When people think of the dinosaurs their minds will predominantly conjure up two thoughts; one regarding their lives – a fairly basic, and popular, Jurassic Park view – and one on the end of their lives. Many people are fascinated by just what it was that did in the dinosaurs. And though now the Alvarez hypothesis – the position that a large asteroid impacted the Yucatan Peninsula sixty-five million years ago – holds sway as lead theory, there is more to it than just “big asteroid go kablooie!”
The basic information behind the Alvarez hypothesis – beyond that which I laid out above – focuses upon the mass extinction that we know took place, sixty-five million years ago, known as the Cretaceous-Tertiary extinction event.
Naturally, the next step had been to decipher what it was that had done in the dinosaurs, and that was where father and son team Luis and Walter Alvarez stepped in, in 1980.
The primary evidence to support the Alvarez theory comes in the form of iridium, found within the sedimentary layers all over the world at the time of the Cretaceous-Tertiary period. Iridium is extremely rare in the earth’s crust because it is very dense, and thus normally sinks in to the earth’s core while the earth was still molten. The Alvarez thus posited that an impact event – which would have brought the iridium back in to play – took place at that point in time.
Geophysicists have recently constructed the world’s most detailed 3-D seismic image of the predominantly submerged Chicxulub impact crater. The data reveal that the asteroid may have impacted further off the coast than previously believed – the coast being a fluctuating location. As such, they theorize that due to the deeper water, about 6.5 times more water vapor would have been released in to the atmosphere as previously thought.
"The greater amount of water vapor and consequent potential increase in sulfate aerosols needs to be taken into account for models of extinction mechanisms," said Sean Gulick, a geophysicist at the University of Texas at Austin who led the study.
The findings – which include the discovery of sulfur-rich conditions in the crater, which would have caused the water vapor to create sulfur aerosols, thus making the impact even that more deadlier – will be published in the February edition of Natural Geosciences.
Gulick, along with many others, believe that the impact did not do the entire job. Environmental effects must be looked at to see what part they played in the cataclysmic end to the dinosaurs, and almost 70% of life on Earth.
This is not news that is going to reshift the thinking of the world in which we live; but for those of us who enjoy the history of the planet, the geology science history, then this news is continually intriguing.
[url=http://www.livescience.com/environment/080123-impact-crater.html]http://www.livescience.com/environment/080123-impact-crater.html[/url]
Joshua Hill, a Geek’s-Geek from Melbourne, Australia, Josh is an aspiring author with dreams of publishing his epic fantasy, currently in the works, sometime in the next 5 years. A techie, nerd, sci-fi nut and bookworm.
