Greenland megatsunami led to week-long oscillating fjord wave

Seismological Society of America

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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.”

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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

 

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.

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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.

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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

 

Marine algae use massive enzymes of unprecedented size to biosynthesize fish-killing toxins

Peer-Reviewed Publication

American Association for the Advancement of Science (AAAS)

Marine algae Prymnesium parvum use massive enzymes dubbed PKZILLAs – some of the largest proteins ever to be identified in nature – to make large and complex prymnesin neurotoxins responsible for mass fish kills during harmful algal blooms worldwide, researchers report. “The discovery and initial characterization of the prymnesin PKZILLA gigasynthases now elucidates the long-standing question about how microalgae biosynthesize their giant polyketide polyether molecules,” write the authors. It also expands expectations of genetic and enzymatic size limits in biology. Many marine microbes produce exotic organic molecules with varied biological functions. Some microalgae, like P.  parvum, are known for producing some of the largest nonpolymeric carbon chain molecules in nature, including polyketide polyether biotoxins. During harmful algal blooms, neurotoxic prymnesins compounds are notorious for causing environmental damage, including massive environmental fish kills. However, despite decades of extensive research, how these microalgae produce such large and complex compounds is poorly understood. Using a customized gene annotation strategy, Timothy Fallon and colleagues discovered genes in P. parvum, which they named PKZILLAs (PKZILLA-1 and PKZILLA-2), that are involved in the production of polyketide synthase (PKS) enzymes. Notably, Fallon et al. found that these enzymes were massive, with PKZILLA-1 being one of the largest proteins ever identified at 4.7 megadaltons and containing 140 enzyme domains. Although slightly smaller, PKZILLA-2 is 3.2 megadaltons with 99 enzyme domains. According to the findings, these massive PKS gigasynthases are responsible for the biosynthesis of the 90-carbon backbone of prymnesin toxins. The authors also characterized a variant, PKZILLA-B1, which produces a shorter version of these toxins.

 

For reporters interested in other research that challenges prevailing views of the size limits of biological entities, a 2022 Science Research Article reported discovering discovering a bacterium so large that it can be seen by the naked eye.

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Journal

Science

DOI

10.1126/science.ado3290 

Article Title

Giant polyketide synthase enzymes in the biosynthesis of giant marine polyether toxins

Article Publication Date

9-Aug-2024

Largest protein yet discovered builds algal toxins

The findings could enhance monitoring efforts for harmful algal blooms, and unlock potential for new medicines or materials

University of California - San Diego

 

image: 

Figure courtesy of Tim Fallon, PhD. Stylistic size comparison of PKZILLA-1 and human titin, not to scale, wherein PKZILLA-1 is shown as roughly 25% larger than titin. Abbreviations: megadalton (MDa), acyl carrier protein (ACP), ketosynthase (KS), ketoreductase (KR), dehydratase (DH), enoylreductase (ER), fibronectin (Fn), immunoglobulin (Ig). Titin figure adapted from https://pdb101.rcsb.org/motm/185 under Creative Commons license, attribution: David S. Goodsell, RCSB Protein Data Bank (PDB). ACP structure modeled from bacterial ACP (PDB id: 2FAE). KS, KR, DH, ER, modeled from mammalian fatty acid synthase (PDB id: 2VZ8). 

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Credit: Figure courtesy of Tim Fallon, PhD

While seeking to unravel how marine algae create their chemically complex toxins, scientists at UC San Diego’s Scripps Institution of Oceanography have discovered the largest protein yet identified in biology. Uncovering the biological machinery the algae evolved to make its intricate toxin also revealed previously unknown strategies for assembling chemicals, which could unlock the development of new medicines and materials.  

Researchers found the protein, which they named PKZILLA-1, while studying how a type of algae called Prymnesium parvum makes its toxin, which is responsible for massive fish kills. 

“This is the Mount Everest of proteins,” said Bradley Moore, a marine chemist with joint appointments at Scripps Oceanography and Skaggs School of Pharmacy and Pharmaceutical Sciences and senior author of a new study detailing the findings. “This expands our sense of what biology is capable of.”

PKZILLA-1 is 25% larger than titin, the previous record holder, which is found in human muscles and can reach 1 micron in length (0.0001 centimeter or 0.00004 inch).

Published today in Science and funded by the National Institutes of Health and the National Science Foundation, the study shows that this giant protein and another super-sized but not record-breaking protein – PKZILLA-2 – are key to producing prymnesin – the big, complex molecule that is the algae’s toxin. In addition to identifying the massive proteins behind prymnesin, the study also uncovered unusually large genes that provide Prymnesium parvum with the blueprint for making the proteins.

Finding the genes that undergird the production of the prymnesin toxin could improve monitoring efforts for harmful algal blooms from this species by facilitating water testing that looks for the genes rather than the toxins themselves. 

“Monitoring for the genes instead of the toxin could allow us to catch blooms before they start instead of only being able to identify them once the toxins are circulating,” said Timothy Fallon, a postdoctoral researcher in Moore’s lab at Scripps and co-first author of the paper.

Discovering the PKZILLA-1 and PKZILLA-2 proteins also lays bare the alga’s elaborate cellular assembly line for building the toxins, which have unique and complex chemical structures. This improved understanding of how these toxins are made could prove useful for scientists trying to synthesize new compounds for medical or industrial applications. 

“Understanding how nature has evolved its chemical wizardry gives us as scientific practitioners the ability to apply those insights to creating useful products, whether it’s a new anti-cancer drug or a new fabric,” said Moore.  

Prymnesium parvum, commonly known as golden algae, is an aquatic single-celled organism found all over the world in both fresh and saltwater. Blooms of golden algae are associated with fish die offs due to its toxin prymnesin, which damages the gills of fish and other water breathing animals. In 2022, a golden algae bloom killed 500-1,000 tons of fish in the Oder River adjoining Poland and Germany. The microorganism can cause havoc in aquaculture systems in places ranging from Texas to Scandinavia. 

Prymnesin belongs to a group of toxins called polyketide polyethers that includes brevetoxin B, a major red tide toxin that regularly impacts Florida, and ciguatoxin, which contaminates reef fish across the South Pacific and Caribbean. These toxins are among the largest and most intricate chemicals in all of biology, and researchers have struggled for decades to figure out exactly how microorganisms produce such large, complex molecules.

Beginning in 2019, Moore, Fallon and Vikram Shende, a postdoctoral researcher in Moore’s lab at Scripps and co-first author of the paper, began trying to figure out how golden algae make their toxin prymnesin on a biochemical and genetic level.

The study authors began by sequencing the golden alga’s genome and looking for the genes involved in producing prymnesin. Traditional methods of searching the genome didn’t yield results, so the team pivoted to alternate methods of genetic sleuthing that were more adept at finding super long genes. 

“We were able to locate the genes, and it turned out that to make giant toxic molecules this alga uses giant genes,” said Shende.

With the PKZILLA-1 and PKZILLA-2 genes located, the team needed to investigate what the genes made to tie them to the production of the toxin. Fallon said the team was able to read the genes’ coding regions like sheet music and translate them into the sequence of amino acids that formed the protein.

When the researchers completed this assembly of the PKZILLA proteins they were astonished at their size. The PKZILLA-1 protein tallied a record-breaking mass of 4.7 megadaltons, while PKZILLA-2 was also extremely large at 3.2 megadaltons. Titin, the previous record-holder, can be up to 3.7 megadaltons – about 90-times larger than a typical protein.

After additional tests showed that golden algae actually produce these giant proteins in life, the team sought to find out if the proteins were involved in making the toxin prymnesin. The PKZILLA proteins are technically enzymes, meaning they kick off chemical reactions, and the team played out the lengthy sequence of 239 chemical reactions entailed by the two enzymes with pens and notepads. 

“The end result matched perfectly with the structure of prymnesin,” said Shende. 

Following the cascade of reactions that golden algae uses to make its toxin revealed previously unknown strategies for making chemicals in nature, said Moore. “The hope is that we can use this knowledge of how nature makes these complex chemicals to open up new chemical possibilities in the lab for the medicines and materials of tomorrow,” he added.

Finding the genes behind the prymnesin toxin could allow for more cost effective monitoring for golden algae blooms. Such monitoring could use tests to detect the PKZILLA genes in the environment akin to the PCR tests that became familiar during the COVID-19 pandemic. Improved monitoring could boost preparedness and allow for more detailed study of the conditions that make blooms more likely to occur.

Fallon said the PKZILLA genes the team discovered are the first genes ever causally linked to the production of any marine toxin in the polyether group that prymnesin is part of. 

Next, the researchers hope to apply the non-standard screening techniques they used to find the PKZILLA genes to other species that produce polyether toxins. If they can find the genes behind other polyether toxins, such as ciguatoxin which may affect up to 500,000 people annually, it would open up the same genetic monitoring possibilities for a suite of other toxic algal blooms with significant global impacts. 

In addition to Fallon, Moore and Shende from Scripps, David Gonzalez and Igor Wierzbikci of UC San Diego along with Amanda Pendleton, Nathan Watervoort, Robert Auber and Jennifer Wisecaver of Purdue University co-authored the study.

Golden alga (Prymnesium parvum) fish kill - Lake Granbury March 2007 (image by Texas Parks and Wildlife Department/TPWD)

Credit

Image by Texas Parks and Wildlife Department/TPWD

 

Prymnesium parvum cell (images by Greg Southard, TPWD)

Credit

Image by Greg Southard, Texas Parks and Wildlife Department

Journal

Science

Method of Research

Experimental study

Article Title

Giant polyketide synthase enzymes in the biosynthesis of giant 1 marine polyether toxins

Article Publication Date

8-Aug-2024

 

The long-lasting impact of war on global diabetes prevalence

How the conflict in Ukraine and linked supply chain disruptions could lead to up to 180,000 additional cases of type 2 diabetes

Complexity Science Hub

 

image: 

The war in Ukraine highlighted the vulnerability of the global food supply system. With this visualization (https://vis.csh.ac.at/food-supply-shocks/), users can see which food products are lost and which countries are most affected when a specific supplier stops producing a specific food product. The visualization shows a variety of scenarios related to Ukraine, including the one showing what would happen if Ukraine could no longer produce wheat.

 

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Credit: Complexity Science Hub

[Vienna, August 7 2024] — The ongoing war between Russia and Ukraine has led to severe humanitarian crises, including widespread food shortages. According to the United Nations World Food Programme, an estimated 11 million Ukrainians—about one-third of the population—were at risk of hunger in 2023. This crisis, exacerbated by supply chain disruptions and extreme weather events, could increase diabetes prevalence not only in Ukraine but globally, argue Peter Klimek and Stefan Thurner from the Complexity Science Hub in a commentary published in the journal Science.

Malnutrition during early pregnancy is known to elevate diabetes risk later in life. With 187,000 children born in Ukraine in 2023, Klimek and Thurner suggest that the current diabetes prevalence rate of 7.1% could result in an additional 13,000 to 19,000 cases of diabetes in this birth cohort alone.

Global impact

Globally, the disruption of crucial food exports due to the conflict has pushed an estimated 23 million people into hunger. Considering other supply chain interruptions and weather-related shocks, projections suggest that up to 122 million more people could suffer from hunger compared to 2019. “This could potentially lead to up to 180,000 additional Type 2 diabetes cases worldwide,” the researchers say.

They caution that while these estimates are not intended to be quantitative predictions, they do underscore the profound and often overlooked—especially indirect—effects of geopolitical events on public health. 

Ukraine – a key producer

Prior to the war, Ukraine was a major global agricultural producer, ranking as the largest exporter of sunflower oil, the fourth-largest exporter of corn, and the fifth-largest exporter of wheat. The modeled impacts of Ukraine’s agricultural production loss suggest that countries like Moldova, Libya, Lebanon, and Tunisia could face significant wheat shortages, with extensive repercussions for food products that rely on wheat as an ingredient.

Why this matters

Klimek and Thurner emphasize the importance of addressing these indirect consequences of conflicts and supply chain disruptions: "Our estimates are meant to illustrate the scale of the impact on public health, so that health authorities can become aware of these emerging high-risk groups and potentially adjust screening and early prevention measures for the coming decades," the researchers stated. They also stress the urgent need to diversify global food supply chains and reduce dependencies.

 

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Famine and diabetes

The link between hunger and diabetes is well-documented, with studies from historical famines in the Netherlands, China, and Austria, for example, showing that malnutrition during early pregnancy can significantly increase type 2 diabetes risk later in life. Recent research into the Ukrainian famine of 1932-33 by Lumey et al. has provided new insights into this relationship at a more granular level. By analyzing monthly birth cohorts and regional variations in famine severity, they found that severe malnutrition during early pregnancy can increase diabetes risk by 1.5 to 2 times.

This heightened risk is believed to stem from metabolic changes triggered by fetal exposure to poor nutrition, which prepares the body for a nutrient-scarce environment. When this environment changes, the mismatch can result in a higher likelihood of developing diabetes.

 

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About CSH

The Complexity Science Hub (CSH) is Europe’s research center for the study of complex systems. We derive meaning from data from a range of disciplines – economics, medicine, ecology, and the social sciences – as a basis for actionable solutions for a better world. Established in 2015, we have grown to over 70 researchers, driven by the increasing demand to gain a genuine understanding of the networks that underlie society, from healthcare to supply chains. Through our complexity science approaches linking physics, mathematics, and computational modeling with data and network science, we develop the capacity to address today’s and tomorrow’s challenges.

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Journal

Science

DOI

10.1126/science.adr1425 

Method of Research

Computational simulation/modeling

Subject of Research

People

Article Title

The lasting effects of famine

Article Publication Date

8-Aug-2024

Early prenatal exposure to famine increases Type 2 diabetes risk in adulthood, shows study of historical Ukraine event

American Association for the Advancement of Science (AAAS)

Prenatal exposure to famine significantly increases the risk of developing Type 2 diabetes mellitus (T2DM) in adulthood, according to a new study of people impacted by the 1932-1933 Holodomor famine in Ukraine. While the immediate and short-term effects of famines on mortality and morbidity are well-documented, deciphering famines’ long-term health consequences – as this study did – has been more difficult. Previous research has suggested a link between prenatal nutrition and adult health outcomes, including metabolic disorders like diabetes. However, these studies were limited by small sample sizes and uncertainties of famine exposure. The Holodomor famine in Ukraine, which was caused by Soviet policies and resulted in the deaths of millions through extreme food scarcity, presents a unique opportunity to examine this link due to its extreme severity, well-defined time frame, large population size, and extensive documentation. Here, L. H. Lumey and colleagues studied individuals born during this period, investigating how severe nutritional deprivation in early gestation impacts health decades later. Lumey et al. conducted an ecological study using data from 128,225 type-2 diabetes mellitus (T2DM) cases diagnosed between 2000 and 2008 among more than 10 million individuals born in Ukraine between 1930 and 1938. They found that individuals born in early 1934, who were in early gestation during the peak famine period in mid-1933, had a more than two-fold increased likelihood of developing T2DM in adulthood compared to those unexposed to the famine. Notably, no T2DM increase was seen among infants exposed to famine in mid or late gestation or in the first years of life. The findings identified a critical time window for when severe prenatal malnutrition has the greatest impact on future health, highlighting the importance of early gestational nutrition. In a Perspective, Peter Klimek and Stefan Thurner discuss the study and the implications of its findings on understanding and preventing global health threats related to food scarcity.

Podcast: A segment of Science's weekly podcast with L. H. Lumey, related to this research, will be available on the Science.org podcast landing page after the embargo lifts. Reporters are free to make use of the segments for broadcast purposes and/or quote from them – with appropriate attribution (i.e., cite "Science podcast"). Please note that the file itself should not be posted to any other Web site.

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Journal

Science

DOI

10.1126/science.adn4614 

Article Title

Fetal exposure to the Ukraine famine of 1932–1933 and adult type 2 diabetes mellitus

Article Publication Date

9-Aug-2024

THE HOLE THING

Researchers show nanovoids improve material performance

Chinese Academy of Sciences Headquarters

Voids or pores have usually been viewed as fatal flaws that severely degrade a material's mechanical performance and should be eliminated in manufacturing.

However, a research team led by Prof. JIN Haijun from the Institute of Metal Research (IMR) of the Chinese Academy of Sciences has proposed that the presence of voids is not always hazardous. Instead, voids can be beneficial if they are added "properly" to the material.

The team demonstrated that a metal with a large number of nanoscale voids shows improved mechanical performance compared to samples without voids.

This work was published in Science.

The new material developed by the team has been dubbed nanovoid dispersed gold (NVD Au). It contains a huge number of nanoscale voids, with sizes ranging from a few nanometers to several hundred nanometers. These voids are distributed uniformly throughout the material. Manufacturing NVD Au combines a corrosion process called dealloying with compression and thermal annealing treatments.

The researchers found that NVD Au shows improved strength and ductility in tension in comparison with fully dense Au. In other words, NVD Au with dispersed nanovoids is capable of withstanding higher loads and can be pulled to greater lengths without fracture.

This is the exact opposite of the effect observed in materials with large voids that are prepared by powder sintering or additive manufacturing. The excellent properties of NVD Au are attributed to enhanced dislocation-surface interactions and suppressed crack nucleation in this structure.

"We achieved both NVD strengthening and density reduction simultaneously, and thus realized lightweighting," said JIN. "Also, it does not involve any change of composition or phase, so that the excellent physical/chemical properties of the base material can be largely preserved."

This strengthening approach may be explored for use in many areas, ranging from portable electronics to aviation manufacturing.

The study was conducted in collaboration with scientists from Liaoning Academy of Materials and Nanjing University of Science and Technology.

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Journal

Science

Article Publication Date

8-Aug-2024