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{{Main|Alvarez hypothesis}}
{{Main|Alvarez hypothesis}}


Alvarez and his father [[Luis W. Alvarez]] are most widely known for their discovery (with [[Frank Asaro]] and [[Helen Michel]]) that a [[clay]] layer occurring right at the [[Cretaceous]]-[[Tertiary]] (K-T) boundary was highly enriched in the element [[iridium]]. Since iridium enrichment is common in [[asteroid]]s, but very uncommon on the Earth, they further postulated that the layer had been created by the [[impact event|impact]] of a large asteroid with the Earth and that this impact event was the likely cause of the [[Cretaceous–Paleogene extinction event]].<ref>[http://www.pbs.org/wgbh/aso/databank/entries/do80di.html People and Discoveries: Alvarez finds evidence of dinosaur-killing asteroid, 1980], PBS website, accessed April 17, 2011</ref>
Alvarez and his father [[Luis W. Alvarez]] are most widely known for their discovery (with [[Frank Asaro]] and [[Helen Michel]]) that a [[clay]] layer occurring right at the [[Cretaceous–Paleogene boundary|Cretaceous–Paleogene (K-Pg) boundary]] was highly enriched in the element [[iridium]]. Since iridium enrichment is common in [[asteroid]]s, but very uncommon on the Earth, they further postulated that the layer had been created by the [[impact event|impact]] of a large asteroid with the Earth and that this impact event was the likely cause of the [[Cretaceous–Paleogene extinction event]].<ref>[http://www.pbs.org/wgbh/aso/databank/entries/do80di.html People and Discoveries: Alvarez finds evidence of dinosaur-killing asteroid, 1980], PBS website, accessed April 17, 2011</ref>


This iridium enrichment has now been observed in many other sites around the world.{{where|date=June 2014}} And further, the very large [[Chicxulub crater]] was identified and is now regarded as the definitive evidence of a large impact.{{citation needed|date=June 2014}} Consequently, a majority of scientists now accept the impact scenario as the most likely cause for the Cretaceous–Paleogene extinction event which occurred 66 million years ago and eliminated 75% of all species,<ref name="Schulte10" >{{Cite journal | last = Schulte | first = Peter | author2 = Alegret, Laia |author3=Arenillas, Ignacio |author4=Arz, Jose A. |author5=Barton, Penny J. |author6=Bown, Paul R. |author7=Bralower, Timothy J. |author8=Christeson, Gail L. |author9=Claeys, Philippe |author10=Cockell, Charles S. |author11=Collins, Gareth S. |author12=Deutsch, Alexander |author13=Goldin, Tamara J. |author14=Goto, Kazuhisa |author15=Grajales-Nishimura, José M. |author16=Grieve, Richard A. F. |author17=Gulick, Sean P. S. |author18=Johnson, Kirk R. |author19=Kiessling, Wolfgang |author20=Koeberl, Christian |author21=Kring, David A. |author22=MacLeod, Kenneth G. |author23=Matsui, Takafumi |author24=Melosh, Jay |author25=Montanari, Alessandro |author26=Morgan, Joanna V. |author27=Neal,Clive R. |author28=Nichols, Douglas J. |author29=Norris, Richard D. |author30=Pierazzo, Elisabetta |author31=Ravizza, Greg |author32=Rebolledo-Vieyra, Mario |author33=Reimold, Wolf Uwe |author34=Robin, Eric |author35=Salge, Tobias |author36=Speijer, Robert P. |author37=Sweet, Arthur R. |author38=Urrutia-Fucugauchi, Jaime |author39=Vajda, Vivi |author40=Whalen, Michael T. |author41=Willumsen, Pi S.| title = The Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous- Paleogene Boundary | journal = [[Science (journal)|Science]] | volume = 327 | issue = 5970 | pages = 1214–1218 | date = 5 March 2010 | url = http://www.sciencemag.org/cgi/content/abstract/327/5970/1214 | doi = 10.1126/science.1177265 | accessdate = 2010-03-08 | pmid = 20203042 | bibcode=2010Sci...327.1214S}}</ref> including all non-avian [[dinosaur]]s. His book, ''[[T. Rex and the Crater of Doom]]'', details the discovery of the [[Cretaceous–Paleogene extinction event]].
This iridium enrichment has now been observed in many other sites around the world.{{where|date=June 2014}} And further, the very large [[Chicxulub crater]] was identified and is now regarded as the definitive evidence of a large impact.{{citation needed|date=June 2014}} Consequently, a majority of scientists now accept the impact scenario as the most likely cause for the Cretaceous–Paleogene extinction event which occurred 66 million years ago and eliminated 75% of all species,<ref name="Schulte10" >{{Cite journal | last = Schulte | first = Peter | author2 = Alegret, Laia |author3=Arenillas, Ignacio |author4=Arz, Jose A. |author5=Barton, Penny J. |author6=Bown, Paul R. |author7=Bralower, Timothy J. |author8=Christeson, Gail L. |author9=Claeys, Philippe |author10=Cockell, Charles S. |author11=Collins, Gareth S. |author12=Deutsch, Alexander |author13=Goldin, Tamara J. |author14=Goto, Kazuhisa |author15=Grajales-Nishimura, José M. |author16=Grieve, Richard A. F. |author17=Gulick, Sean P. S. |author18=Johnson, Kirk R. |author19=Kiessling, Wolfgang |author20=Koeberl, Christian |author21=Kring, David A. |author22=MacLeod, Kenneth G. |author23=Matsui, Takafumi |author24=Melosh, Jay |author25=Montanari, Alessandro |author26=Morgan, Joanna V. |author27=Neal,Clive R. |author28=Nichols, Douglas J. |author29=Norris, Richard D. |author30=Pierazzo, Elisabetta |author31=Ravizza, Greg |author32=Rebolledo-Vieyra, Mario |author33=Reimold, Wolf Uwe |author34=Robin, Eric |author35=Salge, Tobias |author36=Speijer, Robert P. |author37=Sweet, Arthur R. |author38=Urrutia-Fucugauchi, Jaime |author39=Vajda, Vivi |author40=Whalen, Michael T. |author41=Willumsen, Pi S.| title = The Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous- Paleogene Boundary | journal = [[Science (journal)|Science]] | volume = 327 | issue = 5970 | pages = 1214–1218 | date = 5 March 2010 | url = http://www.sciencemag.org/cgi/content/abstract/327/5970/1214 | doi = 10.1126/science.1177265 | accessdate = 2010-03-08 | pmid = 20203042 | bibcode=2010Sci...327.1214S}}</ref> including all non-avian [[dinosaur]]s. His book, ''[[T. Rex and the Crater of Doom]]'', details the discovery of the [[Cretaceous–Paleogene extinction event]].

Revision as of 03:17, 23 October 2016

For the physicist (his father), see Luis Walter Alvarez. For the physician (his grandfather), see Walter C. Alvarez.
Walter Alvarez
Luis and Walter Alvarez (L-R) at the K-T Boundary in Gubbio, Italy 1981
Born
Walter Alvarez

(1940-10-03) October 3, 1940 (age 84)
Berkeley, California, USA
Alma materCarleton College
Princeton University
Known forKT Impact Dinosaur Extinction Event
Spouse
Milly Alvarez
​
(m. 1963)​
AwardsG. K. Gilbert Award (1985)
Penrose Medal (2002)
Vetlesen Prize (2008)
Barringer Medal (2013)
Scientific career
FieldsGeology
InstitutionsUniversity of California, Berkeley

Walter Alvarez (born October 3, 1940) is a professor in the Earth and Planetary Science department at the University of California, Berkeley. He is most widely known for the theory that dinosaurs were killed by an asteroid impact, developed in collaboration with his father, Nobel Prize winning physicist Luis Alvarez.

Biography

Born in Berkeley, California, Alvarez is the son of Luis Walter Alvarez, a Nobel prize-winner in physics. His grandfather was the famed physician Walter C. Alvarez and his great-grandfather, Spanish-born Luis F. Alvarez, worked as a doctor in Hawaii and developed a method for the better diagnosis of macular leprosy. His great-aunt Mabel Alvarez was a noted California artist and oil painter.[1]

Alvarez earned his B.A. in geology in 1962 from Carleton College in Minnesota and Ph.D. in geology from Princeton University in 1967. He worked for American Overseas Petroleum Limited in the Netherlands, and in Libya at the time of Colonel Gadaffi’s revolution. Having developed a side interest in archaeological geology, he left the oil company and spent some time in Italy, studying the Roman volcanics and their influence on patterns of settlement in early Roman times.[1]

Alvarez then moved to Lamont-Doherty Geological Observatory of Columbia University, and began studying the Mediterranean tectonics in the light of the new theory of plate tectonics. His work on tectonic paleomagnetism in Italy led to a study of the geomagnetic reversals recorded in Italian deep-sea limestones. Alvarez and his colleagues were able to date the reversals for an interval of more than 100 million years of the Earth's history by using Foraminifera biostratigraphy.[1][2]

Impact theory

Main article: Alvarez hypothesis

Alvarez and his father Luis W. Alvarez are most widely known for their discovery (with Frank Asaro and Helen Michel) that a clay layer occurring right at the Cretaceous–Paleogene (K-Pg) boundary was highly enriched in the element iridium. Since iridium enrichment is common in asteroids, but very uncommon on the Earth, they further postulated that the layer had been created by the impact of a large asteroid with the Earth and that this impact event was the likely cause of the Cretaceous–Paleogene extinction event.[3]

This iridium enrichment has now been observed in many other sites around the world.[where?] And further, the very large Chicxulub crater was identified and is now regarded as the definitive evidence of a large impact.[citation needed] Consequently, a majority of scientists now accept the impact scenario as the most likely cause for the Cretaceous–Paleogene extinction event which occurred 66 million years ago and eliminated 75% of all species,[4] including all non-avian dinosaurs. His book, T. Rex and the Crater of Doom, details the discovery of the Cretaceous–Paleogene extinction event.

In addition to his interest in extinction events and impacts, Alvarez has contributed to the understanding of Mediterranean tectonics, Roman geology and archeology, and the establishment of magnetostratigraphic correlations.[1][2]

Big History

Alvarez helped to organize a meeting of Big Historians at the Geological Observatory at Coldigioco in Italy in 2010 which resulted in the establishment of the International Big History Association.

Alvarez began teaching a course in Big History at UC Berkeley in 2006 under the title "Big History: Cosmos, Earth, Life, Humanity." [5] According to Alvarez, Big History is the "attempt to understand, in a unified and interdisciplinary way, the history of the Cosmos, Earth, Life and Humanity." This definition was later adopted by the International Big History Association (IBHA).[6] Alvarez's course is open to all majors and grade levels and seeks to provide a broad understanding of the past, present and future.

Alvarez helped organize a meeting of Big Historians at the Geological Observatory at Coldigioco in Italy in 2010[7] which resulted in the establishment of the International Big History Association. In 2011, the IBHA is a 501(c)3 non-profit organization.[8]

Alvarez was one of the founding members of the IBHA,[9] and served on the advisory board until August 7, 2014 when he stepped down at the 2014 IBHA conference held at Dominican University of California.

ChronoZoom

Alvarez presented "Earth History in the Broadest Possible Context" at Chevron Auditorium on the UC Berkeley campus where ChronoZoom was first publicly demonstrated in 2012.

Alvarez's most recent contribution to the field of Big History has been the creation of a free, open source, zoomable timeline in partnership with Microsoft Research called ChronoZoom.[10] ChronoZoom is a computer-graphical approach to dealing with this problem of visualizing and understanding time scales, and presenting vast quantities of historical information in a useful way.[11] ChronoZoom was introduced at the 97th Annual Faculty Research Lecture at UC Berkeley.[12]

Awards and honors

Alvarez is the recipient of numerous awards and honors. He was elected a Fellow of the American Academy of Arts and Sciences in 1983, and elected a member of the National Academy of Sciences in 1991.[13] He was awarded the 2006 Nevada Medal, the 2008 Vetlesen Prize,[14] and the Penrose Medal from the Geological Society of America. In 2005, he received the doctorate "Honoris Causa" in Geological Sciences from the University of Siena, Italy.

Works

  • T. Rex and the Crater of Doom by Walter Alvarez (Princeton University Press, 1997) ISBN 0-375-70210-5
  • The Mountains of Saint Francis: The Geologic Events that Shaped Our Earth by Walter Alvarez (W. W. Norton, December 2008)

References

  1. ^ a b c d "Walter Alvarez". Department of Earth and Planatery Science at UCB. Retrieved 9 February 2014.
  2. ^ a b Alvarez, Walter. "The historical record in the Scaglia limestone at Gubbio: magnetic reversals and the Cretaceous-Tertiary mass extinction" (PDF). Sedimentology. Retrieved 10 February 2014.
  3. ^ People and Discoveries: Alvarez finds evidence of dinosaur-killing asteroid, 1980, PBS website, accessed April 17, 2011
  4. ^ Schulte, Peter; Alegret, Laia; Arenillas, Ignacio; Arz, Jose A.; Barton, Penny J.; Bown, Paul R.; Bralower, Timothy J.; Christeson, Gail L.; Claeys, Philippe; Cockell, Charles S.; Collins, Gareth S.; Deutsch, Alexander; Goldin, Tamara J.; Goto, Kazuhisa; Grajales-Nishimura, José M.; Grieve, Richard A. F.; Gulick, Sean P. S.; Johnson, Kirk R.; Kiessling, Wolfgang; Koeberl, Christian; Kring, David A.; MacLeod, Kenneth G.; Matsui, Takafumi; Melosh, Jay; Montanari, Alessandro; Morgan, Joanna V.; Neal,Clive R.; Nichols, Douglas J.; Norris, Richard D.; Pierazzo, Elisabetta; Ravizza, Greg; Rebolledo-Vieyra, Mario; Reimold, Wolf Uwe; Robin, Eric; Salge, Tobias; Speijer, Robert P.; Sweet, Arthur R.; Urrutia-Fucugauchi, Jaime; Vajda, Vivi; Whalen, Michael T.; Willumsen, Pi S. (5 March 2010). "The Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous- Paleogene Boundary". Science. 327 (5970): 1214–1218. Bibcode:2010Sci...327.1214S. doi:10.1126/science.1177265. PMID 20203042. Retrieved 2010-03-08.
  5. ^ Letters and Science Discovery Courses
  6. ^ International Big History Association (IBHA)
  7. ^ Origins of the International Big History Association
  8. ^ International Big History Association Articles of Incorporation
  9. ^ Contacts for the International Big History Association
  10. ^ Abstracts - Microsoft Research
  11. ^ ChronoZoom Project Information
  12. ^ "ChronoZoom debuts at UC Berkeley Faculty Research Lecture Series". University of California Berkeley Library. The Regents of the University of California. Retrieved 29 May 2014.
  13. ^ "Book of Members, 1780-2010: Chapter A" (PDF). American Academy of Arts and Sciences. Retrieved 17 April 2011.
  14. ^ Geologist Who Linked Cosmic Strike to Dinosaurs' Extinction Takes Top Prize; The Vetlesen, on Level with Nobel, Goes to Walter Alvarez, Columbia University Earth Institute, October 16, 2008
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