What Killed the Dinosaurs?
The Chicxulub Meteorite and the K-T Extinction;
Where did Sea Serpents come from?
There was no warning. Almost all life ended within seconds.
Asteroid 243 Ida, photographed by the Gallilio spacecraft.
Ida is about the same size as the Chicxulub meteorite. NASA photograph.
The chunk of rough, pock-marked rock and iron was at least six and one-half miles in its largest dimension, larger than Mount Everest by more than a mile. Some estimates claim it was twice that size. Asteroids are material left over from the formation of the solar system more than four and one-half billion years ago, material from “The Big Bang” that never coalesced into a planet. These minor planets still continue orbiting the sun in what is known as the asteroid belt, situated mainly just outside the orbit of Mars. Earth is on the edge of the belt and some asteroids are inside Earth’s orbit. Occasionally one of these asteroids collides with a planet of the solar system. Our moon and the planet Mars are a mosaic of such impact craters. When on a collision course with Earth they are called meteoroids. When entering the atmosphere, friction with the air causes heat which builds up and usually disintegrates the meteoroid before it hits the surface; the burning long tail is visible and is known as a comet. If the meteoroid is large and does not burn up completely, but impacts Earth, it is called a meteorite. Most impacts involve small meteorites causing little or no damage. But not all meteorites are small.
The asteroid heading for Earth 65-million years ago (MYA) has been estimated to have weighed more than 100-billion tons, possibly ten times more. Silently speeding through the vacuum of space, it was headed for an intersection with the orbit of a small blue-green planet, third from its solar system’s sun. An abundance of life on land and in the oceans populated the planet. Life had been evolving for 500-million years. The land was now ruled by reptilian dinosaurs, Tyrannosaurus Rex, Triceratops and many others, but not by mammals, although a few species of small mammals scampered about searching for food. Many species of plants covered the planet with lush vegetation. Marine reptiles, corals, fish and bivalves lived in the clear oceans teeming with organisms.
The meteoroid entered the planet’s atmosphere at 45,000 miles per hour, more than fifty-eight times the speed of sound. Animals on the surface of the planet hardly had time to look up and blink at the sudden burst of the enormous fireball. They were dead before the deafening sound of the huge mountain breaking the sound barrier reached earth. Immediately before impact the sea below boiled from the intense heat. The temperature of the burning meteoroid was approximately 18,000° Celsius (32,400° F), or three times hotter than the sun. The mountain approached at an angle from the southwest and the impact in shallow water around the Yucatan Peninsula, Mexico, at latitude 21°20' N, longitude 89°30' W, spewed fire and debris across what is now North America. Every part of the continent was in flames within minutes. Global firestorms lasted several months. One theory suggests that methane gas was released from the ocean floors around the world by earthquakes and tsunamis, and this methane ignited adding to the global firestorms. Even the atmosphere would have been ablaze.
The magnitude of the catastrophe was far greater than we can imagine. The impact crater, Chicxulub (cheek-shoe-lube'), a Mayan word loosely meaning "tail of the devil," is approximately one-hundred and ten miles wide and greater than one mile deep. It is located under the town of Chicxulub, Yucatan, Mexico. The energy of the impact was equivalent to 15-billion (15,000,000,000) World War II atomic bombs detonated at the same time in one place. Giant tsunamis scoured the coastal areas of Earth and destroyed anything in the path. Oceans around the globe were disrupted in one day. What is now Texas, Louisiana and Alabama were slammed with tsunamis up to 325-feet high. Magnitude-10 earthquakes shook earth to the very core, literally. The earthquakes produced more tsunamis. Billions of tons of sulfur, rocks and other materials were thrown into and above the atmosphere, encircling the planet. So much debris and dust polluted the atmosphere that within one hour sunlight did not penetrate to Earth anywhere. When the debris thrown above the atmosphere fell back to Earth it ignited as smaller meteorites while passing through the atmosphere due to friction, causing more forest fires and death to vegetation and animals. Temperature of this debris was high enough to cause vegetation to ignite spontaneously. Winds of 2,000 miles per hour flattened the landscape. Darkness and resulting cold temperatures lasted more than six months, possibly two or three years. Without sunlight global temperatures plunged near freezing.
Most of the great dinosaurs were wiped out by the blast and fires. The huge amounts of sulfur thrown into the atmosphere chemically generated sulfuric acid. The effect of acid rain and toxic contamination of the atmosphere lasted several years. Deadly amounts of sulfur dioxide, sulfuric acid as strong as battery acid, nitric acid, and fluoride compounds saturated the air. Acid rain included the extremely potent sulfuric acid which poisoned the ground and killed many smaller animals. Without sunlight for photosynthesis, and without a warm environment, plants quickly died depleting the food supply for many animals world wide. Plants, through photosynthesis, take in carbon dioxide and give off oxygen essential to animal life. Before plants emerged on Earth the oxygen content of the atmosphere was so low that animal life could not be supported; the land masses of Earth were totally barren. In the Pre-Cambian period, 570 MYA, green algae formed in the oceans and gave Earth its much needed oxygen for evolution through photosynthesis. At the time of the Chicxulub meteorite impact oxygen supported global combustion, and there were no plants to generate more oxygen. Without food and oxygen essential to life, animals died. The entire food chain of the world was affected. More than 90 percent of the plankton in the oceans was destroyed leading to a severe disruption to the food chain of sea life. Any life not immediately destroyed by the blast or fires faced extinction from the cold and lack of food.
This was the end of Earth’s Cretaceous period and the beginning of the Tertiary period, 65 MYA. The sudden and catastrophic change to Earth is known as the K-T Extinction; K is for Kreide, meaning chalk in German, referring to the chalky sediment layer that formed, and T is for Tertiary, the next geologic period. (K is used to denote the Cretaceous period rather than C to avoid confusion with the Cambrian period). The K-T boundary layer is found in rock formations everywhere around the globe. Although 70 percent of all animals and 90 percent of all vegetation became extinct, some creatures including sharks, horseshoe crabs, sea turtles, starfish, and fish such as coelacanth did adapt and survive into the Tertiary period. The oceans cooled more slowly than the land and many marine creatures adapted. It took 11 million years for life on Earth to grow and evolve again.
“By forces seemingly antagonistic and destructive Nature accomplishes her beneficent designs - now a flood of fire, now a flood of ice, now a flood of water; and again in the fullness of time an outburst of organic life.” - John Muir
Nature continued marching forward toward a new world with new life. Over the next 11-million years a greenhouse warming effect set in making the following period of time, the Eocene Epoch, 58 MYA until 36 MYA, warmer and tropical, at least in the beginning. Other factors would come into play millions of years later to change that. The name Eocene comes from the Greek eos (dawn) and ceno (new), meaning “Dawn of New Life” refering to the new mammals that emerged during this time period. Where reptiles ruled the Cretaceous, mammals ruled the Eocene. They, too, would face extinction 22 million years later. But some would survive. The Eocene Epoch saw new monsters evolve including one that the stage for a tidal wave of controversy surging around Jason Seabury’s final whaling voyage. The controversy rages even today.
Copyright © 2007, 2008 Thomas Lytle. All rights reserved.
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Preface - The Voyage - The Sighting - The Capture
The Sea Monster - Sea Serpents - K-T Extinction - Jason Seabury Ancestors
When was the capture? - Links - Bibliography