Kurzgesagt – In a Nutshell
Sources – Dinosaur Apocalypse
We would like to thank the following experts for their support:
Prof. Sean Gullick
Research Professor for Geological Science at the University of Texas
Prof. Timothy Bralower
Professor of Geoscience at the Pennsylvania State University
Professor Kliti Grice FRACI CChem, FGSEAG, FAA
Founding Director of Western Australian-Organic and Isotope Geochemistry Centre (WA-OIGC) School of Earth and Planetary Sciences, Curtin University, Australia
Bettina Schaefer
PhD candidate, Western Australian-Organic and Isotope Geochemistry Centre (WA-OIGC) School of Earth and Planetary Sciences, Curtin University, Australia
Cathy Ezrailson, Ph.D
Co-author, Chicxulub: The Impact and Tsunami (w/ David Shonting, ScD.
Albert Chen
Department of Earth Sciences, University of Cambridge
Sources:
This sequence of events is calculated by Paul Birch. Here is the table of stages of cooling and how long they take:
– 66 million years ago, the continuity of the dinosaurs had been going on for around 165 million years and it didn’t seem this would change any time soon.
Throughout this document we speak of different periods and eras Earth's history. Here is a brief overview of the geological timescale:
#International Chronostratigraphic Chart, 2020
https://stratigraphy.org/ICSchart/ChronostratChart2020-03.pdf
The Mesozoic is the Era when dinosaurs wandered on Earth. It is divided into three periods: The Triassic, the Jurassic and the Cretaceous. The Cretaceous ends 66 million years ago and is the period in which our story takes place.
#When did dinosaurs live?, NHM London
https://www.nhm.ac.uk/discover/when-did-dinosaurs-live.html
Quote: “Non-bird dinosaurs lived between about 245 and 66 million years ago, in a time known as the Mesozoic Era.”
– The world was warm and pleasant and most of the land was covered with lush forests with an incredible diversity of trees, flowers, ferns and trillions of critters.
#Blogs of the European Geosciences Union, What can the Cretaceous tell us about our climate?, 2018.
https://blogs.egu.eu/divisions/cl/2018/08/20/what-can-the-cretaceous-tell-us-about-our-climate/
Quote: “Another intriguing aspect of the Cretaceous period is the warm and stable climate, with tropical and polar temperatures higher than today, lower gradient from the Equator to the Poles, as well as from the land to the ocean and fewer seasonal extremes. Rainfall and atmospheric greenhouse gas concentrations (e.g. CO2, CH4) were higher in the Cretaceous compared to today explaining partly the relatively warmer climate at the global scale.”
#The Cretaceous Period, UCMP, 2011
https://ucmp.berkeley.edu/mesozoic/cretaceous/cretaceous.php
Quote: “No great extinction or burst of diversity separated the Cretaceous from the Jurassic Period that had preceded it. In some ways, things went on as they had. Dinosaurs both great and small moved through forests of ferns, cycads, and conifers. Ammonites, belemnites, other molluscs, and fish were hunted by great "marine reptiles," and pterosaurs and birds flapped and soared in the air above. Yet the Cretaceous saw the first appearance of many lifeforms that would go on to play key roles in the coming Cenozoic world.
Quote: “Perhaps the most important of these events, at least for terrestrial life, was the first appearance of the flowering plants, also called the angiosperms or Anthophyta. First appearing in the Lower Cretaceous around 125 million years ago, the flowering plants first radiated in the middle Cretaceous, about 100 million years ago. [...] Ferns dominated open, dry and/or low-nutrient lands. Typical Jurassic vegetation, including conifers, cycads, and other gymnosperms, continued on into the Lower Cretaceous without significant changes. At the beginning of this period, conifer diversity was fairly low in the higher latitudes of the Northern Hemisphere, but by the middle of the period, species diversification was increasing exponentially. Swamps were dominated by conifers and angiosperm dicots. [...] Forests evolved to look similar to present day forests, with oaks, hickories, and magnolias becoming common in North America by the end of the Cretaceous.”
– Dinosaurs were ubiquitous and had diversified into hundreds of species of all sizes and forms. Titanosaurs, large gentle giants shared the world with famous beasts like Tyrannosaurus rex or Edmontosaurus. Pectinodon hunted in the undergrowth while Edmontosaurus wandered coastlines and swamps.
The time we are describing here is the Cretaceous. It is the last period and the peak of the Mesozoic, the era of the dinosaurs.
#Cretaceous Period: Biotic Diversity and Biogeography – An Introduction, 2016
Quote: “Many of the giant sauropods were extinct by the end of the Jurassic, and by the Early Cretaceous they were being “replaced” by other plant-eating dinosaurs, notably the ornithopods. Theropod dinosaurs, including the iconic Tyrannosaurus rex, were the top terrestrial predators until the end of the Cretaceous.”
#How many dinosaur species were there? Fossil bias and true richness estimated using a Poisson sampling model, 2016
https://royalsocietypublishing.org/doi/10.1098/rstb.2015.0219
Quote: “For the final stages of the Cretaceous, Wang & Dodson [18] estimated 200–300 genera of dinosaurs roaming our planet, corroborated by our estimates of 221 and 227 genera for Campanian and Maastrichtian respectively (see the electronic supplementary material, figure S5 and table S2).”
Fossils of Edmontosaurus have been found in the Prince Creek Formation, an area that provides many fossils from the Upper Cretaceous:
#Re-examination of the cranial osteology of the Arctic Alaskan hadrosaurine with implications for its taxonomic status, 2020
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0232410
Quote: “The Prince Creek Formation hadrosaurine possesses a short dorsolateral process of the laterosphenoid, one of the diagnostic characters of Edmontosaurus. The Prince Creek Formation hadrosaurine also shows affinity to Edmontosaurus regalis in the presence of a horizontal shelf of the jugal.”
“Almost all of the hadrosaurid body fossils in Alaska come from the Upper Cretaceous Prince Creek Formation (PCF), which crops out along the Colville River, North Slope, Alaska.”
#Theropod teeth from the Prince Creek Formation (Cretaceous) of northern Alaska, with speculations on Arctic Dinosaur paleoecolo, 2000
Quote. “Theropod teeth are taxonomically diagnostic components of dinosaur assemblages. Seventy teeth have been recovered from six different localities in the Kogosukruk Tongue of the Prince Creek Formation (Upper Cretaceous) of the North Slope of Alaska”
Since most fossils of Edmontosaurus were found in coastal areas, it is believed that it used to live near coastlines:
#Theropod teeth from the Prince Creek Formation (Cretaceous) of northern Alaska, with speculations on Arctic Dinosaur paleoecolo, 2000
Quote: Based on the abundance of organic rich layers, megafloral remains, and wood, and paleogeographic reconstructions that place the rising Brooks Range 100s of kilometers away from the area, we postulate that the Prince Creek Formation was formed in a well-vegetated,
coastal, lowland environment.
Pectinodon is only known from one tooth, which makes it hard to describe it in great detail, but it is believed to have looked similar to Stenonychosaurus:
#Multivariate Analyses of Small Theropod Dinosaur Teeth and Implications for Paleoecological Turnover through Time, 2013
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0054329
Quote: “The holotype specimens of other species are inadequate for these kinds of analyses because they are either single teeth (Pectinodon bakkeri, Richardoestesia isosceles, Troodon formosus, Zapsalis abradens), or the teeth of the type specimen are germ teeth (Richardoestesia gilmorei) that are incompletely erupted.”
#Stenonychosaurus pictures and facts, dinosaurs database, 2020
https://dinosaurpictures.org/Stenonychosaurus-pictures
– Things were good for our feathered dinosaur buddies. Until a tiny, tiny detail in the sky changed.
The hypothesis that many of the dinosaurs actually had feathers has been broadly accepted since the first discovery of perfectly preserved specimens in China in the 1990s.
This is the original study. Unfortunately you can access only the abstract:
#An exceptionally well-preserved theropod dinosaur from the Yixian Formation of China, 1998
https://www.nature.com/articles/34356
Quote: “Both specimens have interesting integumentary structures that could provide information about the origin of feathers.”
National Geographic provides a good summary of the whole discussion on feathered dinosaurs, including a description of theses ancient feathers, which looked very different to modern day feathers:
#Dinosaur Feathers Changed With Age, 2010
https://www.nationalgeographic.com/news/2010/4/100428-new-dinosaur-feathers-change-age/
Quote: “New found fossils of a feathered dinosaur suggest that the extinct reptiles might have possessed a diversity in plumage types that puts modern birds to shame.”
Due to the light material feathers are made of, it is very unlikely for them to preserve, but based on the few fossils we have we can make assumptions on other dinosaur species as well. For example, T-Rex most probably had feathers even though we haven’t found one specimen that showed feathers.
#Finally, You Can See Dinosaurs in All Their Feathered Glory, 2016
Quote: ““One of the most important things about the Yutyrannus is that we can infer from it that the Tyrannosaurus rex must also have had feathers,” says Norell. While these larger dinosaurs couldn’t fly, they likely used their primitive plumage for insulation or visual displays, the same way modern peacocks attract mates. And fossil evidence shows that feathered dinosaurs probably came in a rainbow of colors.”
Some dinosaur species got to live on after the asteroid impact and eventually transformed into birds:
#How Dinosaurs Shrank and Became Birds, 2015
https://www.scientificamerican.com/article/how-dinosaurs-shrank-and-became-birds/
Quote: “Modern birds descended from a group of two-legged dinosaurs known as theropods, whose members include the towering Tyrannosaurus rex and the smaller velociraptors. The theropods most closely related to avians generally weighed between 100 and 500 pounds — giants compared to most modern birds — and they had large snouts, big teeth, and not much between the ears. A velociraptor, for example, had a skull like a coyote’s and a brain roughly the size of a pigeon’s.”
#Downsized Dinosaurs: The Evolutionary Transition to Modern Birds, 2009
https://evolution-outreach.biomedcentral.com/articles/10.1007/s12052-009-0133-4
Quote: “The origin of modern birds from animals similar to Tyrannosaurus rex is among the most remarkable examples of an evolutionary transition.”
– A tiny dot, that for many weeks slowly became bigger and brighter. Until one fateful day, it seemed to be like another, small moon in the night sky. And then it faded from sight as it dipped into earth’s shadow. For a few more hours the illusion of continuity was upheld.
#David Shonting and Cathy Ezrailson, Chicxulub: The Impact and Tsunami, 2017. P.xx
https://www.springer.com/gp/book/9783319394855
Quote: “From our vantage point, the asteroid appears to grow in size and intensity each night, soon surpassing the brightness of the “evening star” – the planet Venus Within 6 hours of its early morning Earth impact, this disc will have increased, appearing as a smaller version of our full Moon. As its position changes relative to our vantage point and that of the sun, it begins to move into Earth’s shadow, briefly appearing as a brilliant crescent. Soon, the object becomes fully eclipsed, vanishing into a black void as if turned off by a galactic switch.”
– Until it ws not anymore. In the morning the object suddenly appears again. Now almost as large as the sun in the sky and growing every moment, heading for the coast near the Yucatan Peninsula. It takes the asteroid only two seconds to pass through the thin layer between space and the ground to make contact. As it enters the atmosphere at almost 60 times the speed of sound...
#David Shonting and Cathy Ezrailson, Chicxulub: The Impact and Tsunami, 2017.
https://www.springer.com/gp/book/9783319394855
Quote: “Just before the object’s collision with Earth, it enters the thin upper atmosphere white ball streaked with yellow and reds. It continues to punch downwards, as if a sudden quarter-sized Sun gone amuck”
“Within seconds, the fiery object, with its blinding silver-white contrail, traverses its way through some 50 km of atmosphere.”
A study from 2020 simulated the consequences of the impact using two different velocities: 12 km/s and 20 km/s, but they state that 20 km/s is more probable.
#A steeply-inclined trajectory for the Chicxulub impact, 2020.
https://www.nature.com/articles/s41467-020-15269-x
Quote: “The simulations assumed a flat, […] two impact speeds (12 and 20 km/s)."
The impact simulations shown in Figs. 2 and 3 employ an impact speed of 12 km/s, only slightly larger than the minimum possible speed—Earth’s escape velocity of 11.2 km/s. While these results are likely to be representative of the ~25% of all impacts that occur at speeds below 15 km/s, we also conducted another suite of simulations with a more probable impact speed of 20 km/s (close to Earth’s mean and median asteroid impact speed23)
The speed of sound is about 331.29 m/s.
#Speed of Sound, Britannnica, 2021
https://www.britannica.com/science/speed-of-sound-physics
Quote: “Speed of sound, speed at which sound waves propagate through different materials. In particular, for dry air at a temperature of 0 °C (32 °F), the modern value for the speed of sound is 331.29 metres (1,086.9 feet) per second. The speed of sound in liquid water at 8 °C (46 °F) is about 1,439 metres (4,721 feet) per second.”
We calculate with a velocity of 20km/s, which is 20.000 m/s, making it 60 times faster than the speed of sound in our atmosphere.
What we describe here as “thin layer between space and the ground” is the stratosphere that reaches up to 50 km above the Earth’s surface.
– Larger than Mount Everest, it reaches from the ocean high into the atmosphere, higher than passenger planes would fly millions of years later.
The range given for the diameter of the asteroid is huge, ranging from 10 to 80 km:
#Assessments of the energy, mass and size of the Chicxulub Impactor, 2014
https://arxiv.org/abs/1403.6391
Quote: “Finally, the diameter of the object is in the range of 10.6 km to 80.9 km”
This study from 2020 performed a 3D simulation on the effects of the impact for different impact angles, diameters and velocities. They used a diameter of 17 km and of 21 km :
#Collins GS et al., A steeply-inclined trajectory for the Chicxulub impact, 2020.
https://www.nature.com/articles/s41467-020-15269-x
This study performed their calculations on a 12 km - sized asteroid.
#Sean P. S. Gulick, The first day of the Cenozoic, 2019.
https://www.pnas.org/content/116/39/19342
Quote: “A) Approaching 12-km-sized impactor over the preimpact target of the Yucatán peninsula. “
So these estimates are on the lower end of the range, which is still higher than an average passenger airplane travels and than Mount Everest. We decided to go with a cautious size estimate for our video.
#Why can't an airplane just fly into space? Why do we need rockets?
https://spaceplace.nasa.gov/review/dr-marc-technology/rockets.html
Quote: “Large passenger planes can't fly much higher than about 12 kilometers (7.5 miles). The air is too thin above that altitude to hold the plane up.”
The height of Everest, Encyclopedia Britannica
https://www.britannica.com/place/Mount-Everest/The-height-of-Everest
Quote: “The figure 29,028 feet (8,848 metres), plus or minus a fraction, was established by the Survey of India between 1952 and 1954 and became widely accepted”
– As the asteroid hits the shallow ocean and the bedrock below, the energy of billions of nuclear weapons is released all at once as the asteroid vaporizes.
#David Shonting and Cathy Ezrailson, Chicxulub: The Impact and Tsunami, 2017. P.26
https://www.springer.com/gp/book/9783319394855
Quote: “The initial blast pressures, and heat equivalent to 108 Mt (around 7 billion Hiroshima bombs”
The energy released by nuclear weapons is typically measured in TNT equivalent. The nuclear bombs dropped on Hiroshima and Nagasaki had a TNT-equivalent of 13-18 kilotons and 19-23 kilotons.
#John Malik, The Yields of the Hiroshima and Nagasaki Nuclear Explosions, Los Alamos National Laboratory, 1985.
https://permalink.lanl.gov/object/tr?what=info:lanl-repo/lareport/LA-08819
Quote: “The yield of the Fat Man has been determined rather well, being given variously from 19-24 kt. (Present official yield is 23 kt.1) Estimates 2-7 for the Little Boy have ranged from 6-23 kt. (The current official yield is 13 kt.1) ”
The energy released by the asteroid that killed the dinosaurs is estimated to be around 100 million megaton:
#Regional Effects, Chicxulub Impact Event, Lunar and Planetary Institute
https://www.lpi.usra.edu/science/kring/Chicxulub/regional-effects/
Quote: “The Chicxulub impact event was an ~100 million megaton blast that devastated the Gulf of Mexico region.”
This is roughly 100 billion times more powerful than the two nuclear weapons used during world war 2.
– A flash of light illuminates the sky as an eerie bright white sphere grows over the Gulf of Mexico.
#David Shonting and Cathy Ezrailson, Chicxulub: The Impact and Tsunami, 2017. P xxi
https://www.springer.com/gp/book/9783319394855
Quote: “After several more seconds, a reborn white sphere began to rise brightly in the west – illuminating the horizon like the dawn of a giant sun.”
– Bedrock melts into seething hot plasma tens of thousands of degrees hot. The thermal radiation from the explosion travels with the speed of light and immediately burns everything in a radius of about 1500 kilometers.
#Sean P. S. Gulick, The first day of the Cenozoic, 2019.
https://www.pnas.org/content/116/39/19342
Quote: “For Chicxulub, the plume is considered to emit sufficient thermal radiation to ignite flora up to 1,000 to 1,500 km from the impact site”
Thermal radiation released by an explosion travels always travels at the speed of light.
#Thermal Radiation, Britannica, 2021
https://www.britannica.com/science/thermal-radiation
Quote: “Thermal radiation, process by which energy, in the form of electromagnetic radiation, is emitted by a heated surface in all directions and travels directly to its point of absorption at the speed of light”
– The energy from the impact pushes so hard against earth’s crust that it loses all strength and flows away from the impact site like a liquid, creating a hole 25 kilometers deep and 100 kilometers wide. The ocean is pushed back for hundreds of kilometers, like when a kid jumps into a puddle.
Panel B of the image below shows the depth and width of the crater.
#Sean P. S. Gulick, The first day of the Cenozoic, 2019.
https://www.pnas.org/content/116/39/19342
– As the crust bounces back, melted and flowing crust forms a temporary mountain reaching 10 kilometers into the sky. An incredible amount of material is bombarded into higher atmosphere or even space, as much as 60 times the original mass of the asteroid.
Panel C of the image below shows the temporary mountain reaching 10 km in height.
#Sean P. S. Gulick, The first day of the Cenozoic, 2019.
https://www.pnas.org/content/116/39/19342
#David Shonting and Cathy Ezrailson, Chicxulub: The Impact and Tsunami, 2017. P.26
https://www.springer.com/gp/book/9783319394855
Quote: “The impact explosion had propelled a mix of Gulf water, asteroid debris, sea bottom sediments, limestone and other fine rock fragments, into the atmosphere – totaling some 60 times the object’s mass.”
– The violence of the strike is felt everywhere on earth within minutes. An earthquake of the magnitude 11, maybe the most powerful quake any living thing ever witnessed in billions of years. It is so insanely strong that in India it might have shaken gigantic lava fields and causes volcanic eruptions that would last for 30,000 years and cover half of the indian subcontinent with lava. Even on the side of earth opposite to the impact, the ground still moved by several meters.
Unfortunately the original study isn’t available online:
#Triggering of the largest Deccan eruptions by the Chicxulub impact, 2015
Here is a summary:
#Massive Lava Flows Linked to Dinosaur-Killing Impact, 2015
https://www.livescience.com/50737-deccan-traps-chicxulub-impact-linked.html
Quote: “According to an international research team, the Chicxulub meteor impact 66 million years ago may have triggered a magnitude-11 earthquake that shook loose massive amounts of lava in India.”
#Evolution after Chicxulub asteroid impact: Rapid response of life to end-cretaceous mass, 2020
https://www.sciencedaily.com/releases/2020/07/200714121748.htm
Quote: “Local and regional-scale effects of the K-Pg impact included earthquakes of magnitude 10-11, causing continental and marine landslides, tsunamis hundreds of meters in height that swept more than 300 km onshore, shock waves and air blasts, and the ignition of wildfires.“
This study however is highly debated among scientists, Some believe that lava streams
in India were actually not caused by the asteroid impact, but only made the situation worse:
#Did dinosaur-killing asteroid trigger largest lava flows on Earth?, 2015
Quote: ““It’s inconceivable that the impact could have melted a whole lot of rock away from the impact site itself, but if you had a system that already had magma and you gave it a little extra kick, it could produce a big eruption,” Manga said.”
– Back at the site of impact, the gigantic explosion crashes against the atmosphere with unprecedented violence and causes a shockwave that reaches speeds of more than 1,000 kilometers per hour near the site of impact, similar to the hyper hurricanes on gas giants like Neptune.
#Regional Effects, Chicxulub Impact Event, Lunar and Planetary Institute
https://www.lpi.usra.edu/science/kring/Chicxulub/regional-effects/
Quote: “The Chicxulub Impact event produced a shock wave and air blast that radiated across the seas, over coastlines, and deep into the continental interior. Winds far in excess of 1000 kilometers per hour were possible near the impact site, although they decreased with distance from the impact site.”
#Supersonic Wind, NASA Visualization Explorer, 2013.
https://svs.gsfc.nasa.gov/11349
Quote: “Neptune, the eighth and farthest planet from the sun, has the strongest winds in the solar system. At high altitudes speeds can exceed 1,100 mph. That is 1.5 times faster than the speed of sound.”
– In middle America, basically any soil, vegetation or animal is just shredded into pieces and catapulted thousands of km away.
#A seismically induced onshore surge deposit at the KPg boundary, North Dakota, 2018
https://www.pnas.org/content/116/17/8190
Quote: “Persistent marine influence throughout the upper Hell Creek Formation, supported by marine and brackish fossils found as far west as the Little Missouri River at the Montana–North Dakota border (west of Tanis) and as far east as Bismarck, North Dakota (over 250 km to the east), as well as two marine incursions—the Breien and Cantapeta transgressions—indicate that the fluctuating, reticulated terminal-Cretaceous shoreline was not far away from the Tanis region in southwestern North Dakota”
#Regional Effects, Chicxulub Impact Event, Lunar and Planetary Institute
https://www.lpi.usra.edu/science/kring/Chicxulub/regional-effects/
Quote: “An initial estimate of the area damaged by an air blast was a radius 1500 kilometers. There are several factors that can affect this estimate, so the uncertainty might be better reflected in a range of radii from ~900 to ~1800 km.
Along the Campeche bank, 350 to 600 kilometers from Chicxulub, impact deposits of ~50 to ~300 meters have been logged in boreholes. ”
#Trajectories and distribution of material ejected from the Chicxulub impact crater: Implications for postimpact wildfires, 2002
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2001JE001532
Quote: “These calculations indicate that low‐energy ejecta produces centimeter‐ to meter‐thick deposits within ∼4000 km of the point of impact, although its azimuthal distribution depends on the incident angle of the projectile with the surface of the Earth.“
– As the temporary mountain splashes back to earth and collapses into a ring of debris around the site of impact and a gigantic mushroom cloud grows high into the sky.
Panel D of the image below shows that the mountain didn’t last too long, but after half an hour was already collapsing:
#Sean P. S. Gulick, The first day of the Cenozoic, 2019.
https://www.pnas.org/content/116/39/19342
– Now the formally displaced oceans return. As the temporary mountain at the site of impact collapses, a ring of tsunamis as high as one kilometer, enough to cover all skyscrapers humans would ever build, heads into all directions. As they crash into the coasts of the continents surrounding the impact, they will drown thousands of kilometers of coastlines.
#Huge Global Tsunami Followed Dinosaur-Killing Asteroid Impact, 2018
https://eos.org/articles/huge-global-tsunami-followed-dinosaur-killing-asteroid-impact
Quote: “But millions of years ago, a truly inconceivable set of waves—the tallest roughly 1,500 meters high—rammed through the Gulf of Mexico and spread throughout the ancient ocean, producing wave heights of several meters in distant waters, new simulations show.”
#Regional Effects, Lunar and Planetary Institute, 2020
https://www.lpi.usra.edu/science/kring/Chicxulub/regional-effects/
Quote: “Estimates of the sizes of the waves vary. Lower estimates suggest the waves were “only” 50 to 100 meters high, while some estimates suggest the tsunamis were 100 to 300 meters high when they crashed onto gulf shores and tore through coastal ecosystems. The tsunamis may have penetrated more than 100 kilometers inland before the backwash swept continental debris back into the Gulf of Mexico, where it was deposited in seafloor channels. Both”
#David Shonting and Cathy Ezrailson, Chicxulub: The Impact and Tsunami, 2017. P.103
https://www.springer.com/gp/book/9783319394855
Quote: “Around the ancient Gulf area the pounding of the towering breakers upon the ancient shorelines caused violet land erosion and turbulent mixing of bottom sediments, drowning of thousands of kilometers of coastline.
– 15 hours later some of the waves that get refracted around South America will still tower as much as 100 meter into the sky.
#David Shonting and Cathy Ezrailson, Chicxulub: The Impact and Tsunami, 2017. P.105
https://www.springer.com/gp/book/9783319394855
Quote: “Within 10 – 15 hrs, the wave fronts refracted around and onto the coasts of South America and Africa. Then rounding South Africa, they raced eastward through the ancient Indian Ocean, inundating those coasts and islands with still 100 m high breakers.”
– A lot of the debris yeeted into space will orbit earth for thousands of years, some hit the moon or even Mars.
#David Shonting and Cathy Ezrailson, Chicxulub: The Impact and Tsunami, 2017. P.26
https://www.springer.com/gp/book/9783319394855
Quote: “Larger solid objects which had attained an escape velocity of ~ 11 km/s, were projected through the outer atmosphere into deep space, having been committed to spend, at least, a few million years orbiting the Sun.”
#Trajectories and distribution of material ejected from the Chicxulub impact crater: Implications for postimpact wildfires, 2002
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2001JE001532
Quote: “The high‐energy ejecta rose far above the Earth's atmosphere, some of it carried on trajectories that extended halfway to the Moon, before reaccreting to the Earth. The material enveloped the entire planet and was distributed globally, but was concentrated near the impact site and at the antipode.”
Dr. Sean Gullick, one expert who helped with the video, mentioned in an interview with the New York Times, that some of the material would have reached the moon almost certainly.
#A New Timeline of the Day the Dinosaurs Began to Die Out, 2019
https://www.nytimes.com/2019/09/10/science/chicxulub-asteroid-impact-dinosaurs.html
Quote: ““Almost certainly some of the material would have reached the Moon,”“
– But most of it is coming right back. When things fall through the atmosphere at such speeds they get very hot, like hundreds of degrees hot. And this happens to millions of tons of material everywhere. This rapidly heats up the atmosphere to insane temperatures. We don’t know exactly how hot it got or how long this heat shock lasted but there are two ideas here.
#Impact -Generated Wildfires, Lunar and Planetary Institute, 2020
https://www.lpi.usra.edu/science/kring/epo_web/impact_cratering/enviropages/wildfiresweb.html
Quote: “The particles of material in the ejecta plume, just like falling meteors, heated the atmosphere. The particles of material in the ejecta plume, just like falling meteors, heated the atmosphere. There was so much debris falling through the atmosphere at the same time, that it heated the atmosphere to far higher temperatures than individual meteors. A large fraction of this heat was radiated to the ground, raising surface temperatures to several hundreds of degrees and causing vegetation to burst into flames.”
#David Shonting and Cathy Ezrailson, Chicxulub: The Impact and Tsunami, 2017. P.26
https://www.springer.com/gp/book/9783319394855
Quote: “Some 90,000 Gigatons of ejecta mixture blasted tens of kilometers into the atmosphere.
– Either the air was hundreds of degrees hot, for a few minutes. Or thousands of degrees hot, for around one minute. In any case, the air becomes as hot as the inside of an industrial oven.
There are different theories on the reasons for the heatsurge and how long it lasted. The Bradbury Science museum summarizes the different theories on their website:
#November’s Science on Tap Question, Bradbury Science Museum, 2019
https://www.lanl.gov/museum/news/newsletter/2019/11/sot-question.php
Quote: “An alternative theory is that debris (ejecta) from the impact was thrown into the upper reaches of the atmosphere and into low orbit. Scientists surmise that then, within 24 hours, most of that super-heated material fell back to Earth within 24 hours. These millions of airborne, incandescent heaters in the sky would have cooked the surface of the earth to hundreds, possibly even thousands of degrees F. In this scenario, any life on the surface was most certainly dead within 24 hours of the asteroid’s impact.”
#Dinosaur-killing impact set Earth to broil, not burn, 2009
https://www.newscientist.com/article/dn18246-dinosaur-killing-impact-set-earth-to-broil-not-burn/
Quote: “The models predicted the rain of shock-heated debris would radiate heat as intensely as an oven set to “broil” (260 °C) for at least 20 minutes, and perhaps a couple of hours. Intense heating for that long would heat wood to its ignition temperature, causing global wildfires.”
– How bad the global effects of this were is contested but if enough heat reached the surface a lot of plants and animals would have died very quickly if they couldn’t bury themselves or escape into caves. The heat together with raining debris also may have ignited material on forest floors and sparked wildfires as the earth rotated under the searing hot plume. In a few hours massive wildfires were probably burning around the globe. Some of them may have lasted for months and turned earth into a horrifying hot hell-ish version of itself.
On this website of the Lunar and Planetary Institute you can find an animation of how fast and where wildfires might have developed:
#Global Effects, Lunar and Planetary Institute, 2020
https://www.lpi.usra.edu/science/kring/Chicxulub/global-effects/
Sidenote: By talking to experts we learned that the dinosaurs that managed to survive must have been mostly very small or airborne, the ancestors of our modern-day birds. Pectinodon might have been a little too big already, so we took some artistic liberty here in letting him survive a bit longer.
– The gigantic plume of vaporized material reaches the upper atmosphere and spreads around the whole globe. Together with the soot from the burning planet and the aerosols generated at the impact, the planet sinks into a deep darkness, with only the remaining raging fires illuminating the scenery. Whatever plants survive the firstorms will now be starved for sunlight as global photosynthesis is temporarily shut down.
#Trajectories and distribution of material ejected from the Chicxulub impact crater: Implications for postimpact wildfires, 2002
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2001JE001532
Quote: “The high‐energy ejecta or vapor plume rises through the atmosphere and isotropically expands at the top of the atmosphere.”
#Global Effects, Lunar and Planetary Institute, 2020
https://www.lpi.usra.edu/science/kring/Chicxulub/global-effects/
Quote: “Material from the vaporized impactor and target rocks rose from the Chicxulub crater in a vapor-rich plume (left panel) that accelerated through the Earth’s atmosphere and began to reaccrete to the top of the atmosphere on ballistic trajectories (second panel).“
– Within days the temperatures crash as much as 25° celcius.
#Global Effects, Lunar and Planetary Institute, 2020
https://www.lpi.usra.edu/science/kring/Chicxulub/global-effects/
Quote: “The dust, aerosols, and soot may have caused significant decreases in surface temperature of several degrees to a few tens of degrees.”
– The oceans were especially hit hard. The lack of sunlight killed over 90% of plankton which form the basis for the food web of marine life. Ultimately this would kill off the large marine reptiles and ammonites that used to dominate the seas.
#Algal plankton turn to hunting to survive and recover from end-Cretaceous impact darkness, 2020
https://advances.sciencemag.org/content/6/44/eabc9123
Quote: “Together, the selective loss of key open ocean photoautotrophs and prevalence of phagotophy in the surviving algal groups suggests that primary production was drastically disrupted by the K/Pg bolide impact, pointing to a complete cessation of all marine photosynthesis during peak impact darkness.”
“Coccolithophores were almost entirely eradicated (>90% species extinction) at the K/Pg boundary”
– Ash, debris and the burned remains of the formerly lush and blooming life cover the ground, the sky is dark and it is cold and fresh food is scarce, while fungi thrive.
#Global Effects, Lunar and Planetary Institute, 2020
https://www.lpi.usra.edu/science/kring/Chicxulub/global-effects/
Quote: “Calculations of an atmosphere choked with dust and sulphate aerosols from the impact event, and soot from post-impact wildfires, suggest surface temperatures fell and sunlight was unable to reach the Earth’s surface, shutting down photosynthesis.”
#Updating the fungal infection-mammalian selection hypothesis at the end of the Cretaceous Period, 2020
Quote: The combination of massive amounts of decaying vegetation, darkness, and cooler temperatures are conditions known to favor fungal proliferation, for which there is fossil evidence [8]. Fungal proliferation in the form of mushrooms growing in the decayed vegetation could have provided nutrition for surviving mammals and reptiles, which are known to eat these fungi
– For months and years the planet will be a hostile and deadly place. The sudden global winter will last for decades. At least 75% of all species on earth will just vanish from existence.
The surviving dinosaurs have been mainly small or airborne, the survivors were the ancestors of our modern-day birds and mammals. We took some artistic liberty here in showing a couple larger dinosaurs wandering about.
https://www.lpi.usra.edu/science/kring/Chicxulub/global-effects/
#Asteroid Dust Found in Crater Closes Case of Dinosaur Extinction, 2021
https://news.utexas.edu/2021/02/24/asteroid-dust-found-in-crater-closes-case-of-dinosaur-extinction/
Quote: “The asteroid impact led to the extinction of 75% of life, including all non-avian dinosaurs.”
– Birds that are the direct descendents from the dinosaurs and mammals that eventually would become the dominant animals on the planet.
Today there is very good evidence that modern day birds are actually dinosaurs:
#How Dinosaurs Shrank and Became Birds, 2015
https://www.scientificamerican.com/article/how-dinosaurs-shrank-and-became-birds/
Quote: “Modern birds descended from a group of two-legged dinosaurs known as theropods, whose members include the towering Tyrannosaurus rex and the smaller velociraptors”
#Downsized Dinosaurs: The Evolutionary Transition to Modern Birds, 2009
https://evolution-outreach.biomedcentral.com/articles/10.1007/s12052-009-0133-4
Quote: “The origin of modern birds from animals similar to Tyrannosaurus rex is among the most remarkable examples of an evolutionary transition.”
Pectinodon, the theropod we show throughout the video, is very closely related to birds, but it was probably too big to have been among the survivors of the mass extinction. As mentioned before, we took some artistic liberty here when we let him survive until the end of the day the asteroid hit. The surviving ancestors of birds would have already looked essentially like some types of modern birds, maybe similar to Tinamous or quails.
Even though bird-like dinosaurs like Pectinodon might have survived the impact, we can’t really say this with certainty only safely, since bird-like bones very rarely become fossilized. One “crown bird” we have a nearly complete skull of is Asteriornis.
#Late Cretaceous neornithine from Europe illuminates the origins of crown birds, 2020
https://www.nature.com/articles/s41586-020-2096-0
Quote: “Our understanding of the earliest stages of crown bird evolution is hindered by an exceedingly sparse avian fossil record from the Mesozoic era.”
“Asteriornis maastrichtensis, gen. et sp. nov., from the Maastrichtian age of Belgium (66.8–66.7 million years ago), is represented by a nearly complete, three-dimensionally preserved skull and associated postcranial elements.”
– Without the Asteroid, who knows what life on earth would look like today. Without the sudden disruption of dinosaur continuity, that completely changed the planet and all life on it, we might have never gotten the opportunity to become what we are today.
There are not many events in our planet's history that were similarly impactful on the evolution on Earth. 75% of Earth’s life forms vanishing from the face of our planet also enabled the survivors to diversify and develop further. Some scientists even argue that it might have been a necessary step for human evolution to take place:
#Epilogue: Possible Chicxulub Effects on the Path of Human Evolution, 2017
https://link.springer.com/content/pdf/bbm%3A978-3-319-39487-9%2F1.pdf
Quote: “The Chicxulub event was another instance where a throw of the dice may have played a vital role, say, in the human evolutionary outcome. At the time of Chicxulub, dinosaurs had already roamed the Earth for at least some 200 million years so their longevity to that time was pretty much a success story. Now, if (following Gould) we rewind the “tape of life” from the present back 65.5 million years, we note that it was the survival of the small mammals who replaced the dinosaurs and who later evolved into larger mammals and much later—into ourselves. Thus, we might muse about which events contributed most heavily to the evolution of the early Lucy-like creatures and eventu-ally to us (Homo sapiens). “
– So far we have been around for 0.1% of the time the dinosaurs were.
Non-avian dinosaurs, that means dinosaurs that were no predecessors to our modern-day birds, lived for around 170 million years.
#When did dinosaurs live?, NHM London
https://www.nhm.ac.uk/discover/when-did-dinosaurs-live.html
Quote: “Non-bird dinosaurs lived between about 245 and 66 million years ago, in a time known as the Mesozoic Era.”
The oldest of a homo sapiens is around 200.000 years old:
#Oldest Homo sapiens fossil claim rewrites our species' history, 2017
https://www.nature.com/news/oldest-homo-sapiens-fossil-claim-rewrites-our-species-history-1.22114
This means humans have been around for about 0.1% of the time that the dinosaurs wandered on Earth’s surface.
Further Reading:
This is a very interesting book about all the aspects of the asteroid impact and helped us a lot during our research:
#David Shonting and Cathy Ezrailson, Chicxulub: The Impact and Tsunami, 2017. P.26
https://www.springer.com/gp/book/9783319394855
And this is the latest and most detailed study on the events of that day, written by Sean Gullick and Timothy Bralower, two experts who helped us with the script:
#The first day of the Cenozoic, 2019.
https://www.pnas.org/content/116/39/19342
And this is the study that set all these analyses in motion. It was the very first study to claim that the dinosaurs went extinct by an asteroid impact:
#Extraterrestrial Cause for the Cretaceous-Tertiary Extinction, 1980
https://science.sciencemag.org/content/208/4448/1095