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Microearthquakes on the Galapagos spreading centre and the seismicity of fast-spreading ridges
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924 DZIEWONSKI, AM HARVARD UNIV. CAMBRIDGE, MASS. USA GILBERT, P UNIV. CALIFORNIA, SAN DIEGO, USA Temporal variation of the seismic movement tensor and the evidence of precursive compression for two deep earthqt~ke s.3F, 17R. NATURE, V. 247, JAN. 25,1974, P185-188. The general approach to the source mechanism problem has now become feasible because of the development of a novel method of processing the Fourier spectra of observed seismograms. The procedure applied depends on the availability of digitlsed recordings from a large number of well-distributed stations. Results presented for two deep earthquakes, indicate t~Jat the hypocentral region began to experience compression about 80s before the abrupt onset of each.
925 MACDONALD, KC MUDIE, JD Microearthquakes on the Galapagos spreading centre and the seismicity of fast-spreading ridges. 8F, 27R. GEOPHYS. J. ROY. ASTR. SOC .V36, N2,1974, P245- 257. Fast-spreading centres such as the Galapagos spreading centre often show hiatuses hundreds of kilometres in length in WWSSN (World Wide Stargardized Seismic Network) recorded seismic activity. Sonobuoys were deployed over a seismically quiet segment of the Galapagos spreading centre to measure the seismicity at a close range. Auth.
Frost a c t i o n , p e r m a f r o s t and frozen ground
Hydrogeology 932 WONG, HY CI~MENPATION RES.LTD. HERTS. GB YONG, RN MCGILL UNIV.MONTREAL, CDN Engineering problems in unsaturated soils;4F, IT,8R. CIV.ENGNG.I~BL WORKS REV.V68,NS06,1973,P759-765. This paper presents a review of the common methods of determining a soll water dlffusivlty parameter (a parameter of mathematical convenience used in soil water content distribution calculations) together with a discussion of their respective shortcomings. A modified method involving a very simple testing technique as well as simple calculation procedures is proposed. The suitability of this method is then assessed by testing its reproducibility using different sets of test data from the same type of test soil. 933 BERNAIY, J Drainage o rok fissures by use of smell canals. Congress. Disct~ssion. In French. 2F. PROc~'D. 2 CONGRESS, IIvrEMNAT.SOC. ROCK MECH.BELGRAD,
1970, v4,1974, ~99- 5o1. The writer describes an interesting approach to a favourable arrangement of drainage measures in a rock mass with permeable Joints.
934
MILOVANOVlC,D See also abstract: 916.
926 ARSENTEV, AI MIDHALLOV, GS ZHUKOV, AV Performance of mining equipment under polar conditions. In Russian. 4R. PHYSICS AND TECHNOLOGY OF MINING, LENINGRAD, NAUKA, 1970, P198- 203.
927 SRUVALOV,IV VAINBLKT,AB Calculating bearing capacity of coal pillars urger permafrost conditions. In Russian. NEW INVESTIGATIONS IN MINING,LENINGRAD,1969,P93-98.
928 TEXTBOOK Methodical recmendations on prognosis of frost crack formation in ground. Textbook. In Russian. English table of contents. 5R. MOSCOW, 1972, 38P. 929 TEXTBOOK Principles of predicting thermal stresses and deformations in frozen ground. Textbook. In Russian. English table of contents. 29R. MOSCOW, 1970, 53P. 930 SYMPOSIUM Road research. Symposium on frost action on roads.Oslo, October 197B.In French and English.Refs. PARIS, O. E. C.D. 3VOLS, OCT, 1973, PI3- 22. 931 JOHANSEN, 0 Thermal conductivity of soils.Measurements and methods of predlction;Proc.Symposium on frost action on roads, Oslo, 1973, 20R. PARIS, O.E.C .D.V1,1973, P165-188.
Drainage system in gravity dams. Congress. Discussion. In French. 6F. PROCEED. 2 CONGRESS, INTERNAT.SOC.ROCKMECH.BELGRAD, 1970,V4,197~,P528-529.
G rou n d w a t e r 935 SHARP, JC Flow and drainage problems within rock masses. Congress. Discussion. 3F. PROCEED. 2 CONGRESS, INTERNAT. SOC.ROCK MECH.BELGRAD, 1970, V4,1974, P519-521. Investigations at Imperial College London, to determine representative flow laws for natural fissures and to use these in a three-dimensional mathematical model are reported. The effects of Joint opening, geometrical characteristics and flow direction were studied.
936 SUNADA, DK Geohydrattlics at the unconformity between bedrock and alluvial aquifers. COLO. STATE UNIV. FORT COLLINS.ENVIRONM. RESOURCES CENTRE, REPORT PB-211 64~,JUNE,1972,175P.
M e a s u r e m e n t of w a t e r pressure and its effects 937 VORONIN, AD SKALABAN, VD Measuring soil moisture potential by a cryoscoplc method. In Russian. English summary, llR. MRTEOROL. GIDROLOG.N9,1973, P56-65.
924 DZIEWONSKI, AM HARVARD UNIV. CAMBRIDGE, MASS. USA GILBERT, P UNIV. CALIFORNIA, SAN DIEGO, USA Temporal variation of the seismic movement tensor and the evidence of precursive compression for two deep earthqt~ke s.3F, 17R. NATURE, V. 247, JAN. 25,1974, P185-188. The general approach to the source mechanism problem has now become feasible because of the development of a novel method of processing the Fourier spectra of observed seismograms. The procedure applied depends on the availability of digitlsed recordings from a large number of well-distributed stations. Results presented for two deep earthquakes, indicate t~Jat the hypocentral region began to experience compression about 80s before the abrupt onset of each.
925 MACDONALD, KC MUDIE, JD Microearthquakes on the Galapagos spreading centre and the seismicity of fast-spreading ridges. 8F, 27R. GEOPHYS. J. ROY. ASTR. SOC .V36, N2,1974, P245- 257. Fast-spreading centres such as the Galapagos spreading centre often show hiatuses hundreds of kilometres in length in WWSSN (World Wide Stargardized Seismic Network) recorded seismic activity. Sonobuoys were deployed over a seismically quiet segment of the Galapagos spreading centre to measure the seismicity at a close range. Auth.
Frost a c t i o n , p e r m a f r o s t and frozen ground
Hydrogeology 932 WONG, HY CI~MENPATION RES.LTD. HERTS. GB YONG, RN MCGILL UNIV.MONTREAL, CDN Engineering problems in unsaturated soils;4F, IT,8R. CIV.ENGNG.I~BL WORKS REV.V68,NS06,1973,P759-765. This paper presents a review of the common methods of determining a soll water dlffusivlty parameter (a parameter of mathematical convenience used in soil water content distribution calculations) together with a discussion of their respective shortcomings. A modified method involving a very simple testing technique as well as simple calculation procedures is proposed. The suitability of this method is then assessed by testing its reproducibility using different sets of test data from the same type of test soil. 933 BERNAIY, J Drainage o rok fissures by use of smell canals. Congress. Disct~ssion. In French. 2F. PROc~'D. 2 CONGRESS, IIvrEMNAT.SOC. ROCK MECH.BELGRAD,
1970, v4,1974, ~99- 5o1. The writer describes an interesting approach to a favourable arrangement of drainage measures in a rock mass with permeable Joints.
934
MILOVANOVlC,D See also abstract: 916.
926 ARSENTEV, AI MIDHALLOV, GS ZHUKOV, AV Performance of mining equipment under polar conditions. In Russian. 4R. PHYSICS AND TECHNOLOGY OF MINING, LENINGRAD, NAUKA, 1970, P198- 203.
927 SRUVALOV,IV VAINBLKT,AB Calculating bearing capacity of coal pillars urger permafrost conditions. In Russian. NEW INVESTIGATIONS IN MINING,LENINGRAD,1969,P93-98.
928 TEXTBOOK Methodical recmendations on prognosis of frost crack formation in ground. Textbook. In Russian. English table of contents. 5R. MOSCOW, 1972, 38P. 929 TEXTBOOK Principles of predicting thermal stresses and deformations in frozen ground. Textbook. In Russian. English table of contents. 29R. MOSCOW, 1970, 53P. 930 SYMPOSIUM Road research. Symposium on frost action on roads.Oslo, October 197B.In French and English.Refs. PARIS, O. E. C.D. 3VOLS, OCT, 1973, PI3- 22. 931 JOHANSEN, 0 Thermal conductivity of soils.Measurements and methods of predlction;Proc.Symposium on frost action on roads, Oslo, 1973, 20R. PARIS, O.E.C .D.V1,1973, P165-188.
Drainage system in gravity dams. Congress. Discussion. In French. 6F. PROCEED. 2 CONGRESS, INTERNAT.SOC.ROCKMECH.BELGRAD, 1970,V4,197~,P528-529.
G rou n d w a t e r 935 SHARP, JC Flow and drainage problems within rock masses. Congress. Discussion. 3F. PROCEED. 2 CONGRESS, INTERNAT. SOC.ROCK MECH.BELGRAD, 1970, V4,1974, P519-521. Investigations at Imperial College London, to determine representative flow laws for natural fissures and to use these in a three-dimensional mathematical model are reported. The effects of Joint opening, geometrical characteristics and flow direction were studied.
936 SUNADA, DK Geohydrattlics at the unconformity between bedrock and alluvial aquifers. COLO. STATE UNIV. FORT COLLINS.ENVIRONM. RESOURCES CENTRE, REPORT PB-211 64~,JUNE,1972,175P.
M e a s u r e m e n t of w a t e r pressure and its effects 937 VORONIN, AD SKALABAN, VD Measuring soil moisture potential by a cryoscoplc method. In Russian. English summary, llR. MRTEOROL. GIDROLOG.N9,1973, P56-65.