Shock waves, landslides may have caused 'rare' volcano tsunami: experts

Experts said volcano-triggered tsunamis are rare but not unheard of.

A rare volcano-triggered tsunami sparked by the eruption of Hunga Tonga-Hunga Ha'apai in Tonga could have been caused by shock waves or shifting underwater land, experts said Monday.

"A volcanic-source tsunami event is rare but not unprecedented," a post on the website for New Zealand's geological hazard monitoring system GNS said Monday.

GNS Tsunami Duty Officer Jonathan Hanson said it probably occurred in part thanks to a previous eruption of the same volcano one day earlier.

"It is likely that the earlier 14 January eruption blew away part of the volcano above water, so water flowed into the extremely hot vent," wrote Hanson.

"This meant that the Saturday evening eruption initially occurred underwater and exploded through the ocean, causing a widespread tsunami," he said.

Two days after Hunga Tonga-Hunga Ha'apai's massive explosion, the nation's 100,000 population remained virtually cut off from the rest of the world with crippled communications and stalled emergency relief efforts.

The volcano cloaked Tonga in a film of ash, sent a column of ash and gas 20 kilometres into the air and shock waves that could be seen from space rippling across the planet.

It also triggered a Pacific-wide tsunami whose waves were strong enough to drown two women in Peru more than 10,000 kilometres (6,000 miles) away.

Factfile on the Hunga Tonga-Hunga Ha'apai volcano eruption.

Ring of Fire

Hunga Tonga-Hunga Ha'apai is located in the so-called Ring of Fire, where a rift between shifting tectonic plates results in increased seismic activity.

In a volcanic eruption, magma rising to the surface of the Earth's crust causes volcanic gases to be released that then push their way out from underground, creating pressure.

When the gases reach water it expands into water vapour, creating even more pressure.

Volcano expert Ray Cas of Monash University in Australia said he suspected the intensity of the explosion suggested a large amount of gas had risen into the vent.

"The tsunamis could have been triggered by shock waves propagating through water," he commented on the Australian Science Media Centre.

"But more likely largely by a landslide on the submarine part of the volcanic edifice triggered by the explosive eruption."

Yet another possibility is that the volcano's special location just beneath the surface of the ocean could have made its effects worse.

The Pacific Ring of Fire.

The volcano's 1,800 metres of height is almost entirely submerged beneath the surface of the ocean, the edge of its crater forming an uninhabited island.

"When eruptions happen deep in the ocean, the water tends to muffle the activity. When it happens in the air, the risks are concentrated to the immediate area," Paris-based geologist Raphael Grandin told AFP.

"But when it's just under the surface, that's when the tsunami risk is greatest," he said.

Exceptionally loud eruption

People are reported to have heard Hunga Tonga-Hunga Ha'apai's eruption as far away as Alaska, 9,000 kilometres from the source, which Grandin said is "exceptional".

"As far as I know the last explosion that was audible at that distance was caused by the Krakatoa volcano in Indonesia in 1883—it killed 36,000 people," he said.

Experts also said that while the volcano could experience further activity, past research shows an eruption of Saturday's scale probably only occurs every 1,000 years.

Scientists who commented on the phenomenon said they would know more about how it took place once communication with the Pacific nation of some 170 islands could be restored.Tongans warned of acid rain after volcanic eruption

© 2022 AFP

Genetic strategy reverses insecticide resistance

Researchers replace resistant gene with susceptible counterpart, opening the door to new methods that could fight malaria and reduce pesticide use

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SAN DIEGO

 

IMAGE: REVERSING INSECTICIDE RESISTANCE WITH A NEW TYPE OF GENE-DRIVE SYSTEM: TREATMENT OF FIELDS WITH INSECTICIDES LEADS TO THE EMERGENCE OF INSECTICIDE-RESISTANT INSECT PESTS AND REDUCED DIVERSITY OF BENEFICIAL INSECTS. A NEW PROOF-OF-PRINCIPLE STUDY PUBLISHED IN NATURE COMMUNICATIONS SHOWS THAT GENE DRIVES ENGINEERED TO BIAS INHERITANCE CALLED ALLELIC-DRIVES CAN BE APPLIED IN THE ABSENCE OF PESTICIDE TREATMENT TO RESTORE INSECTICIDE SUSCEPTIBILITY AND BALANCED NATURAL LEVELS OF INSECT POPULATIONS. view more 

CREDIT: BIER LAB, UC SAN DIEGO

Insecticides play a central role in efforts to counter global impacts of mosquito-spread malaria and other diseases, which cause an estimated 750,000 deaths each year. These insect-specific chemicals, which cost more than $100 million to develop and bring to market, also are critical to controlling insect-driven crop damage that poses a challenge to food security.

But in recent decades many insects have genetically adapted to become less sensitive to the potency of insecticides. In Africa, where long-lasting insecticide-treated bed nets and indoor spraying are major weapons in the fight against malaria, many species of mosquitoes across the continent have developed insecticide resistance that reduces the efficacy of these key interventions. In certain areas climate change is expected to exacerbate these problems.

University of California San Diego biologists have now developed a method that reverses insecticide resistance using CRISPR/Cas9 technology. As described in Nature Communications, researchers Bhagyashree Kaduskar, Raja Kushwah and Professor Ethan Bier with the Tata Institute for Genetics and Society (TIGS) and their colleagues used the genetic editing tool to replace an insecticide-resistant gene in fruit flies with the normal insecticide-susceptible form, an achievement that could significantly reduce the amount of insecticides used.

“This technology also could be used to increase the proportion of a naturally occurring genetic variant in mosquitoes that renders them refractory to transmission or malarial parasites,” said Bier, a professor of Cell and Developmental Biology in UC San Diego’s Division of Biological Sciences and senior author of the paper.

The researchers used a modified type of gene-drive, a technology that uses CRISPR/Cas9 to cut genomes at targeted sites, to spread specific genes throughout a population. As one parent transmits genetic elements to their offspring, the Cas9 protein cuts the chromosome from the other parent at the corresponding site and the genetic information is copied into that location so that all offspring inherit the genetic trait. The new gene-drive includes an add-on that Bier and his colleagues previously engineered to bias the inheritance of simple genetic variants (also known as alleles) by also at the same time cutting an undesired genetic variant (e.g., insecticide resistant) and replacing it with the preferred variant (e.g., insecticide susceptible).

In the new study, the researchers employed this “allelic drive” strategy to restore genetic susceptibility to insecticides, similar to insects in the wild prior to their having developed resistance. They focused on an insect protein known as the voltage-gated sodium channel (VGSC) which is a target for a widely used class of insecticides. Resistance to these insecticides, often called the knockdown resistance, or “kdr,” results from mutations in the vgsc gene that no longer permit the insecticide to bind to its VGSC protein target. The authors replaced a resistant kdr mutation with its normal natural counterpart that is susceptible to insecticides.

Starting with a population consisting of 83% kdr (resistant) alleles and 17% normal alleles (insecticide susceptible), the allelic drive system inverted that proportion to 13% resistant and 87% wild-type in 10 generations. Bier also notes that adaptions conferring insecticide resistance come with an evolutionary cost, making those insects less fit in a Darwinian sense. Thus pairing the gene drive with the selective advantage of the more fit wild-type genetic variant results in a highly efficient and cooperative system, he says.

Similar allelic drive systems could be developed in other insects, including mosquitoes. This proof-of-principle adds a new method to pest- and vector-control toolboxes since it could be used in combination with other strategies to improve insecticide-based or parasite-reducing measures to drive down the spread of malaria.

“Through these allelic replacement strategies, it should be possible to achieve the same degree of pest control with far less application of insecticides,” said Bier. “It also should be possible to design self-eliminating versions of allelic drives that are programmed to act only transiently in a population to increase the relative frequency of a desired allele and then disappear. Such locally acting allelic drives could be reapplied as necessary to increase the abundance of a naturally occurring preferred trait with the ultimate endpoint being no GMO left in the environment.”

“An exciting possibility is to use allelic drives to introduce novel versions of the VGSC that are even more sensitive to insecticides than wild-type VGSCs,” suggested Craig Montell (UC Santa Barbara), a co-author on this study. “This could potentially allow even lower levels of insecticides to be introduced into the environment to control pests and disease vectors.”

The study’s authors are: Bhagyashree Kaduskar (UC San Diego and Tata Institute for Genetics and Society), Raja Babu Singh Kushwah (UC San Diego and Tata Institute for Genetics and Society), Ankush Auradkar (UC San Diego), Annabel Guichard (UC San Diego and Tata Institute for Genetics and Society), Menglin Li (UC Santa Barbara), Jared Bennett (UC Berkeley), Alison Henrique Ferreira Julio, John Marshall (UC Berkeley), Craig Montell (UC Santa Barbara) and Ethan Bier (UC San Diego and Tata Institute for Genetics and Society).

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JOURNAL

Nature Communications

DOI

10.1038/s41467-021-27654-1 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Reversing insecticide resistance with allelic-drive in Drosophila melanogaster

ARTICLE PUBLICATION DATE

12-Jan-2022

COI STATEMENT

Bier has equity interest in two companies he co-founded: Synbal Inc. and Agragene, Inc., which may potentially benefit from the research results. He also serves on Synbal’s board of directors and the scientific advisory board for both companies.

Disclaimer: AAAS and EurekAlert! are not responsible for the

National Award Honors research leading to habitat restoration for people, birds

Collaborations in Baltimore and Missouri exemplify forest service research mission

Grant and Award Announcement

USDA FOREST SERVICE - NORTHERN RESEARCH STATION

 

IMAGE: RESEARCH ECOLOGISTS NANCY SONTI AND RICH HALLETT WALK THROUGH THE FOREST AT STILLMEADOW PEACEPARK. view more 

CREDIT: PHOTO BY: BILL SHEWBRIDGE, UMBC NEW MEDIA STUDIO.

In Missouri, USDA Forest Service science was instrumental in habitat restoration, culminating in the reintroduction of a songbird that had disappeared from the state a century ago. In Baltimore, research is helping parishioners and community volunteers restore a forest that is important to public and ecological health, community bonds, and climate resilience in an under-served neighborhood. Both projects were among a handful of recipients of the Forest Service’s 2021 National “Chief’s Awards.” 

“These awards reflect the difference the Northern Research Station is making in our forests and communities through our unique science role in the most forested and the most populated region of the nation,” said Cynthia West, Director of the Northern Research Station and the Forest Products Laboratory. “These two projects exemplify what we try to achieve -- improve the sustainability of forests and the species that depend on them, and improve the lives of people who live in urban areas through nature.”

The Forest Service’s 2021 Chief’s Awards were announced on January, 13 and included 19 projects that advance the agency’s four goals: Sustain our Nation’s Forests and Grasslands, Deliver Benefits to the Public, Apply Knowledge Globally, and Excel as a High Performing Agency. Northern Research Station scientists are part of two of the project honored this year.

Situated in the heart of the Beechfield and Irvington neighborhoods in southwest Baltimore City, Maryland, Stillmeadow Community Fellowship Church owns a parcel of forest land with a stream, known as the Stillmeadow Community PeacePark & Forest. The forest has lost ash trees to the invasive emerald ash borer and has been further degraded by invasive vegetation. Multiple branches of the Forest Service, including scientists at the Northern Research Station’s Urban Field Stations, collaborated to assist the community in restoring the forest as a green space.

“People and nature are inextricably linked,” said Morgan Grove, who leads the team of scientists working with Stillmeadow Community Church. “What we learn in the restoration of Stillmeadow PeacePark and Forest will help us devise strategies that can be used nationwide to develop partnerships like this one, leading to healthier communities and natural areas.”

CAPTION

Two brown-headed nuthatches perch in a shortleaf pine tree.

CREDIT

Photo courtesy of Noppadol Paohtong/Missouri Department of Conservation.

In Missouri, a collaboration among the Northern Research Station and the Eastern and  Southern Regions of the USDA Forest Service, along with other partners, was  recognized for decades of work that culminated in the restoration of critical habitat and the reintroduction of a native bird that had been extinct in the state for a century. Scientists based in the Northern Research Station’s Columbia, Mo., research unit collaborated with the Ouachita National Forest in Arkansas and the Mark Twain National Forest and other partners to restore shortleaf pine-oak woodlands, the primary habitat of the Brown-headed Nuthatch. Restoration of woodlands was a major goal of the Mark Twain National Forest Plan, and progress in the restoration was advanced by the Missouri Pine-Oak Woodlands Restoration Project, part of the national Collaborative Forest Landscape Restoration Program developed by the Forest Service.

The reintroduction of Brown-headed Nuthatch began in 2020 when a team that included the Missouri Department of Conservation and the University of Missouri translocated birds from the Ouachita National Forest in Arkansas to the Mark Twain National Forest. The team moved 46 nuthatches to the Mark Twain National Forest in the summer of 2020 and documented their survival and nesting the following spring. In August 2021, they successfully translocated an additional 56 birds and will monitor them under a proposed extension of the Missouri Pine-Oak Woodlands Restoration Project.

“This project demonstrates the value of collaboration and the value of working incrementally to achieve restoration goals,” said Frank Thompson, a research wildlife biologist based in the Northern Research Station’s lab in Columbia, Mo. “I am very proud of the outcome, and I am even more proud of the science and management collaboration behind habitat restoration and the Brown-headed Nuthatch reintroduction.”

A complete list of Chief’s Award projects and recording of the presentation will be released in the coming days.

Powerful volcanic blast not the cause for 2018 Indonesian island collapse – new research

Peer-Reviewed Publication

UNIVERSITY OF BIRMINGHAM

The dramatic collapse of Indonesia’s Anak Krakatau volcano in December 2018 resulted from long-term destabilising processes, and was not triggered by any distinct changes in the magmatic system that could have been detected by current monitoring techniques, new research has found.

The volcano had been erupting for around six months prior to the collapse, which saw more than two-thirds of its height slide into the sea as the island halved in area. The event triggered a devastating tsunami, which inundated the coastlines of Java and Sumatra and led to the deaths of more than 400 people.

A team led by the University of Birmingham examined volcanic material from nearby islands for clues to determine whether the powerful, explosive eruption observed after the collapse had itself triggered the landslide and tsunami. Their results are published in Earth and Planetary Science Letters.

Working with researchers at the Bandung Institute of Technology, the University of Oxford and the British Geological Survey, the team looked at the physical, chemical and microtextural characteristics of the erupted material. They concluded that the large explosive eruption associated with the collapse was probably caused by the underlying magmatic system becoming destabilised as the landslide got underway.

This means the disaster was less likely to have been caused by magma forcing its way to the surface and triggering the landslide. Current volcano monitoring methods record seismic activity and other signals caused by magma rising through the volcano, but since this event was not triggered from within, it would not have been detected using these techniques.

Dr Sebastian Watt, in the University of Birmingham’s School of Geography, Earth and Environmental Sciences, is senior author on the paper. He said: 'This type of volcanic hazard is rare, extremely hard to predict and often devastating. Our findings show that, although there was a dramatic, explosive eruption after the collapse of Anak Krakatau, this was triggered by the landslide releasing pressure on the magma system – like a champagne cork popping.'

The results present a challenge for predicting future hazards at volcanic islands. Dr Mirzam Abdurrachman, from the Bandung Institute of Technology, explains: 'If large volcanic landslides occur as a result of long-term instability, and can take place without any distinctive change in the magmatic activity at the volcano, this means they can happen suddenly and without any clear warning.

'This finding is important for people who live in regions surrounded by active volcanoes and volcanic islands in places such as Indonesia, Philippines and Japan.'

Lead author, Kyra Cutler, at the University of Oxford said: 'Evaluating longer-term growth and deformation patterns of volcanoes will help to provide a better understanding of the likelihood of failure – this is will be particularly relevant for Anak Krakatau as it rebuilds. Identifying susceptible areas, along with efforts to develop non-seismic tsunami detection, will improve overall hazard management strategies for communities who are at risk.'

Professor David Tappin, (British Geological Survey, University College, London) led the marine surveys that  mapped the deposits resulting from the 2018 Anak Krakatau eruption collapse (Hunt et al. 2021). He said: ‘It is rare that we have the opportunity to study such an eruption and tsunami, with the last event, Ritter island, over 100 years ago. The results in the paper reveal that the driving mechanism was from long term destabilisation, rather than an instantaneous explosive event. This is a major surprise discovery and will lead to a re-evaluation of how to mitigate the hazard from volcanic failures and their associated tsunamis.’

ENDS

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JOURNAL

Earth and Planetary Science Letters

DOI

10.1016/j.epsl.2021.117332 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Downward-propagating eruption following vent unloading implies no direct magmatic trigger for the 2018 lateral collapse of Anak Krakatau

ARTICLE PUBLICATION DATE

15-Jan-2022

Researchers use AI to analyze tweets debating vaccination and climate change

Peer-Reviewed Publication

UNIVERSITY OF WATERLOO

Using artificial intelligence (AI) researchers have found that between 2007 and 2016 online sentiments around climate change were uniform, but this was not the case with vaccination. 

Climate change and vaccinations might share many of the same social and environmental elements, but that doesn’t mean the debates are divided along the same demographics.

A research team from the University of Waterloo and the University of Guelph trained a machine-learning algorithm to analyze a massive number of tweets about climate change and vaccination.

The researchers found that climate change sentiment was overwhelmingly on the pro side of those that believe climate change is because of human activity and requires action. There was also a significant amount of interaction between users with opposite sentiments about climate change.

However, in the snapshot of the timeframe of the dataset, vaccine sentiment was nowhere near so uniform. In fact, only some 15 or 20 per cent of users expressed a clearly pro-vaccine sentiment, while around 70 per cent expressed no strong sentiment. Perhaps more importantly, individuals and entire online communities with differing sentiments toward vaccination interacted much less than the climate change debate.

“It is an open question whether these differences in user sentiment and social media echo chambers concerning vaccines created the conditions for highly polarized vaccine sentiment when the COVID-19 vaccines began to roll out,” said Chris Bauch, professor of applied mathematics at the University of Waterloo. “If we were to do the same study today with data from the past two years, the results might be wildly different. Vaccination is a much hotter topic right now and appears to be much more polarized given the ongoing pandemic.”

The research goal was to learn how sentiments on climate change and vaccination may be related, how users form networks and share information, the relationship between online sentiments, and how people act and make decisions in daily life.

“There’s been some work done on the polarization of opinions in Twitter and other social media,” said Madhur Anand, professor of environmental sciences at the University of Guelph. “Most other research looks at these as isolated issues, but we wanted to look at these two issues of climate change and vaccination side-by-side. Both issues have social and environmental components, and there are lots to learn in this research pairing.”

The dataset for the project was drawn from a few sources, including some that were purchased from Twitter. In total, the analysis takes into consideration roughly 87 million tweets. The time range for the tweets is between 2007 and 2016.

This means that the data precedes COVID-19 and offers a snapshot of vaccine sentiment in the years leading up to the pandemic.

The AI ranked the millions of tweets as either pro, anti or neutral sentiment on the issues and then classified users in pro, anti or neutral categories. It also analyzed the structure of online communities and the degree to which users with opposing sentiments interacted.

“We expected to find that user sentiment and how users formed networks and communities to be more or less the same for both issues,” said Bauch. “But actually, we found that the way climate change discourse and vaccine discourse worked on Twitter were quite different.”

Anand, Bauch and team members Justin Schonfeld, Edward Qian, Jason Sinn, and Jeffrey Cheng published their findings, “Debates about vaccines and climate change on social media networks: a study in contrasts,” in the journal Humanities and Social Sciences Communications.

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JOURNAL

Humanities and Social Sciences Communications

In the Atlantic Forest, the lowland tapir is at risk of extinction

Peer-Reviewed Publication

PENSOFT PUBLISHERS

 

IMAGE: LOWLAND TAPIR view more 

CREDIT: PATRICIA MEDICI

Lowland tapir populations in the Atlantic Forest in South America are at risk of almost complete disappearance, scientists have estimated. Weighing up to 250 kg, the animal can adapt to most habitats in South America—but its populations continue to decline across its range.

Today, its survival is seriously threatened: it can be found in just 1.78% of its original distributional range in the Atlantic Forest biome, which covers parts of Brazil, Argentina and Paraguay. The main long-term threat to its well-being is population isolation, as hunting and highways keep populations away from each other.

Urgent measures need to be taken to connect isolated populations and ensure the long-term conservation of tapirs, warn the authors of a new study on the distribution and conservation status of lowland tapirs in the South American Atlantic Forest, published in the open-access journal Neotropical Biology and Conservation. 

The research was done by Kevin Flesher, PhD, researcher at the Biodiversity Study Center, Michelin Ecological Reserve, Bahia, and Patrícia Medici, PhD, coordinator of the Lowland Tapir Conservation Initiative, a project developed by the Institute for Ecological Research in Brazil, and chair of the Tapir Specialist Group at the Species Survival Commission in the International Union for Conservation of Nature.

 "Of the 48 tapir populations identified during the study, between 31.3% and 68.8% are demographically unviable (low number of individuals), and between 70.8% and 93.8% of the populations are genetically unviable (low gene flow). Only 3-14 populations are still viable in the long run when both criteria are considered. The evidence suggests that with the appropriate conservation actions, the lowland tapir could be broadly distributed throughout the Atlantic Forest," says Kevin Flesher. 

CAPTION

Lowland tapir

CREDIT

Patricia Medici

"Tapirs have low reproductive potential, including a long reproductive cycle with the birth of just one young after a gestation period of 13-14 months and intervals of up to three years between births. Our populational simulations clearly show how, in the case of small populations, even the loss of a single individual per year can result in rapid extinction of an entire local population," adds Medici. 

Kevin Flesher dedicated 15 years to visiting 93 reserves in the Atlantic Forest, talking to people and analyzing 217 datasets, before he compiled the necessary data to design conservation actions that can ensure the survival of tapirs in the area. 

The states of São Paulo and Paraná in Brazil have the largest number of remaining populations: 14 and 10, respectively. The two largest populations are in Misiones, Argentina, and in the neighboring Iguaçu and Turvo reserves, in Paraná and Rio Grande do Sul, Brazil.

CAPTION

Lowland tapir

CREDIT

Alexander Blanco

CAPTION

Primary forests, a habitat for the lowland tapir

CREDIT

Kevin Flesher

"As far as our knowledge goes, there is no evidence of movement of tapirs between these populations," points out Medici.

The distance between population fragments, however, is not what is stopping them.

"The central problem is the multiple threats they face while crossing the habitat," explains Flesher. Highways are one major obstacle that limits the access of tapirs to forests with adequate habitat. "For example, the heavy traffic on highway BR-101 (which cuts the Brazilian Atlantic Forest from North to South) is a death trap to wildlife. Tapirs often die when attempting to cross it," explains Medici. 

The construction of highways and expansion of traffic in and around natural areas is a serious threat to large tapir populations that might otherwise have the chance to thrive, like those in Misiones, Argentina, and Serra do Mar, Brazil. 

CAPTION

Lowland tapir

CREDIT

Bill Konstant

"Roadkill is a significant cause of death in six of the eight reservations in which highways cross tapir populations, and the expansion of the roadway grid in the country threatens to cause population fragmentation in at least four populations,” points out Flesher. This is why finding ways to allow tapirs to cross highways safely is an urgent conservation priority.

The results of the study, however, give cause for “cautious optimism” for the future of tapirs in the area: after decades of dedicated conservation efforts, the situation is starting to improve. 

"Despite these continuing challenges for tapir conservation, most populations appear to be stable or increasing and the conservation outlook for the species is better than several decades ago, when the first efforts to protect the species began," Kevin Flesher concludes.

  

CAPTION

Tapirs adapt well to the secondary forest habitats that dominate the Atlantic Forest biome

CREDIT

Kevin Flesher

Original source:

Flesher KM, Medici EP (2022) The distribution and conservation status of Tapirus terrestris in the South American Atlantic Forest. Neotropical Biology and Conservation 17(1): 1-19. https://doi.org/10.3897/neotropical.17.e71867

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JOURNAL

Neotropical Biology and Conservation

DOI

10.3897/neotropical.17.e71867 

ARTICLE TITLE

The distribution and conservation status of Tapirus terrestris in the South American Atlantic Forest

CAPTION

Atlantic Forest reserves have hard edges with largely deforested agricultural lands. Tapirs readily use these habitats if not hunted.

CREDIT

Kevin Flesher

SwRI collaborates to create sCO2 turbomachinery for concentrated solar power plant

DOE’s APOLLO program helped support project

Business Announcement

SOUTHWEST RESEARCH INSTITUTE

SAN ANTONIO — Jan. 17, 2022 — Southwest Research Institute worked with government and commercial collaborators to successfully develop and demonstrate full-scale turbomachinery for one of the world’s first supercritical carbon dioxide (sCO2) power systems for a concentrated solar power (CSP) plant. The technology combines sCO2 power cycles with integrated thermal energy storage.

The project was supported by the U.S. Department of Energy’s APOLLO program, which was created to improve performance and reduced the cost of electricity from CSP plants.  The 10MW sCO2 turbomachinery has successfully completed performance and endurance tests in a closed-loop environment.

sCO2 is carbon dioxide held above a critical temperature and pressure, which causes it to act like a gas while having the density of a liquid. It’s also nontoxic and nonflammable, having been used in dry cleaning processes, low-GHG refrigeration systems, as well as to decaffeinate coffee.

The fluid properties in its supercritical state makes sCO2 a highly efficient fluid to generate power due to high density, low viscosity and favorable heat transfer properties.

“Advancing grid-scale energy storage is an important step to enabling full penetration of renewables into power generation. Utilizing sCO2 as a working fluid can increase the efficiency of a CSP plant by as much as 10 percentage points,” said Dr. Jason Wilkes, manager of SwRI’s Rotating Machine Dynamics Section. “The high efficiency of the sCO2 cycle also allows the turbomachinery to have a smaller footprint — it is 1/20th the size of a standard steam turbine, allowing for improved installation in most environments.”

CSP technology uses mirrors or lenses to concentrate a large amount of sunlight onto a receiver, which typically converts concentrated light into heat and extracts thermal energy to generate power using steam turbines. The system stores the energy as heat, which can then be converted to on-demand energy using sCO2 power cycles, improving efficiency and reducing operating costs.

“sCO2 power cycle technology is a fraction of the size of conventional turbomachinery, offering improved performance for numerous applications. The successful MW-scale demonstration of sCO2 technology at full-cycle conditions is an exciting milestone,” said Dr. Tim Allison, director of SwRI’s Machinery Department.

SwRI and Hanwha Power Systems, a global energy equipment company with headquarters in South Korea, developed and demonstrated the new integrally geared sCO2 turbomachinery tested at full-scale compressor conditions and full-pressure full-temperature testing of the turbine at unprecedented MW-scale conditions of up to 720 °C and 275 bar. The system is planned to be integrated into a CSP pilot plant at a future date.

This material is based upon work supported by the Department of Energy, Office of Energy Efficiency and Renewable Energy (EERE), under Award Number DE-0007114.

For more information, visit Supercritical Carbon Dioxide Power Systems.

 

Enhanced statistical models will aid conservation of killer whales and other species

Understanding wild animal behaviors is important when building species conservation plans, however following animals can be expensive, dangerous, or sometimes impossible in the case of animals that move underwater or into areas we can’t easily reach

Peer-Reviewed Publication

UNIVERSITY OF BRITISH COLUMBIA

 

IMAGE: DIVE DEPTH (TOP PANEL) AND THREE-DIMENSIONAL ACCELERATION (BOTTOM THREE PANELS) FROM A KILLER WHALE OVER APPROXIMATELY 5 H. AN EXACT PHYSICAL INTERPRETATION OF EACH COMPONENT OF ACCELERATION IS DIFFICULT DUE TO VARIATIONS IN TAG ORIENTATION. THERE ARE DATA GAPS OCCURRING FROM AROUND HOURS 1.5 TO 1.8 AND FROM AROUND HOURS 3.2 TO 4.5. BOTH DATA GAPS ARE EXCLUDED FROM ANALYSES. view more 

CREDIT: EVAN SIDROW

Ecologists need to understand wild animal behaviours in order to conserve species, but following animals around can be expensive, dangerous, or sometimes impossible in the case of animals that move underwater or into areas we can’t reach easily.

Scientists turned to the next best thing: bio-logging devices that can be attached to animals and capture information about movement, breathing rate, heart rate, and more.

However, retrieving an accurate picture of what a tagged animal does as it journeys through its environment requires statistical analysis, especially when it comes to animal movement, and the methods statisticians use are always evolving to make full use of the large and complex data sets that are available.

A recent study by researchers at the Institute for the Oceans and Fisheries (IOF) and the UBC department of statistics has taken us a step closer to understanding the behaviours of northern resident killer whales by improving statistical tools useful for identifying animal behaviours that can’t be observed directly.

“The thing we really tackled with this paper was trying to get at some of those fine-scale behaviours that aren’t that easy to model,” said Evan Sidrow, a doctoral student in the department of statistics and the study’s lead author. “It’s a matter of finding behaviours on the order of seconds—maybe 10 to 15 seconds. Usually, it’s a matter of a whale looking around, and then actively swimming for a second to get over to a new location. We are trying to observe fleeting behaviours, like a whale catching a fish.”

The research team improved a statistical tool that is based on what is called a hidden Markov model, which is helpful for unlocking the mysteries hidden inside animal movement datasets.

“Traditional hidden Markov models break down at very fine scales,” Sidrow said. “That’s because there’s structure in the data you can’t capture using the basic type of hidden Markov model. We’re trying to capture it with this model—we’re trying to account for this ‘wigglyness' that a traditional hidden Markov model wouldn’t be able to account for.”

In other words, now that tags can collect data almost continuously, researchers are left with an immense number of data points taken fractions of seconds apart, and traditional Markov models and statistical methods struggle to interpret such high-frequency information—hence the need for the more advanced Markov model proposed in the study.

Using the enhanced hidden Markov models, the team found some undiscovered northern resident killer whale behaviours. The whale they used to develop the model preferred to save energy by gliding through the water when making deep dives, and when it was closer to the surface, it moved more actively, accelerating faster and ‘fluking’ its tail more often.

Understanding these diving patterns will be crucial for whale conservation because it will help researchers learn how much energy the whales require to sustain themselves.

And the method’s applications extend far beyond whale movement data, according to Sidrow.

“It could be applied to pretty much any animal movement data,” he said. "If you’re tagging animals and you want to understand fine-scale behaviours, then this method that could be useful—even for things like the flapping of birds’ wings.”

It could even prove useful in areas outside of ecology, such as determining when machines are likely to break by classifying when the parts inside of them are vibrating abnormally.

The work is one of the first steps on the road to fully understanding why southern resident killer whales are not faring as well as their northern counterparts, according to Dr. Marie Auger-Méthé, senior author of the study and an assistant professor in the department of statistics and the Institute for the Oceans and Fisheries.

“Using our methods to detect when the animals are catching prey and to model their energy expenditure will be key to understanding the differences between these neighbouring whale populations,” she said.

The next goal is to understand when the whales are capturing prey and applying the models to both northern and southern resident killer whale populations to see how they are behaving differently.

“The paper offers many ‘building block’ solutions that can be used together or independently,” Dr. Auger-Méthé said. “In essence, we are providing a toolbox to researchers using high-frequency movement data, and other similar high-frequency time series.”

"Modelling multi-scale, state-switching functional data with hidden Markov models" was published in The Canadian Journal of Statistics.

 

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JOURNAL

Canadian Journal of Statistics

DOI

10.1002/cjs.11673 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Modelling multi-scale, state-switching functional data with hidden Markov models