Friday, August 09, 2024

South Africa’s controversial lion farming industry is fueling the illegal international trade in big cat bones

Pensoft Publishers

image:
Lion at a commercial breeding facility in South Africa.
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Credit: Roberto Vieto / World Animal Protection.

A new research paper published in the scientific journal Nature Conservation has uncovered concerning activities within South Africa's captive lion industry, shedding light on the urgent need for comprehensive governmental action.

The study by World Animal Protection, conducted through direct interviews with workers at two closed-access lion facilities in South Africa’s North West Province, reveals disturbing practices. These include:

The use of legal activities such as commercial captive lion breeding and canned hunting to mask involvement in the illegal international trade of lion and tiger bones.
Animal welfare violations including reports of malnutrition, lack of clean water, filthy enclosures and animals being deliberately starved throughout the low-hunting season.
Illegal hunting practices such as reports of animals being drugged and hunted within an hour of release in enclosures that violate legal minimum size requirements.
Unsafe working conditions including reports of a lack of protective gear for workers when preparing the bodies of hunted animals.
Potential shifts towards commercial exploitation of other felid species like tigers which could be used as substitutes for lion bones.
Poaching incidents of big cats from commercial captive lion farms by unaffiliated actors, with often only the heads and paws of the animals harvested by the poachers.

Facility workers detailed the use of various strategies, including security cameras, patrols, and messaging apps, to evade detection during inspections. These findings emphasise the complexity and severity of issues within the captive lion industry, necessitating immediate and decisive action.

Lead researcher Dr Angie Elwin, Research Manager at World Animal Protection said: “Our study highlights the troubling reality of South Africa's captive lion industry. Legal activities are being exploited to facilitate illegal trade, and this is compounded by serious animal welfare violations and unsafe conditions for workers. Urgent action is needed to protect lions and people”.

Although the commercial captive breeding and canned hunting of lions remains legal, though poorly regulated in South Africa, the export of lion skeletons - including claws and teeth – was declared unconstitutional by the South African High Court in 2019.

In 2021, the South African Government announced its intention to immediately halt the “domestication and exploitation of lions, and to ultimately close all captive lion facilities in South Africa”.

However, a lack of enforcement of regulations and clarity on the future of the industry, has left a legal grey area, enabling some farms to operate what on the surface appear to be legitimate captive lion breeding and ‘canned’ trophy hunting businesses - but which in reality supply the illegal international big cat bone trade facilitated by organised crime gangs.

In light of these revelations, the study calls for the South African Government to implement a comprehensive and well-managed plan to transition away from current practices in the captive lion industry. Key recommendations include:

Full Audit of the Industry: To ensure all commercial captive lion farms are officially registered and compliant with regulations until the industry is phased out.
Breeding Moratorium: Establish an immediate moratorium on lion breeding to prevent further growth of the commercial captive lion population.
Prevention of Bone Stockpiling: Develop and enforce plans to prevent the accumulation of lion bones, which risks fuelling the illegal international lion bone trade.
Phase out Plan: Enact a time bound strategic plan to phase out the captive lion farming industry, ensuring ethical treatment of animals and safety for workers.

Senior researcher Dr Neil D’Cruze, Head of Wildlife Research at World Animal Protection said: "The South African Government must take immediate action to fulfil its public pledge to end the controversial captive lion industry. Without a comprehensive time-bound plan and stringent enforcement, this commercial industry will continue to pose significant legal, animal cruelty, and conservation concerns".

It is estimated that between 8,000-12,000 lions and other big cats, including tigers, are bred and kept in captivity in more than 350 facilities across the country.

This study serves as a crucial call to action for both the South African Government and the international community to address and resolve the complex issues surrounding the captive lion industry.

The publication comes at a time when South African NGO Blood Lions encourages the public to raise their voice by sharing the 2024 World Lion Day “You’re killing them softly” campaign message, aimed at informing tourists and visitors to lion farms about the hidden suffering and cruelty involved, and to sign this petition urging the South African government among others to extend the ban on captive lion breeding and trading to other predators.

Lions at a commercial breeding facility in South Africa.

Credit

Roberto Vieto / World Animal Protection

Prepared lion skeleton.

Credit

Lord Ashcroft KCMG PC.

Original source:

Elwin A, Asfaw E, D'Cruze N (2024) Under the lion’s paw: lion farming in South Africa and the illegal international bone trade. Nature Conservation 56: 1–17. https://doi.org/10.3897/natureconservation.56.124555

Journal

Nature Conservation

DOI

10.3897/natureconservation.56.124555

Article Title

Under the lion’s paw: lion farming in South Africa and the illegal international bone trade

Article Publication Date

8-Aug-2024

Weather 'whiplash' in Antarctica may help predict effects of future climate change

Virginia Tech

The McMurdo Dry Valleys of Antarctica live up to their name. The region is one of the driest places on Earth — mountains form a wall around the valleys and prevent melting glacier water from intruding, humidity is extremely low, and no rain was documented in the valleys between the 1960s and the early 2020s.

So when Virginia Tech biological sciences Professor J.E. “Jeb” Barrett learned of a March 2022 day in the McMurdo Dry Valleys that the thermometer rocketed to more than 70 degrees Fahrenheit above its average, he thought examining the extreme weather change would be revealing.

In a paper published Aug. 5 in the American Geophysical Union journal Earth’s Future, Barrett and colleagues reported findings indicating that the March 2022 “weather whiplash” led to record-high death rates for invertebrate organisms that count on surviving winter in an “inactive freeze-dried state.”

The event that triggered Barrett’s work happened on March 18, 2022. On that day, a subtropical river of air in the atmosphere swept over Antarctica, creating an almost instant heat wave on a continent that had already begun freezing into the dark polar night of winter. The temperature jump in the McMurdo Dry Valleys that March paralleled that of the past few days when an Antarctica heat wave has alarmed scientists and others.

“Unfortunately, atmospheric scientists expect more weather anomalies like this in Antarctica,” Barrett said. “Studying the impact of the March 2022 event can help us predict how the ecosystem and creatures in it will respond to future climate changes."

The McMurdo Dry Valleys are especially valuable for scientific research because they may be the only place in Antarctica that have a three-decade-long record of meteorology, stream flow, and soil organisms.

The extreme climate of the McMurdo Dry Valleys limits the organisms that can live there to microscopic or nearly microscopic animals such as rotifers, tardigrades, and nematodes. In March in Antarctica, the equivalent of autumn in the Northern Hemisphere, these animals are transitioning into a dry, frozen status that is critical to their ability to survive the coldest months of the year.

Barrett and the team took advantage of multispectral satellite images to determine how much the March 18 spike in temperatures melted the frozen ground. They examined satellite shots from before March 18, then looked for areas that had darkened on the images immediately after the warm weather.

“Only two things could have resulted in the darker images that we saw: shadows from cloud cover or mountainous topography or the addition of water from melting ice,” Barrett said.

Once they eliminated the possibility of shadows on the satellite images, Barrett and other researchers knew the unusually hot day had resulted in a rapid, massive thaw. The valleys had been swamped. Anything near the surface would no longer be frozen.

In December 2022, researchers collected soil from areas within the valleys and counted the number of live or dead invertebrates. They found a mortality rate of more than 50 percent in areas that had wetted up during the March 2022 event. The only other cases of a mortality rate nearing that have occurred during experiments exploring extreme “freeze-thaw treatments.”

“Our findings from this weather event should be eye-opening for us all,” Barrett said. “As we’ve seen in Southwest Virginia recently as well as in many other U.S. communities, the weather can now change like the flip of a switch. Rapid changes to the environment are difficult for microscopic animals, and they are challenging for people, animals, and plants as well.”

A satellite image of the McMurdo Dry Valleys in Antarctica.

Credit

Photo courtesy of J.E. "Jeb" Barrett.

Journal

Earth s Future

Article Title

Response of a Terrestrial Polar Ecosystem to the March 2022 Antarctic Weather Anomaly

Article Publication Date

5-Aug-2024

The search for the earliest traces of life on Earth

uOttawa team explores carbon in 3.9-billion-year-old Canadian rocks

University of Ottawa

The search for the earliest traces of life on Earth — image:
“Our study focuses on chemical sedimentary rocks found in the Saglek-Hebron. These rocks, among the oldest on Earth, dating back 3.9 billion years, are created through oceanic precipitation”
Jonathan O’Neil
— Associate professor in the Department of Earth and Environmental Sciences
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Credit: University of Ottawa

uOttawa team explores carbon in 3.9-billion-year-old Canadian rocks

The isotopic composition of carbon in iron formations from the Saglek-Hebron Complex in Nunatsiavut (northern Labrador) has been seen as evidence of the earliest traces of life on Earth. But a new study by the University of Ottawa, Carleton University and University College London suggests otherwise.

The study shows that the petrographic, geochemical and spectroscopic features in the graphite (the crystalline form of carbon) found in the Saglek-Hebron chemical sedimentary rocks are in fact “abiotic,” that is, nonliving physical or chemical aspects of an environment or devoid of life.

This enhances our understanding of how early biomass transformed on Earth, emphasizing the interaction between non-biological processes and ancient life remnants. Studying graphitic materials is key to decoding carbon cycling on the early Earth.

This study is crucial to the search for ancient life on Earth and potentially on neighboring planets.

What the researchers did

Researchers used micro-Raman spectroscopy and revisited the isotopic signatures in these rocks. Their findings show that graphite may come from liquid substances containing carbon, hydrogen and oxygen, probably originating from the breakdown of old organic materials.

“Our study focuses on chemical sedimentary rocks found in the Saglek-Hebron. These rocks, among the oldest on Earth, dating back 3.9 billion years, are created through oceanic precipitation. They include banded iron formations that may have been formed by the activity of bacteria,” explains co-author Jonathan O’Neil, an associate professor in the Department of Earth and Environmental Sciences at uOttawa.

“They are ideal for studying ancient biological processes. Our study challenges the previous interpretation that the carbon isotopic composition of these rocks is indicative of a biological origin, but their spectroscopic properties rather suggesting abiotic characteristics. This prompts us to reconsider the processes responsible for isotopic signatures and how they could be linked to the action of micro-organisms,” O’Neil adds.

Research over the past year has focused on samples collected in Nunatsiavut during a field campaign in 2016. Petrological characterization was carried out in Ottawa and spectroscopic analysis of graphitic carbon was carried out in London, U.K.

Formed by fluids

“Graphitic carbon from chemical sedimentary rock samples has been studied in three sedimentary rock samples that are nearly 3.9 billion years old. Spectroscopic analysis of this graphitic carbon suggests that it was formed from metamorphic fluids (at temperatures of over 500oC), rather than by processes involving bacterial action,” says O’Neil.

The research shows that graphite in rocks may have formed without organic life, possibly through a carbon-extraction process. The degree of crystallization of the graphite correlates with the rocks’ metamorphism, indicating that metamorphism affects the preservation and change of carbon-based materials.

The study, titled “Abiotic synthesis of graphitic carbons in the Eoarchean Saglek-Hebron metasedimentary rocks,” was published in Nature Communications.

Journal

Nature Communications

DOI

10.1038/s41467-024-50134-1

Method of Research

Meta-analysis

Subject of Research

Not applicable

Article Title

Abiotic synthesis of graphitic carbons in the Eoarchean Saglek-Hebron metasedimentary rocks

Article Publication Date

6-Jul-2024

AMERIKA

Not just an urban problem: new study reports higher rate of shootings by police across suburbs and rural areas

From 2015-2020, 45% of all incidents of shootings by police occurred in rural areas and 22% in the suburbs, reports a new study in the American Journal of Preventive Medicine

Peer-Reviewed Publication

Elsevier

Ann Arbor, August 8, 2024 – Media coverage of shootings by police typically involve urban incidents, giving the impression that the issue is unique to cities. However, national data built from the Gun Violence Archive tells a different story, showing a higher rate of shootings by police in rural and suburban areas than in cities during 2015-2020. A new study in the American Journal of Preventive Medicine, published by Elsevier, reports on the first nationwide, descriptive analysis of where, how often, and under what circumstances individuals in the US are injured or killed in shootings by police in urban, suburban and rural areas.

Lead investigator Julie A. Ward, PhD, MN, RN, Assistant Professor of Medicine, Health, and Society and Public Policy Studies at Vanderbilt University, explains the underlying rationale for the study, "As a public health nurse, I have seen how physically and emotionally impactful fatal and nonfatal shootings can be. Experiences in times of crisis and in encounters with police carry a lot of weight in shaping personal and community feelings of safety, but the federal government doesn’t require policing agencies to report when officers shoot and injure someone. Before our study, existing research on shootings by police in nonurban areas was very limited. Our systematic examination of the circumstances of incidents across the urban to rural continuum brings to light an overlooked population health concern affecting how people experience public safety across large regions of the US.”

The study found that over the six years of data analyzed, 45% of shootings by police occurred in rural zip codes; 22% happened in suburban zip codes.

The findings also show that racial disparities exist across the urban-rural continuum. Black and Native American residents of urban areas were most disproportionately affected, but injury rates were also high among suburban Black residents, rural Black residents, and rural Native American residents. Nationally, these groups’ per capita rates of injury from shootings by police were three-to-five times higher than rates of injury among White residents living in the same rurality designation. Rates of injury to Hispanic residents of urban, suburban, and rural areas were nearly two times higher than non-Hispanic White residents’ rates of injury.

Dr. Ward notes, “This is an equity issue. Public safety should not just be a euphemism for policing. All residents should have access to services to help them stay safe and healthy, including in times of crisis.”

The most common types of policing encounters associated with the shootings were traffic stops, domestic violence events, shots-fired reports, attempts to serve warrants or complete arrests, and incidents involving behavioral health needs. Less than half of shootings in rural zip codes involved shots fired only by local police. Fifty-six percent of these shootings in rural areas involved shots fired by sheriffs’ offices, state police, other agencies, or multiple policing agencies.

Dr. Ward adds, “We often use ‘police’ as shorthand for agencies that engage in law enforcement and other policing activities. But this research makes it clear that if we only focus on improving accountability among local police departments, we will miss a big part of the picture experienced by nonurban residents. This suggests potential for wide-reaching prevention nationally if local and national responses include nonurban jurisdictions and nonurban police and sheriffs’ departments.”

She continues, “Over the past several years, we’ve seen huge growth in the national dialog around police use of force, police accountability systems, and alternative responses. A number of communities have introduced new dispatch services, dedicated behavioral health response teams, co-responder models, and other innovative approaches. To have a broad impact nationally, these potential improvements need to not only focus on urban areas or local police departments.”

Journal

American Journal of Preventive Medicine

DOI

10.1016/j.amepre.2024.05.021

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Characteristics of Injurious Shootings by Police Along the Urban–Rural Continuum

Link found between sociocultural institutions in ethnic enclaves and resident health

UC Irvine-led study used novel measures in Asian American and Hispanic neighborhoods

University of California - Irvine

Irvine, Calif., Aug. 8, 2024 — The number of sociocultural institutions within ethnic enclaves may play a significant role in positively influencing the health of immigrant Asian American and Hispanic populations, according to recent research led by the University of California, Irvine.

For the study, published online in the journal Social Science and Medicine, researchers created and validated two novel measures – Asian- and Hispanic-serving sociocultural institutions – to identify the different mechanisms that link majority minority neighborhoods to health outcomes.

“Our new measures capture aspects of local economies that may support residents through in-language and culturally appropriate services, employment and social groups that help us estimate how they impact community health,” said corresponding author Brittany Morey, associate professor of health, society and behavior in the Joe C. Wen School of Population & Public Health. “Rather than census data, we used business listings to identify organizations that promote cultural and social identity, including arts, civic, historical, religious, social service and membership.”

An online audit of 1,627 businesses within 12 cities was conducted using keyword searches to determine potential Asian- or Hispanic-serving sociocultural institutions and assess their density within census tracts. Exploratory regression analyses showed that a high presence of SCIs may be associated with neighborhood-level health indicators. Researchers discovered a larger percentage of residents in a majority Asian tract who had received an annual checkup and fewer current smokers in both majority Asian and majority Hispanic tracts when there were more SCIs.

“Our approach advances methodology in measurement of neighborhood SCIs by capturing data that have been previously overlooked,” Morey said. “Further studies will be conducted to examine the impact that economic resources, social capital and the built environment have on positively influencing community-level well-being. Their potential suggests that support for neighborhood SCIs may lessen health inequities by race and ethnicity.”

Other team members included faculty, research scientists, postdoctoral fellows and graduate students from UC Irvine, UC San Francisco, the University of Southern California, Columbia University, Kaiser Permanente Northern California and New York’s Roswell Park Comprehensive Cancer Center. The full list can be found here.

This research was supported by the National Cancer Institute under grant numbers R01CA230440, R01CA241125 and U01CA195565.

About the University of California, Irvine: Founded in 1965, UC Irvine is a member of the prestigious Association of American Universities and is ranked among the nation’s top 10 public universities by U.S. News & World Report. The campus has produced five Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UC Irvine has more than 36,000 students and offers 224 degree programs. It’s located in one of the world’s safest and most economically vibrant communities and is Orange County’s second-largest employer, contributing $7 billion annually to the local economy and $8 billion statewide. For more on UC Irvine, visit www.uci.edu.

Media access: Radio programs/stations may, for a fee, use an on-campus studio with a Comrex IP audio codec to interview UC Irvine faculty and experts, subject to availability and university approval. For more UC Irvine news, visit news.uci.edu. Additional resources for journalists may be found at https://news.uci.edu/media-resources.

Journal

Social Science & Medicine

Article Title

A validation study for measuring Asian- and Hispanic-serving sociocultural institutions in neighborhoods using business listing data and potential implications for health

Article Publication Date

8-Aug-2024

Report examines Michigan families’ experience with food access and assistance, outlines changes for improved support

University of Michigan School of Public Health

Each year, hundreds of thousands of Michigan parents worry whether they can afford to feed their children. Increased food prices, the state’s housing crisis, and the end of COVID-era financial support have all led to more Michigan families experiencing food insecurity today than before the pandemic. Now, a new report led by the University of Michigan School of Public Health details the first-hand experiences of these families; their challenges signing up for food assistance, the stress and shame of having to ask for help with food, and parents’ deep commitment to making sure their children are fed—even if it means that they go without.

Called “Feeding MI Families: Michigan Families’ Lived Experience of Food Access and Food Assistance,” the report describes the findings of the Feeding MI Families community-based participatory research project, which has engaged nearly 1,300 parents from urban and rural communities across the state. The goal of the project is to elevate the lived experience of food insecurity in order to spur improvements in federal, state, and local food systems so they work better for families.

Feeding MI Families was established in 2021 with a grant from the W.K. Kellogg Foundation to elevate the experiences of food-insecure families from Detroit, Grand Rapids, and Battle Creek. In 2022, with support from Michigan Farm Bureau Family of Companies, Feeding MI Families expanded to include families from the state’s 57 rural counties. Rural communities often have food insecurity rates comparable to urban areas. According to the report, 22% of children in Michigan’s Wayne and Roscommon counties are food insecure.

“While we think that living in Michigan’s Upper Peninsula could not be more different than living in Detroit, over and over, we heard the same challenges when it comes to buying food, whether it be lack of transportation, high food prices at local grocery stores, or not being able to find brands that can be purchased with WIC benefits,” says Kate Bauer, director of Feeding MI Families and an associate professor of Nutritional Sciences at Michigan Public Health. “While the solutions to these challenges may differ based on location, families' needs and wants are the same.”

Feeding MI Families approach: We’re Listening. We’re Learning.

Aligning with the project’s motto, “We’re Listening. We’re Learning,” Feeding MI Families gathered parents’ experiences through text message-based surveys and in-depth phone interviews offered in English and Spanish. Parents were asked to share their perspectives on formal and informal food assistance programs, including:

Supplemental Nutrition Assistance Program/Food Assistance Program (SNAP/FAP)
Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)
Pandemic EBT (P-EBT) benefits
School food distribution during COVID-19
Charitable food systems

Three overarching themes emerged from parents’ experiences:

Stigma and discrimination are central barriers to food security
Small modifications make big differences to families
Families want dignified access to fresh and safe produce, proteins, and dairy products

Within each of these themes, the report provides parent-driven recommendations for policy and programmatic change at all levels of government and within the nonprofit and for-profit sectors.

One recommendation that emerged is to change the design of the state’s EBT card, called the Bridge Card, which is loaded with food assistance benefits and can be used like a credit card at grocery stores.

“Parents reported feeling shame and embarrassment when purchasing food with a Bridge Card because it is brightly colored and easily identifiable,” Bauer explains. “One mother said she only uses self-checkout so she can hide her Bridge Card from the people behind her in line. While we need to end discrimination at its root, making the Bridge Card more discreet is a simple strategy to improve the shopping experience.”

Elevating family experiences through storytelling

In addition to the survey and interview findings, the report elevates compelling personal stories from families and highlights unique Michigan populations with consistent barriers to healthy food access, including Hispanic/Latino families, families living in the Upper Peninsula, and families that include individuals with disabilities.

Bauer notes that many food assistance programs want client and community input but don’t have the resources to gather this information, and that there are often disconnects between those who hold power and those who rely on services.

“There are a lot of stereotypes and assumptions about families experiencing food insecurity,” Bauer says. “We hope that Feeding MI Families helps dispel these inaccuracies and motivates more organizations to meaningfully engage individuals with lived experience in decision making. Communities know what they need to overcome food insecurity. We need to listen and learn from them.”

Read the report at feedingmifamilies.org.

About the University of Michigan School of Public Health

Since 1941, the University of Michigan School of Public Health has been pursuing a healthier, more equitable world through education, research and action. Ranked among the top schools of public health in the country, Michigan Public Health trains more than 1,300 graduate and undergraduate students each year. With more than 190 faculty and researchers across six academic departments and numerous collaborative centers and institutes, the school produces impactful research aimed at finding lasting solutions to pressing public health challenges. Compassion, innovation and inclusion drive Michigan Public Health faculty, staff, students and more than 19,000 alumni worldwide to pursue positive change and make a lasting impact on the health of the world. Learn more at publichealth.umich.edu.

Greenland megatsunami led to week-long oscillating fjord wave

Seismological Society of America

In September 2023, a megatsunami in remote eastern Greenland sent seismic waves around the world, piquing the interest of the global research community.

The event created a week-long oscillating wave in Dickson Fjord, according to a new report in The Seismic Record.

Angela Carrillo-Ponce of GFZ German Research Centre for Geoscience and her colleagues identified two distinct signals in the seismic data from the event: one high-energy signal caused by the massive rockslide that generated the tsunami, and one very long-period (VLP) signal that lasted over a week.

Their analysis of the VLP signal—which was detected as far as 5000 kilometers away—suggests that the landslide and resulting tsunami created a seiche, or a standing wave that oscillates in a body of water. In this case, the seiche was churning for days between the shores of Dickson Fjord.

“The fact that the signal of a rockslide-triggered sloshing wave in a remote area of Greenland can be observed worldwide and for over a week is exciting, and as seismologists this signal was what mostly caught our attention,” said Carrillo-Ponce.

“The analysis of the seismic signal can give us some answers regarding the processes involved and may even lead to improved monitoring of similar events in the future. If we had not studied this event seismically, then we would not have known about the seiche produced in the fjord system,” she added.

The findings will help researchers as they study the impacts of landslides in Greenland and similar regions around the world where global warming and the loss of permafrost are making rocky slopes and glaciers increasingly unstable.

In western Greenland, recent tsunamis have had devastating consequences, such as the 2017 Karrat Fjord event where an avalanche caused a tsunami that flooded the village of Nuugaatsiaq and killed four people. Megatsunamis over 100 meters high off the east coast of Greenland have also reached Europe.

The 16 September 2023 megatsunami took place in Dickson Fjord in a remote part of East Greenland, and was first noted in social media posts and in a report of waves hitting a military installation on Ella Island.

Carrillo-Ponce and colleagues studied both seismic signals and satellite imagery from the area to precisely locate and reconstruct the series of events.

Their analysis of an initial high-energy seismic signal, combined with satellite images of a missing rock patch along a cliff along Dickson Fjord, allowed them to trace the direction of the landslide as it picked up glacier ice and became a mixed rock-ice avalanche before it reached the water. The resulting megatsunami run-up was more than 200 meters near the water entry point and an average of 60 meters along a 10-kilometer stretch of the fjord.

“While we were able to obtain information on the direction and magnitude of the force exerted by the landslide, we do not have data to investigate the original cause of the landslide,” Carrillo-Ponce said.

The strength, radiation pattern and duration of the later seismic VLP signal best fit a scenario where the tsunami created a long-lasting seiche in the fjord, the researchers found.

VLP signals have been observed previously in Greenland, but they are usually associated with iceberg collapse due to glacial earthquakes. “In our case we observed a VLP signal too, but the main difference is the long duration,” Carrillo-Ponce explained. “It is quite impressive to see that we could use good-quality data from stations located as far as Germany, Alaska and North America, and that those records were strong enough for at least one week.”

The researchers say their approach might prove useful in studying similar past events, and their possible link to climate and environmental change.

“We have compared our results with remote sensing data to validate our solutions, and our study shows that the force produced by the signals is well resolved,” Carrillo-Ponce said. “Therefore it becomes a useful analysis as seismic signals contain information on the type of source generating the signal and how the energy is radiated.”

Journal

The Seismic Record

DOI

10.1785/0320240013

Method of Research

Observational study

Subject of Research

Not applicable

Article Title

The 16 September 2023 Greenland Megatsunami: Analysis and Modeling of the Source and a Week‐Long, Monochromatic Seismic Signal

Article Publication Date

8-Aug-2024

Landslide triggers megatsunami in narrow fjord

Seismologists measure tremors up to 5000 km away.

GFZ GeoForschungsZentrum Potsdam, Helmholtz Centre

Map showing the fjord and seismic stations nearby — image:
Overview of seismic stations on Greenland (black triangles), the location of the tsunami (red circle) and the nearest seismic station (red triangle), whose filtered signals are shown.
view more
Credit: Angela Carillo Ponce et al.

It was a monster wave that hit a fjord on Greenland's east coast on 16 September 2023: In certain places, the traces of the flooding reached 200 metres high. Researchers led by Angela Carrillo Ponce from the German Research Centre for Geosciences (GFZ) have now evaluated the seismic signals from earthquake measuring stations worldwide and discovered another unusual event: Triggered by the megatsunami, a standing wave sloshed back and forth in the narrow bay of the uninhabited Dickson Fjord for more than a week. The international team published their work in the current issue of the scientific journal “The Seismic Records”.

Rockslide as triggering event

The tsunami was triggered by a large landslide. Earthquake measuring stations up to 5,000 kilometres away registered the shaking caused by the landslide as a short signal. However, there was also a very long-period (VLP) signal that was recorded by the seismometers for more than a week. Angela Carrillo Ponce, who works as a doctoral student in the “Physics of Earthquakes and Volcanoes” section of the GFZ, says: “The mere fact that the VLP signal of a wave sloshing back and forth triggered by a landslide in a remote area of Greenland can be observed worldwide and for over a week is exciting. That's why we in seismology have been most concerned with this signal.” Fortunately, the researcher adds, no people were harmed. Only a military base, which was without personnel at the time of the tsunami, was devastated.

Analysis of the seismic signals – shock waves that travel thousands of kilometers in the earth's crust – showed that a so-called standing wave formed in the fjord after the landslide. Initially, the parts of the flank that fell into the water triggered a giant wave that spread through the entire fjord to the offshore island of Ella, more than 50 kilometres away. Near the point where the rockslide entered the fjord, the maximum height was more than 200 metres, along the coast an average of 60 meters. Parts of the wave apparently spilled back from the steep banks in the narrow fjord and a standing wave began to form, which undulated back and forth for more than a week. However, this wave measured only around 1 metre in height.

Standing wave persisted unusually long

Such standing waves and the resulting long-period signals are already known in research. Such VLP signals are normally associated with large break-offs from glacier edges. “In our case, we also registered a VLP signal”, says Angela Carrillo Ponce, “the unusual thing about it was the long duration”. What was particularly impressive was that the data from seismic stations in Germany, Alaska and other parts of North America were of very good quality for the analysis. A comparison with satellite images confirmed that the cause of the first seismic signals corresponded well with the strength and direction of the rockfall that triggered the megatsunami. In addition, the authors were able to model the slow decay and the dominant oscillation period of the VLP signals.

This gives the researchers hope that they will be able to detect and analyze other similar events from the past. It is obvious that the retreat of glaciers, which previously filled entire valleys, and the thawing of permafrost are leading to increased landslides. Climate change is accelerating the melting of glaciers and could therefore increase the risk of megatsunamis.

Seismic signals of the megatsunami

Depending on the frequency range filtered out, the rockfall triggering the tsunami can be seen as a single peak (top), the standing wave sloshing back and forth as an undulating pattern in the recordings (middle, with several hours depicted) or the overall signal of the rockfall and the tsunami over the course of a week with strongly decreasing intensity of the oscillations (bottom).
Credit
Angela Carillo Ponce et al.

Journal

The Seismic Record

DOI

10.1785/0320240013

Method of Research

Data/statistical analysis

Subject of Research

Not applicable

Article Title

The 16 September 2023 Greenland Megatsunami: Analysis and Modeling of the Source and a Week-Long, Monochromatic Seismic Signal

Article Publication Date

8-Aug-2024