Backround: The Alvarez Extinction Theory
In 1980 Luis Alvarez, his geologist son Walter Alvarez, nuclear chemist Frank Asaro, and paleontologist Helen Michael published a theory on the extinction of the dinosaurs. The Alvarezes discovered the likeliness of this theory while looking for ways to measure space dust in years. They discovered that 1 cm of space dust equals 10000 years. Before the Alvarezes dicovered the crater Chicxulub in New Mexico, they came up with this theory. The theory was as follows, in exact wording from Enhanced Learning Software;
An asteroid 4-9 miles (6-15 km) in diameter hit the Earth. The impact would have penetrated the Earth's crust, scattering dust and debris into the atmosphere, and caused huge fires, volcanic activity, tsunamis, severe storms with high winds and highly acidic rain. The impact could have caused chemical changes in the Earth's atmosphere, increasing concentrations of sulfuric acid, nitric acid, and fluoride compounds. The heat from the impact's blast wave would have incinerated all the life forms in its path. The dust and debris thrust into the atmosphere would have blocked most of the sunlight for months, and lowered the temperature globally. Those organisms that could not adapt to the temperature and light changes would die out. Since plants' energy is derived from the sun, they would likely be the first to be affected by changes in climate. Many families of phytoplankton and plants would die out, and the Earth's oxygen levels may well have dramatically decreased, both on land and in the oceans, suffocating those organisms which were unable to cope with the lower oxygen levels. Major changes in the food chain would result from all of these environmental upheavals. The herbivores (plant eaters) who ate those plants would starve soon after the plants died. Then, at the top of the food chain, the carnivores (meat eaters), having lost their prey, would have to eat each other, and eventually die out. Their large carcasses must have provided smaller animals with food for quite a while.