37 research outputs found
DESIGN AND DEVELOPMENT OF THE AFRICAN PLASMODIUM FALCIPARUM DATABASE – (afriPFdb)
The detailed investigation of mantle structure from the dispersion of surface
waves is a young but vigorous field of study. Observations have been accumulating
rapidly in the past few years because of the wide-spread installation of
long-period instruments. Modern methods of data analysis used in conjunction
with high-speed digital computers have made it possible to determine dispersion
with greater precision and over a broader spectrum than has previously been
possible. Observations now extend out to the fundamental periods of free
oscillations of the whole earth. Interpretation has lagged behind observation
because of the difficulties inherent in the problem of dispersion over realistic
models of a spherical earth. This problem is now well in hand and dispersion
appropriate to the standard earth models suggested by earlier body waves
studies has been calculated. Even with digital computers, however, the computations
are so formidable that until recently only the most tentative efforts have
been made to modify the standard earth structures to give a more satisfactory
fit to the data. A review as recent as the one by Bolt in the preceding volume of
this series was, of necessity, limited to a discussion of the various standard earth
models with no attempt made to use the full power of surface waves as an independent
technique. Recent developments have made detailed surface wave
interpretations possible and new information, rather than generalized verification
of old information, should be rapidly forthcoming. Project Mohole and
the International Upper Mantle Project have focused the attention of many
earth scientists on the upper mantle. Because of this renewed emphasis present
information and speculation on the properties of the mantle based on a variety
of sources is summarized and re-examined in some detail. This provides the
guide-lines for potentially fruitful further research and points out the nature of
some of the discrepancies and limitations in our present knowledge that may be
resolved by the surface wave method
Delermination of earthquake magnitude and intensity in the USSR
La determinazione della magnitudo dei terremoti nella Unione Sovieticaè basala su osservazioni strumentali in base alla scala di magnitudointernazionale.La relazione tra gradazione B di intensità , magnitudo M e profondità focale E è stata determinata interpretando alcune centinaia di terremoti:B = 1.5 M — 3.5 Ig M + 3 .La formula è vera per terremoti con profondità focali non superiori a60 km (N. V. Shebalin).Si presume che le caratteristiche del mezzo tra il fuoco e la superficiedella terra siano ovunque eguali.Per effettuare una più precisa determinazione di B e necessario tenerpresente V'influenza della struttura geologica locale della regione epicentrica,rispetto all'ampiezza delle oscillazioni