AUTHOR: Fajklewicz, Z.
     TITLE: Origin of the anomalies of gravity and its vertical gradient
            over cavities in brittle rock
AUTH AFFIL: Univ. Min. and Metall., Inst. Geophys.; Cracow; Poland
    SOURCE: Geophysical Prospecting, v.34, n.8, p.1233-1254
REFERENCES: 26
      YEAR: 1986
  LANGUAGE: English
  PUB TYPE: Serial, Analytic
    FORMAT: illus.
  ABSTRACT: The depth range of the gravity method for detecting cavities is
            considerably greater than expected from theoretical calculations
            of the depth and shape of the cavity. The cavity generates its
            own gravity field that is the sum of the activity of the cavity
            itself and the density changes caused in the surrounding rocks
            by their destruction as the cavities expand in several cases of
            gravity detection of cavities. The extent of the zones of
            changed density in surrounding rocks, and their actual shape,
            depend on many parameters. Thus, cavity depth determinations
            cannot be made by comparing measured and theoretical curves of
            gravity anomalies. The location of the center of gravity of the
            area disturbed by the cavity or upper boundary of its
            development towards the ground surface can be determined by
            denoting the singular point of gravity as a result of the
            downward analytical continuation of g. The Strakhov-Grigorieva-
            Lapina (1977) method fulfils the necessary conditions in the
            field.--Modified abstract.
      ISSN: 0016-8025
     CODEN: GPPRAR
MAJOR DESC: underground installations; geophysical methods
DESCRIPTOR: site exploration; gravity methods; applications; rock mechanics;
            underground space; density; gravity anomalies; land subsidence;
            safety; abandoned mines; brittle deformation