Report on the U.S. Program for the International Geophysical Year July 1, 1957 - December 31, 1958 (1965) / Chapter Skim
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Pages 465-502
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X I SEISMOLOGY PROGRAM Seismograph Va u l t at Lament G e o l o g i c a l Observatory
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SEISMOLOGY PROGRAM Page A Organization of T e c h n i c a l Panel on Seismology and G r a v i t y 463 B
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SEISMOLOGY 2. Order of Pro.iect D e s c r i p t i o n .
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SEISMOLOGY P r o j e c t 11.2 - A n t a r c t i c Seismology Personnel 1. Ob.iectives.
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SEISMOLOGY P r o j e c t 11.3 - A n t a r c t i c Seismograph Equipment 1.
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SEISMOLOGY P r o j e c t 11.6 - A n t a r c t i c Seismograph Equipment 1.
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SEISMOLOGY Robert L Kovach and Frank P r e s s : "Surface Wave D i s p e r s i o n and C r u s t a l S t r u c t u r e i n A n t a r c t i c a and Surrotmding Oceans." A n n a l l d i G e o f i s i c a 14, 1961, pp.
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SEISMOLOGY P r o j e c t 11.7 - Reduction of Seismic Records on A n t a r c t i c T r a v e r s e s 1.
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SEISMOLOGY eo'w 70 'W 1 7 0 ' E h l 6 0 *
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SEISMOLOGY Surface heights u s u a l l y were c a l c u l a t e d by the summation of e l e v a t i o n i n t e r v a l s measured between t r a v e r s e v e h i c l e s as they t r a v e l e d s e v e r a l k i l o m e t e r s a p a r t . The normal c o r r e c t i o n s f o r temperature and humidity were a p p l i e d , and a l s o a c o r r e c t i o n for pressure g r a d i e n t between v e h i c l e s , as estimated from the wind v e l o c i t y two meters above the s u r f a c e .
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SEISMOLOGY The g e o l o g i c a l evidence tends to support the hypothesis of a topographic low exp r e s s i n g the break between the folded mountains of the Palmer Peninsula type and the b l o c k - f a u l t e d mountains of the A n t a r c t i c Horst. However, even i f t h i s f e a t u r e e x i s t s , i t would be i n no way comparable to the major channel between the Ross and B e l l i n g hausen Seas.
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SEISMOLOGY 6. Bibliography.
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SEISMOLOGY G.P. Woollard: "The Land i n the A n t a r c t i c .
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:rn SEISMOLOGY Project 11.8 - Sea Expl o r a t i o n , A t l a n t i c Ocean 1. Ob.iectives.
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SEISMOLOGY b. Continental Border Area of East South America: Approximately 70 measurements were made along the Argentine coast, mostly w i t h i n the c o n t i n e n t a l shelf area.
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SEISMOLOGY d. South Georgia Area- The measurements i n t h i s area consist of a traverse extending from about 48° to 57°S l a t i t u d e , which crosses the i s l a n d arc and i t s associated foredeep.
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SEISMOLOGY 6. Bibliography.
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SEISMOLOGY Project 11.9 - Seismic Sea Exploration of the Southeast P a c i f i c 1. Objectives.
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SEISMOLOGY The measurements i n Peru-Chile Trench area are of p a r t i c u l a r i n t e r e s t . Off Antofagasta, C h i l e , the l i n e of measurements p a r a l l e l t o the axis of the trench and located about h a l f way between the trench axis and the top of the c o n t i n e n t a l slope shows that the base of the cru s t i s a t about -23 km.
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SEISMOLOGY P r o j e c t 11.10 - C o n t i n e n t a l Seismic E x p l o r a t i o n I 1 Ob.iectives. T h i s p r o j e c t of the U n i v e r s i t y of Wisconsin provided for s e i s m i c r e f r a c t i o n e x p l o r a t i o n s of the c r u s t a l s t r u c t u r e m regions of p a r t i c u l a r , i n t e r e s t , to attempt to shed l i g h t on the d i s p a r i t y of r e s u l t s between , c r u s t a l s t r u c t u r e s i n f e r r e d from previous s e i s m i c e x p l o r a t i o n s and s t u d i e s of g r a v i t y j a n o m a l i e s , r e c e n t work on the study of c r u s t a l s t r u c t u r e by observing the earthquake s u r f a c e s e i s m i c waves a t t h i s time did not lend unequivocal support to e i t h e r the g r a v i t y or s e i s m i c method.
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SEISMOLOGY was detected. The surface rocks are a l l c r y s t a l l i n e , and f o r the most p a r t b a s a l t w i t h some gabbro and g r a n i t i c s c h i s t and gneiss.
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SEISMOLOGY been present without having been recorded as a f i r s t a r r i v a l , and the presence of such a l a y e r would have given an o v e r a l l t h i c k n e s s of about 44 km for the c r u s t . A more complete r e p o r t on t h i s study i s given m IGY General Report S e r i e s , No.
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SEISMOLOGY Project 11.11 - Seismic Exploration of Continental Structure i n South America 1. Objectives.
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SEISMOLOGY two records r a t h e r than one. A l l the trucks and equipment went by ocean f r e i g h t from Baltimore t o Callao, Peru.
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SEISMOLOGY a r r i v a l s from the base of the c r u s t i n the a l t i p l a n o although f i r s t a r r i v a l s were obtained to the south and west over the f l a n k area. The v e l o c i t y s t r u c t u r e observed was about 5.5 km/sec f o r the surface m a t e r i a l , 6.0 km/sec to possibly 6.4 km/sec w i t h a d e f i n i t e i n d i c a t i o n by f i r s t a r r i v a l s of a 7.0 km/sec basal layer o v e r l y i n g the mantle w i t h a v e l o c i t y of about 8.0 km/sec.
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SEISMOLOGY r LA YANQUERA QUI SALIN ANTOFSGASIA 5. LEGEND STATION INSTALLED I960 O STATION EXPECTED 1961 A OTHER SEISMIC EQUPMENT OPERATING SCALE IN KILOMETERS 100 0 200 400 75 70 65 LONGITUDF WEST OF GREENWICH Figure 8.
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SEISMOLOGY Projects 11.12 & 11.19 - Study of Long-Period Seismic Waves 1. Objectives.
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SEISMOLOGY Project 11.13 - Lg and Rg Phase Study 1. Objectives.
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SEISMOLOGY Project 11.14 - Crustal Strain Accumulation 1. Objectives.
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SEISMOLOGY 30m Figure 9. Extensometer i n s t a l l a t i o n , Nana, Peru.
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SEISMOLOGY The gravest spheroidal mode shows a s p l i t spectral peak with periods to 54.7 and 53.1 minutes. The theoretical prediction for the Bullen B model according to Alterman, Perkeris, and Jarosch is 53.7 min.
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SEISMOLOGY Projects 11.15, 11.18, 11.20 - Antarctic, Arctic and Pacific Seismic Observatories 1. Objectives.
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SEISMOLOGY Supplies including replacement galvanometers, recorders, chronometers, and expendables such as photo paper, chemicals, etc. were shipped to Antarctica during the summers of 1957 and 1958.
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SEISMOLOGY Project 11.16 - Long-Period and Lg Phase Data Reduction and Publication 1. Objectives.
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