Case Studies in Earth & Environmental Science Journalism

K/T Boundary Extinction

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Questions to Ponder and Discuss

• Why do so many people find dinosaurs so fascinating?
• McLauren (1970) proposed a meteor impact as cause of a mass extinction in the Paleozoic. His paper generated little or no excitement in either the scientific community or the press. Why not?
• During 1979, dozens of newspapers and magazine articles presented the original Alvarez hypothesis on the basis of only a talk at the American Geophysical Union meeting (Washington, May 1979) and accompanying abstract (Alvarez et al 1979). At this time, the scientists were out on a limb, and the journalists climbed out there with them, by publishing a tantalizing but not yet substantiated idea. Examine the articles dated 1979 and note the different strategies that journalists used to indicate the degree of tentativeness of the idea.
• During the first several years following the publication of Alvarez et al 1980 Science paper, a wide range of publications ran longer reflective articles about the impact hypothesis and related topics. Read the articles from Science (Research Notes section of magazine), Discover, Mosaic (a publication of the National Science Foundarion), The Magazine of Fantasy & Science Fiction, the Conservationist (a publication of the New York State Department of Conservation), the New York Times, Science Now (a British popular magazine ), Popular Science. and the Bulletin of the Science Fiction Writers of America. How did each author shape the story to match the interests and knowledge-base of the particular audience he/she was writing for?
• The Alvarez hypothesis generated great excitement in the scientific community and wide coverage in the non-specialist press. In the words of Glen, 1994 (p.8): "Career goals have been refocused, dormant areas of research rejuvenated, tacit assumptions hastily re-examined, and scientists in widely separated fields swept into an unprecedented array of collaborative efforts." Why? Exactly what characteristics of this discovery/hypothesis made it so exciting?
• One of your challenges as a science journalist is to find out about those ideas/hypotheses/discoveries that could cause this same kind of realignment of scientific thinking (careers refocused, tacit assumptions re-examined, etc.). Furthermore, you want to find the ideas when they are new and fresh and not yet widely publicised. How could you do this?
• What position should a journalist take when when crucial data are not made available to scientific community? PEMEX (Mexican oil company) gravity & magnetic data of Chicxulub Crater; only a simplified version was released (Beatty 1991 article). What was the motive for non-release of data? Contrast with Yucca Mountain case.
• Look at series of popular articles about Chicxulub Crater that came out in 1991 & 1992.
  • consider the balance between impact/Chicxulub proponents & skeptics
  • describe the devices used by authors to catch readers' attention
• The Geological Society of America meeting in November 1995, featured a special session on the Chicxulub impact structure. Look through the abstracts from this special session. If you had been attending this conference as a science journalist, which of these speakers would you have tried to interview, and why?
• For the biologists among us: Clemens (1994) claims that outside of their own narrow specialties, even science specialists gained their understanding of the K/T extinction debates from the popular press rather than from the scientific literature. As a consequence, scientists tended have a simplistic view of the evidence and questions outside their specialties, and this shaped the course of the interdisciplinary debate. Her prime example is that non-biologists held an oversimplified view (at the popular science or children's literature level) of the paleobiological evidence from the fossil record. Do you agree?

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Readings

Background information:

Glen, W., 1994. What the Impact/Volcanism/Mass-Extinction Debates are About. In: W. Glen (Ed.), The Mass Extinction Debates: How Science Works in a Crisis. Stanford University Press, Palo Alto, CA, pp. 7-38.

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Scientific Papers: Impact as cause of K/T Extinction

McLaren, D. J., 1970. Presidential Address: Time, Life & Boundaries. Jour. of Paleo., 44: 801-815. (Focus on last section about the F-F boundary)

Alvarez, W., Alvarez, L. W., Asaro, F. and Michel, H. V., 1979. Experimental evidence in support of an extra-terrestrial trigger for the Cretaceous-Tertiary extinctions (abstract). EOS, 60: 734.

Alvarez, L. W., Alvarez, W., Asaro, F. and Michel, H. V., 1980. Extraterrestrial cause for the Cretaceous-Tertiary extinction. Science, 208: 1095-1108.

Smit, J. and G, K., 1981. Sanidine spherules at the Cretaceous-Tertiary boundary indicate a large impact event. Nature, 292: 47-.

Bohor, B. F., Foord, E. E., Modreski, P. J. and Triplehorn, D. M., 1984. Mineralogic Evidence for an Impact Event at the Cretaceous-Tertiary Boundary. Science, 224: 867-869.

Bohor, B. F., Modreski, P. J. and Foord, E. E., 1987. Shocked quartz in the Cretaceous-Tertiary boundary clays: Evidence for a global distribution. Science, 236: 705-709.

Alvarez, W., 1986. Towards a theory of impact crises. EOS, 67: 649+.

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Popular Articles: Impact as cause of K/T extinction

-------------------------1979 --------------post Alvarez AGU talk --------------------------

Kates, M., 1979, Why the dinosaurs died--a new theory, Berkeley Gazette, p. 1, May 28, 1979.

Petit, C., 1979, New clue to how dinosaurs died, San Francisco Chronicle, p. 1+, May 29, 1979.

Anonymous, 1979, Dinosaurs' extinction tied to bombardment of cosmic radiation, New York Times, p. ?, May 29, 1979. (similiar to articles in many other papers, derived from AP report)

Anonymous, 1979, Bursting star blamed for dinosaurs' doom, San Mateo Times, p. ?, May 29, 1979.

Anonymous, 1979. Dinosaur demise: Extraterrestrial Source?, in Science News. June 2, 1979. p. 356.

Alexander, G., 1979, Rare metal linked to death of dinosaurs, Los Angeles Times, p. 3+, June 25, 1979.

Anonymous, 1979. Doomed Dino: Puzzling over its demise, in Time. July 16, 1979. p. ?

Asimov, I., 1979. Nearly wiped out, in American Way. November 1979. p. 10-11.

------------------ 1980 -1983 ------ post Alvarez et al Science paper ---------------------

Kerr, R. A., 1980. Asteroid Theory of Extinctions Strengthened, in Science. October 31, 1980. p. 514-517.

Davis, M., 1980. Apocalyse Then, in Discover. November 1980. p. 66-69.

Fisher, A., 1981. The World's Great Dyings, in Mosaic. March/April 1981. p. 2-10.

Asimov, I., 1981. The Noblest Metal of Them All, in The Magazine of Fantasy & Science Fiction. March 1981. p. 129-138.

Schwartz, S., 1982. Twilight of the Dinosaurs?, in The Conservationist. September-October 1981. p. 30-34.

Sullivan, W., 1982, Mass Extinctions Increasingly Blamed on Catastrophes from the Sky, New York Times, p. C1+, January 19, 1982.

Anonymous, 1982. The Dinosaur's Day of Reckoning, in Science Now. 1982. p. 106-109.

Fisher, A., 1983. How science traced the killer asteroid, in Popular Science. February 1983. p. 36-40.

Preuss, P., 1983. Neutrons and Dinosaurs, in Bulletin of the Science Fiction Writers of America. spring 1983. p. 20-25.

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Scientific Papers: Chicxulub Crater

Hildebrand, A. R. and Penfield, G. T., 1990. A buried 180-km diameter probable impact crater on the Yucatan Penninsula. EOS, 71: 1425.

Sigurdsson, H., D'Hondt, S., Arthur, M. A., Bralower, T. J., Zachos, J. C., van Fossen, M. and Channell, J. E. T., 1991. Glass from the Cretaceous/Tertiary boundary in Haiti. Nature, 349: 482-487.

Pope, K. O., Ocampo, A. C. and Duller, C. E., 1991. Mexican site for K/T impact crater? Nature, 351: 105. (May 1991)

Hildebrand, A. R., Penfield, G. T., Kring, D. A., Pilkington, M., Camargo, A., Jacobsen, S. B. and Boynton, W. v., 1991. Cicxulub Crater: A possible Cretaceous/Tertiary boundary impact crater on the Yucatan Peninsula, Mexico. Geology, 19: 867-871. (Sept 1991)

Swisher, C. C., III, Grajales-Nishimura, J. M., Montanari, A., Margolis, S. V., Claeys, P., Alvarez, W., Renne, P., Cedillo-Pardo, E., Maurrasse, F. J.-M. R., Curtis, G. H., Smit, J. and McWilliams, M. O., 1992. Coeval 40Ar/39Ar ages of 65.0 Million years ago from Chicxulub Crater melt rock and Cretaceous-Tertiary tektites. Science, 257: 954-958. (14 August 1992)

Sharpton, V. L., Dalrymple, G. B., marin, L. E., Ryder, G., Schuraytz, B. C. and Urrutia-Fucugauchi, J., 1992. New links between the Chicxulub impact structure and the Cretaceous/Tertiary boundary. Nature, 359: 819-821. (October 1992)

Alvarez, W., Smit, J., Lowrie, W., Asaro, F., Margolis, S. V., Claeys, P., Kastner, M. and Hildebrand, A. R., 1992. Proximal impact deposits at the Cretaceous-Tertiary boundary in the Gulf of Mexico: A restudy of DSDP Leg 77 Sites 536 and 540. Geology, 20: 697-700.

Smit, J., Montanari, A., Swinburne, N. H. M., Alvarez, W., Hildebrand, A., Margolis, S. V., Claeys, P., Lowrie, W. and Asaro, F., 1992. Tektite bearing deep-water clastic unit at the Cretaceous-Tertiary boundary in northeastern Mexico. Geology, 20: 99-103.

abstracts from Geological Society of America meeting, November 1995, session on "Impact in the Caribbean: Chicxulub"

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Popular Articles: Chicxulub Crater

Kerr, R. A., 1990. Commotion over Caribbean Impacts, in Science. p. 1081. (November 1990)

Wilford, J. N., 1991, For dinosaur extinction theory, a "smoking gun", New York Times, p. ?, February 7, 1991.

Kerr, R. A., 1991. Yucatan Killer Impact Gaining Support, in Science. April, 1991. p. 377.

Jaroff, L., 1991. At last, the smoking gun?, in Time. July 1, 1991. p. 60-61.

Dietz, R. S., 1991. Demise of the Dinosaurs: A Mystery Solved, in Astronomy. July 1991. p. 30-37.

Beatty, J. K., 1991. Killer crater in the Yucatan?, in Sky & Telescope. July, 1991. p. 38-40.

Monastersky, R., 1992. Closing in on the Killer, in Sci. News. Jan. 25, 1992. p. 56-58.

Monastersky, R., 1992. Giant Crater linked to mass extinction, in Sci. News, v. 142, August 15, 1992. p. 100.

Benton, M. J. and Little, C. T. S., 1994. Impact in the Caribbean and death of the dinosaurs, in Geology Today. Nov-Dec 1994. p. 222-227.

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A Sociologist's Reflections on Popular Writings about the Impact Hypothesis (and the impact of those writings)

Clemens, E. S., 1994. The impact hypothesis and popular science: Conditions and consequences of interdisciplinary debate. In: W. Glen (Ed.), The Mass Extinction Debates: How Science Works in a Crisis. Stanford University Press, Stanford, CA, pp. 92-120.

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