Measurements of plasma parameters with spacecraft have provided radically new information about the phenomena in space. To better understand the physical phenomena discovered and to test whether the current concepts are correct mathematical and laboratory simulation is widely used. Observations of artificially induced perturbations are important in non-stationary processes investigation. Active experiments as well as laboratory and mathematical simulation of some cosmic phenomena are considered in the paper.

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A study of the data from the high-latitude North American IMS network of magnetic stations suggests that there is a component in substorm perturbations that corotates with the earth. It is as yet not certain whether the existence of this component stems from the corotation of a part of the magnetospheric plasma involved in the substorm mechanism or if it is a ‘phase change’ resulting from the control of the substorm manifestations by the earth's main magnetic field which is not axially symmetric. There are other geophysical phenomena showing a persistence of longitudinal variations corotating with the earth. These phenomena are of significance for a better understanding of ionosphere-magnetosphere coupling.

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The Yamasaki fault is a transcurrent fault extending over a distance of 80km in the western part of Japan along which microearthquakes occur densely. Electromagnetic investigation has been conducted in this area. The results of electrical resistivity measurements conducted during the period from 1975 to 1978 are presented in this paper.
Resistivity measurements were made by several different methods, such as direct current methods and electromagnetic induction techniques. It has been revealed by the direct current methods that there is a belt along the fault in which the electrical resistivity is low, ranging from 100 to 400ohm-m, whereas the resistivity is higher than 10, 000ohm-m far outside. This belt is about 1km wide at some places. Inside this low resistivity belt, there run streaks of extremely low resistivity, such as 20ohm-m. The locations of these streaks correspond to the surface traces of the fault plane. Magnetotelluric investigations for a frequency range of 8 to 20Hz have indicated that the low resistive belt is circumscribed by a zone with intermediate resistivity of 1, 000ohm-m. Outside the area, on the other hand, the resistivity is higher than 10, 000ohm-m. From the investigations so far conducted, it may be said that the low resistive zone has a three-fold structure consisting of an inner low resistive belt of 100 to 400ohm-m, the outer zone of 1, 000ohm-m, and narrow streaks of very low (20ohm-m) resistivity inside the inner belt.
The low resistive zone is suggestive of existence of a fractured zone with high water content along the fault. The difference between the low and the relatively low resistivity zone might arise from difference in degree of fracture and degree of water content. On the other hand, extremely low resistivity streaks perhaps indicate the surface traces of the fault plane along which clay mineral saturated with water has been developed.

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Eight potshards from the archeological site of Pointe du Buisson near Montreal were used to derive the variation in local geomagnetic intensity in the period between 500 B. C. and 1400 A. D. (seriation dates) and to compare the results to those obtained for Indian potshards from Southwestern Ontario. Each shard yielded two or three specimens suitable for treatment using the double heating method of Thellier. The results are complicated probably on account of the presence of chemical remanence and the high temperature results above 400 or 500°C are usually erratic. Selection criteria applied to the individual results were based on the quality of the Thellier plots and on within-shard consistency. Some of the results for seven shards were retained and shard averages and age averages computed with their standard deviations where applicable. These results were plotted against age, and the results from the sole earlier study on Canadian Indian shards were added to examine all data available for Canada. These data show good agreement in the position of average values, and, in spite of the large scatter, the data tentatively suggest a slight increase in geomagnetic intensity in Ontario-Quebec between 900 and 1700 A. D., and a decrease between 500 B. C. and 500 A. D.

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