Dr. Walter Alvarez spoke to students Thursday, Nov. 12, in Farthing Auditorium, on the effects of meteorite impacts, in a speech titled “T. rex and the Crater of Doom.” 

Alvarez began the speech with a brief  discussion as to the nature of geological studies and the battle between uniformitarianism  and catastrophism. 

The fact that “the Atlantic Ocean between Africa and South America grew at exactly the same rate as... fingernails grow” was one of many discoveries which led to uniformitarianism dominance. 

Under the theory of uniformitarianism, “geology became a gradual science.” 

Some scientists, Alvarez included, maintained that occasional catastrophes do occur which dramatically alter the earth. 

Astounding proof came when Comet Shoemaker-Levy impacted Jupiter. Now scientists “not only know [catastrophes] happen, but have seen them happen;  fortunately on someone else’s planet.” 

Having assured the audience of the reality of catastrophes, Alvarez spoke at great length on the Chixculub Crater. 

He discussed deposits of  black glass, iridium and shocked limestone, which  he believes are connected to the crater.  Those deposits have been dated to the boundary of the Cretaceous and Tertiary Periods. That boundary also marks the time when the dinosaurs, along with possibly half the genera of earth, became extinct. 

Alvarez showed slides which gave an impression of what the impact may have looked like and pointed out that any pictures with perishing dinosaurs were not a photograph. As to the extinction of the dinosaurs, Alvarez expressed no sorrow, and was instead, “glad to be looking out at an audience of mammals.” 

In addition to the Chixculub Crater, Alvarez discussed smaller impact craters on the earth and theorized on the effects of impacts by larger objects. He said, the “ impact of an object of  [100 kilometers] would sterilize the earth [because it would] boil the oceans.” 

The impact of a larger object, about the size of Mars, may have broken off a piece of the earth and caused the formation of the moon. 

Alvarez is the author of “T-Rex and the Crater of Doom” and teaches at the University of California at Berkeley. 

In 1977, when he started working at UC Berkeley, Alvarez began his study of mass extinction, focusing on the end of the Cretaceous period, as recorded in Italian limestones. According to Alvarez, evidence from iridium measurements suggested that extinction at that time was due to a giant asteroid or comet hitting the earth, according to an ASU News Bureau press release. 

Earlier in his career, Alvarez worked for American Overseas Petroleum Limited in Holland and Libya.  He developed a side interest in archeological geology and left the oil company to study Roman volcanic rocks and their influence on settlement patterns in early Roman times. 

Along with his father, Lewis Alvarez, a Nobel Laureate in Physics, he was influential in validating the theory that the Chixculub Crater on the Yucatan Penisula may be the remains of the meteorite which caused the extinction of the dinosaurs.