A marine geophysical data processing system is constructed by an 8-bit personal computer, 8-inch floppy disk drives, a digital tape transport with universal buffered interface ( 8-bit parallel, RS-232C and GP-IB ), as digital X-Y plotter and others. This system creates marine geophysical data files, which consist of positional, gravity, geomagnetic and depth data, on floppy disks, and produces graphic displays of the data files on the plotter. 30-days cruise data logged by one minute interval can be stored in two sheets of the 8-inch floppy disk.

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Topographic profiles are frequently utilized for geological studies. However, the drawing work is fairly complicated. In this report, an example of the drawing method by a personal computer system is presented. The accuracy of the profiles drawn by this system is nearly equal to one by hand work and, furthermore, the required time is very short. This system is considered as a promising means for topographical and geological works.

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GEOCAPS (Geochemical Data Analysis Program System) is a BASIC program system for interactive data-processing mainly of chemical analysis with graphic plotters. The system comprises three groups of programs: a) for general chemical data including related two-dimensional digital data, b) for chemical analysis of igneous rocks especially with CIPW normative calculation, and c) for water analysis data. Each group is composed of 10 to 12 programs such as: 1) creating the data-files, 2) inputting and editing data, 3) printing the data (with the normative calculation), 4) arithmetic operating among components and making tables of the results, 5) calculating mean values and standard deviations, 6) calculating correlation coefficients, 7) plotting histograms, 8) plotting X-Y correlation diagrams, 9) plotting multi-dimensional X-Y correlation diagrams, 10) plotting triangular or tetragonal diagrams, 11) plotting key diagrams (for water analysis), and 12) plotting hexa diagrams (do.) .
Following functions of this system are especially useful for the processes of geochemical purposes: The data can be sorted every time in a quick way and also be re-arranged into their original order, if necessary. They are picked out for processing by means of classification codes defined by the user on any four factors of them. Data can be calculated to make their total into 100 percent and also be converted into molecular numbers, or equivalents in case of water analysis. Values of any components are, of course, able to be processed. Total Fe₂O³ and total FeO are treated as if they are in one component in case that both of them are found in the component-file. Results of normative calculation including the differentiation index (D.I.) can be processed. Interactive arithmetic operations can easily be held among values of all the components mentioned above in every data-processing program without any modifications of the program in segments. Because the user gives the formulas as string data in performing instead that he stops the execution to edit the program statements.

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This paper introduces our current system for analysis of geological boring data on a personal computer, which consists of three steps of procedures as follows: (1) coding and formating of geological boring data, (2) storage and retrieval of the coded data and (3) graphic presentation of the retrieved data including graphic displays of the geological cross section and the panel diagram in any direction.This system has made it possible to analize the geological structure speedy much more than the previous hand-works.

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This paper introduces an algorithm for digital image processing of a complicated-shaped solid. The algorithm consists of two digital processings : (1) The height is calculated automatically through image correlation of a set of stereo photographs and (2) the shape of the solid is reconstructed on 3-dimensional matrix combining several sets of height data. The matrix will be used to show a shape of the solid as a cross section in any direction or to calculate the surface area, the cubic volume, the center of gravity and other geometrical values of the solid.

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A computer program has been used in our laboratory in order to visualize the nature of grid data as a contour map. The main part of the program is a subroutine SCONT, which draws contour (s) of one value by tracing points with equal value on grid lines. This paper presents a simple explanation of the subroutine SCONT together with the program list in Appendix.

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A computer program for stereographic illustrations of grid data (for examples, stereographic contour map and block diagram) has been used in our laboratory. The basic part of the program is a subroutine SPLOT, which projects closing two points three-dimensionally on the plane normal to the line connecting the origin of coordinates and a view (eye) point and draws only the visible part (s) on the line connecting the projected points. This paper presents a simple explanation of the subroutine SPLOT together with the program list in Appendix.

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In this paper, we present a new method to display earthquake data, depending on both time and space, by two sets of stereo-diagrams, which are called Time-Space Stereographic Diagrams. By the diagrams, we can see characteristics of the earthquake data in the multi-dimensional space. This method is applied to visualize earthquake activity before and after major earthquakes based on the data catalogue by the Japanese Meteorological Agency.

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