EARTH 520
Plate Tectonics and People

Dr. Lynn R. Sykes

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(Image available from:  http://www.ldeo.columbia.edu/~sykes/images/sykes_portrait_2002_5x7_300pp...)

Biographical Information

Lynn Sykes was born April 16, 1937 in Pittsburgh, Pennsylvania.  His father worked for the United States Weather Bureau and his mother was a homemaker.  Lynn was an only child.  Always interested in the sciences, particularly chemistry, Lynn Sykes remembers first becoming interested in the Earth Sciences when, out on a bike ride, he found a metallic sample by the side of the road that he longed to have identified.

Lynn Sykes attended MIT where he earned both a B.S. and M.S. in Geology and Geophysics in 1960.  He then went to Columbia University where he earned a Ph.D. in Geology in 1965.

Dr. Sykes spent his career researching seismic activity, seafloor spreading, and the affects of nuclear weapons testing on seismic activity.  He earned 26 scholarships, fellowships, awards, and honors and has authored or coauthored more than 130 scientific papers.  Dr. Sykes now works at Professor Emeritus of Earth and Environmental Sciences at Columbia University.

Dr. Sykes lives in Palisades, New York with his wife Kathleen Mahoney Sykes.

Specific contributions to plate tectonic theory:

In 1964, Lynn Sykes, Bryan Isacks, and Jack Oliver were studying seismic data in order to determine the foci of earthquakes near the South Pacific island of Tonga.  Their data indicated that there was a plane tilting down from the ocean floor at about 45 degrees.  They determined that this slab was quite thick (60 miles) and was capable of producing and sustaining seismic activity as it descended into the mantle.  They determined that it was not simply crust that was descending, but referred to the slab as Tuzo Wilson had, as a "plate".  They then determined that this plate was rigid and moving around on a soft, flowing asthenosphere layer of the earth.

Lynn Sykes was able to gather most of his seismic data using the Worldwide Standard Seismographic Network (WWSSN) of the U.S. Coast and Geodetic Survey.  This was a seimographic network originally intended for detecting nuclear bombs.  This network allowed him to gather data that offered solid proof of seafloor spreading and faulting in the South East Pacific Rise.  He determined that seafloor spreading occurred at transform faults and that seismic activity is confined to the area between ridge crests, leaving the interiors of oceanic "plates" nearly free of earthquake activity.  He then published his paper on the Mechanism of Earthquakes and Nature of Faulting on the Mid-Oceanic Ridge (abstract).

epicenter

Image 1: Diagram from Mechanism of Earthquakes and Nature of Faulting on the Mid-Oceanic Ridge where Lynn Sykes illustrates earthquake epicenters and establishes mechanisms for the earthquakes (transform faults between ridge crests)

Dr. Sykes is also known for his contribution to the idea of "new global tectonics".  New global tectonics expands on the idea of Xavier LePichon that "plates form an integrated system where the sum of all crust generated at oceanic ridges is balanced by the cumulative amount destroyed in all subduction zones."  Sykes, Isacks, and Oliver attributed the larger part of the Earth's seismic activity to this phenomenon.  Their results can be found in the paper "Seismology and the New Global Tectonics" (abstract).

block diagram

Image 2:  Diagram from Seismology and the New Global Tectonics that illustrates the "mobile lithosphere" hypothesis, explaining that crust that is created at one point is destroyed at another.

It is often said that Frederick Vine and Drummond Matthews developed a hypothesis, Tuzo Wilson explained the causes, and Sykes proved it.

Other interesting scientific contributions:

Besides his important work in the area of plate tectonics, transform faults, and seafloor spreading, Dr. Lynn Sykes was also heaviliy involved in other earthquake research and in nuclear weapons control.  He worked to achieve a comprehensive nuclear test ban treaty and works toward nuclear arms control.  In fact, 35 of his published works are in the verification of nuclear testing.

His continued work in the the earth sciences is in the evolution of stresses and earthquake activity in California, in general earthquake prediction, in interior plate quakes and seismic stress, and in earthquake activity in New York.

Other cool stuff you should know:

As a child, Lynn Sykes was an avid stamp collector, with over 20,000 stamps in his collection.  He would often take the train from his home in Arlington, VA to Washington DC to buy stamps and visit the Smithsonian, helping spark his interest in the Earth Sciences.

When Lynn Sykes attended MIT, he was on scholarship from Proctor and Gamble to cover the $900/year tuition.

In 1974, Dr. Sykes was a member of the U.S. Delegation that negotiated the Threshold Test Ban Treaty with the U.S.S.R.

Dr. Sykes won the Walter H Bucher medal from the American Geophysical Union for "original contribution to the basic knowledge of the Earth's crust" in 1975.

Dr. Sykes gave a lecture on the 1906 San Francisco earthquake, a passionate subject of his, on its 100th anniversary.

Bibliography

100th Anniversary of the San Francisco Earthquake. (n.d.). The Earth Institute at Columbia University. Retrieved January 27, 2010, from www.earth.columbia.edu/videos/watch/82


Cloos, Mark. "Plate tectonics." World Book Advanced. World Book, 2010. Web.  31 Jan. 2010.


Dr. Lynn Sykes. (n.d.). Lamont-Doherty Earth Observatory | . Retrieved January 31, 2010, from http://www.ldeo.columbia.edu/~sykes/

 

Isacks, Bryan, Oliver, Jack, and Sykes, Lynn.  (1968).  Seismology and the New Global Tectonics.  Journal of Geophysical Research. p. 5855-5899.


Lynn Sykes' proof of seafloor spreading. (n.d.). Geowords. Retrieved January 31, 2010, from geowords.com/histbookpdf/g07.pdf


Lynn Sykes. (n.d.). Oracle ThinkQuest Library . Retrieved January 31, 2010, from http://library.thinkquest.org/17175/people/sykes.html


Oral History Transcript — Dr. Lynn Sykes. (n.d.). The American Institute of Physics -- Physics Publications and Resources. Retrieved January 31, 2010, from http://www.aip.org/history/ohilist/6994_1.html


Plate Tectonics, 1972. (n.d.). AGU - Over 90 Years of Quality Research in the Geosciences. Retrieved January 31, 2010, from http://www.agu.org/books/cr/plate-tectonics.html


Plate Tectonics. (2010). In Encyclopædia Britannica. Retrieved January 31, 2010, from Encyclopædia Britannica Online: http://search.eb.com/eb/article-261571


Plate Tectonics. (2010). In Encyclopædia Britannica. Retrieved January 31, 2010, from Encyclopædia Britannica Online: http://search.eb.com/eb/article-261576


Sykes, Lynn R. (1967).   Mechanisms of Earthquakes and Nature of Faulting on the Mid-Oceanic Ridges.  Journal of Geophysical Research. p. 2131-2153.


USGS CMG InfoBank: Transform Faults . (n.d.). Home Page - USGS Western Coastal and Marine Geology. Retrieved January 31, 2010, from http://walrus.wr.usgs.gov/infobank


When the Earth moves. (n.d.). Beyond Discovery. Retrieved January 31, 2010, from www.beyonddiscovery.org/content/view.page.asp?I=234