Chemical Formula: Al2(SiO4)O Locality: Common world wide. Name Origin: From the Greek kyanos = “blue.”
Kyanite, whose name derives from the Greek word kuanos sometimes referred to as “kyanos”, meaning deep blue, is a typically blue silicate mineral, commonly found in aluminium-rich metamorphic pegmatites and/or sedimentary rock. Kyanite in metamorphic rocks generally indicates pressures higher than four kilobars. Although potentially stable at lower pressure and low temperature, the activity of water is usually high enough under such conditions that it is replaced by hydrous aluminosilicates such as muscovite, pyrophyllite, or kaolinite. Kyanite is also known as disthene, rhaeticite and cyanite.
Kyanite is a member of the aluminosilicate series, which also includes the polymorph andalusite and the polymorph sillimanite. Kyanite is strongly anisotropic, in that its hardness varies depending on its crystallographic direction. In kyanite, this anisotropism can be considered an identifying characteristic.
Occurrence
Kyanite occurs in gneiss, schist, pegmatite, and quartz veins resulting from high pressure regional metamorphism of principally pelitic rocks. It occurs as detrital grains in sedimentary rocks. It occurs associated with staurolite, andalusite, sillimanite, talc, hornblende, gedrite, mullite and corundum.
Kyanite occurs in Manhattan schist, formed under extreme pressure as a result of the two landmasses that formed supercontinent Pangaea.
Physical Properties
Cleavage: {100} Perfect, {010} Imperfect Color: Blue, White, Gray, Green, Black. Density: 3.56 – 3.67, Average = 3.61 Diaphaneity: Translucent to transparent Fracture: Brittle – Generally displayed by glasses and most non-metallic minerals. Hardness: 4-7 Luminescence: Non-fluorescent. Luster: Vitreous – Pearly Streak: white
Danish and Swedish researchers have dated the enormous Hiawatha impact crater, a 31 km-wide meteorite crater buried under a kilometer of Greenlandic ice. The dating ends speculation that the meteorite impacted after the appearance of humans and opens up a new understanding of Earth’s evolution in the post-dinosaur era. Ever since 2015, when researchers at the University of Copenhagen’s GLOBE Institute discovered the Hiawatha impact crater in northwestern Greenland, uncertainty about the crater’s age has been the subject of considerable speculation. Could the asteroid have slammed into Earth as recently as 13,000 years ago, when humans had long populated the planet? Could its impact have catalyzed a nearly 1,000-year period of global cooling known as the Younger Dryas? New analyses performed on grains of sand and rocks from the Hiawatha impact crater by the Natural History Museum of Denmark and the GLOBE Institute at the University of Copenhagen, as well as the Swedish Museum of Natural History in Stockholm, demonstrate that the answer is no. The Hiawatha impact crater is far older. In fact, a new study published in the journal Science Advances today reports its age to be 58 million years old. “Dating the crater has been a particularly tough nut to crack, so it’s very satisfying that two laboratories in Denmark and Sweden, using different dating methods arrived at the same conclusion. As such, I’m convinced that we’ve determined the crater’s actual age, which is much older than many people once thought,” says Michael Storey of the Natural History Museum of Denmark. “Determining the new age of the crater surprised us all. In the future, it will help us investigate the impact’s possible effect on climate during an important epoch of Earth’s history” says Dr. Gavin Kenny of the Swedish Museum of Natural History. As one of those who helped discover the Hiawatha impact crater in 2015, Professor Nicolaj Krog Larsen of the GLOBE Institute at the University of Copenhagen is pleased that the crater’s exact age is now confirmed. “It is fantastic to now know its age. We’ve been working hard to find a way to date the crater since we discovered it seven years ago. Since then, we have been on several field trips to the area to collect samples associated with the Hiawatha impact,” says Professor Larsen.
A pair of Charles Darwin’s iconic notebooks have been returned to their rightful home more than 20 years after they were mysteriously stolen. The contents of the notebooks include the naturalist’s first doodle of the “tree of life,” which he sketched out decades before formulating his theory of evolution by natural selection.
The notebooks are part of the Darwin Archive at Cambridge University Library in the U.K., which contains journals, manuscripts and more than 15,000 letters written by Darwin. The journals were originally stored in the library’s high-security Special Collections Strong Rooms but were removed from storage in November 2000 for a photo shoot. Library officials assumed that the notebooks had been returned to safety after the photo shoot, but during a routine audit in January 2001, librarians discovered that the notebooks were missing. The library staff initially suspected that the notebooks had been misplaced, but in 2020, the staff conducted a new search for the documents — the largest in the library’s history — and came up empty-handed. The library concluded that the notebooks had most likely been stolen, Live Science previously reported.
But now, they’ve finally turned up: Librarians found the notebooks March 9 outside the door of a fourth-floor office in the 17-story building. The journals were swathed in plastic wrap and left in a box inside a bright-pink gift bag, along with a printed note that read “Librarian Happy Easter X,” according to a statement from the library.
“My sense of relief at the notebooks’ safe return is profound and almost impossible to adequately express,” Jessica Gardner, a librarian at Cambridge University Library, said in the statement. “I was heartbroken to learn of their loss, and my joy at their return is immense.”
The leather-bound notebooks are in “remarkably good condition,” and all the pages are accounted for, according to the statement. Experts think the notebooks have barely been handled, and special analysis of the ink has confirmed that the notebooks are almost certainly genuine, according to the BBC.
The notebooks are part of the “Transmutation Notebooks,” a collection of journals in which Darwin first laid out his ideas of how animals transmute, or change, over time, which we now know is the result of adaptations caused by genetic mutations in DNA. The recently recovered books were the second and third installments of the Transmutation Notebooks and are labeled “B” and “C.” Darwin wrote the Transmutation Notebooks in 1837, when he was 28 years old, shortly after returning from his five-year voyage around the world on the HMS Beagle.
The standout feature of the notebooks is a sketch of a rudimentary tree of life in notebook B showing how species diverge from a common ancestor over time, above which he simply wrote, “I think.” This was more than 20 years before Darwin published his theory of evolution in the book “On the Origin of Species” in 1859. “They may be tiny, just the size of postcards, but the notebooks’ impact on the history of science cannot be overstated,” Gardner said in the statement.
The library will reunite the notebooks with the rest of the Darwin Archive at Cambridge University Library, alongside the archives of other famous scientists, such as Sir Isaac Newton and Stephen Hawking, according to the statement. The three scientists are also buried right next to each other at Westminster Abbey in London, Live Science previously reported.
Members of the public can see the notebooks when they go on display as a part of the “Darwin in Conversation” exhibition showcasing Darwin’s letters and notebooks at Cambridge University Library in July. The exhibition will also be transferred to the New York Public Library in 2023. Digital copies of the two notebooks, B and C, can be viewed online.
Police are continuing to investigate the notebooks’ disappearance, but currently, there are no clues as to who stole the notebooks or where they have been for the past 20 years.
A violent encounter with a rival dinosaur may explain why Big John, the most massive Triceratops skeleton ever found, has a keyhole-shaped opening on its frill, a new study finds.
This fight happened more than 66 million years ago, but scientists think they know the assailant’s identity: It was likely another Triceratops, according to the study, published online Thursday (April 7) in the journal Scientific Reports(opens in new tab).
“The location, shape and size of the lesion suggest that it was caused by the horn of another Triceratops of similar size,” study lead researcher Ruggero D’Anastasio, a professor of biological anthropology at G. d’Annunzio University of Chieti-Pescara in Italy, told Live Science in an email.
As the name indicates, Big John was a big dinosaur: It measured about 26 feet (8 meters) long, and its skull was about 6.6 feet (2 m) wide. The skeleton, discovered in the Hell Creek Formation in South Dakota in 2014, is about 60% complete. These enormous features helped Big John make headlines last year when its fossilized remains sold for about $7.2 million (6.6 million euros(opens in new tab)) at an auction house in Paris.
Before the auction, Big John was taken to Italy, where study co-researcher Flavio Bacchia, of the fossil restoration company Zoic, prepared the specimen. Bacchia noticed the hole on the right side of Big John’s frill, which prompted him to reach out to scientists at Italian universities who could help analyze the lesion.
The “traumatic injury,” about 7.9 inches (20 centimeters) long and 2 inches (5 cm) wide, is longer than a person’s hand, D’Anastasio said. And it likely wasn’t made by a head-on attack.
Big John’s squamosal bone, which shows the traumatic lesion. (Image credit: Zoic LLC)
“The impact probably came from behind, as suggested by the location of the lesion itself and the shape of the ‘exit hole,’ which resembles the bullet holes described in forensic cases,” D’Anastasio said. The team tested this idea in the laboratory, simulating the impact with a cast of a Triceratops horn, “and the result confirms the hypotheses based on the size and shape of the lesion,” he said.
The wound, however, didn’t kill Big John, at least not right away. “Big John survived the trauma,” D’Anastasio said. “There are clear signs of bone healing, although the Triceratops died before healing was complete.”
An analysis of the bone remodeling at the lesion, compared with healing rates of traumatic injuries observed in modern reptiles, suggests that Big John got gored at least six months before dropping dead. “Perhaps the animal died after a few months from an infection following the trauma, but this is only a hypothesis to be demonstrated,” he noted.
A side view of Big John’s restored skull. (Image credit: Zoic LLC)
Big John’s fossilized remains after their restoration at Zoic in Trieste, Italy. (Image credit: Zoic LLC)
Big John is hardly the only horned dinosaur to have a hole in its skull. Scientists have long thought these holes were the remnants of wounds made by other horned dinosaurs, said Spencer Lucas, curator of paleontology at the New Mexico Museum of Natural History and Science in Albuquerque, who was not involved in the study. But this study is the first to actually investigate this claim, he said.
“It’s a good study,” Lucas told Live Science. “I think it’s very convincing.” However, it’s not a slam dunk: The perpetrator could have been another horned dinosaur, like Torosaurus, which lived alongside Triceratops, Lucas said.
“There’s really no way to know for sure, unless you find part of the horn sticking out of the wound or something like that, which is not likely,” Lucas said.
The finding also fits with the idea that Triceratops lived in social groups, “something like a herd,” Lucas added. In modern animals that face off against their own species, “a lot of times these types of combat or battles are basically to establish dominance or to establish territory,” Lucas said. So, perhaps Triceratops individuals living at the end of the Cretaceous period (145 million to 66 million years ago) were doing the same thing.
“That’s the real significance of the study,” Lucas said. “It’s giving us an insight into the behavior of at least this particular individual.”
However, Lucas did have a bone to pick with Big John, or at least its owner: Only a small sample of Big John’s lesion is available to researchers at G. D’Annunzio University, according to D’Anastasio. D’Anastasio was told by Zoic and the gallery that handled the auction that the buyer — whose identity is not known publicly — will soon make Big John’s skeleton available for scientific study. But that’s not the same as a museum or public institution owning a specimen, Lucas said. Individuals who privately own specimens can make these fossils available (or unavailable) to researchers at any time, meaning that scientists might not always have access to them.
“All published fossils should be available for scientific study,” Lucas said. “One wonders whether that will be the case with this fossil (apparently in private hands) in 10, 20 or 50 years.”
An immaculately preserved dinosaur leg uncovered in North Dakota may be a relic from the day a massive asteroid slammed into Earth, bringing the age of the nonavian dinosaurs to an end, scientists claim. That said, not all experts are convinced that the dino actually died on that fateful day 66 million years ago — or at least, they’re witholding judgment until more data is available for review.
“We need the whole story,” Kirk Johnson, the Sant Director of the Smithsonian National Museum of Natural History in Washington, D.C., told Live Science.
A team led by Robert DePalma, a doctoral student at the University of Manchester in the United Kingdom, uncovered the fossilized leg, which still has skin attached, and suggested that the dinosaur died and became buried during the famous asteroid impact, BBC News reported. The specimen has not yet been described in a peer-reviewed scientific journal.
Johnson said he’s frustrated about the way this discovery and previous ones from DePalma and his colleagues have been presented, with a “big media splash” preceding the release of any detailed, published data. This approach has made many scientists wary of any discoveries made at the fossil site in North Dakota, known as Tanis, he said. “It looks like it’s an amazing site, and the way it’s been rolled out has increased the controversy and doubt about the site,” he said.
According to Paul Barrett, a merit researcher at London’s Natural History Museum, the newfound dinosaur leg belongs to Thescelosaurus, an herbivorous dinosaur whose name means “wonderful lizard” in ancient Greek. “It’s from a group that we didn’t have any previous record of what its skin looked like, and it shows very conclusively that these animals were very scaly like lizards,” Barrett told BBC News. “They weren’t feathered like their meat-eating contemporaries.”
Based on his examination of the fossil, Barrett said the dinosaur’s leg was likely ripped off very quickly, and the limb bears no signs of disease or having been picked apart by scavengers. Barrett examined the fossil on behalf of BBC One, which will soon premiere a documentary(opens in new tab) about Tanis, where the specimen was recovered.
“It’s a cool fossil, if it’s what it looks like,” Johnson said. From the BBC photos and videos, it appears that the dinosaur leg has been mummified. “I don’t think we’ve ever seen a mummy of a Thescelosaurus before,” he told Live Science.
BBC One also called in Steve Brusatte, a vertebrate paleontologist and evolutionary biologist at the University of Edinburgh in Scotland, as an outside consultant on the project. Brusatte told BBC News that he’s skeptical of the idea that the Thescelosaurus perished on the exact day the dino-killing asteroid came whizzing through the sky and punched a huge hole, known as the Chicxulub crater, into the Yucatán Peninsula.
It’s possible that the Thescelosaurus and other animals discovered at the North Dakota site died days or years before but were violently uncovered during the asteroid impact and then reburied along with debris from the planet-rocking event, Brusatte said.
The Tanis site has drawn similar skepticism in the past, Science magazine reported(opens in new tab) in 2019.
That year, Robert DePalma, then a graduate student in paleontology at the University of Kansas, and his colleagues reported finding at the site fossilized fish whose gills were riddled with small glass spheres called spherules. These freshwater fish included sturgeon and paddlefish and were found jumbled together in a 4.2-foot-thick (1.3 meters) deposit, surrounded by scattered remnants of tree trunks and thick mud speckled with more glass spheres, according to Science.
New international research led by the University of St Andrews presents a novel way to understand the structure and formation of our oldest continents.
The research, published in the journal Earth and Planetary Science Letters reveals how the team from St Andrews, Greenland, Australia, Denmark, and Canada, used magmatic rocks, sourced from deep within the Earth, to sample the interior of cratons as a means to understand how they were formed.
Cratons are the ancient, stable, heart of the Earth’s continents, and their formation was a prerequisite for the evolution of complex life. The North Atlantic Craton extends from Northern Scotland through Greenland to North America, and contains the oldest crust known on Earth—up to 3.8 billion years old. How these ancient cratons were built is a major scientific debate, informing on one of the most fundamental questions in Earth science: when did plate tectonics begin operating?
Plate tectonics—the cycle of rigid tectonic plates in constant horizontal motion across the surface of the planet—makes Earth unique within the rocky planets of the solar system. Plate tectonics started at some point after the Earth formed 4.6 billion years ago, but it is unclear exactly when. Some scientists believe craton formation occurred as a result of plate tectonics, whereby they were assembled via horizontal stacking of crust. Others believe cratons were formed through non-plate tectonic processes, growing via so-called “vertical tectonics.”
The ability to understand the architecture of cratons and therefore how and when they were formed is, however, problematic, due to the difficulty in sampling rocks from within the deep crust and mantle, which in West Greenland is up to 250 km thick.
To address this, the research team used deep-sourced magmatic rocks known as kimberlites to sample the deep parts of the North Atlantic Craton. Kimberlites, which are famous for bringing diamonds to the surface, originate from the upper mantle, more than 100 km below Earth’s surface. As they ascend through the craton, their magma collects pieces of crust along the way, pieces that are hidden at the surface. In this way, kimberlites can sample parts of the deep continent that are otherwise inaccessible.
The researchers sampled a kimberlite from the coast of West Greenland, near Maniitsoq, and extracted from it microscopic zircon grains, each less than the width of a human hair, originating from crust deep within the craton. The team analysed these grains using high-precision laser ablation mass spectrometry.
Analysis revealed the age and chemistry of the zircon grains, which suggested that beneath the 3.0 billion-years old crust which today forms the Maniitsoq region, lies much older 3.8 billion-year-old crust. This older crust is today only found at the surface 150 km south of the kimberlite locality. Therefore, for it to have been sampled by the kimberlite, parts of it must have been transported laterally beneath the crust that is now at the surface, sometime after 3.0 billion years ago.
Lead scientist Dr. Nick Gardiner of the School of Earth and Environmental Sciences, University of St Andrews, said: “The kimberlite sample offers up these ancient zircon grains which imply the North Atlantic Craton was assembled by horizontally stacking different-aged slices of continental crust, likely in the late Archaean Eon after 3.0 billion years ago. These findings imply some cratons were formed through plate tectonic processes.”
The paper, “North Atlantic Craton architecture revealed by kimberlite-hosted crustal zircons,” is published in Earth and Planetary Science Letters
Reference: Nicholas J. Gardiner et al. North Atlantic Craton architecture revealed by kimberlite-hosted crustal zircons, Earth and Planetary Science Letters (2020). DOI: 10.1016/j.epsl.2020.116091
Curtin researchers have developed a new technique by studying the age of ancient grains of sand from beaches, rivers and rocks from around the world to reveal previously hidden details of the Earth’s distant geological past.
Lead researcher Dr Milo Barham, from the Timescales of Mineral Systems Group within Curtin’s School of Earth and Planetary Sciences, said the team devised a metric, which determines the ‘age distribution fingerprint’ of minerals known as zircon within sand, shedding new light on the evolution of the Earth’s surface over the last few billion years.
“While much of the original geological record is lost to erosion, durable minerals like zircon form sediments that effectively gather information from these lost worlds to paint a vivid picture of the planet’s history, including changing environments, the development of a habitable biosphere, the evolution of continents, and the accumulation of mineral resources at ancient plate boundaries,” Dr Barham said.
“This new approach allows a greater understanding of the nature of ancient geology in order to reconstruct the arrangement and movement of tectonic plates on Earth through time.
“The world’s beaches faithfully record a detailed history of our planet’s geological past, with billions of years of Earth’s history imprinted in the geology of each grain of sand and our technique helps unlock this information.”
Co-author Professor Chris Kirkland, also from the Timescales of Mineral Systems Group within Curtin’s School of Earth and Planetary Sciences, said the new method can be used to trace the Earth’s history with greater detail than previously achievable.
“Zircons contain chemical elements that allow us to date and reconstruct the conditions of mineral formation. Much like human population demographics trace the evolution of countries, this technique allows us to chart the evolution of continents by identifying the particular age population demographics of zircon grains in a sediment,” Professor Kirkland said.
“The way the Earth recycles itself through erosion is tracked in the pattern of ages of zircon grains in different geological settings. For example, the sediment on the west and east coasts of South America are completely different because there are many young grains on the west side that were created from crust plunging beneath the continent, driving earthquakes and volcanoes in the Andes. Whereas, on the east coast, all is relatively calm geologically and there is a mix of old and young grains picked up from a diversity of rocks across the Amazon basin.”
Dr Barham and Professor Kirkland are affiliated with The Institute for Geoscience Research (TIGeR), Curtin’s flagship Earth Sciences research institute and the research was funded by the Minerals Research Institute of Western Australia.
Reference: M. Barham, C.L. Kirkland, A.D. Handoko. Understanding ancient tectonic settings through detrital zircon analysis. Earth and Planetary Science Letters, 2022; 583: 117425 DOI: 10.1016/j.epsl.2022.117425
Provided by Curtin University. Original written by Lucien Wilkinson.
Totality will last nearly 5 minutes in some places.
Exactly two years from today, a total solar eclipse will sweep across North America, plunging tens of millions of people into the stunning darkness known as totality, when the moon passes in front of the sun, completely blocking its rays.
This eclipse, which will take place on Monday, April 8, 2024, will pass over Mexico, across the U.S. and through Canada, and will mesmerize even more people than the 2017 Great American Total Solar Eclipse. That blockbuster event had a nearly 70-mile-wide(opens in new tab) (113 kilometers) path of totality that passed from Oregon to South Carolina, where 12.25 million people lived. In contrast, the 2024 total solar eclipse’s 115-mile-wide (185 km) path of totality in the U.S. will pass from Texas through Maine and wow a region where 31.5 million people live, according to Kelly Korreck, head of science operations and project manager for the Solar Wind Electrons Alphas and Protons at NASA.
Even the length of totality will be longer. “The maximum duration of totality will be 4 minutes and 26 seconds in southwest Texas, so that’s almost double what we saw in 2017,” Korreck told Live Science. “That’s a lot more time in that darkness with the sun blotted out by the moon.”
During a total solar eclipse, the sun, moon and Earth line up on an imaginary 180-degree line. When this occurs, the moon blocks the sun’s light, plunging parts of Earth into a few minutes of darkness. During this darkness, or totality, temperatures can drop more than 15 degrees Fahrenheit(opens in new tab) (8.3 degrees Celsius). Despite it being daytime, many animals act like it’s nighttime, with birds roosting and crickets chirping, Korreck added.
On April 8, 2024, the total solar eclipse will make landfall at Isla Socorro, about 370 miles (600 km) off the coast of Mexico. Then it will pass through the Mexican cities of Mazatlán, Torreón and Durango before crossing into Texas at 1:27 p.m. CDT (2:27 p.m. EDT).
Once in the U.S., the total solar eclipse will pass through 15 states: Texas, Oklahoma, Arkansas, Missouri, Kentucky, Tennessee, Illinois, Indiana, Ohio, Michigan, Pennsylvania, New York, Vermont, New Hampshire, and Maine, exiting at 3:35 p.m. EDT (2:35 p.m. CDT). Finally, the path of totality will extend over parts of Canada, including New Brunswick, Nova Scotia and Newfoundland.
Even for those not along the path of totality, a celestial show awaits: “The entire U.S. will see a partial eclipse,” in which the moon partly covers the sun, Korreck said.
This animation shows the path of totality during the total lunar eclipse on April 8, 2024. (Image credit: Michael Zeiler, GreatAmericanEclipse.com)
During totality, people can look at the sky without protective eye gear, but that’s not the case for partial eclipse viewers. Before and after totality occurs and for people watching a partial eclipse from outside the path, it’s critical to wear protective eyewear — such as solar eclipse glasses (these are different from sunglasses). Other gadgets, such as solar eclipse viewers, can help people see the eclipse safely projected on a background. (Never look directly at a solar eclipse unless you are in complete totality, according to the American Academy of Ophthalmology(opens in new tab). Looking directly at the sun can damage your eyes.)
These tools will also come in handy for the Oct. 14, 2023 annular solar eclipse, which will pass over North America (from Oregon to Texas), Central America and South America. However, there will be no totality during this eclipse; rather, the moon will pass in front of the sun but not completely block its rays, leaving a “ring of fire” around the moon’s edges.
“It’s not as dramatic [as totality] but it’s still very beautiful — it’s the ring of fire,” Korreck said. This happens when the sun, moon and Earth line up, but “the moon is farthest from the Earth at that point when it passes between the Earth and the sun. That’s why you don’t get total coverage.”
For people who want to experience totality but don’t live in the projected path for the 2024 total solar eclipse, now is the time to reserve lodgings. After all, the next total solar eclipse to cross over the United States won’t happen again until Aug. 12, 2045.
“So in some ways, get your eclipse now,” Korreck said.
The super-rare Greenland shark that washed ashore in England last month had a brain infection when it died, according to an animal autopsy of its remains.
Pathologists discovered evidence of meningitis, an inflammation of the protective membranes that cover the brain and spinal cord, according to a statement from the Zoological Society of London(opens in new tab) (ZSL). This is the first reported disease-related death in a Greenland shark (Somniosus microcephalus), an elusive, long-lived species that lives in the deep waters of the Arctic and North Atlantic.
“During the post-mortem examination, the brain did look slightly discoloured and congested and the fluid around the brain was cloudy, raising the possibility of infection,” James Barnett, a pathologist with Cornwall Marine Pathology Team, a part of the U.K. Cetacean Strandings Investigation Programme (CSIP) and ZSL, said in the statement.
A microscopic examination of the Greenland shark’s brain fluid revealed Pasteurella, a species of bacteria. “This may well have been the cause of the meningitis,” Barnett said.
The Greenland shark was likely about 100 years old when it died. This may sound old, but it’s quite young for a Greenland shark, making this individual a juvenile female. While it’s unknown how long these sharks can live, they can make it to at least 272 years of age, a 2016 study published in the journal Science(opens in new tab) found.
The deceased shark, which measured 13 feet (4 meters) long and weighed 628 pounds (285 kilograms), stranded near Newlyn Harbour in Cornwall, in southwest England, on March 13, but the tide swept the animal’s body back out to sea, Live Science previously reported. A recreational boating company recovered the shark’s body on March 15, making it the U.K.’s second recorded Greenland shark stranding to date.
The meningitis found during the necropsy, or animal autopsy, likely explains why the shark had ventured out of its natural deep-water habitat and eventually stranded, according to the statement.
The shark’s body was damaged, and there were signs of hemorrhaging within the soft tissue around the pectoral fins, which, coupled with the silt found in its stomach, suggested the shark was still alive when it washed ashore, Barnett said. “As far as we’re aware, this is one of the first post-mortem examinations here in the U.K. of a Greenland shark and the first account of meningitis in this species,” Barnett said.
The shark’s death gives “insight into the life and death of a species we know little about,” Rob Deaville, CSIP project lead, said in the statement. “Ultimately, like most marine life, deep sea species such as Greenland sharks may also be impacted by human pressures on the ocean, but there is not enough evidence at this stage to make any connections.”
The team plans to publish a research study on the shark’s postmortem report.
This wave was taller than the Empire State Building.
In July 1958, an 8.3-magnitude earthquake at the Fairweather Fault rocked Alaska’s southern coast. The ground-shaking event caused a massive landslide at nearby Lituya Bay, which triggered a devastating tsunami that ripped through the narrow body of water and killed five people.
The colossal wave leveled trees on the steep slopes surrounding the bay up to a maximum height of 1,719 feet (524 meters) above sea level — higher than New York’s Empire State Building (which stands at 1,454 feet, or 443 m). This is known as the runup height, or the height the wave reaches after it makes landfall.
“It is the largest wave ever recorded and witnessed by eyewitnesses,” Hermann Fritz, a professor of civil and environmental engineering at the Georgia Institute of Technology who specializes in tsunamis and hurricanes, told Live Science. There have likely been larger waves in Earth’s history, which can be inferred from geological deposits, but these are open to interpretation, he added.
Fritz was the lead author of a study published in 2009 in the journal Pure and Applied Geophysics(opens in new tab) that recreated the Lituya Bay tsunami using a specialized 1:675 scale laboratory tank mimicking the shape of the bay. The team found that the maximum height of the wave responsible for leveling the trees was around 492 feet (150 m) tall, which makes it taller than any wave crest recorded on Earth.
For the tsunami to reach this height, the landslide that triggered it would have likely dumped around 1.1 billion cubic feet (30 million cubic meters) of rock into Lituya Bay, the researchers estimated. But while the extreme scale of the landslide provided the force to create such a massive wave, the shape of the bay is the real reason why the wave was so tall, Fritz said.
An aerial photo of Lituya Bay. The stripped back treeline created by the wave is visible around the water’s edge. (Image credit: Getty Images)
Lituya Bay is a fjord — a long and narrow coastal inlet with steep sides that was created by an ancient glacier. The bay is around 9 miles (14.5 kilometers) long and around 2 miles (3.2 km) across at its widest point. It has a maximum depth of 722 feet (220 m) and is connected to the Gulf of Alaska by a 984-feet-wide (300 m) opening. The landslide that triggered the 1958 tsunami occurred at Gilbert Inlet, at the end of the fjord furthest from the ocean.
During a typical landslide-generated tsunami, the resulting wave radiates out in a fan shape. But the narrow shape and steep slopes of Lituya Bay, as well as the point of origin, meant that the full power of the wave was channeled in one direction. And because there was nowhere else for the water to go, it was pushed up the surrounding slopes, which is why it had such a massive runup height, Fritz said.
In 2019, a study published in the journal Natural Hazards and Earth System Sciences(opens in new tab) created a visual simulation of the wave using computer models (see below).
(Image credit: José Manuel González-Vida et al. 2019)
This type of extreme wave is known as a megatsunami — a term initially coined by the media that refers to extremely large waves caused by landslides or volcanic island collapses, Fritz said.
Landslide-generated tsunamis are much rarer than tectonic tsunamis, which are caused by disruptions to the seafloor due to the movement of tectonic plates (such as the 2011 tsunami in Japan) and make up more than 90% of all tsunamis, Fritz said. Landslide-generated tsunamis are much more short-lived than tectonic tsunamis, he added.
“Landslide-generated tsunamis can be very large near the source but decay rapidly,” Fritz said. On the other hand, tectonic tsunamis start as small waves only a few feet high that travel enormous distances and increase in height when they reach the coast, he noted.
During the Lituya Bay tsunami, the wave had reduced to a height of less than 328 feet (100 m) by the time it reached the narrow opening of the fjord and did not radiate much further into the Gulf of Alaska, Fritz said.
Related: Why isn’t Earth perfectly round?
The 1958 tsunami was not the first of its kind in Lituya Bay. Geologists had previously discovered evidence of smaller tsunamis that occurred there in 1853, 1854 and 1936, but all evidence of these was washed away by the much bigger megatsunami, according to a report by the Western States Seismic Policy Council(opens in new tab) (WSSPC).
