Extreme fire weather

Researchers model the regional impacts of specific anthropogenic activities and their influence on extreme fire weather risk

UNIVERSITY OF CALIFORNIA - SANTA BARBARA

Research News

 

When the Thomas Fire raged through Ventura and Santa Barbara counties in December 2017, Danielle Touma, at the time an earth science researcher at Stanford, was stunned by its severity. Burning for more than a month and scorching 440 square miles, the fire was then considered the worst in California's history.

Six months later the Mendocino Complex Fire upended that record and took out 717 square miles over three months. Record-setting California wildfires have since been the norm, with five of the top 10 occurring in 2020 alone.

The disturbing trend sparked some questions for Touma, who is now a postdoctoral researcher at UC Santa Barbara's Bren School for Environmental Science & Management.

"Climate scientists knew that there was a climate signal in there but we really didn't understand the details of it," she said of the transition to a climate more ideal for wildfires. While research has long concluded that anthropogenic activity and its products -- including greenhouse gas emissions, biomass burning, industrial aerosols (a.k.a. air pollution) and land-use changes -- raise the risk of extreme fire weather, the specific roles and influences of these activities was still unclear.

Until now. In the first study of its kind, Touma, with fellow Bren School researcher Samantha Stevenson and colleagues Flavio Lehner of Cornell University and the National Center for Atmospheric Research (NCAR), and Sloan Coats from the University of Hawaii, have quantified competing anthropogenic influences on extreme fire weather risk in the recent past and into the near future. By disentangling the effects of those man-made factors the researchers were able to tease out the roles these activities have had in generating an increasingly fire-friendly climate around the world and the risk of extreme fire weather in decades to come.

Their work appears in the journal Nature Communications.

"By understanding the different pieces that go into these scenarios of future climate change, we can get a better sense of what the risks associated with each of those pieces might be, because we know there are going to be uncertainties in the future," Stevenson said. "And we know those risks are going to be expressed unequally in different places too, so we can be better prepared for which parts of the world might be more vulnerable."

Warm, Dry and Windy

"To get a wildfire to ignite and spread, you need suitable weather conditions -- you need warm, dry and windy conditions," Touma said. "And when these conditions are at their most extreme, they can cause really large, severe fires."

Using state-of-the-art climate model simulations available from NCAR, the researchers analyzed the climate under various combinations of climate influences from 1920-2100, allowing them to isolate individual effects and their impacts on extreme fire weather risk.

According to the study, heat-trapping greenhouse gas emissions (which started to increase rapidly by mid-century) are the dominant contributor to temperature increases around the globe. By 2005, emissions raised the risk of extreme fire weather by 20% from preindustrial levels in western and eastern North America, the Mediterranean, Southeast Asia and the Amazon. The researchers predict that by 2080, greenhouse gas emissions are expected to raise the risk of extreme wildfire by at least 50% in western North America, equatorial Africa, Southeast Asia and Australia, while doubling it in the Mediterranean, southern Africa, eastern North America and the Amazon.

Meanwhile, biomass burning and land-use changes have more regional impacts that amplify greenhouse gas-driven warming, according to the study -- notably a 30% increase of extreme fire weather risk over the Amazon and western north America during the 20th century caused by biomass burning. Land use changes, the study found, also amplified the likelihood of extreme fire weather in western Australia and the Amazon.

Protected by Pollution?

The role of industrial aerosols has been more complex in the 20th century, actually reducing the risk of extreme fire weather by approximately 30% in the Amazon and Mediterranean, but amplifying it by at least 10% in southeast Asia and Western North America, the researchers found.

"(Industrial aerosols) block some of the solar radiation from reaching the ground," Stevenson said. "So they tend to have a cooling effect on the climate.

"And that's part of the reason why we wanted to do this study," she continued. "We knew something had been compensating in a sense for greenhouse gas warming, but not the details of how that compensation might continue in the future."

The cooling effect may still be present in regions such as the Horn of Africa, Central America and the northeast Amazon, where aerosols have not been reduced to pre-industrial levels. Aerosols may still compete with greenhouse gas warming effects in the Mediterranean, western North America and parts of the Amazon, but the researchers expect this effect to dissipate over most of the globe by 2080, due to cleanup efforts and increased greenhouse gas-driven warming. Eastern North America and Europe are likely to see the warming and drying due to aerosol reduction first.

Southeast Asia meanwhile, "where aerosols emissions are expected to continue," may see a weakening of the annual monsoon, drier conditions and an increase in extreme fire weather. risk.

"Southeast Asia relies on the monsoon, but aerosols cause so much cooling on land that it actually can suppress a monsoon," Touma said. "It's not just whether you have aerosols or not, it's the way the regional climate interacts with aerosols."

The researchers hope that the detailed perspective offered by their study opens the door to more nuanced explorations of the Earth's changing climate.

"In the broader scope of things, it's important for climate policy, like if we want to know how global actions will affect the climate," Touma said. "And it's also important for understanding the potential impacts to people, such as with urban planning and fire management."

###

Scientists shed light on how and why some people report "hearing the dead"

TAYLOR & FRANCIS GROUP

Research News

 

IMAGE: THE FOX SISTERS: KATE (1838-92), LEAH (1814-90) AND MARGARET (OR MAGGIE) (1836-93). LITHOGRAPH AFTER A DAGUERREOTYPE BY APPLEBY. PUBLISHED BY N. CURRIER, NEW YORK. IN 1848, TWO SISTERS FROM UPSTATE... view more 

CREDIT: N. CURRIER, NEW YORK

Spiritualist mediums might be more prone to immersive mental activities and unusual auditory experiences early in life, according to new research.

This might explain why some people and not others eventually adopt spiritualist beliefs and engage in the practice of 'hearing the dead', the study led by Durham University found.

Mediums who "hear" spirits are said to be experiencing clairaudient communications, rather than clairvoyant ("seeing") or clairsentient ("feeling" or "sensing") communications.

The researchers conducted a survey of 65 clairaudient spiritualist mediums from the Spiritualists' National Union and 143 members of the general population in the largest scientific study into the experiences of clairaudient mediums.

They found that these spiritualists have a proclivity for absorption - a trait linked to immersion in mental or imaginative activities or experience of altered states of consciousness.

Mediums are also are more likely to report experiences of unusual auditory phenomena, like hearing voices, often occurring early in life.

Many who experience absorption or hearing voices encounter spiritualist beliefs when searching for the meaning behind, or supernatural significance of, their unusual experiences, the researchers said.

The findings are published in the journal Mental Health, Religion and Culture. The research is part of Hearing the Voice - an interdisciplinary study of voice-hearing based at Durham University and funded by the Wellcome Trust.

Spiritualism is a religious movement based on the idea that human souls continue to exist after death and communicate with the living through a medium or psychic.

Interest in Spiritualism is increasing in Britain with several organisations supporting, training, and offering the services of practising mediums. One of the largest, the SNU, claims to serve at least 11,000 members through its training college, churches, and centres.

Through their study, the researchers gathered detailed descriptions of the way that mediums experience spirit 'voices', and compared levels of absorption, hallucination-proneness, aspects of identity, and belief in the paranormal.

They found that 44.6 per cent of spiritualist participants reported hearing the voices of the deceased on a daily basis, with 33.8 per cent reporting an experience of clairaudience within the last day.

A large majority (79 per cent) said that experiences of auditory spiritual communication were part of their everyday lives, taking place both when they were alone and when they were working as a medium or attending a spiritualist church.

Although spirits were primarily heard inside the head (65.1 per cent), 31.7 per cent of spiritualist participants said they experienced spirit voices coming from both inside and outside the head.

When rated on scales of absorption, as well as how strongly they believe in the paranormal, spiritualists scored much more highly than members of the general population.

Spiritualists were less likely to care about what others thought of them than people generally, and they also scored more highly for proneness to unusual hallucination-like auditory experiences.

Both high levels of absorption and proneness to such auditory phenomena were linked to reports of more frequent clairaudient communications, according to the findings.

For the general population, absorption was associated with levels of belief in the paranormal, but there was no significant corresponding link between belief and hallucination-proneness.

There was also no difference in levels of superstitious belief or proneness to visual hallucinations between spiritualist and non-spiritualist participants.

Spiritualists reported first experiencing clairaudience at an average age of 21.7 years. However, 18 per cent of spiritualists reported having clairaudient experiences 'for as long as they could remember' and 71 per cent had not encountered Spiritualism as a religious movement prior to their first experiences.

The researchers say their findings suggest that it is not giving in to social pressure, learning to have specific expectations, or a level of belief in the paranormal that leads to experiences of spirit communication.

Instead, it seems that some people are uniquely predisposed to absorption and are more likely to report unusual auditory experiences occurring early in life. For many of these individuals, spiritualist beliefs are embraced because they align meaningfully with those unique personal experiences.

Lead researcher Dr Adam Powell, in Durham University's Hearing the Voice project and Department of Theology and Religion, said: "Our findings say a lot about 'learning and yearning'. For our participants, the tenets of Spiritualism seem to make sense of both extraordinary childhood experiences as well as the frequent auditory phenomena they experience as practising mediums.

"But all of those experiences may result more from having certain tendencies or early abilities than from simply believing in the possibility of contacting the dead if one tries hard enough."

Dr Peter Moseley, co-author on the study at Northumbria University, commented: "Spiritualists tend to report unusual auditory experiences which are positive, start early in life and which they are often then able to control. Understanding how these develop is important because it could help us understand more about distressing or non-controllable experiences of hearing voices too"

Durham's researchers are now engaged in further investigation of clairaudience and mediumship, working with practitioners to gain a fuller picture of what it is like to be on the receiving end of such unusual and meaningful experiences.

###

A new archaeology for the Anthropocene era

MAX PLANCK INSTITUTE FOR THE SCIENCE OF HUMAN HISTORY

Research News

 

IMAGE: ARCHAEOLOGICAL STUDIES OF LOW-DENSITY, AGRARIAN-BASED CITIES SUCH AS ANCIENT ANGKOR WAT IN CAMBODIA ARE INCREASINGLY BEING USED TO INFORM THE DEVELOPMENT OF MORE SUSTAINABLE URBAN CENTRES IN THE FUTURE.... view more 

CREDIT: ALISON CROWTHER

Indiana Jones and Lara Croft have a lot to answer for. Public perceptions of archaeology are often thoroughly outdated, and these characterisations do little to help.

Yet archaeology as practiced today bears virtually no resemblance to the tomb raiding portrayed in movies and video games. Indeed, it bears little resemblance to even more scholarly depictions of the discipline in the entertainment sphere.

A paper published today in Nature Ecology and Evolution aims to give pause to an audience that has been largely prepared to take such out-of-touch depictions at face value. It reveals an archaeology practiced by scientists in white lab coats, using multi-million-euro instrumentation and state of the art computers.

It also reveals an archaeology poised to contribute in major ways to addressing such thoroughly modern challenges as biodiversity conservation, food security and climate change.

"Archaeology today is a dramatically different discipline to what it was a century ago," observes Nicole Boivin, lead author of the study and Director of the Institute's Department of Archaeology. "While the tomb raiding we see portrayed in movies is over the top, the archaeology of the past was probably closer to this than to present-day archaeology. Much archaeology today is in contrast highly scientific in orientation, and aimed at addressing modern-day issues."

Examining the research contributions of the field over the past few decades, the authors reach a clear conclusion - archaeology today has a great deal to contribute to addressing the challenges of the modern era.

"Humans in the present era have become one of the great forces shaping nature," emphasizes Alison Crowther, coauthor and researcher at both the University of Queensland and the MPI Science of Human History. "When we say we have entered a new, human-dominated geological era, the Anthropocene, we acknowledge that role."

CAPTION

Information from disciplines like archaeology, history, historical ecology and palaeoecology has an important role to play in shaping sustainable solutions to the challenges of the Anthropocene.

CREDIT

Michelle O'Reilly

How can archaeology, a discipline focused on the past, hope to address the challenges we face in the Anthropocene?

"It is clear that the past offers a vast repertoire of cultural knowledge that we cannot ignore," highlights Professor Boivin.

The two researchers show the many ways that data about the past can serve the future. By analysing what worked and didn't work in the past - effectively offering long-term experiments in human society - archaeologists gain insight into the factors that support sustainability and resilience, and the factors that work against them. They also highlight ancient solutions to modern problems.

"We show how researchers have improved the modern world by drawing upon information about the ways people in the past enriched soils, prevented destructive fires, created greener cities and transported water without fossil fuels," notes Dr. Crowther.

People also continue to use, and adapt, ancient technologies and infrastructure, including terrace and irrigation systems that are in some cases centuries or even millennia old.

But the researchers are keen to highlight the continued importance of technological and social solutions to climate change and the other challenges of the Anthropocene.

"It's not about glorifying the past, or vilifying progress," emphasizes Professor Boivin. "Instead, it's about bringing together the best of the past, present and future to steer a responsible and constructive course for humanity."

CAPTION

Around the world today, we can find many examples of how past cultural and technological practices and solutions are being revived to address pressing environmental and land management challenges. Examples include (left to right) mobilization of ancient terra preta (anthropogenic dark earth) technology, revitalization of landesque capital (long-term landscape investments) and adoption of traditional fire management regimes.

CREDIT

Michelle O'Reilly

New management approach can help avoid species vulnerability or extinction

New tools will help ecologists predict when species may be at risk

ARIZONA STATE UNIVERSITY

Research News

 

IMAGE: NEW RESEARCH CAN HELP ECOSYSTEM MANAGERS IDENTIFY SPECIES VULNERABILITIES AND PREVENT POPULATIONS FROM BECOMING AT RISK, LIKE THE ENDANGERED MEXICAN GRAY WOLF. view more 

CREDIT: U.S. FISH AND WILDLIFE SERVICE

More than 3,000 animal species in the world today are considered endangered, with hundreds more categorized as vulnerable. Currently, ecologists don't have reliable tools to predict when a species may become at risk.

A new paper published in Nature Ecology and Evolution, "Management implications of long transients in ecological systems," focuses on the transient nature of species' and ecosystem stability and illustrates how management practices can be adjusted to better prepare for possible system flips. Some helpful modeling approaches are also offered, including one tool that may help identify potentially endangered populations.

One of the challenges of predicting species at risk is presented when a shift from relative security to vulnerability is that transient risk factors may not be known.

"A species or an ecosystem may seem perfectly stable when it unpredictably becomes vulnerable, even in the absence of an obvious stressor," said Tessa Francis, lead ecosystem ecologist at the Puget Sound Institute, University of Washington Tacoma, managing director of the Ocean Modeling Forum, University of Washington, and lead author of the paper. "In some cases, modeling interactions between species or ecosystem dynamics can help managers identify potential corrective actions to take before the species or system collapses."

Ying-Cheng Lai, a professor of electrical engineering and physics at Arizona State University, focused on the mathematical modeling process of the research.

"The Mexican gray wolf is an example of an endangered species that is experiencing a population resurgence in some areas, yet remains vulnerable in others," said Lai. "The predator-prey relationship between the Mexican gray wolf and elk, mule, white-tailed deer, pronghorn, javelina, rabbits, and other small mammals is an example of how interspecies relationships can affect endangerment. In a general predator-prey relationship, a significant reduction in the prey population can make the predator endangered.

"These kinds of interactions, plus other factors such as the species decay rate, migration, the capacity of the habitat, and random disturbances, are included in the mathematical prediction model," Lai continued, "and it turns out that, more common than usually thought, the system evolution dynamics can just be transient. Transients in ecosystems can be good or bad, and we want to develop control strategies to sustain the good ones and eliminate the bad ones," said Lai.

Alan Hastings, a theoretical ecologist at UC Davis and an external faculty member at the Santa Fe Institute, notes that "As we apply these mathematical models to understanding systems on realistic, ecologic time scales, we unveil new approaches and ideas for adaptive management.

"The goal is to develop management strategies to both extend a positive ecosystems as long as possible and to design recovery systems to support resurgence from vulnerable states," said Hastings. "Over time, as successful predictions are incorporated into the mathematical model, the tool will become more accurate."

But mathematical models are not a panacea, cautions Dr. Francis. "While models can be useful in playing out 'what ifs' and understanding hypothetical consequences of management interventions, just as important is changing the way we view ecosystems and admitting that things are often less stable than they appear."

###

Additional contributors to the research include: Karen C. Abbott, Case Western Reserve University; Kim Cuddington, University of Waterloo; Gabriel Gellner, University of Guelph; Andrew Morozov, University of Leicester, Russian Academy of Sciences; Sergei Petrovskii: University of Leicester, and Mary Lou Zeeman: Bowdoin College.

The team, with sponsorship from the National Institute for Mathematical and Biological Synthesis (NIMBioS) through the University of Tennessee, has been working together as a study group named "NIMBioS Working Group: Long Transients and Ecological Forecasting." The group has produced a number of papers focused on developing mathematical models to understand long transients in ecosystems.

A 'super-puff' planet like no other

UNIVERSITY OF MONTREAL
NEWS RELEASE 18-JAN-2021


IMAGE: ARTISTIC RENDITION OF THE EXOPLANET WASP-107B AND ITS STAR, WASP-107. SOME OF THE STAR'S LIGHT STREAMS THROUGH THE EXOPLANET'S EXTENDED GAS LAYER. view more

CREDIT: ESA/HUBBLE, NASA, M. KORNMESSER.

The core mass of the giant exoplanet WASP-107b is much lower than what was thought necessary to build up the immense gas envelope surrounding giant planets like Jupiter and Saturn, astronomers at Université de Montréal have found.

This intriguing discovery by Ph.D. student Caroline Piaulet of UdeM's Institute for Research on Exoplanets (iREx) suggests that gas-giant planets form a lot more easily than previously believed.

Piaulet is part of the groundbreaking research team of UdeM astrophysics professor Björn Benneke that in 2019 announced the first detection of water on an exoplanet located in its star's habitable zone.

Published today in the Astronomical Journal with colleagues in Canada, the U.S., Germany and Japan, the new analysis of WASP-107b's internal structure "has big implications," said Benneke.

"This work addresses the very foundations of how giant planets can form and grow," he said. "It provides concrete proof that massive accretion of a gas envelope can be triggered for cores that are much less massive than previously thought."

As big as Jupiter but 10 times lighter

WASP-107b was first detected in 2017 around WASP-107, a star about 212 light years from Earth in the Virgo constellation. The planet is very close to its star -- over 16 times closer than the Earth is to the Sun. As big as Jupiter but 10 times lighter, WASP-107b is one of the least dense exoplanets known: a type that astrophysicists have dubbed "super-puff" or "cotton-candy" planets.

Piaulet and her team first used observations of WASP-107b obtained at the Keck Observatory in Hawai'i to assess its mass more accurately. They used the radial velocity method, which allows scientists to determine a planet's mass by observing the wobbling motion of its host star due to the planet's gravitational pull. They concluded that the mass of WASP-107b is about one tenth that of Jupiter, or about 30 times that of Earth.

The team then did an analysis to determine the planet's most likely internal structure. They came to a surprising conclusion: with such a low density, the planet must have a solid core of no more than four times the mass of the Earth. This means that more than 85 percent of its mass is included in the thick layer of gas that surrounds this core. By comparison, Neptune, which has a similar mass to WASP-107b, only has 5 to 15 percent of its total mass in its gas layer.

"We had a lot of questions about WASP-107b," said Piaulet. "How could a planet of such low density form? And how did it keep its huge layer of gas from escaping, especially given the planet's close proximity to its star?

"This motivated us to do a thorough analysis to determine its formation history."

A gas giant in the making

Planets form in the disc of dust and gas that surrounds a young star called a protoplanetary disc. Classical models of gas-giant planet formation are based on Jupiter and Saturn. In these, a solid core at least 10 times more massive than the Earth is needed to accumulate a large amount of gas before the disc dissipates.

Without a massive core, gas-giant planets were not thought able to cross the critical threshold necessary to build up and retain their large gas envelopes.

How then do explain the existence of WASP-107b, which has a much less massive core? McGill University professor and iREx member Eve Lee, a world-renowned expert on super-puff planets like WASP-107b, has several hypotheses.

"For WASP-107b, the most plausible scenario is that the planet formed far away from the star, where the gas in the disc is cold enough that gas accretion can occur very quickly," she said. "The planet was later able to migrate to its current position, either through interactions with the disc or with other planets in the system."

Discovery of a second planet, WASP-107c

The Keck observations of the WASP-107 system cover a much longer period of time than previous studies have, allowing the UdeM-led research team to make an additional discovery: the existence of a second planet, WASP-107c, with a mass of about one-third that of Jupiter, considerably more than WASP-107b's.

WASP-107c is also much farther from the central star; it takes three years to complete one orbit around it, compared to only 5.7 days for WASP-107b. Also interesting: the eccentricity of this second planet is high, meaning its trajectory around its star is more oval than circular.

"WASP-107c has in some respects kept the memory of what happened in its system," said Piaulet. "Its great eccentricity hints at a rather chaotic past, with interactions between the planets which could have led to significant displacements, like the one suspected for WASP-107b."

Several more questions

Beyond its formation history, there are still many mysteries surrounding WASP-107b. Studies of the planet's atmosphere with the Hubble Space Telescope published in 2018 revealed one surprise: it contains very little methane.

"That's strange, because for this type of planet, methane should be abundant," said Piaulet. "We're now reanalysing Hubble's observations with the new mass of the planet to see how it will affect the results, and to examine what mechanisms might explain the destruction of methane."

The young researcher plans to continue studying WASP-107b, hopefully with the James Webb Space Telescope set to launch in 2021, which will provide a much more precise idea of the composition of the planet's atmosphere.

"Exoplanets like WASP-107b that have no analogue in our Solar System allow us to better understand the mechanisms of planet formation in general and the resulting variety of exoplanets," she said. "It motivates us to study them in great detail."

###

About this study

"WASP-107b's density is even lower: a case study for the physics of gas envelope accretion and orbital migration," by Caroline Piaulet et al., was posted today in the Astronomical Journal. DOI: 10.3847/1538-3881/abcd3c. In addition to Piaulet (iREx Ph.D. student, Université de Montréal) and professors Björn Benneke (iREx, Université de Montréal) and Eve Lee (iREx, McGill Space Institute, McGill University), the research team includes Daniel Thorngren (iREx Postdoctoral Fellow, Université de Montréal) and Merrin Peterson (iREx M.Sc student), and 19 other co-authors from Canada, the United States, Germany and Japan.

Land deals meant to improve food security may have hurt

UNIVERSITY OF NOTRE DAME

Research News

 

Large-scale land acquisitions by foreign investors, intended to improve global food security, had little to no benefit, increasing crop production in some areas while simultaneously threatening local food security in others, according to researchers who studied their effects.

The study, published in the Proceedings of the National Academy of Sciences and led by the University of Notre Dame, combined satellite imagery with agricultural surveys as well as household dietary datasets of 160 large-scale land acquisitions across four continents between 2005 and 2015. It is the first comprehensive global analysis of the impact of the land acquisitions of its kind.

"These land deals have been happening for the last two decades on a massive scale," said Marc Muller, assistant professor in the Department of Civil and Environmental Engineering and Earth Sciences at Notre Dame and lead author of the study. "Our goal was to use empirical data to sort out whether or not large-scale land acquisitions have improved food security by using empirical data. But what we found was that there was either no impact or a negative impact. There was no positive impact."

Following a global food crisis during the early 2000s, foreign investors purchased more than 220 million acres of land in middle-income and developing countries, according to the study's estimates, to increase crop production and contribute to the global food supply.

"In many countries throughout the world land is being commodified, so it is becoming easier to buy and sell land. Those, and rising food prices, were drivers for these companies," Muller said.

There are two competing arguments when it comes to land acquisitions. Proponents view the multinational companies that purchased the land as better positioned to improve production and increase crop yields. But those who oppose argue that the acquisitions encroach on natural resources, lead to displacement of local farm workers and can have a negative impact on local residents -- including giving rise to livelihood losses, social instability and/or violence in those regions.

While scientists have analyzed these types of acquisitions using modeling studies, and others have looked at specific situations as a result of the land deals through case studies, Muller said this is the first global analysis of this scale.

Muller and his team analyzed land deals across Latin America, eastern Europe, Africa and Asia. By combining satellite imagery, researchers could see whether crop lands expanded and/or intensified. "We also used data from agriculture surveys to identify what types of crops had been planted in and around those lands prior to the acquisition compared to after, to account for potential transitions from local crops to export-bound crops, and crops that can also be used for biofuel," such as palm oil and sugar cane, Muller said.

According to the study, trends differed depending on the region -- and in some cases the acquisitions had a negative effect on household diets.

In Latin America and eastern Europe -- where countries are considered middle-income -- investors purchased land in intensified agricultural areas, where crops were already export-bound and local residents already consumed food from global markets. "So, in that sense, these land deals didn't really change much," said Muller. "They didn't increase crop production and they didn't cause more damage to local food insecurity than what was already taking place. In Africa and Asia, things looked very different."

The research showed that those land acquisitions increased cropland, cultivating previously uncultivated land, and showed a clear transition from local staple crops such as tapioca to export-bound crops such as wheat and flex crops for potential use as biofuel.

"These crops are interesting for investors because if the price of food is low and the price of energy is high, you can then use the crops for energy," said Muller. "But these types of crops are not nutrient dense, so it's not great in terms of food security. As a matter of fact, the data from the household surveys we studied showed a consistent decrease in diet diversity after the deals took place."

The study is the first in a series the research team will produce based on their analysis. Forthcoming studies will look at the impact of large-scale land acquisitions in relation to water, energy and environment.

###

Muller is an affiliated member of Notre Dame's Environmental Change Initiative and a faculty fellow with the Kellogg Institute for International Studies.

Co-authors of the study include Gopal Penny, also at Notre Dame; Meredith T. Niles at the University of Vermont; Vincent Ricciardi at the University of British Columbia; Davide Danilo Chiarelli and Maria Cristina Rulli at the Polytechnic University of Milan; Kyle Frankel Davis at the University of Delaware; Jampel Dell'Angelo at the University of Amsterdam; Paolo D'Odorico and Lorenzo Rosa at the University of California, Berkeley; and Nathan D. Mueller at Colorado State University.

The National Science Foundation, the United States Agency for International Development and the Mava Foundation funded the study.

 Story tips: Volcanic microbes, unbreakable bonds and flood mapping

DOE/OAK RIDGE NATIONAL LABORATORY

Research News

 

IMAGE: DEEP-SEA HYDROTHERMAL VENT CHIMNEYS ON BROTHER'S VOLCANO'S NORTHWEST CALDERA WALL CREATE A UNIQUE ENVIRONMENT FOR MICROBES. view more 

CREDIT: ANNA-LOUISE REYSENBACH/NSF, ROV JASON AND 2018 ©WOODS HOLE OCEANOGRAPHIC INSTITUTION

Biology - Volcanic microbes

Oak Ridge National Laboratory contributed to an international study that found almost 300 novel types of microbes living near a deep sea volcano. These microbes, which could be used in biotechnology, reveal new insights about their extreme underwater environment.

Two distinct communities of heat-loving and many acid-loving microbes live near Brother's Volcano, located about 200 miles northeast of New Zealand and 6,000 feet underwater. Known as extremophiles, these microbes thrive in water heated by magma and hydrothermal vents.

Though they live close to one another, the microbial communities reflect differences in water chemistry and temperature from geological features. In analyzing the new bacterial and archaeal families, ORNL's Mircea Podar thinks microbes like these can help better characterize extreme environments.

"We're heading to a point where microbes can be very informative about the environment they came from and even reflect some of the past," Podar said. "With more data, we can use microbes as a proxy to characterize environments where traditional measurements are challenging to capture."

Media Contact: Kim Askey, 865.576.2841, askeyka@ornl.gov

Image: https://www.ornl.gov/sites/default/files/2021-01/Hydrothermal%20vent.jpg

Caption: Deep-sea hydrothermal vent chimneys on Brother's Volcano's northwest caldera wall create a unique environment for microbes. Credit: Anna-Louise Reysenbach/NSF, ROV Jason and 2018 ©Woods Hole Oceanographic Institution

Image: https://www.ornl.gov/sites/default/files/2021-01/Magmatic%20vent.jpg

Caption: Magmatic hydrothermal venting at the cone site in Brother's Volcano creates a microbial community distinctly different from those at nearby geological features. Credit: Anna-Louise Reysenbach, NSF, ROV Jason and 2018 ©Woods Hole Oceanographic Institution

Image: https://www.ornl.gov/sites/default/files/2021-01/IMG_0546v2.jpg

Caption: ORNL contributed to the international study, which was led by Portland State University, and leveraged submersible technology from Woods Hole Oceanographic Institute. Credit: Anna-Louise Reysenbach

CAPTION

ORNL researchers produced self-healable and highly adhesive elastomers, proving they self-repair in ambient conditions and underwater. Credit: ORNL/U.S. Dept. of Energ

Buildings - The unbreakable bond

Researchers at Oak Ridge National Laboratory developed self-healing elastomers that demonstrated unprecedented adhesion strength and the ability to adhere to many surfaces, which could broaden their potential use in industrial applications.

Elastomers, commonly used in the construction industry as sealants, are known for their durability. However, they can develop cracks when exposed to certain environments, leading to air and water leaks.

In a study, ORNL researchers used a blend of a self-healing polymer with curable elastomers to produce a series of self-healable and highly adhesive materials. The team proved that these elastomers can self-repair in ambient temperatures and conditions, as well as underwater, with their adhesive force only minimally impacted by surface dust.

"These tough elastomers can be made simply and efficiently through a scalable process, enabling a wider range of uses for the building, automotive and electronics industries," ORNL's Diana Hun said.

Media Contact: Jennifer Burke, 865.414.6835, burkejj@ornl.gov

Image: https://www.ornl.gov/sites/default/files/2021-01/Buildings%20-%20Unbreakable%20bond-%20lr.png

Caption: ORNL researchers produced self-healable and highly adhesive elastomers, proving they self-repair in ambient conditions and underwater. Credit: ORNL/U.S. Dept. of Energy

CAPTION

The TRITON model provides a detailed visualization of the flooding that resulted when Hurricane Harvey stalled over Houston for four days in 2017.

CREDIT

Mario Morales-Hernández/ORNL, U.S. Dept. of Energy

Modeling - Mapping the flood

A new tool from Oak Ridge National Laboratory can help planners, emergency responders and scientists visualize how flood waters will spread for any scenario and terrain.

The Two-dimensional Runoff Inundation Toolkit for Operational Needs, or TRITON, leverages the power of modern supercomputing to quickly create detailed flood forecasts based on meteorology, hydrology, terrain and surface conditions.

Free and available for use, TRITON can be downloaded in formats compatible with standard computer systems and with advanced architectures such as ORNL's Summit supercomputer. Running the model on Summit's modern architecture speeds processing by 40 times compared to conventional high-performance computing.

"The ultimate aim of this model is to support operational inundation forecasting for a range of applications, from infrastructure safety to national security," said ORNL's Shih-Chieh Kao who leads the project. "Understanding how a flood wave will propagate across a region or city enables appropriate planning and response."

Media Contact: Kim Askey, 865.576.2841, askeyka@ornl.gov

Video: https://youtu.be/mgo78s7iJ7g Image: https://www.ornl.gov/sites/default/files/2021-01/TRITON%20screenshot.png

Caption: The TRITON model provides a detailed visualization of the flooding that resulted when Hurricane Harvey stalled over Houston for four days in 2017. Credit: Mario Morales-Hernández/ORNL, U.S. Dept. of Energy

###

Research finds tiny bubbles tell tales of big volcanic eruptions

Study: Nanocrystals may explain staggering number of bubbles in erupted lava

RICE UNIVERSITY

Research News

 

IMAGE: SAHAND HAJIMIRZA IS A POSTDOCTORAL RESEARCH ASSOCIATE IN RICE UNIVERSITY'S DEPARTMENT OF EARTH, ENVIRONMENTAL AND PLANETARY SCIENCES. view more 

CREDIT: PHOTO COURTESY OF S. HAJIMIRZA/RICE UNIVERSITY

HOUSTON - (Jan. 19, 2021) - Microscopic bubbles can tell stories about Earth's biggest volcanic eruptions and geoscientists from Rice University and the University of Texas at Austin have discovered some of those stories are written in nanoparticles.

In an open-access study published online in Nature Communications, Rice's Sahand Hajimirza and Helge Gonnermann and UT Austin's James Gardner answered a longstanding question about explosive volcanic eruptions like the ones at Mount St. Helens in 1980, the Philippines' Mount Pinatubo in 1991 or Chile's Mount Chaitén in 2008.

Geoscientists have long sought to use tiny bubbles in erupted lava and ash to reconstruct some of the conditions, like heat and pressure, that occur in these powerful eruptions. But there's been a historic disconnect between numerical models that predict how many bubbles will form and the actual amounts of bubbles measured in erupted rocks.

Hajimirza, Gonnermann and Gardner worked for more than five years to reconcile those differences for Plinian eruptions. Named in honor of Pliny the Younger, the Roman author who described the eruption that destroyed Pompeii in A.D. 79, Plinian eruptions are some of the most intense and destructive volcanic events.

"Eruption intensity refers to the both the amount of magma that's erupted and how quickly it comes out," said Hajimirza, a postdoctoral researcher and former Ph.D. student in Gonnermann's lab at Rice's Department of Earth, Environmental and Planetary Sciences. "The typical intensity of Plinian eruptions ranges from about 10 million kilograms per second to 10 billion kilograms per second. That is equivalent to 5,000 to 5 million pickup trucks per second."

One way scientists can gauge the speed of rising magma is by studying microscopic bubbles in erupted lava and ash. Like bubbles in uncorked champagne, magma bubbles are created by a rapid decrease in pressure. In magma, this causes dissolved water to escape in the form of gas bubbles.

"As magma rises, its pressure decreases," Hajimirza said. "At some point, it reaches a pressure at which water is saturated, and further decompression causes supersaturation and the formation of bubbles."

As water escapes in the form of bubbles, the molten rock becomes less saturated. But if the magma continues to rise, decreasing pressure increases saturation.

"This feedback determines how many bubbles form," Hajimirza said. "The faster the magma rises, the higher the decompression rate and supersaturation pressure, and the more abundant the nucleated bubbles."

In Plinian eruptions, so much magma rises so fast that the number of bubbles is staggering. When Mount St. Helens erupted on May 18, 1980, for example, it spewed more than one cubic kilometer of rock and ash in nine hours, and there were about one million billion bubbles in each cubic meter of that erupted material.

"The total bubbles would be around a septillion," Hajimirza said. "That's a one followed by 24 zeros, or about 1,000 times more than all the grains of sand on all Earth's beaches."

In his Ph.D. studies, Hajimirza developed a predictive model for bubble formation and worked with Gardner to test the model in experiments at UT Austin. The new study builds upon that work by examining how magnetite crystals no larger than a few billionths of a meter could change how bubbles form at various depths.

"When bubbles nucleate, they can form in liquid, which we call homogeneous nucleation, or they can nucleate on a solid surface, which we call heterogeneous," Hajimirza said. "A daily life example would be boiling a pot of water. When bubbles form on the bottom of the pot, rather than in the liquid water, that is heterogeneous nucleation."

Bubbles from the bottom of the pot are often the first to form, because heterogeneous and homogeneous nucleation typically begin at different temperatures. In rising magma, heterogeneous bubble formation begins earlier, at lower supersaturation levels. And the surfaces where bubbles nucleate are often on tiny crystals.

"How much they facilitate nucleation depends on the type of crystals," Hajimirza said. "Magnetites, in particular, are the most effective."

In the study, Hajimirza, Gonnermann and Gardner incorporated magnetite-mediated nucleation in numerical models of bubble formation and found the models produced results that agreed with observational data from Plinian eruptions.

Hajimirza said magnetites are likely present in all Plinian magma. And while previous research on hasn't revealed enough magnetites to account for all observed bubbles, previous studies may have missed small nanocrystals that would only be revealed with transmission electron microscopy, a rarely used technique that is only now becoming more broadly available.

To find out if that's the case, Hajimirza, Gonnermann and Gardner called for a "systematic search for magnetite nanolites" in material from Plinian eruptions. That would provide observational data to better define the role of magnetites and heterogeneous nucleation in bubble formation, and could lead to better models and improved volcanic forecasts.

"Forecasting eruptions is a long-term goal for volcanologists, but it's challenging because we cannot directly observe subsurface processes," said Hajimirza. "One of the grand challenges of volcano science, as outlined by the National Academies in 2017, is improving eruption forecasting by better integration of the observational data we have with the quantitative models, like the one we developed for this study."

Gonnermann is a professor of Earth, environmental and planetary sciences at Rice. Gardner is a professor of geological sciences in UT's Jackson School of Geosciences.

The research was supported by the National Science Foundation (EAR-1348072, EAR-1348050).

Links and resources:

The DOI of the Nature Communications paper is: 10.1038/s41467-020-20541-1

A copy of the paper is available at: https://doi.org/10.1038/s41467-020-20541-1

High-resolution IMAGES are available for download at:

https://news-network.rice.edu/news/files/2021/01/0113_BUBBLES-smH-b.jpg CAPTION: Sahand Hajimirza is a postdoctoral research associate in Rice University's Department of Earth, Environmental and Planetary Sciences. (Photo courtesy of S. Hajimirza/Rice University)

https://www.usgs.gov/media/images/plinian-eruption-column-may-18-1980-mount-st-helens CAPTION: An aerial view from the southwest of Mount St. Helens, Washington, May 18, 1980. The Plinian eruption was the deadliest and most costly volcanic disaster in U.S. history. (Photo by Krimmel, Robert. Public domain.)

https://earthobservatory.nasa.gov/images/19887/chaiten-volcano-erupts CAPTION: A volcanic plume flows southeast from Chile's Mount Chaitén in this May 3, 2008 image from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite. The Plinian plume rose over the Andes Mountains and drifted across Argentina before dissipating over the Atlantic Ocean. (Image courtesy Jeff Schmaltz/MODIS Rapid Response Team/NASA Goddard Space Flight Center)

This release can be found online at news.rice.edu.

Follow Rice News and Media Relations via Twitter @RiceUNews.

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,978 undergraduates and 3,192 graduate students, Rice's undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for lots of race/class interaction and No. 1 for quality of life by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance.