Intriguing correlation between earthquakes and cosmic radiation

Peer-Reviewed Publication

THE HENRYK NIEWODNICZANSKI INSTITUTE OF NUCLEAR PHYSICS POLISH ACADEMY OF SCIENCES

 

IMAGE: IN SPACE YOU CAN SEE IMPENDING EARTHQUAKES. NOT SO LITERALLY, AS IN THE ABOVE COLLAGE OF PHOTOS, BUT STILL CLEARLY – IN THE CHANGES IN THE INTENSITY OF COSMIC RAYS RECORDED BY OBSERVATORIES ON THE SURFACE OF OUR PLANET. view more 

CREDIT: SOURCE: IFJ PAN/NASA/JSC

 

There is a clear statistical correlation between global seismic activity and changes in the intensity of cosmic radiation recorded at the surface of our planet, potentially helping to predict earthquakes. Surprisingly, it exhibits a periodicity that escapes unambiguous physical interpretation.

Strong earthquakes usually result in many human casualties and huge material losses. The scale of the tragedy could be significantly reduced if we had the ability to predict the time and place of such cataclysmic events. The CREDO project, initiated in 2016 by the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) in Cracow, attempts to verify the previously known hypothesis that earthquakes could potentially be predicted by observing changes in... cosmic radiation. Statistical analyses have shown that a correlation between the two phenomena does indeed exist, but manifests characteristics that no one had expected.

The international CREDO (Cosmic Ray Extremely Distributed Observatory) project is a virtual cosmic ray observatory, open to all, that collects and processes data not only from sophisticated scientific detectors, but also from a large number of smaller detectors, among which the CMOS sensors in smartphones are leading the way (to turn a smartphone into a cosmic ray detector, simply install the free CREDO Detector app). One of CREDO's main tasks is to monitor global changes in the flux of secondary cosmic radiation reaching the surface of our planet. This radiation is produced in the Earth's stratosphere most intensely within the so-called Regener-Pfotzer maximum, where particles of primary cosmic radiation collide with the gas molecules of our atmosphere and initiate cascades of secondary particles.

“At first glance, the idea that there is a link between earthquakes and cosmic radiation, in its primary form reaching us mainly from the Sun and deep space, may seem strange. However, its physical foundations are fully rational”, emphasises Dr. Piotr Homola (IFJ PAN and AstroCeNT CAMK PAN), coordinator of CREDO and first author of the article describing the discovery in the Journal of Atmospheric and Solar-Terrestrial Physics.

The main idea here is the observation that eddy currents in the liquid core of our planet are responsible for generating the Earth's magnetic field. This field deflects the paths of charged particles of primary cosmic radiation. Thus, if large earthquakes were associated with disturbances in the flows of matter that drive the Earth's dynamo, these disturbances would alter the magnetic field, which in turn would affect the tracks of the particles of primary cosmic radiation in a manner that depends on the dynamics of the disturbances inside our planet. As a result, ground-based detectors should see some changes in the numbers of secondary cosmic ray particles detected.

CREDO physicists analysed cosmic ray intensity data from two stations of the Neutron Monitor Database project (collected over the last half-century) and the Pierre Auger Observatory (collected since 2005). The choice of observatories was determined by the fact that they are located on both sides of the equator and use different detection techniques. The analyses included changes in solar activity, as described in the database maintained by the Solar Influences Data Analysis Centre. Key information on Earth's seismic activity was in turn sourced from the U.S. Geological Survey programme.

The analyses were carried out using several statistical techniques. In each case, for the period studied, a clear correlation emerged between changes in the intensity of secondary cosmic radiation and the summed magnitude of all earthquakes with magnitudes greater-than or equal to 4. Importantly, this correlation only becomes apparent when the cosmic ray data are shifted 15 days forward relative to the seismic data. This is good news, as it suggests the possibility of detecting upcoming earthquakes well in advance.

Unfortunately, it is not clear from the analyses whether it will be possible to pinpoint locations of  cataclysms. Correlations between changes in cosmic ray intensity and earthquakes are not apparent in location-specific analyses. They only appear when seismic activity is taken into account on a global scale. This fact may mean that in changes in cosmic ray intensity one can see a phenomenon to which our planet is subjected as a whole.

“In the scientific world, it is accepted that a discovery can be said to have been made when the statistical confidence level of the corroborating data reaches five sigma, or standard deviations. For the observed correlation, we obtained more than six sigma, which means a chance of less than one in a billion that the correlation is due to chance. We therefore have a very good statistical basis for claiming that we have discovered a truly existing phenomenon. The only question is, is it really the one we were expecting?” wonders Dr. Homola.

Indeed, it turns out that the global nature of the observed phenomenon and the 15-day advance in seismic activity evident in cosmic radiation are not the only intriguing puzzles associated with the discovery. A major surprise is the large-scale periodicity of the correlation – a phenomenon that no one had expected. Analyses show that the correlation maximum occurs every 10-11 years, a period similar to the solar activity cycle. However, it does not coincide at all with the maximum activity of our star!

Furthermore, there are other common periodicities of unknown nature in both cosmic ray and seismic data. Examples include periodic changes in seismic activity and the intensity of secondary cosmic radiation over a cycle corresponding to the Earth's stellar day (equal to 24 hours minus ~236 seconds). Could it be, then, that cosmic-seismic correlations are caused by some factor reaching us from outside the Solar System, capable of simultaneously producing radiation and seismic effects? Only what conventional physical phenomenon could even qualitatively explain the apparent correlations?

The lack of classical explanations for the observed periodicities provokes consideration of the possible role of other, less conventional phenomena. One of these could be the passage of the Earth through a dark matter stream modulated by the Sun and other massive bodies in our planetary system. The Earth, with its large magnetic field, is an extremely sensitive particle detector, many times larger than human-built detectors. It is therefore reasonable to allow for the possibility that it may respond to phenomena that are invisible to existing measuring devices.

“Regardless of the source of the observed periodicities, the most important thing at this stage of the research is that we have demonstrated a link between the cosmic radiation recorded at the surface of our planet and its seismicity – and if there is anything we can be sure of, it is that our observation points to entirely new and exciting research opportunities,” concludes Dr. Homola.

The Henryk Niewodniczański Institute of Nuclear Physics (IFJ PAN) is currently one of the largest research institutes of the Polish Academy of Sciences. A wide range of research carried out at IFJ PAN covers basic and applied studies, from particle physics and astrophysics, through hadron physics, high-, medium-, and low-energy nuclear physics, condensed matter physics (including materials engineering), to various applications of nuclear physics in interdisciplinary research, covering medical physics, dosimetry, radiation and environmental biology, environmental protection, and other related disciplines. The average yearly publication output of IFJ PAN includes over 600 scientific papers in high-impact international journals. Each year the Institute hosts about 20 international and national scientific conferences. One of the most important facilities of the Institute is the Cyclotron Centre Bronowice (CCB), which is an infrastructure unique in Central Europe, serving as a clinical and research centre in the field of medical and nuclear physics. In addition, IFJ PAN runs four accredited research and measurement laboratories. IFJ PAN is a member of the Marian Smoluchowski Kraków Research Consortium: "Matter-Energy-Future", which in the years 2012-2017 enjoyed the status of the Leading National Research Centre (KNOW) in physics. In 2017, the European Commission granted the Institute the HR Excellence in Research award. As a result of the categorization of the Ministry of Education and Science, the Institute has been classified into the A+ category (the highest scientific category in Poland) in the field of physical sciences.

 

 

CONTACTS:

 

Dr. Piotr Homola

Institute of Nuclear Physics, Polish Academy of Sciences

tel.: +48 12 6628341

email: piotr.homola@ifj.edu.pl

 

 

SCIENTIFIC PUBLICATIONS:

 

“Observation of large scale precursor correlations between cosmic rays and earthquakes with a periodicity similar to the solar cycle”

P. Homola, V. Marchenko, A. Napolitano, R. Damian, R. Guzik, D. Alvarez-Castillo, S. Stuglik, O. Ruimi, O. Skorenok, J. Zamora-Saa, J.M. Vaquero, T. Wibig, M. Knap, K. Dziadkowiec, M. Karpiel, O. Sushchov, J.W. Mietelski, K. Gorzkiewicz, N. Zabari, K. Almeida Cheminant, B. Idźkowski, T. Bulik, G. Bhatta, N. Budnev, R. Kamiński, M.V. Medvedev, K. Kozak, O. Bar, Ł. Bibrzycki, M. Bielewicz, M. Frontczak, P. Kovacs, B. Łozowski, J. Miszczyk, M. Niedźwiecki, L. del Peral, M. Piekarczyk, M. D. Rodriguez Frias, K. Rzecki, K. Smelcerz, T. Sośnicki, J. Stasielak, A. A. Tursunov

Journal of Atmospheric and Solar-Terrestrial Physics 2023, 247, 106068

DOI: https://doi.org/10.1016/j.jastp.2023.106068

 

 

LINKS:

 

http://www.ifj.edu.pl/

The website of the Institute of Nuclear Physics, Polish Academy of Sciences.

 

http://press.ifj.edu.pl/

Press releases of the Institute of Nuclear Physics, Polish Academy of Sciences.

 

IMAGES:

IFJ230614b_fot01s.jpg                                 

HR: http://press.ifj.edu.pl/news/2023/06/14/IFJ230614b_fot01.jpg

In space you can see impending earthquakes. Not so literally, as in the above collage of photos, but still clearly – in the changes in the intensity of cosmic rays recorded by observatories on the surface of our planet. (Source: IFJ PAN/NASA/JSC)

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JOURNAL

Journal of Atmospheric and Solar-Terrestrial Physics

DOI

10.1016/j.jastp.2023.106068 

ARTICLE TITLE

Observation of large scale precursor correlations between cosmic rays and earthquakes with a periodicity similar to the solar cycle

 SPACE

Scientists report ‘benchmarks’ for extreme space weather

Peer-Reviewed Publication

BRITISH ANTARCTIC SURVEY

High-energy ‘relativistic’ electrons - so-called “killer” electrons - are a major source of radiation damage to satellites and so understanding their patterns of activity is crucial. Bursts of charged particles and magnetic fields from the Sun can tear open the Earth’s magnetic field, giving rise to geomagnetic storms. During these events the number of killer electrons in the outer radiation belt can increase by orders of magnitude and become a significant space weather hazard.

Dr Nigel Meredith of BAS led an international team who analysed 20 years of data from a US GPS satellite to determine the 1 in 10, 1 in 50, and 1 in 100-year event levels. A 1 in 100-year event is an event of a size that will be equalled or exceeded on average once every 100 years.

Satellite operators, manufacturers, insurers, and governments need to prepare and mitigate against the risks posed by these electrons. Society is increasingly reliant on satellites for a variety of applications including communication, navigation, Earth observation and defence. As of April 2022, there were 5,465 operational satellites in Earth orbit, and most are exposed to energetic electrons for at least some of their orbit. In 2021, the overall global space economy generated revenues of $386 billion, an increase of four percent compared to the previous year.

Dr Nigel Meredith, space weather scientist and lead author of the study says:

“The 1 in 100 year event levels reported in this study are important for industry and government. They serve as benchmarks against which to compare other extreme space weather events and to assess the potential impact of an extreme event.”

These findings are vitally important to the satellite industry as engineers and operators require realistic estimates of the largest electron fluxes encountered in GPS orbit to prepare for the impacts of these extreme events and to improve the resilience of future satellites. The findings are essential for satellite insurers to help them ensure satellite operators are doing all they can to reduce risk and to evaluate realistic disaster scenarios

The difference between the 1 in 10 year and 1 in 100-year event varies depending on the energy of the electrons and the distance from Earth. These differences are largest at the highest energies furthest from the planet, varying between a factor of 3 and 10 for some of the highest electron energies over 35,000 km from the Earth’s surface. Such substantial increases could pose a significant additional risk to satellites operating in this region.

Like weather on our planet, space weather can vary greatly over minutes, days, seasons and the 11-year solar cycle. The researchers found that the majority of these killer electron events occurred during the solar cycle’s declining phases — seen twice during the 20-year period they studied — but the largest event was elsewhere, showing that extreme events can happen at any time.

Professor Richard Horne, FRS, from BAS and a co-author on the study, says:

"The space sector is part of our Critical National Infrastructure. This research will help us assess the resilience of satellites to a severe space weather event."

Severe space weather was added to the UK National Risk Register of Civil Emergencies in 2011. The impacts of space weather on satellites can range from momentary interruptions of service to total loss of capabilities. In 2003 a major storm caused 47 satellites to experience anomalies, over 10 to be out of action for more than a day and one was a complete loss.

Extreme Relativistic Electron Fluxes in GPS Orbit: Analysis of NS41 BDD-IIR Data by Nigel P. Meredith, Thomas E. Cayton, Michael D. Cayton, Richard B. Horne is published in the journal Space Weather

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JOURNAL

Space Weather

DOI

10.1029/2023SW003436 

ARTICLE TITLE

Extreme Relativistic Electron Fluxes in GPS Orbit: Analysis of NS41 BDD-IIR Data

Researchers demystify the unusual origin of the Geminids meteor shower

Princeton researchers used data from NASA's Parker Solar Probe to deduce that a catastrophic event likely created the prolific Geminids meteoroid stream.

Peer-Reviewed Publication

PRINCETON UNIVERSITY

 

VIDEO: PRINCETON RESEARCHERS USED OBSERVATIONS FROM NASA’S PARKER SOLAR PROBE MISSION TO DEDUCE THAT IT WAS LIKELY A VIOLENT, CATASTROPHIC EVENT – SUCH AS A HIGH-SPEED COLLISION WITH ANOTHER BODY OR A GASEOUS EXPLOSION – THAT CREATED THE GEMINIDS METEOROID STREAM. view more 

CREDIT: NASA/JOHNS HOPKINS APL/BEN SMITH

The Geminids meteoroids light up the sky as they race past Earth each winter, producing one of the most intense meteor showers in our night sky.

Mysteries surrounding the origin of this meteoroid stream have long fascinated scientists because, while most meteor showers are created when a comet emits a tail of ice and dust, the Geminids stem from an asteroid — a chunk of rock that normally does not produce a tail. Until recently, the Geminids had only been studied from Earth. 

Now, Princeton researchers used observations from NASA’s Parker Solar Probe mission to deduce that it was likely a violent, catastrophic event — such as a high-speed collision with another body or a gaseous explosion — that created the Geminids. The findings, which were published in the Planetary Science Journal on June 15, narrow down hypotheses about this asteroid’s composition and history that would explain its unconventional behavior. 

“Asteroids are like little time capsules for the formation of our solar system,” said Jamey Szalay, research scholar at the Princeton University space physics laboratory and co-author on the paper. “They were formed when our solar system was formed, and understanding their composition gives us another piece of the story.” 

An unusual asteroid 

Unlike most known meteor showers that come from comets, which are made of ice and dust, the Geminids stream seems to originate from an asteroid — a chunk of rock and metal — called 3200 Phaethon.

“Most meteoroid streams are formed via a cometary mechanism, it’s unusual that this one seems to be from an asteroid,” said Wolf Cukier, undergraduate class of 2024 at Princeton and lead author on the paper. 

“Additionally, the stream is orbiting slightly outside of its parent body when it’s closest to the sun, which isn’t obvious to explain just by looking at it,” he added, referring to a recent study with Parker Solar Probe images of the Geminids led by Karl Battams of the Naval Research Laboratory.

When a comet travels close to the Sun it gets hotter, causing the ice on the surface to release a tail of gas, which in turn drags with it little pieces of ice and dust. This material continues to trail behind the comet as it stays within the Sun’s gravitational pull. Over time, this repeated process fills the orbit of the parent body with material to form a meteoroid stream.

But because asteroids like 3200 Phaethon are made of rock and metal, they are not typically affected by the Sun’s heat the way comets are, leaving scientists to wonder what causes the formation of 3200 Phaethon’s stream across the night sky.

“What’s really weird is that we know that 3200 Phaethon is an asteroid, but as it flies by the Sun, it seems to have some kind of temperature-driven activity,” Szalay said. “Most asteroids don’t do that.” 

Some researchers have suggested that 3200 Phaethon may actually be a comet that lost all of its snow, leaving only a rocky core resembling an asteroid. But the new Parker Solar Probe data show that although some of 3200 Phaethon’s activity is related to temperature, the creation of the Geminids stream was likely not caused by a cometary mechanism, but by something much more catastrophic. 

Opening the time capsule 

To learn about the origin of the Geminids stream, Cukier and Szalay used the new Parker Solar Probe data to model three possible formation scenarios, then compared these models to existing models created from Earth-based observations.

“There are what’s called the ‘basic’ model of formation of a meteoroid stream, and the ‘violent’ creation model,” Cukier said. “It’s called ‘basic’ because it’s the most straight-forward thing to model, but really these processes are both violent, just different degrees of violence.”

These different models reflect the chain of events that would transpire according to the laws of physics based on different scenarios. For example, Cukier used the basic model to simulate all of the chunks of material releasing from the asteroid with zero relative velocity — or with no speed or direction relative to 3200 Phaethon — to see what the resulting orbit would look like and compare it to the orbit shown by the Parker Solar Probe probe data.

He then used the violent creation model to simulate the material releasing from the asteroid with a relative velocity of up to one kilometer per hour, as if the pieces were knocked loose by a sudden, violent event.

He also simulated the cometary model — the mechanism behind the formation of most meteoroid streams. The resulting simulated orbit matched the least with the way the Geminids orbit actually appears according to the Parker Solar Probe data, so they ruled out this scenario. 

In comparing the simulated orbits from each of the models, the team found that the violent models were most consistent with the Parker Solar Probe data, meaning it’s likely that a sudden, violent event — such as a high-speed collision with another body or a gaseous explosion, among other possibilities — created the Geminids stream. 

The research builds on the work of Szalay and several colleagues of the Parker Solar Probe mission, built and assembled at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, to assemble a picture of the structure and behavior of the large cloud of dust that swirls through the innermost solar system.

They took advantage of Parker’s flight path — an orbit that swings it just millions of miles from the Sun, closer than any spacecraft in history — to get the best direct look at the dusty cloud of grains shed from passing comets and asteroids.

Although the probe doesn’t measure dust particles directly, it can track dust grains in a clever way: as dust grains pelt the spacecraft along its path, the high-velocity impacts create plasma clouds. These impact clouds produce unique signals in electric potential that are picked up by several sensors on the probe's FIELDS instrument, which is designed to measure the electric and magnetic fields near the Sun.

“The first-of-its-kind data our spacecraft is gathering now will be analyzed for decades to come,” said Nour Raouafi, Parker Solar Probe project scientist at APL. “And it’s exciting to see scientists of all levels and skills digging into it to shed light on the Sun, the solar system and the universe beyond.” 

Reaching for the stars 

Cukier said his passion for learning about outer space combined with departmental support are what motivated him to pursue this project.

After taking a hands-on lab class offered by the Princeton space physics laboratory — where he gained practical experience building space instruments, like those currently sampling the Sun’s environment aboard Parker Solar Probe — and serving as treasurer for the undergraduate astronomy club, he decided he wanted to pursue extracurricular research.

He was met with enthusiasm when he reached out to scientists in the Princeton Space Physics group. “Everyone is very supportive of undergraduate research, especially in astrophysics, because it’s really part of the departmental culture,” he said. 

“It’s always wonderful when our students like Wolf can contribute so strongly to this sort of space research,” said David McComas, head of the Space Physics group and vice president for the Princeton Plasma Physics Laboratory (PPPL). “Many of us have been in awe of the Geminids meteor displays for years and it is awesome to finally have the data and research to show how they likely formed.”

Cukier said that he’s been drawn to watching the sky since he was a kid. “Planetary science is surprisingly accessible,” he said. “For the Geminids, for instance, anyone can go outside on December 14 this year at night and look up. It’s visible from Princeton, and some of the meteors are really bright. I’d highly recommend seeing it.”

“Formation, Structure, and Detectability of the Geminids Meteoroid Stream” by W.Z. Cukier and J.R. Szalay was published June 15, 2023 by Planetary Science Journal (DOI 10.3847/PSJ/acd538). The research was supported by the Parker Solar Probe Guest Investigator Program (80NSSC21K1764). Parker Solar Probe is part of NASA's Living with a Star program to explore aspects of the Sun-Earth system that directly affect life and society. The program is managed by NASA's Goddard Space Flight Center for the Heliophysics Division of NASA's Science Mission Directorate. APL manages the Parker Solar Probe mission for NASA.

Artist’s concept of the Parker Solar Probe spacecraft approaching the sun. Launched in 2018, the probe is increasing our ability to forecast major space-weather events that impact life on Earth.

CREDIT

NASA/Johns Hopkins APL/Steve Gribben

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JOURNAL

Planetary Science

DOI

10.3847/PSJ/acd538 

METHOD OF RESEARCH

Computational simulation/modeling

ARTICLE TITLE

Formation, Structure, and Detectability of the Geminids Meteoroid Stream

ARTICLE PUBLICATION DATE

15-Jun-2023

Discovery of white dwarf pulsar sheds light on star evolution

The discovery of a rare type of white dwarf star system provides new understanding into stellar evolution

Peer-Reviewed Publication

UNIVERSITY OF WARWICK

 

IMAGE: CREDIT DR MARK GARLICK//UNIVERSITY OF WARWICK view more 

CREDIT: CREDIT DR MARK GARLICK//UNIVERSITY OF WARWICK

The discovery of a rare type of white dwarf star system provides new understanding into stellar evolution.

White dwarfs are small, dense stars typically the size of a planet. They are formed when a star of low mass has burnt all its fuel, losing its outer layers. Sometimes referred to as “stellar fossils”, they offer insight into different aspects of star formation and evolution.

A rare type of white dwarf pulsar has been discovered for the second time only, in research led by the University of Warwick. White dwarf pulsars include a rapidly spinning, burnt-out stellar remnant called a white dwarf, which lashes its neighbour – a red dwarf – with powerful beams of electrical particles and radiation, causing the entire system to brighten and fade dramatically over regular intervals. This is owing to strong magnetic fields, but scientists are unsure what causes them.

A key theory which explains the strong magnetic fields is the “dynamo model” – that white dwarfs have dynamos (electrical generators) in their core, as does the Earth, but much more powerful. But for this theory to be tested, scientists needed to search for other white dwarf pulsars to see if their predictions held true.

Published today in Nature Astronomy, scientists funded by the UK Science and Technology Facilities Council (STFC) describe the newly detected white dwarf pulsar, J191213.72-441045.1 (J1912-4410 for short). It is only the second time such a star system has been found, following the discovery of AR Scorpii (AR Sco) in 2016.

773 light years away from Earth and spinning 300 times faster than our planet, the white dwarf pulsar has a size similar to the Earth, but a mass at least as large as the Sun. This means that a teaspoon of white dwarf material would weigh around 15 tons. White dwarfs begin their lives at extremely hot temperatures before cooling down over billions of years, and the low temperature of J1912−4410 points to an advanced age.

Dr Ingrid Pelisoli, STFC Ernest Rutherford Research Fellow at the University of Warwick’s Department of Physics, said: “The origin of magnetic fields is a big open question in many fields of astronomy, and this is particularly true for white dwarf stars. The magnetic fields in white dwarfs can be more than a million times stronger than the magnetic field of the Sun, and the dynamo model helps to explain why. The discovery of J1912−4410 provided a critical step forward in this field.

“We used data from a few different surveys to find candidates, focusing on systems that had similar characteristics to AR Sco. We followed up any candidates with ULTRACAM, which detects the very fast light variations expected of white dwarf pulsars. After observing a couple dozen candidates, we found one that showed very similar light variations to AR Sco. Our follow-up campaign with other telescopes revealed that every five minutes or so, this system sent a radio and X-ray signal in our direction.

“This confirmed that there are more white dwarf pulsars out there, as predicted by previous models. There were other predictions made by the dynamo model, which were confirmed by the discovery of J1912−4410. Due to their old age, the white dwarfs in the pulsar system should be cool. Their companions should be close enough that the gravitational pull of the white dwarf was in the past strong enough to capture mass from the companion, and this causes them to be fast spinning. All of those predictions hold for the new pulsar found: the white dwarf is cooler than 13,000K, spins on its axis once every five minutes, and the gravitational pull of the white dwarf has a strong effect in the companion.

“This research is an excellent demonstration that science works – we can make predictions and put them to test, and that is how any science progresses.”

Dr Pelisoli is one of the first group of research fellows and PhD students supported by a £3.5 million private philanthropic donation from a Warwick alumnus. One of the largest gifts towards the study of astronomy and astrophysics in the UK, the donation is enabling the next generation of astronomers to explore the furthest reaches of our universe.

Axel Schwope, Leibniz Institute for Astrophysics Potsdam (AIP), who is leading a complementary study published as a letter in Astronomy and Astrophysics, added: "We are excited to have independently found the object in the X-ray all-sky survey performed with SRG/eROSITA. The follow-up investigation with the ESA satellite XMM-Newton revealed the pulsations in the high-energy X-ray regime, thus confirming the unusual nature of the new object and firmly establishing the white dwarf pulsars as a new class.”

Read the paper here https://www.nature.com/articles/s41550-023-01995-x

University of Warwick press office contact: 

Annie Slinn

Communications Officer | Press & Media Relations | University of Warwick 
Email: annie.slinn@warwick.ac.uk

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JOURNAL

Nature Astronomy

DOI

10.1038/s41550-023-01995-x 

How antelopes under threat from the climate crisis have responded to rising temperatures

Scientists tracked the activity levels of different southern African antelopes to understand how they handle higher heat on a warming planet

Peer-Reviewed Publication

FRONTIERS

The climate crisis is turning the temperature up all over the world, but in southern Africa, the rise has been particularly concerning. Wild animals dependent on delicate ecosystems which are already dry, so that food and water scarcity limits their ability to cope with increased heat, are at serious risk. Scientists studied the behavior of three different species of antelope with overlapping ranges in Namibia to try to understand how animals of different sizes and behaviors adapt to the heat.

“Even the indigenous wildlife, adapted to hot and arid conditions, shows sensitivity to extreme heat,” said Paul Berry of the University of Potsdam, lead author of the study in Frontiers in Ecology and Evolution. “We need to consider the possibility that additional anthropogenic influences such as habitat fragmentation may compound the effect of rising temperatures.”

Tackling thermal stress

Animals can respond to high heat in several different ways, including genetic change, migration, and behavior changes, but the most flexible response is changing their behavior. Animals may move into cooler areas within their territories or change their posture, change their times of activity or the amount of activity they do, pant or decrease their energy intake. All these ways of countering heat stress impose physical costs and have limitations, but we can’t understand the trade-offs without first understanding how animals use them.

The team studied three species of antelope: small springbok, medium-sized kudu, and large eland. Springbok prefer open habitats and are highly mobile, while kudu favor woodland and travel less. Eland are also relatively mobile, occurring in a broad range of habits, and like springbok they are largely independent of water provided that there is sufficient moisture in their food. The scientists fitted adult animals with collars containing accelerometers that measured their movements in the hottest periods of the year between 2019 and 2021. They cross-referenced this data with measurements recorded by a local weather station and maps that track the temperatures across the different species’ ranges.

Springbok most affected

The hotter temperatures affected springbok activity most. Increased heat led to a decline in activity, as they moved less during the day and did not compensate with more nighttime activity. Eland did shift their activity from daytime to nighttime, but were generally less affected, perhaps because they don’t forage in open, exposed areas as much as springbok do. Kudu activity changed very little: they usually prefer the shade and are less mobile than either of the other species. Eland and kudu are also larger, and besides being less affected by predation risk because they are more difficult to hunt, may be able to absorb a greater heat rise before being seriously affected by thermal stress.

“While we showed how antelope differ in their response to extreme heat, it would be insightful to know also how they change their behavior,” said Berry. “We intend to use machine learning models to classify behavior, such as feeding, resting, and movement, based on accelerometer data that has been mapped to behavior by direct observation.”

The scientists also hypothesized that other animals’ heat response could be similarly affected by these body size and habitat preference factors, but more research will be needed to determine this. As heat stress that isn’t lethal can still affect the health and reproductive fitness of an animal population, the authors warned that increased heat stress could lead to changes in the ecosystem, with significant consequences for the local area.

“Managing the land both in an economically viable and an ecologically sustainable way is a complex task with far-reaching implications for the social and economic welfare of the region's inhabitants,” said Dr Niels Blaum of the University of Potsdam, senior author of the study. “Deepening our understanding of arid savanna ecosystems is therefore so important.”

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JOURNAL

Frontiers in Ecology and Evolution

DOI

10.3389/fevo.2023.1172303 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Keeping cool on hot days: Activity responses of African antelope to heat extremes

ARTICLE PUBLICATION DATE

15-Jun-2023

New tracking device to keep better tabs on wolves

Peer-Reviewed Publication

UNIVERSITY OF COPENHAGEN - FACULTY OF SCIENCE

 

IMAGE: RASMUS W. HAVMØLLER MOUNTING THE GPS DEVICE ON A BISON view more 

CREDIT: RASMUS W. HAVMØLLER

Keeping up with the journeys of wolves and welfare of wild horses has never been easier. With a GPS wildlife tracker powered by an animal's own movements, University of Copenhagen researchers have solved a problem faced by biologists and wildlife managers seeking to track wild animals year after year: dead batteries.

The wolf’s comeback in Europe has preoccupied people all across the continent over the last years. Where is it? What is its range? What does it live on? The only way to get solid answers to these questions is through GPS tracking. In December, it was a cause for celebration when a GPS collar was fitted onto a wolf for the first time in Denmark. Only three months later, the signal stopped.

GPS trackers that stop working or run out of power prematurely are a frequent problem and source of frustration among researchers who want to track mammals for longer periods, says biologist and postdoc Rasmus W. Havmøller of the University of Copenhagen. Typically, batteries are the problem:

"When studying wildlife with GPS technology, the biggest limitation is always going to be the battery. It's enormously frustrating. It is not uncommon that one gets to track an animal for a few months at most before the GPS device goes dead. But tracking an animal for a longer period of time is often important, as in the case with wolves here in Denmark. Therefore, we need a more reliable power source," says Rasmus W. Havmøller and continues:

"Solar cells work fine for birds, but solar cells are so fragile that mammals tend to crush them. Moreover, many mammals are nocturnal. So we needed to come up with an alternative. I had long thought about the cleverness of the automatic wristwatches that many of us wear, which harvest energy from our own body's movements."

Together with research colleagues at UCPH, the Max Planck Institute of Animal Behavior and DTU, Havmøller developed a battery-free GPS wildlife tracker that runs on kinetic energy – i.e., the energy generated when an animal moves. The scientific article on the research has been published in the journal PLOS ONE.

Lasts a lifetime, at a tenth of the cost

"It sure as heck works! The more an animal moves, the more energy it generates and the more GPS location messages it sends. Unless the equipment itself breaks, it will work throughout an animal's lifetime. At the same time, it only weighs 150 grams – significantly less than most other GPS trackers – so it can even be fitted onto small mammals," says Havmøller, adding that the device costs less than a tenth of traditional GPS collars, which run up to €3,500-4,000 apiece.

Rasmus W. Havmøller and his colleague, lead author Troels Gregersen, are assembling the GPS trackers themselves in a small laboratory at the Natural History Museum of Denmark.

The device, dubbed "KineFox" by the researchers, has been fitted onto one of the Danish Nature Agency's wild horses and has been sending data on the horse's position for the past six months. The tracker has also been tested on dogs and a bison. The plan is for it to be long-term tested on several animal species.

Ideal for rewilding of animals

Rewilding is one area that the researchers envision the GPS tracker making a difference. The lack of supervision of animals released into the wild is a problem that has given rise to heated debate in recent years.

"The systematic human supervision of wild horses and cattle, to keep them from starving for example, is extremely resource intensive. Our tracker is ready to address this task," says Rasmus W. Havmøller.

Because the tracking unit contains an accelerometer that measures how an animal moves, wildlife managers can get a glimpse of an animal’s condition through its activity pattern.

"Studies with cows and pigs show that they begin moving differently when ill. In this way, it is likely that the tracker will also be able to tell something about an animal’s health. This means that you can comply with supervision legislation without having to get people out there every single day to find and inspect animals," says the researcher.

Can help us protect endangered species

Havmøller points out that Kinefox can also lend a hand to endangered species, wherever knowledge about the way they live and move about is lacking:

"There is no good alternative to this GPS device when it comes to serious long-term studies and studies of how animal species disperse. Because either the equipment is too big, too heavy or too fragile. But it’s really important to understand how a species moves from one place to another, and where they are shot or poisoned, for example – not least if we want to protect them better."

He himself has been frustrated by GPS devices whose batteries died suddenly while studying both endangered leopards and wild dogs:

"There are endangered species where we know incredibly little about what they do for most of their lives. These include tigers, which can travel thousands of kilometers, as well the Asiatic wild dogs and leopards that I’m involved with. When wild dogs reach sexual maturity, leave their mother and set out on their own, they are very vulnerable. But from that moment on, we know nothing about what they’re up to and why some die while others make it. It is a black box. I hope that this invention can remedy that," concludes Rasmus W. Havmøller.

Havmøller and his research colleagues are now in contact with several potential stakeholders about the long-term testing of Kinefox on various animal species.

  

The components in the GPS wildlife tracker

  

Kinefox tracker on bison

CREDIT

Rasmus W. Havmøller

FACT BOX: HOW "KINEFOX" WORKS

• Instead of a battery, "Kinefox'' has a so-called capacitor, which stores the energy that the device harvests through an animal’s movements.
   
• Data from Kinefox is transmitted over Sigfox, a wireless network that is widespread around the world.
   
• Whereas a traditional GPS wildlife tracker typically costs €3,500-4,000, the new transmitter costs around €270 in materials.
   
• The researchers have opted to use an open source design for Kinefox, making the information available to all.

 

FACT BOX: ABOUT THE RESEARCH

• The researchers behind "Kinefox" are Troels Gregersen, Peter Rask Møller, Linnea Worsøe Havmøller and Rasmus Worsøe Havmøller of the University of Copenhagen’s Natural History Museum of Denmark; Timm A. Wild and Martin Wikelski of the Max Planck Institute of Animal Behavior, Germany; and Torben Anker Lenau from DTU Engineering Design and Product Development.
   
• The scientific research article has been published in the journal PLOS ONE.
   
• The research project is funded by the Villum Foundation under the Villum Experiment programme.

 

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JOURNAL

PLoS ONE

DOI

10.1371/journal.pone.0285930 

ARTICLE TITLE

A novel kinetic energy harvesting system for lifetime deployments of wildlife trackers