For the first time, scientists have simulated how far and fast the Chicxulub asteroid, a.k.a. the one that killed the dinosaurs, impact spread around the globe. Besides wiping out the dinosaurs, it changed much more than that about our planet. The asteroid hit the ocean in what is now the Gulf of Mexico, but it was so powerful that it ejected seafloor sediment and even part of the Earth’s crust miles into the atmosphere. It also caused a wave nearly three miles high. Even 10 minutes after impact, the wave was still about a mile tall and was racing outward, already over 130 miles away from the crater. The video below shows the waves that spread around the world spreading devastation.
The scientific team found evidence to back up their simulation’s version of events in the fossil record. In what is now New Zealand, sediment cores show a very jumbled record of time. Though previously attributed to local earthquakes, scientists now think that the asteroid impact 7,500 miles away caused the disarray. Because even if the tsunami waves were “only” 30 feet high, they disturbed the ocean all the way down to the seafloor.
AGU Advances published the open access, peer-reviewed research project, which we saw in Science Alert. This may be the first scientific simulation of the asteroid’s impact, but there have been plenty of non-scientific ones. The Discovery Channel’s video of the devastation caused by a 300-mile-wide asteroid is essentially a disaster movie no one survives. Or if you want to work your way up to that level, there’s also a size comparison of asteroid impacts, starting with ones small enough to burn up in the atmosphere and ending with world-killers.
This news comes just weeks after the discovery of a planet-killer sized asteroid in our astronomical neighborhood. But don’t worry, it’s not predicted to cross paths with Earth anytime soon. And even if it did, NASA now knows how to bonk asteroids off course.
Melissa is Nerdist’s science & technology staff writer. She also moderates “science of” panels at conventions and co-hosts Star Warsologies, a podcast about science and Star Wars. Follow her on Twitter @melissatruth.
SYDNEY, Nov 22 (Reuters) – Authorities in the Solomon Islands said no tsunami warning would be issued after two earthquakes on Tuesday afternoon, including one with a magnitude of 7.0 just off the southwest coast.
The first quake hit at a depth of 15 km (9 miles), about 16 km (10 miles) southwest of the area of Malango, said the United States Geological Survey, which had initially put its magnitude at 7.3.
A second quake, with a magnitude of 6.0, struck nearby 30 minutes later.
The Solomon Islands Meteorological Service said there is no tsunami threat to the country, but warned about unusual sea currents in coastal areas.
“People are also advised to be vigilant as aftershocks are expected to continue,” an employee said on social media.
Widespread power outages are being reported across the island and the Solomon Islands Broadcasting said in a statement on Facebook that all radio services were off air.
The National Disaster Management Office said it has received reports that people felt the quake but are waiting for reports of damage.
“People in Honiara moved up to higher ground in the minutes after the earthquake but some have now moved down,” an official told Reuters by phone.
Seismology Fiji said the quake did not pose an immediate tsunami threat to the archipelago nation roughly 2,000 km to the southeast.
Reporting by Kirsty Needham in Sydney and Akanksha Khushi in Bengaluru;
Writing by Alasdair Pal and Lewis Jackson
Editing by Tom Hogue
Our Standards: The Thomson Reuters Trust Principles.
A tsunami warning was issued after a magnitude 7.0 earthquake struck off the coast of Solomon Islands on Tuesday, the United States Geological Survey said.
The US tsunami warning system said waves between 30cm and one metre could hit Solomon Islands, with waves of up to 30cm possible for Papua New Guinea and Vanuatu.
The office of the Solomon Islands prime minister advised people to move to higher ground, but stressed that no major damage to buildings in the capital Honiara had been reported.
The quake near Malango was shallow, with a depth of 10km, the USGS said.
People reported violent shaking that threw televisions and other items to the ground.
Freelance journalist Charley Piringi said he was standing outside a warehouse next to a primary and a secondary school on the outskirts of the capital, Honiara, when the quake struck, sending the children running.
“The earthquake rocked the place,” he said. “It was a huge one. We were all shocked, and everyone is running everywhere.”
A Twitter account that appeared to belong to the attorney general posted images of offices strewn with files and papers after the earthquake hit.
Honiara got rocked by m7.0 earthquake. pic.twitter.com/CZk6JCbAeY
— John Muria (Jnr) 🇸🇧 (@Jnr_Muria) November 22, 2022
“This was a big one,” Joy Nisha, a receptionist at the Heritage Park Hotel in Honiara, told the AFP news agency. “Some of the things in the hotel fell. Everyone seems OK, but panicky.”
An AFP reporter in the capital said the shaking lasted for about 20 seconds.
Power was out in some areas of the city and people were leaving their offices and fleeing to higher ground.
This is a developing story, please check back for updates.
The government of the island nation of Tonga called for an immediate evacuation inland on Friday following what it said was a 7.9 magnitude earthquake that triggered a tsunami warning.
“A strong earthquake has occurred near Tonga and felt in whole of Tonga. A dangerous tsunami could occur in minutes,” the government said in a statement on its website.
“You are advised to evacuate immediately inland to high ground or to the 3rd level of a steel or concrete building until the threat has passed. Mariners are advised to move to deep ocean away from reefs,” it said.
The Tonga government said the earthquake occurred at a depth of 10 kilometers (6.2 miles) about 200 kilometers (124 miles) east of the city of Neiafu, on the island of Vava’u.
The United States Geological Survey (USGA) said Friday a 7.3 magnitude earthquake had been detected 211 kilometers east of Neiafu, Tonga.
Earlier this year, Tonga was hit by a record-breaking eruption from an underwater volcano, which released a huge plume of ash, gas and steam up to 20 kilometers into the atmosphere and sent tsunami waves rolling across the Pacific.
The main island, Tongatapu, suffered significant damage from the tsunami and was smothered in a thick layer of ash.
LONDON — A tsunami alert has been issued for the tiny island nation of Tonga after a 7.3 magnitude earthquake struck off the country’s coast.
The quake hit at sea just before 11 p.m. local time approximately 128 miles from the Tongan capital of Nukuʻalofa at a depth of 15.4 miles.
“A strong earthquake has occurred near Tonga and felt in whole of Tonga,” the government said in a press release issuing the tsunami alert. “A dangerous tsunami could occur in minutes. You are advised to evacuate immediately inland to high ground or to the 3rd level of a steel or concrete building until the threat has passed. Mariners are advised to move to deep ocean away from reefs.”
In January, a volcanic eruption caused a tsunami that damaged or destroyed villages, resorts and knocked out an underwater communications cable.
This is a developing story. Please check back for updates.
The asteroid that ended the reign of the dinosaurs sixty-six million years ago also created a “mega-tsunami” whose waves grew more than a mile high, according to a new study.
Scientists recreated the impact of the Chicxulub, a nine-mile-wide asteroid that not only wiped out the dinosaurs but destroyed most of Earth’s species and plants. The study, which was published in AGU Advances, outlined the effects of the global tsunami and flooding.
Researchers hope their work can be used to unlock insight surrounding the geology of the Cretaceous period.
“This tsunami was strong enough to disturb and erode sediments in ocean basins halfway around the globe, leaving either a gap in the sedimentary records or a jumble of older sediments,” said Molly Range, the study’s lead researcher at the University of Michigan, in a statement.
NEW DINOSAUR SPECIES IS LARGEST FOUND IN AUSTRALIA, SCIENTISTS SAY
A new study indicates that the Chicxulub asteroid caused a “megatsunami” to spread all over the globe. (Esteban De Armas/Shutterstock)
Researchers simulated the mega-tsunami by using a three-dimensional computer program called a hydrocode, which modeled the first 10 minutes of the event, including crater formation, initiation of the tsunami, and impact.
The team’s simulation showed that the tsunami had spread outside the Gulf of Mexico and into the North Atlantic sea one after impact. Four hours later, waves moved through the Central American seaway and into the Pacific Ocean. 4Forty-eight hours after the Chicxulub asteroid crashed into the Earth, the tsunami waves had reached all of the world’s coastline.
103-MILLION-YEAR-OLD DINOSAUR FOSSIL FOUND IN OREGON
The asteroid was estimated to weigh two quadrillion pounds with a diameter of 8.7 miles with a density of about 165 pounds per cubic foot.
“Depending on the geometries of the coast and the advancing waves, most coastal regions would be inundated and eroded to some extent,” the study authors said in a statement. “Any historically documented tsunamis pale in comparison with such global impact.”
It is believed that the tsunami’s wave heights would have increased upon reaching shallow-bottom waters, with speeds exceeding 20 centimeters per second.
Scientists have discovered that the near 9-mile diameter asteroid that wiped out the dinosaurs also triggered a “mile high” tsunami that spread across the globe, according to EurekAlert.
Researchers from the University of Michigan studied the asteroid’s impact site in Mexico’s Yucatan peninsula — along with 100 other locations around the globe — and managed to recreate simulations of how far monstrous waters actually reached 66 million years ago.
“Any historically documented tsunamis pale in comparison with such global impact,” the authors wrote. “Depending on the geometries of the coast and the advancing waves, most coastal regions would be inundated and eroded to some extent.”
Compared to the devastating Indian Ocean earthquake tsunami of 2004 that took 230,000 lives, this prehistoric tidal wave “was up to 30,000 times larger,” according to the report — published in the journal AGU Advances.
“This tsunami was strong enough to disturb and erode sediments in ocean basins halfway around the globe, leaving either a gap in the sedimentary records or a jumble of older sediments,” lead author Molly Range said.
The research team found that the waters “radiated mainly to the east and northeast into the North Atlantic Ocean” while others flowed southwest into the non-existent Central American Seaway — now the landmass of Central America due to continental drift — before pouring into the South Pacific Ocean.
The asteroid that wiped out the dinosaurs is believed to have created a worldwide tsunami.Getty Images/Science Photo Libra
The other side of the globe — particularly the South Atlantic, North Pacific, Indian Ocean and the Mediterranean — were protected from the worst of the tsunami, according to the research.
Scientists used a “two stage strategy” to recount the ancient extinction level event. First, a computer simulation was made of the asteroid’s impact and crater formation followed by the globally chaotic 10 minutes that followed.
From this it was also discovered that the space rock had been hurtling at 27,000 mph and created a 62-mile wide crater which released “dense clouds of soot and dust into the atmosphere.”
A mere two minutes after impact, a massive wall of water shot up almost 3 miles high before making landfall as a catastrophic wave.
New research shows how the asteroid that wiped out prehistoric life created a monstrous tsunami as well.Getty Images/Science Photo Libra
By the 10-minute mark, the tsunami was already 137 miles from the Yucatan peninsula and on its track for worldwide destruction. It hit the North Atlantic an hour in, passed through the Central American Seaway four hours after, and reached the Indian Ocean on two sides after the currents crossed the Pacific Ocean from the east and the Atlantic from the west.
“Significant tsunami waves” hit almost every coastal region of Earth by hour 48.
Maximum tsunami wave amplitude following the asteroid impact 66 million years ago. Credit: From Range et al. in AGU Advances, 2022
Sixty-six million years ago a miles-wide asteroid struck Earth, wiping out nearly all the dinosaurs and around three-quarters of the planet’s plant and animal species.
It also triggered a monstrous tsunami with mile-high waves that scoured the ocean floor thousands of miles from the impact site on Mexico’s Yucatan Peninsula, according to a new University of Michigan-led study that was published online on October 4 in the journal AGU Advances.
The research study presents the first global simulation of the Chicxulub impact tsunami to be published in a peer-reviewed scientific journal. Additionally, U-M scientists reviewed the geological record at more than 100 sites worldwide and discovered evidence that supports their models’ predictions about the tsunami’s path and power.
“This tsunami was strong enough to disturb and erode sediments in ocean basins halfway around the globe, leaving either a gap in the sedimentary records or a jumble of older sediments,” said lead author Molly Range. She conducted the modeling study for a master’s thesis under U-M physical oceanographer and study co-author Brian Arbic and U-M paleoceanographer and study co-author Ted Moore.
Energy impact
The analysis of the geological record focused on “boundary sections.” These are marine sediments deposited just before or just after the asteroid impact and the subsequent
Modeled tsunami sea-surface height perturbation, in meters, four hours after the asteroid impact. This image shows results from the MOM6 model, one of two tsunami-propagation models used in the University of Michigan-led study. Credit: From Range et al. in AGU Advances, 2022
The researcher’s simulations show that the impact tsunami radiated mainly to the east and northeast into the North Atlantic Ocean, and to the southwest into the South Pacific Ocean through the Central American Seaway (which used to separate North America and South America).
In those basins and in some adjacent areas, underwater current speeds likely exceeded 20 centimeters per second (0.4 mph),. This velocity is powerful enough to erode fine-grained sediments on the seafloor.
In contrast, the South Atlantic, the North Pacific, the Indian Ocean, and the region that is today the Mediterranean were largely shielded from the strongest effects of the tsunami, according to the team’s simulation. In those places, the modeled current speeds were likely less than the 20 cm/sec threshold.
Geological corroboration
U-M’s Moore analyzed published records of 165 marine boundary sections for the review of the geological record. He was able to obtain usable information from 120 of them. Most of the sediments came from cores collected during scientific ocean-drilling projects.
The North Atlantic and South Pacific had the fewest locations with complete, uninterrupted K-Pg boundary sediments. In contrast, the largest number of complete K-Pg boundary sections were uncovered in the South Atlantic, the North Pacific, the Indian Ocean, and the Mediterranean.
Modeled tsunami sea-surface height perturbation, in meters, 24 hours after the asteroid impact. This image shows results from the MOM6 model, one of two tsunami-propagation models used in the University of Michigan-led study. Credit: From Range et al. in AGU Advances, 2022
“We found corroboration in the geological record for the predicted areas of maximal impact in the open ocean,” said Arbic. He is a professor of earth and environmental sciences and oversaw the project. “The geological evidence definitely strengthens the paper.”
Of special significance, according to the authors, are outcrops of the K-Pg boundary on the eastern shores of New Zealand’s north and south islands, which are more than 7,500 miles (12,000 kilometers) from the Yucatan impact site.
The heavily disturbed and incomplete New Zealand sediments, called olistostromal deposits, were originally thought to be the result of local tectonic activity. However, given the age of the deposits and their location directly in the modeled pathway of the Chicxulub impact tsunami, the U-M-led team of researchers suspects a different origin.
“We feel these deposits are recording the effects of the impact tsunami, and this is perhaps the most telling confirmation of the global significance of this event,” Range said.
Comparing models
The modeling portion of the study used a two-stage strategy. First, a large computer program called a hydrocode simulated the chaotic first 10 minutes of the event. This included the asteroid impact, crater formation, and initiation of the tsunami. That work was conducted by co-author Brandon Johnson of Purdue University.
Based on the findings of previous studies, the scientists modeled an asteroid that was 8.7 miles (14 kilometers) in diameter, moving at 27,000 mph (12 kilometers per second). It struck granitic crust overlain by thick sediments and shallow ocean waters, blasting an approximately 62-mile-wide (100-kilometer-wide) crater and ejecting dense clouds of soot and dust into the atmosphere.
Maximum tsunami wave amplitude, in centimeters, following the asteroid impact 66 million years ago. Credit: From Range et al. in AGU Advances, 2022
Two and a half minutes after the asteroid struck, a curtain of ejected material pushed a wall of water outward from the impact site, briefly forming a 2.8-mile-high (4.5-kilometer-high) wave that subsided as the ejecta fell back to Earth.
According to the U-M simulation, 10 minutes after the projectile hit the Yucatan, and 137 miles (220 kilometers) from the point of impact, a 0.93-mile-high (1.5-kilometer-high) tsunami wave—ring-shaped and outward-propagating—began sweeping across the ocean in all directions.
At the 10-minute mark, the results of Johnson’s iSALE hydrocode simulations were entered into two tsunami-propagation models, MOM6 and MOST, to track the giant waves across the ocean. MOM6 has been used to model tsunamis in the deep ocean, and NOAA uses the MOST model operationally for tsunami forecasts at its Tsunami Warning Centers.
“The big result here is that two global models with differing formulations gave almost identical results, and the geologic data on complete and incomplete sections are consistent with those results,” said Moore, professor emeritus of earth and environmental sciences. “The models and the verification data match nicely.”
According to the team’s simulation:
One hour after impact, the tsunami had spread outside the Gulf of Mexico and into the North Atlantic.
Four hours after impact, the waves had passed through the Central American Seaway and into the Pacific.
Twenty-four hours after impact, the waves had crossed most of the Pacific from the east and most of the Atlantic from the west and entered the Indian Ocean from both sides.
By 48 hours after impact, significant tsunami waves had reached most of the world’s coastlines.
Dramatic wave heights
For the current study, the research team did not attempt to estimate the extent of coastal flooding caused by the tsunami.
However, their models indicate that open-ocean wave heights in the Gulf of Mexico would have exceeded 328 feet (100 meters), with wave heights of more than 32.8 feet (10 meters) as the tsunami approached North Atlantic coastal regions and parts of South America’s Pacific coast.
As the tsunami neared those shorelines and encountered shallow bottom waters, wave heights would have increased dramatically through a process called shoaling. Current speeds would have exceeded the 0.4 mph (20 centimeters per second) threshold for most coastal areas worldwide.
“Depending on the geometries of the coast and the advancing waves, most coastal regions would be inundated and eroded to some extent,” according to the researchers. “Any historically documented tsunamis pale in comparison with such global impact.”
The follow-up
Arbic said that a follow-up study is planned to model the extent of coastal inundation worldwide. That study will be led by Vasily Titov of the National Oceanic and Atmospheric Administration’s Pacific Marine Environmental Lab, who is a co-author of the AGU Advances paper.
Reference: “The Chicxulub Impact Produced a Powerful Global Tsunami” by Molly M. Range, Brian K. Arbic, Brandon C. Johnson, Theodore C. Moore, Vasily Titov, Alistair J. Adcroft, Joseph K. Ansong, Christopher J. Hollis, Jeroen Ritsema, Christopher R. Scotese and He Wang, 4 October 2022, AGU Advances. DOI: 10.1029/2021AV000627
In addition to Range, Arbic, Moore, Johnson and Titov, the study authors are Alistair Adcroft of
Funding was provided by the National Science Foundation and the University of Michigan Associate Professor Support Fund, which is supported by the Margaret and Herman Sokol Faculty Awards. The MOM6 simulations were carried out on the Flux supercomputer provided by the University of Michigan Advanced Research Computing Technical Services.
Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more.
CNN
—
When a city-size asteroid slammed into Earth 66 million years ago, it wiped out the dinosaurs – and sent a monster tsunami rippling around the planet, according to new research.
The asteroid, about 8.7 miles (14 kilometers) wide, left an impact crater about 62 miles (100 kilometers) across near Mexico’s Yucatan peninsula. In addition to ending the reign of the dinosaurs, the direct hit triggered a mass extinction of 75% of animal and plant life on the planet.
When the asteroid hit, it created a series of cataclysmic events. Global temperatures fluctuated; plumes of aerosol, soot and dust filled the air; and wildfires started as flaming pieces of material blasted from the impact re-entered the atmosphere and rained down. Within 48 hours, a tsunami had circled the globe – and it was thousands of times more energetic than modern tsunamis caused by earthquakes.
Researchers set out to gain a better understanding of the tsunami and its reach through modeling. They found evidence to support their findings about the path and power of the tsunami by studying 120 ocean sediment cores from across the globe. A study detailing the findings published Tuesday in the journal American Geophysical Union Advances.
It’s the first global simulation of the tsunami caused by the Chicxulub impact to be published in a peer-reviewed scientific journal, according to the authors.
The tsunami was powerful enough to create towering waves more than a mile high and scour the ocean floor thousands of miles away from where the asteroid hit, according to the study. It effectively wiped away the sediment record of what happened before the event, as well as during it.
“This tsunami was strong enough to disturb and erode sediments in ocean basins halfway around the globe, leaving either a gap in the sedimentary records or a jumble of older sediments,” said lead author Molly Range, who began working on the study as an undergraduate student and completed it for her master’s thesis at the University of Michigan.
Researchers estimate that the tsunami was up to 30,000 times more energetic than the December 26, 2004 Indian Ocean tsunami, one of the largest on record, that killed more than 230,000 people. The energy of the asteroid impact was at least 100,000 times larger than the Tonga volcanic eruption earlier this year.
Brandon Johnson, study coauthor and an associate professor at Purdue University, used a large computer program called a hydrocode to simulate the first 10 minutes of the Chicxulub impact, including the formation of the crater and the beginning of the tsunami.
He included the size of the asteroid and its speed, which was estimated to be moving at 26,843 miles per hour (43,200 kilometers per hour) when it hit the granite crust and shallow waters of the Yucatan peninsula.
Less than three minutes later, rocks, sediments and other debris pushed a wall of water away from the impact, creating a 2.8 mile (4.5 kilometer) tall wave, according to the simulation. This wave subsided as exploded material fell back to Earth.
But as the debris fell, it created even more chaotic waves.
Ten minutes after impact, a ring-shaped wave about a mile high began traveling across the ocean in all directions from a point that was located 137 miles (220 kilometers) away from the impact.
This simulation was then entered into two different global tsunami models, MOM6 and MOST. While MOM6 is used to model deep ocean tsunamis, MOST is part of tsunami forecasting at the National Oceanic and Atmospheric Administration’s Tsunami Warning Centers.
Both models delivered almost the exact same results, creating a timeline of the tsunami for the research team.
An hour after impact, the tsunami had travel beyond the Gulf of Mexico into the North Atlantic Ocean. Four hours post-impact, the waves passed through the Central American Seaway and into the Pacific Ocean. The Central American Seaway once separated North and South America.
Within 24 hours, the waves entered the Indian Ocean from both sides after traveling across the Pacific and Atlantic oceans. And by 48 hours after impact, large tsunami waves had reached most of Earth’s coastlines.
The underwater current was strongest in the North Atlantic Ocean, the Central American Seaway and the South Pacific Ocean, exceeding 0.4 miles per hour (643 meters per hour), which is strong enough to blast away sediments on the ocean floor.
Meanwhile, the Indian Ocean, North Pacific, the South Atlantic and the Mediterranean were shielded from the worst of the tsunami, with lesser underwater currents.
The team analyzed information from 120 sediments that largely came from previous scientific ocean-drilling projects. There were more intact sediment layers in the waters protected from the tsunami’s wrath. Meanwhile, there were gaps in the sediment record for the North Atlantic and South Pacific oceans.
The researchers were surprised to find that sediment on the eastern shores of New Zealand’s north and south islands had been heavily disturbed with multiple gaps. Initially, scientists thought this was because of the activity of tectonic plates.
But the new model shows the sediments being directly in the pathway of the Chicxulub tsunami, despite being 7,500 miles (12,000 kilometers) away.
“We feel these deposits are recording the effects of the impact tsunami, and this is perhaps the most telling confirmation of the global significance of this event,” Range said.
While the team didn’t estimate the tsunami’s impact on coastal flooding, the model shows that the North Atlantic coastal regions and South America’s Pacific coast were likely hit with waves taller than 32.8 feet (20 meters). The waves only grew as they neared the shore, causing flooding and erosion.
Future research will model the extent of global flooding after the impact and how far inland the tsunami’s effects could be felt, according to study coauthor and University of Michigan professor and physical oceanographer Brian Arbic.
“Obviously the greatest inundations would have been closest to the impact site, but even far away the waves were likely to be very large,” Arbic said.
The dinosaur-killing asteroid that slammed into Earth 66 million years ago also triggered a jumbo-size tsunami with mile-high waves in the Gulf of Mexico whose waters traveled halfway around the world, a new study finds.
Researchers discovered evidence of this monumental tsunami after analyzing cores from more than 100 sites worldwide and creating digital models of the monstrous waves after the asteroid’s impact in Mexico’s Yucatán Peninsula.
“This tsunami was strong enough to disturb and erode sediments in ocean basins halfway around the globe,” study lead author Molly Range, who conducted the modeling study for a master’s thesis in the Department of Earth and Environmental Sciences at the University of Michigan, said in a statement.
The research on the mile-high tsunami, which was previously presented at the 2019 American Geophysical Union’s annual meeting, was published online Tuesday (Oct. 4) in the journal AGU Advances (opens in new tab).
Related: Could an asteroid destroy Earth?
Range dove into the tsunami’s journey immediately following the asteroid’s collision. Based on earlier findings, her team modeled an asteroid that measured 8.7 miles (14 kilometers) across and was zooming 27,000 mph (43,500 km/h), or 35 times the speed of sound when it struck Earth. After the asteroid hit, many lifeforms died; the nonavian dinosaurs went extinct (only birds, which are living dinosaurs, survive today) and about three-quarters of all plants and animal species were wiped out.
The modeled tsunami sea-surface height perturbation(in meters) four hours after the end-Cretaceous asteroid impact. (Image credit: Range et al. in AGU Advances, 2022)
Researchers are aware of many of the asteroid’s pernicious effects, such as sparking raging fires that cooked animals alive and pulverizing sulfur-rich rocks that led to lethal acid rain and extended global cooling. To learn more about the resulting tsunami, Range and her colleagues analyzed the Earth’s geology, successfully analyzing 120 “boundary sections,” or marine sediments laid down just before or after the mass extinction event, which marked the end of the Cretaceous period.
These boundary sections matched the predictions of their model of wave height and travel, Range said.
The initial energy from the impact tsunami was up to 30,000 times larger than the energy released by the December 2004 Indian Ocean earthquake tsunami that killed more than 230,000 people, the researchers found.
Once the asteroid struck Earth, it created a 62-mile-wide (100 km) crater and kicked up a dense cloud of dust and soot into the atmosphere. Just 2.5 minutes after the strike, a curtain of ejected material pushed a wall of water outward, briefly making a 2.8-mile-tall (4.5 km) wave that crashed down as the ejecta plummeted back to Earth, according to the simulation.
At the 10 minute mark, a 0.93-mile-high (1.5 km) tsunami wave about 137 miles (220 km) away from the impact site swept through the gulf in all directions. An hour after the impact, the tsunami had left the Gulf of Mexico and rushed into the North Atlantic. Four hours following the impact, the tsunami passed through the Central American Seaway — a passage that separated North from South America at the time — and into the Pacific.
A full day after the asteroid’s collision, the waves had traveled through most of the Pacific and the Atlantic, entering the Indian Ocean from both sides, and touching most of the globe’s coastlines 48 hours after the strike.
Related: 52-foot-tall ‘megaripples’ from dinosaur-killing asteroid are hiding under Louisiana
The modeled tsunami sea-surface height perturbation (in meters) 24 hours after the dinosaur-killing asteroid hit Earth. (Image credit: Range et al. in AGU Advances, 2022)
Tsunami’s power
After the impact, the tsunami radiated mostly to the east and northeast, gushing into the North Atlantic Ocean, as well as to the southwest via the Central American Seaway flowing into the South Pacific Ocean. Water traveled so quickly in these areas that it likely exceeded 0.4 mph (0.6 km/h), a velocity that can erode the seafloor’s fine-grained sediments.
Other regions largely escaped the tsunami’s power, including the South Atlantic, the North Pacific, the Indian Ocean and what is now the Mediterranean sea, according to the team’s models. Their simulations showed that the water speeds in these areas were less than the 0.4 mph threshold.
The maximum tsunami wave amplitude (in centimeters) following the asteroid impact that hit Earth 66 million years ago. (Image credit: Range et al. in AGU Advances, 2022)
The team even found outcrops — or exposed rocky deposits — from the impact event on eastern New Zealand’s north and south islands, a distance of more than 7,500 miles (12,000 km) from the Chicxulub crater in Mexico. Originally, scientists thought that these outcrops were from local tectonic activity. But due to their age and location in the tsunami’s modeled route, the study’s researchers pinned it to the asteroid’s massive waves.
“We feel these deposits are recording the effects of the impact tsunami, and this is perhaps the most telling confirmation of the global significance of this event,” Range said.
While the models didn’t assess coastal flooding, they did reveal that open-ocean waves in the Gulf of Mexico would have exceeded 328 feet (100 m), and waves would have reached heights of more than 32.8 feet (10 m) as the tsunami approached the North Atlantic’s coastal regions and parts of the South America’s Pacific coast, according to the statement.
As the water became shallow near the coast, wave heights would have risen dramatically.
“Depending on the geometries of the coast and the advancing waves, most coastal regions would be inundated and eroded to some extent,” the authors wrote in the study. “Any historically documented tsunamis pale in comparison with such global impact.”
