GEODETIC EVIDENCE FOR RIFTING IN AFAR - BRITTLE-ELASTIC MODEL OF THE BEHAVIOR OF THE LITHOSPHERE

被引:56
作者
TARANTOLA, A
RUEGG, JC
LEPINE, JC
机构
[1] Laboratoire d'étude Géophysique de Structures Profondes (L.A. 195), Institut de Physique du Globe de Paris, Université P. et M. Curie, 75230 Paris Cedex 05, 4, place Jussieu
关键词
D O I
10.1016/0012-821X(79)90142-0
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
An important episode of rifting occurred in November 1978 in southwest Afar, in the first subaerial section of the accreting plate boundary between the African and Arabian plates. Horizontal rifting of more than 2 m took place, with vertical displacements of about 1 m, earthquakes of magnitude up to 5.3, and a fissural volcanic eruption of basaltic lavas. Very precise geodetic measurements were carried out in order to study this crisis and strains of the order of 3 × 10-4 were measured, both tensile and compressive. This paper presents an analysis of the mechanical behaviour of the lithosphere. It is shown that an elastic-brittle model with a rebound mechanism fits very well the data, and it is suggested that such a model, with magma injection in the resulting open fissures, should be used to describe accretion at plate boundaries. © 1979.
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页码:435 / 444
页数:10
相关论文
共 22 条
[1]  
AKI K, 1975, J GEOPHYS RES, V81, P23
[2]   UNIQUENESS IN INVERSION OF INACCURATE GROSS EARTH DATA [J].
BACKUS, G ;
GILBERT, F .
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL AND PHYSICAL SCIENCES, 1970, 266 (1173) :123-&
[3]   RESOLVING POWER OF GROSS EARTH DATA [J].
BACKUS, G ;
GILBERT, F .
GEOPHYSICAL JOURNAL OF THE ROYAL ASTRONOMICAL SOCIETY, 1968, 16 (02) :169-&
[4]   RIFTING OF THE PLATE BOUNDARY IN NORTH ICELAND 1975-1978 [J].
BJORNSSON, A ;
JOHNSEN, G ;
SIGURDSSON, S ;
THORBERGSSON, G ;
TRYGGVASON, E .
JOURNAL OF GEOPHYSICAL RESEARCH, 1979, 84 (NB6) :3029-3038
[5]   PRECISE DISTANCE MEASUREMENTS IN ICELAND [J].
BRANDER, JL ;
MASON, RG ;
CALVERT, RW .
TECTONOPHYSICS, 1976, 31 (3-4) :193-206
[6]  
CORNET FH, J APPL MECH
[7]  
COURTILLOT V, PHYS EARTH PLANET
[8]   SOLUTION OF PLANE ELASTICITY PROBLEMS BY DISPLACEMENT DISCONTINUITY METHOD .1. INFINITE BODY SOLUTION [J].
CROUCH, SL .
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, 1976, 10 (02) :301-343
[9]   MODEL FOR EVOLUTION OF AXIAL ZONE OF MID-OCEAN RIDGES AS SUGGESTED BY ICELANDIC TECTONICS [J].
DAIGNIERES, M ;
COURTILLOT, V ;
BAYER, R ;
TAPPONNIER, P .
EARTH AND PLANETARY SCIENCE LETTERS, 1975, 26 (02) :222-232
[10]  
HARRISON CGA, 1975, AFAR DEPRESSION ETHI, P179