On 29 th January 1970, Myojin reef, a submarine volcano, 420 km south of Tokyo (31°56.8'N, 139°59.5' E), known for its 1952-1953 great eruption especially for tragic accident of a missing vessel No. 5 Kaiyo-maru, began its present activity after 10 years quiescence since the last eruption of 21 st July 1960. According to oral communications from the eyewitnesses embarking on the fishing boats and to observations from aeroplanes including the writers' inspections, manifestations of the eruption on the sea surface were recognized at least five times e.g. 29 th January, 7 th February, 16 th and 17 th February, and 23 rd April. Compiling all available informations obtained directly or indirectly from many eyewitnesses and of the writers' own observations, the writers could estimate the scale of each main submarine explosion and the time lag after each main explosion, primarily by observing the shape, size, and colour of the sea contaminated with the volcanic material, and secondly by identifying the floating volcanic ejecta on the sea. As the results of the writers' estimation, eruption of 23 rd April was the largest of the five. Densely contaminated sea water and remarkable amount of floating pumice were still observable even five to ten hours after the largest eruption. Immediately before the first explosion of the present activity, actual scene of the dangerous active volcano beneath the water was innocently caught by the fish-detecting instrument installed on the fishing boat No. 2 Shintoku-maru of Omaezaki port, Shizuoka Prefecture which passed over the active vent. Dome of the volcano and the volcanic spine protruding on it up to 50-70 m beneath the sea surface were clearly traced on the graph drown by the sounding machine, with ash cloud puffing from them. Wave crusts due to underlying spine were once observed, but they disappeared probably due to destruction of the spine of the time of severe largest explosion on 23 rd April. The pumice blocks ejected by the last explosion were collected by several fishing boats at several points, which are exclusively two pyroxene dacite including dark more basic xenoliths. Result of chemical analysis of the white portion of one of these pumice blocks is shown as follows : SiO2 : 68.31, Al2O3 : 14.69, Fe2O3 : 1.79, FeO : 2.54, MgO : 1.64, CaO : 3.44, Na2O : 3.80, K2O : 0.93, H2O+ : 1.05, H2O- : 0.29, TiO : 0.52, P2O5 : 0.09, MnO : 0.11, NaCl : 0.75, Total : 99.95 wt%. It is similar to the white portion of the pumice ejected in previous eruptions. Record of the fishing-detecting machine dated 18 th June by No. 3 Shintoku-maru of the same port makes clear that once formed spine was destructed owing to explosions which occurred near the foot of the spine.
This paper contemplates to bring the engineering geology in relief at its standpoint between natural sciences and practical works in the light that it plays coherent role in the continuous field from geology as a natural science to construction works on the series of science of energy, whereas economic geology lies in the series of science of materials from geology to mining industry. 1. Situation of natural sciences and engineering in relation to social living. Though social living is related to each division of liberal arts at its very foundation, its relations to natural sciences are taken up to consider its relation to geology. The collected relation is listed in Table 1. Situation of technics, engineering, technology, engineering sciences and applied sciences are explained in relation to natural sciences and to social livings in Table 2, taking up the series of medical works and zoology agriculture and botany and then dissolving and synthetic chemical industries and chemistry to let the standpoint of applied or engineering geology more familiar among these fields. 2. Geology as a pure science in relation to other natural sciences. There are two attitudes of science to research into nature, the one being energetic (classical physics) and the other being materialistic (classical chemistry). Besides these, natural sciences have branches classified according to their objects as shown in Table 3. Geology had mainly followed the materialistic way in its developing course and the energetic way had been left rather scanty which has had important bearing upon engineering connection to construction works. Soil- and rock mechanics, geomechanics and main part of structural geology are to fill up this field. 3. Geology in relation to practical works. Geology in the way of materialistic science has had deep contribution to mining industry through oil-, coal- and are deposit geology that are grouped into economic geology which initially had been called applied geology. This series lies as a continuous field of engineering in wide sense covering geological field from scientific geology, applied and engineering sciences, technology, engineering in narrow sense, technics to mining industry, and has had much distinguished contributions as science and technology. On the other hand geology in the way of energetic science lies as a basis for applied geology, engineering geology, geotechnology, geological engineering and construction works as shown in Table 5. The latter series is also a continuous field which is to relate geology to construction works on/in the earth crust as the engineering of the earth crust i.e. geological engineering. This field can also or rather should be taken up for research purposes as well as for practical purposes. 4. Nature and classification of construction works. Construction works place their ultimate purpose on the promotion of civilization in common. Then they are the civilly works in their nature which can be classified into the following four categories in principle, and the engineering for construction works is no less than the civil engineering. Therefore applied geology on this series is rightly called civil engineering geology : (1) improvement of living circumstances, (2) traffics, (3) utilization of energy in nature and (4) management of energy in nature. Their objects, major contents, main structures built in them, kind of elementary works and technology or engineering at their bases are tabulated in Tables 6-9 to see the more important and common engineering bases to construct structures on/in the crust of the earth, because these bases are the bonds to tie not only the structures themselves but also scientific geology to civil works, or in other words for the civil engineering to stand conformably on the rule of Nature.
Contents I. Foreword II. Review of Regional Concepts III. Integration of Regional Methods IV. Nodality of Cities V. Concluding Remarks Geographers are all concerned with regional concepts. There are at least two kind of regions. These are uniform and functional in character. The city region, for example, is a combination of unlike areas which are functionally bound together in the focusing of establishments located peripherally upon establishments in the core. Such functional regions of human organization possess regionality as well as nodality. The purpose of this paper is to outline and discuss an approach to the regional study making use of both concepts concurrently and to explore the future possibility of applying System Analysis, Data Bank and Computer Mapping for the geographical research. Such use is capable of increasing the conformity of regional concepts to reality, thus reducing their arbitrary quality and improving both their significance and utility. The author would like to dedicate this paper to celebrate the sixtith birthday of Dr. Shinzo KIUCHI who has given me stimulating criticisms and constructive advices as a supervisor of my doctoral dissertation.
The bentonites in the present area are altered products of rhyolitic tuff, which is a member of marine formation of the Miocene. They consist principally of montmorillonite associated with cristobalite, quartz, feldspar and mordenite as identified by X-ray diffraction, differential thermal analysis and thermobalance, and chemically belong to the calcium-rich type.