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This programme is about the exciting developments in earthquake prediction and prevention that have taken place in the last few years. In the programme two leading figures in earthquake research, D...r. Barrie Raleigh of the Geological Survey of the United States Department of the Interior and Professor Lynn Sykes of the Lamont-Doherty Geological Observatory of Columbia University, discuss their work and comment on its geophysical and sociological impact. The discussion deals with the new ratio method for the prediction of earthquakes and the experiment in earthquake prevention at Rangely, Colorado. A theoretical earthquake mechanism is related to both premonitory changes in rock properties prior to an earthquake and to recent results from the Rangley project. In addition, the programme is illustrated with examples of earthquake phenomena from Alaska
Metadata describing this Open University video programme
Item code: S2-4; 05
First transmission date: 16-09-1973
Published: 1973
Rights Statement:
Restrictions on use:
Duration: 00:24:22
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Producers: Andrew Crilly; David Jackson; Barrie Whatley
Contributors: Lynn R. Sykes; Paul Vaughan; C. B. Raleigh; David Evans
Publisher: BBC Open University
Keyword(s): Earthquakes; Seismology
Footage description: Shots of Anchorage, Alaska during and after the March, 1964 earthquake. Paul Vaughan introduces Lynn Sykes. Sykes with a geological map of the world. He points out the areas of major earthquake activity. These bound large lithospheric plates. He shows a chart which gives the slip rates for 3 major earthquake regions. Sykes then explains how locations of rupture zones of major earthquakes are mapped. He uses a map of Alaska showing the Aleutian chain to aid his discussion. Sykes explains that this method can be used to predict the sites of future major earthquakes. Paul Vaughan provides the commentary for a film sequence showing the aftermath of the 1966 earthquake in Tashkent, Southern Russia. Vaughan discusses the discovery by Soviet geophysicists after the Tashkent disaster that the Vs/Vp ratio method for predicting the time of earthquake occurrences. Lynn Sykes discusses the Russian work further and then the American work in western New York state which confirmed the Russian discovery. Sykes uses maps, charts and diagrams to aid. Shots of San Francisco after the 1906 earthquake plus animated graphs are shown with a commentary on the cause of differences in Vs/Vp ratio before and after major earthquakes. Aerial shots of California showing the San Andreas fault: shots of modern San Francisco. Several still shots of San Francisco after the 1906 earthquake. Shots of the U.S.Army Rocky Mountain Arsenal, Denver where wastes from manufacture of nerve gas have been pumped underground. Shots of David Evans, A Denver geologist, who argues that the fluid pressure of these wastes caused the 4 major earthquakes in the Denver area which occurred at about that time. More shots of the disposal well at the Arsenal. Evans demonstrates his theory with a model (beer can balanced on an inclined slope). Shots of Denver, Colo. and the Arsenal. Shots of Rangely, Colo, where a controlled test on earthquake prediction was conducted. Commentary explains why Rangely was chosen as a site. C.B.Raleigh continues the commentary in the studio. He explains why Rangely was chosen as the test site. He shows a 3-D model of the site to explain how the experiment was conducted. Raleigh also uses a map showing contours of fluid pressures in the ground at the test site and points out the relationship between fluid pressure and earthquake activity. Raleigh shows a histogram (1969-73) which sums up the results of the experiment - that changes in fluid pressure underground affect earthquake activity. The critical pressure seems to be 4,000 psi. Vaughan and Raleigh discuss the possible practical application of this research in the San Francisco area. Sykes and Vaughan examine the possibility of predicting the next major earthquake in San Francisco. Sykes, Vaughan and Raleigh then discuss the economics of earthquake prediction, particularly for poorer countries. They then give their estimates of the state of the art in 10 years time.
Master spool number: 6HT/70986
Production number: 00525_1017
Videofinder number: 672
Available to public: no