earthquake mechanics known as slip-weakening distance, which geophysicists use to calculate how faults become unstuck. This is the distance over which the frictional strength of a fault weakens before rupturing – something that’s central to accurate modeling of the stability and buildup of energy on earthquake faults. Laboratory experiments have suggested this distance could be as short as tens of microns – equivalent to the width of a hair spliced into a few dozen slivers – while estimates from real earthquakes indicate it could be as long as 20 centimeters.

The new modeling now shows this evolution occurs over no more than 10 millimeters, and possibly much less. “The uncertainties are bigger than they are in the lab, but the friction properties are completely consistent with what’s measured in the laboratory, and that’s very confirming,” Segall said. “It tells us that we’re okay taking those measurements from really small samples and applying them to big tectonic faults because they held true in the behavior we observed in Kīlauea’s collapse.”

The new work also adds realistic complexity to a mathematical piston model, proposed a decade ago by Japanese volcanologist Hiroyuki Kumagai and colleagues, to explain a large caldera collapse on Miyake Island, Japan. While the widely embraced Kumagai model assumed the volcano’s rock surfaces changed as if by flipping a switch from being stationary relative to each other to slipping past one another, the new modeling recognizes that the transition between “static” and “dynamic” friction is more complex and gradual. “Nothing in nature occurs instantaneously,” Segall said.

###

---

JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2101469118

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Repeating caldera collapse events constrain fault friction at the kilometer scale

ARTICLE PUBLICATION DATE

23-Jul-2021

  Solar power and desalination to be efficiently linked for first time in new project

Meeting Announcement

CRANFIELD UNIVERSITY

Cranfield University will join 19 research partners spread through 12 countries to develop a first-of-a-kind plant which couples concentrated solar power (CSP) and desalination techniques.

The 10M€ European Union’s Horizon 2020 funded research and innovation programme will last 4 years. Innovative technologies related to both CSP and desalination will be designed to improve the efficiency of existing concepts. Improvements will be made on the independent systems but also on their coupling, taking advantage from the mutual interaction and potential.

Cranfield University is the only UK partner, and they are building on a long-standing reputation in CSP, the grant is worth 799k€ to them over 4 years. 

Chris Sansom, Cranfield’s Professor of CSP and Head of Centre for Renewable Energy Systems, said: “Generating environmentally-safe and sustainable sources of both power and fresh water is a challenge for many countries. The final demonstration system will be a 2 MWel power plant built in Saudi Arabia bringing together two promising technologies associated for the first time to reach unprecedented efficiencies. For Cranfield, it is further recognition of our research capabilities in both CSP and Water Sciences.”  

The DESOLINATION project focuses on the Gulf Cooperation Council (GCC) region to test and deploy its technology. A first prototype will be built on the premises of King Saud University in Riyadh, Saudi Arabia. 

With high solar resources and high demand for desalinated water, it is expected that the prototype will provide low-cost renewable electricity (<90€/MWh) and low-cost fresh water (<0.9€/m3), matching the countries’ requirements for efficient and accessible production of water. 

Carbon dioxide blends will be the core of the innovation in the concentrated solar process, leading to more efficient and less expensive power cycle. With water, forward osmosis will be developed and linked to membrane distillation using the wasted heat from the power cycle to generate freshwater. Finally, a unique combination of the power and water cycles will allow the disruptive coupled system to work at high waste-heat-to-freshwater conversion efficiency.

The final system will also benefit from a substantial reduction of CO2 emissions compared to traditional desalination systems.

UCF researchers develop new nanomaterial to derive clean fuel from the sea

The material offers the high performance and stability needed for industrial-scale electrolysis, which could produce a clean energy fuel from seawater

Peer-Reviewed Publication

UNIVERSITY OF CENTRAL FLORIDA

ORLANDO, July 28, 2021 – Hydrogen fuel derived from the sea could be an abundant and sustainable alternative to fossil fuels, but the potential power source has been limited by technical challenges, including how to practically harvest it.

Researchers at the University of Central Florida have designed for the first time a nanoscale material that can efficiently split seawater into oxygen and a clean energy fuel — hydrogen. The process of splitting water into hydrogen and oxygen is known as electrolysis and effectively doing it has been a challenge until now.

The stable, and long-lasting nanoscale material to catalyze the reaction, which the UCF team developed, is explained this month in the journal Advanced Materials.

“This development will open a new window for efficiently producing clean hydrogen fuel from seawater,” says Yang Yang, an associate professor in UCF’s NanoScience Technology Center and study co-author.

Hydrogen is a form of renewable energy that—if made cheaper and easier to produce—can have a major role in combating climate change, according to the U.S. Department of Energy.

Hydrogen could be converted into electricity to use in fuel cell technology that generates water as product and makes an overall sustainable energy cycle, Yang says.

How It Works

The researchers developed a thin-film material with nanostructures on the surface made of nickel selenide with added, or “doped,” iron and phosphor. This combination offers the high performance and stability that are needed for industrial-scale electrolysis but that has been difficult to achieve because of issues, such as competing reactions, within the system that threaten efficiency.

The new material balances the competing reactions in a way that is low-cost and high-performance, Yang says.

Using their design, the researchers achieved high efficiency and long-term stability for more than 200 hours.

“The seawater electrolysis performance achieved by the dual-doped film far surpasses those of the most recently reported, state-of-the-art electrolysis catalysts and meets the demanding requirements needed for practical application in the industries,” Yang says.

The researcher says the team will work to continue to improve the electrical efficiency of the materials they’ve developed. They are also looking for opportunities and funding to accelerate and help commercialize the work.

###

More About the Team

Co-authors included Jinfa Chang, a postdoctoral scholar, and Guanzhi Wang, a doctoral student in materials science engineering, both with UCF’s NanoScience Technology Center; and Ruslan Kuliiev ’20MS, a graduate of UCF’s Master’s in Aerospace Engineering program, and Nina Orlovskaya, an associate professor with UCF’s Department of Mechanical and Aerospace Engineering, and Renewable Energy and Chemical Transformation Cluster.

Yang holds joint appointments in UCF’s NanoScience Technology Center and the Department of Materials Science and Engineering, which is part of the university’s College of Engineering and Computer Science. He is a member of UCF’s Renewable Energy and Chemical Transformation (REACT) Cluster. He also holds a secondary joint-appointment in UCF’s Department of Chemistry. Before joining UCF in 2015, he was a postdoctoral fellow at Rice University and an Alexander von Humboldt Fellow at the University of Erlangen-Nuremberg in Germany. He received his doctorate in materials science from Tsinghua University in China.

CONTACT: Robert H. Wells, Office of Research, robert.wells@ucf.edu

---

JOURNAL

Advanced Materials

DOI

10.1002/adma.202101425

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Dual-Doping and Synergism toward High-Performance Seawater Electrolysis

ARTICLE PUBLICATION DATE

8-Jul-2021

COI STATEMENT

The authors declare no conflict of interest.