Angenheister investigated the time of occurrence of the pulsatory oscillation of terrestrial magnetism recorded at several observatories over the world but he could not decide whether it is progressive or stationary owing to instrumental difficulties. In this country, three, quick running magnetographs of the same type were installed at Kakioka, Tsingtau and Toyohara during the Second Polar Year, S. Imamiti investigated the magnetogram and found that each pulsatory oscillation occurs within the limit of a fraction of second at the three places. On the other hand it was investigated by M. Hirayama and authors that the phase difference between the pulsation of terrestrial magnetism and of earth current was less than one second. So it was concluded indirectly if the pulsation of terrestrial magnetism was stationary the pulsation of earth-current should also be stationary. But it is worthy of comparing directly the shape and the time of occurrence of pulsation of earth-current at both places. The proper period (no damping) of the galvanometer was 4.5 sec at Toyohara and 3.4 sec at Kakioka, and the record was taken in critical damping state at respective places. The time scale is 13.5mm per minute at Toyohara and 22mm per minute at Kakioka: Every minute was marked on the sensitised paper in turning off the light source by the electric current through the standard clock, which was regulated by the time signals of llh and 21h of 135°E meridian time. Some examples of the pulsation of earth-current are shown in figures. (Fig. 1-Fig. 5) The difference of the time of occurrence of the pulsation of earth-current (The time of occurrence at Toyohara) -(that at Kakioka) is -0.s858±2.s12. The number of waves compared is 160, which were all of the available. Nextly they were divided into groups according to the hour of the day, to period of oscillation and to the type of oscillation. The difference of the time of occurrence of the pulsation was calculated for every groups.
Recently, a number of geo-physicists have frequently discussed the problems of crustal deformation or Wegener's drift hypothesis by using the results obtained by the revisional surveys. But the quantities to be found are always so small that it is doubtful whether the meteorological effects are negligible. In this report, the vertical refraction is only discussed. The formulae of terrestrial refraction now exist are all not suitable for practical purposes, for these contain many factors which are very difficult to be calculated geodetically. And hence, in this report it was tried to give the convenient expression for numerical calculation. The result is given by (17) The accuracy of this expression is 0"1 for z<87° and s<0.01. Giving the normal distribution to p, T, f and dT/dr we have a normal terrestrial refraction. But as shown in the latter part of this paper, a slight change of these functions produces the anomalous refraction which is in no ways negligible.
Denigès-Atkins' method of the determination of phosphate is discussed here. 1) The author has prepared the stannous chloride solution from pure SnCl22H2O instead of dissolving a tin foil in hydrochloric acid. No differences are found between these two reagents in their reducing actions of phospho-molybdate. 2) There is a marked influence which reduces the amount of phosphate, when silicate is present more than 15mg./l. with respect to SiO2 On the contrary, influences by chloride and iron are quite neglegible, except the colour tint becomes somewhat yellowish, but this is easily eliminated with a yellow glass filter.
The diffusion in the turbulent flow was discussed in the previous work starting from the analogous equation of the Brownian movement. The application to the diffusion in the atmosphere was tried in this paper and found that the diffusion is not isotropic and the horizontal diffusion coefficinet is much larger than the vertical one. (about one hundred of the latter) The dependency of the vertical diffusion on the lapse rate of the temperature was introduced, and the results agree approximately with the observation which is obtained from the daily range of the atmosphere.
In the investigations of some shallow earthquakes made on the previous paper under the same title was remarked the occurrence of the remarkable azimuthal distribution with reference to the maximum amplitude of vertical component in the case of shallow earthquakes. In the present paper these observed facts are taken up to be discussed. Supposing the source to be represented as of a multiplet-type, the refferenced fact may not be explained by the nodal-cone-type, provided that the axis of doublet be horizontal. On the contrary, the azimuthal distribution of amplitude with reference to S waves which are originated from doublet source with its axis being horizontal shows its reconciliation with what already mentioned. This may be shown rigorously applying Prof. Sezawa's and Prof. Sakai's method. At first, the displacement at free surface z=0 due to the dilatational point source, is expressed by equations (1). Hereupon, putting cosω=iα/h into (1), we get equation (2). These just coincide with the formulae, taken n=0 in Prof. Sezawa's solution. Then, putting cosω=iβ/z into (3), the displacements due to distorsional point source are given by (4). So that, by similar way, the author has acquired the following term as the vertical displacement at free surface z=0 due to distorsional doublet, when the inclination of axis equals to zero. Comparing the ws, ω=π/2 with the vertical displacement due to a dilatational simple source, we get Accordingly it may easily be ascertained that ws, ω=π/2 are larger than wp when γ is small. Therefore, we can consider that the maximum amplitudes in vertical component for the azimuthal angles of ω=π/2 and 3π/2 are due to by distorsional source of multiplet-type. For the other azimuth, for example ω=0 and π, we get the relations as follows:- where one of double signs of inequality must be properly taken according to the values of and ξ (depth of focus).
This paper deals with the pulsatory oscillations of ground observed at Tomisaki where situates at the top of Bôsô peninsula projecting into the Pacific Ocean. It must be indisputable that the microseisms are caused by the meteorological agents. The author has tried to investigate the occurrence and decay of microseisms consulting daily weather charts. As the generating agent following four are considered-typhoon, cyclone, strong wind (mainly monsoon) and discontnuity line. The former two are specially treated for three cases according to the travelling path of their center. Thus the microseisms at Tomisaki are treated in many cases taking into account of the kind of meteorological agent and the relation between the maximum amplitude, its time of occurrence and the position of center of cyclone (or typhoon), their barometric depression, the maximum wind velocity etc. is precisely investigated. Moreover the comparison between the microseisms at Tomisaki and Tôkyô, the studies on the mode of oscillation etc. are made. The main results thus obtained are as follows:- (1) The cyclone and typhoon are the most powerful agent to cause microseisms, and the monsoon, discontinuity lines are next to them. By cyclones larger microseisms are caused at Tomisaki than typhoons, while the reverse seems to be the case at Tôkyô. (2) The maximum amplitude of microseisms ordinarily occurs when the depression comes to the nearest place and sometimes when it travels on the Pacific Ocean, east to the northern part of Japan Proper. The latter case is caused by the rapid development of the depression at that place (3) When the depression travels on sea, it gives far larger microseisms compared with the similar case it travelling on land. (4) Microseisms caused by the strong wind blowing there becomes proportionally large according as the wind velocity increases. (5) Extraordinarily large microseisms, such as more than 50μ in amplitude, are observed only when the remarkable depression exists near the observing place. Merely strong wind causes microseisms less than 30μ even when its velocity becomes as 25m/s. By the above results the author has come to the following conclusion about the productive mechanism of microseisms at the coast that the sea waves are the most powerful agent to cause microseisms, and especially powerful when they are generated in the neighbourhood of the center of cyclone or typhoon.
From the theoretical point of view, the Petterssen's method must give the same result as usual one, in which the future position of the centre of depression is determined only by the extrapolating the past and present positions, without considering pressure field. The practical differences between them result from approximate calculations of differential coefficients and the results by Petterssen's method depend on the unit of numerical differentiations. A few examples of application to the weather forecasting in Japan are given