How a Two-Story Boulder Ended Up on a 120-Foot-High Cliff
Just a stone's throw from the ocean, indeed.
Small family farms dot the southern coast of Tongatapu, the largest island of Tonga in the South Pacific. But something lies amid the cassava and banana plants that doesn't belong: a staggeringly large, off-white boulder.
The rock, which features prominently in Tongan mythology, was recently scrutinized by scientists. New results suggest that the object was transported inland thousands of years ago when tsunami waves breached a 120-foot cliff. That event might have been set in motion by an earthquake in the nearby Tonga-Kermadec Trench, the team reported in the journal Marine Geology.
From Japan to the Bahamas, scientists have spotted hulking rocks that simply don't fit their surroundings. Such boulders were likely transported by moving water, and the powerful waves of tsunamis are often invoked as culprits.
Last July, researchers traveled to Tongatapu to analyze several coastal boulders. The team got a tip from a group of Tongan farmers about a boulder nearby on farmland belonging to the Teisina family.
That boulder turned out to be roughly the size of a two-story house. 'It was unreal,' said Martin Köhler, a geoscientist at the University of Queensland in Australia, who led the research. The rock, made of limestone, was nearly completely camouflaged by vegetation. Köhler's team surveyed the rock, known locally as Maka Lahi or 'Big Rock,' and calculated that it weighed more than 1,300 tons.
Maka Lahi is more than 650 feet inland. As there's nothing taller around, the rock must have been dislodged from its earlier home by one or more enormous waves, the team surmised.
Using computer simulations, the researchers modeled waves of different heights that rolled in anywhere from every 10 to 600 seconds. Waves of at least 160 feet high were needed to dislodge the boulder and send it rolling or sliding to its final resting place. Based on the age of the flowstone growing on the lower half of the boulder, the researchers estimated that the massive waves that transported Maka Lahi struck about 7,000 years ago, before the human occupation of Tonga. — KATHERINE KORNEI /NYT
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Observer
4 days ago
- Observer
How a Two-Story Boulder Ended Up on a 120-Foot-High Cliff
Just a stone's throw from the ocean, indeed. Small family farms dot the southern coast of Tongatapu, the largest island of Tonga in the South Pacific. But something lies amid the cassava and banana plants that doesn't belong: a staggeringly large, off-white boulder. The rock, which features prominently in Tongan mythology, was recently scrutinized by scientists. New results suggest that the object was transported inland thousands of years ago when tsunami waves breached a 120-foot cliff. That event might have been set in motion by an earthquake in the nearby Tonga-Kermadec Trench, the team reported in the journal Marine Geology. From Japan to the Bahamas, scientists have spotted hulking rocks that simply don't fit their surroundings. Such boulders were likely transported by moving water, and the powerful waves of tsunamis are often invoked as culprits. Last July, researchers traveled to Tongatapu to analyze several coastal boulders. The team got a tip from a group of Tongan farmers about a boulder nearby on farmland belonging to the Teisina family. That boulder turned out to be roughly the size of a two-story house. 'It was unreal,' said Martin Köhler, a geoscientist at the University of Queensland in Australia, who led the research. The rock, made of limestone, was nearly completely camouflaged by vegetation. Köhler's team surveyed the rock, known locally as Maka Lahi or 'Big Rock,' and calculated that it weighed more than 1,300 tons. Maka Lahi is more than 650 feet inland. As there's nothing taller around, the rock must have been dislodged from its earlier home by one or more enormous waves, the team surmised. Using computer simulations, the researchers modeled waves of different heights that rolled in anywhere from every 10 to 600 seconds. Waves of at least 160 feet high were needed to dislodge the boulder and send it rolling or sliding to its final resting place. Based on the age of the flowstone growing on the lower half of the boulder, the researchers estimated that the massive waves that transported Maka Lahi struck about 7,000 years ago, before the human occupation of Tonga. — KATHERINE KORNEI /NYT
Observer
03-06-2025
- Observer
This Dinosaur Had Feathers and Probably Flew Like a Chicken
In 1861, scientists discovered Archaeopteryx, a dinosaur with feathers, in 150 million-year-old limestones in Solnhofen, Germany. They didn't know it at the time, but that fossilized skeleton — and the several that followed — provided a key piece of evidence for the theory of evolution, as well as for the fact that birds were actually dinosaurs. Since then, researchers have pored over every detail of available specimens, trying to puzzle out how birds came to fly. So you might expect that such a well-studied fossil species wouldn't be capable of surprises. But in a new paper, a team led by Jingmai O'Connor, a paleontologist at the Field Museum in Chicago, revealed previously unrecorded soft tissues and skeletal details from a new specimen, known as the Chicago Archaeopteryx. What they found also helps explain why some feathered dinosaurs got off the ground, if only for short-haul flights. Many Archaeopteryx specimens are too flattened by geology to discern important skeletal details. The latest specimen, acquired by the Field Museum in 2022, let O'Connor's team address some of the anatomical uncertainties. Unlike other specimens, the bones of the Chicago Archaeopteryx were preserved in three dimensions, allowing the researchers to better evaluate the skull's palate. That showed the earliest signs of an evolutionary trajectory toward the skulls of modern birds. In another accident of fossilization, the carcass's wings were separated from the body, leaving them 'pristinely preserved.' The team confirmed that rather than having two layers of wing feathers, Archaeopteryx actually had three. In modern birds, that third layer helps link the shorter forearm to the body to create a continuous lift surface, which allows for sustained flight. — ASHER ELBEIN / NYT
Observer
05-05-2025
- Observer
A Roman Gladiator and a Lion Met in Combat. Only One Walked Away.
Gladiators battled lions and other wild animals in the arenas of the Roman Empire. But for all the tales of combat depicted in ancient texts, marble reliefs and mosaics, and then retold in movies and other modern media, archaeologists have never found direct physical evidence, such as skeletons of gladiators bearing animal-induced wounds. At last, proof of classical combat between man and beast has been found in the form of a skeleton from a Roman settlement in Britain. The skeleton was discovered 20 years ago, in an excavation spurred by a couple hoping to renovate the yard of their home in the English city of York. An initial survey turned up evidence of an ancient cemetery, halting the construction plans. 'Britain is rich with Roman archaeology,' said Tim Thompson, an anthropologist at Maynooth University in Ireland and an author of a paper that describes the discovery in the journal PLOS One. 'You pretty much can't shove a spade in the ground without hitting something ancient and archaeological.' The larger site contained the buried remains of more than 80 individuals, and many of their bodies showed signs of trauma. The demographics of the deceased, the types of injuries in their bones and the manner in which they were interred suggested that they had fought as gladiators about 1,800 years ago, when what is now York was an outpost of the Roman Empire. One skeleton in particular, identified by researchers as 6DT19, had unusual wounds: small indentations in the hip bones. Other researchers had noted that these notches looked like bite marks from a large animal, perhaps a lion. To determine if the indentations of 6DT19's hip really were bite marks, Thompson and his colleagues first had to collect data on what the bite marks of large mammals look like. For that, they made a somewhat unusual request of several British zoos: a chance to examine their lions' leftovers. By shining a grid of light on the bones gnawed on by zoo animals, the researchers created a map of the dimensions and depth of the animals' bites. They then created a map of 6DT19's hip bones and compared the bite marks left by the different animals with the indentations on the skeleton. Sure enough, the Roman combatant's injuries were best explained by a lion's bite. However, the hip bite probably isn't what killed 6DT19. 'We think the individual was incapacitated in some way, and then the animal came along, bit and dragged the body away,' Thompson said. — KATE GOLEMBIEWSKI /NYT
