Geologist Who Linked Cosmic Strike to Dinosaurs’ Extinction Takes Top Prize
Walter Alvarez, the maverick geologist who convinced a skeptical world that dinosaurs and many other living things on Earth were wiped out by a huge fireball from space, has won the highly esteemed Vetlesen Prize. Considered by many the earth sciences’ equivalent of a Nobel, the $250,000 award is funded by the New York-based G. Unger Vetlesen Foundation and administered by Lamont-Doherty Earth Observatory, a member of Columbia University’s Earth Institute.
Alvarez was not the first to propose that sudden disasters had drastically altered past life on earth, but the idea ran against conventional wisdom. Since the 1800s, geologists and biologists had seen earth’s history mainly in terms of gradual processes, and a stock explanation for dinosaurs’ extinction was slowly changing climate. In the mid-1970s, Alvarez was a young field geologist at the University of California, Berkeley, when he was working on an outcrop of limestone near the Italian town of Gubbio. In it, he found a thin layer of red clay in which the shells of tiny sea creatures that previously had existed for eons suddenly disappeared. The seemingly instant extinction dated to 65 million years—around the time dinosaurs died out. Together with his father--the Nobel-winning physicist Luis Alvarez--and Berkeley chemists Frank Asaro and Helen Michel, Alvarez discovered that this layer harbored an abnormal amount of iridium, a metal rare in earth’s crust but typical of comets and asteroids. In 1980, the scientists proposed that most species of life, including all the dinosaurs, were extinguished when a giant comet or meteorite struck, sending out fireballs and tsunamis, then cooling and darkening the skies with a years-long pall of debris. Among the survivors who later thrived: mammals.
For a decade, Alvarez met with skepticism and even scorn, given lack of a known crater of the right size and age. However, he persisted. Eventually he and others found the iridium layer in many locations. In the western United States and elsewhere, researchers also found shocked or melted rocks, and signs of tsunamis, all coinciding with the 65-million year Cretaceous-Tertiary, or K-T, boundary, as it became known. The clincher came in 1990, when a team following Alvarez’s leads found conclusive evidence of a well-hidden 110-mile (180-kilometer)-wide crater spanning the seafloor and coast of Mexico’s Yucatán Peninsula. Named the Chicxulub Crater, it was made by a Mt. Everest-size object right at the K-T boundary. Alvarez was seen as vindicated, though some scientists still say huge volcanic eruptions may also have played a role in the mass extinctions, or that there may have been more than one impact.
“Research conducted and inspired by Walter Alvarez has changed the way we view the history of the Earth,” says the Vetlesen Prize committee’s citation. “For more than a century the dominant view of how Earth evolved was one of ‘uniformitarianism”—a slow, gentle change caused by processes observable today. [His] work proved that major catastrophic events can shape the evolution of our planet.”
G. Michael Purdy, director of Lamont-Doherty, said: “Alvarez’s research showed that life on earth is affected by how our planet interacts with the cosmos. He not only moved the study of extraterrestrial impacts from science fiction into the mainstream; he forever changed the way we view our world and its evolution.”
With modern catastrophism—including a growing wariness of potential dangers from future cosmic collisions--now firmly embedded in books, movies and museum exhibits, the prize committee said that Alvarez has succeeded in “bridging the scientific world and that of popular culture.”
The Vetlesen Prize is given “for scientific achievement resulting in a clearer understanding of the Earth, its history, or its relations to the universe.” It was established in 1959 by the trustees of G. Unger Vetlesen, a Norwegian immigrant to the United States who became a leading shipbuilder, World War II military leader and pioneer in transatlantic air travel. Vetlesen passed away in 1955. Designed to recognize sweeping achievements on par with the Nobel (which has no regular prize in earth sciences) it is given every several years by a jury appointed by the president of Columbia University. The most recent awards were in 2004 to climate-change scientists Sir Nicholas Shackleton of the United Kingdom and W. Richard Peltier of Canada. Others among the previous 25 recipients have been the Dutch astrophysicist Jan Hendrik Oort and several scientists at Lamont-Doherty itself, including marine geologist Walter Pitman and seismologist Lynn Sykes.
Alvarez told the story of his discovery in his 1997 book T. Rex and the Crater of Doom. More recently, he has been working on questions relating to plate tectonics, the origins of Italy’s Apennine Mountains, and geology’s influence on ancient Rome—subjects related in his upcoming book The Mountains of St. Francis.
Alvarez will receive the award and accompanying medal from Columbia president Lee Bollinger at the university’s Low Library on Nov. 21.
For more information about the Vetlesen Prize go to: www.ldeo.columbia.edu/vetlesen