The mobility of the whole population in a given region or the facility with which passengers as a whole move from one place to another, cannot be estimated adequately in terms of the travel time of each transport or the fastest transport alone. So the mobility should be estimated by considering the rate of passengers taking each transport (that is, modal split). Therefore the concept of mean travel time is defined in accordance with the basic understanding mentioned above. It is a kind of mean value of the travel time of all available transports, which is calculated by the travel time and modal split of each transport. We calculate each mean travel time from each capital city of prefecture to Tokyo in 1965, 1975, and 1985, and then examine the relationship between mean travel time and travel distance to Tokyo. The results are summarized as follows: 1. Mean travel time defined by modal split may be useful as an index of passenger mobility, since changes in the mobility caused by the shift of passengers to an existing faster transport can be evaluated even if there is no advent of any new transport of still higher speed. 2. There have been great differences in the reduction of mean travel time to Tokyo from each prefecture between 1965 and 1985. There is a general tendency that distant regions from Tokyo, such as Hokkaido, Shikoku and Kyushu, have fairly large reductions of mean travel time, while the neighbouring regions of Tokyo, such as Kanto, Chubu and Tokai region which Shinkansen can be available have small reductions. This difference may be ascribed to two factors. First factor is that the use of air transportation has been promoted, because air transportation is relatively more convenient than railroad transportation, in the distant regions which are farther from Tokyo than the neighbouring regions and intervened by sea. Second factor is that since the latter cannot have their own airports because of "traffic shadow effect", they still have to use land transport. 3. Although movement distance strongly influenced mean travel time in 1965, their relationship became weaker in 1985. People in distant regions from Tokyo, such as Shikoku and Kyushu districts can now reach Tokyo sooner than those in prefectures in Chugoku and Kinki districts in terms of mean travel time. 4. The air transportation has not well developed in regions where the Shinkansen or bullet train is available and more convenient than air transportation. As a result, in above regions movement distance still influences mean travel time. On the other hand, people in distant regions have gradually come to travel by air instead of train in regions where the bullet train is not so available or less convenient than air transport. So the influence of movement distance on mean travel time has gradually become weaker. 5. From the results of the mean travel time over the past 20 years in terms of travel distance to Tokyo, the decreasing rates are high in distant regions with more than 600 km in travel distance in the period between 1965 and 1974, while in regions with 200-600 km travel distance in the period between 1975 and 1948 their decreasing rates are high. For this reason the former period may be called "the age of promotion in the use of air transport in regions of long distance from Tokyo" and the latter period "the age of air transport promotion in the regions of intermediate distance from Tokyo".

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Mr. Masao Nishiki was born in a small village facing the Seto Inland Sea in Hiroshima Prefecture in 1883. He was a studious geographer locally resided. He became an assistant teacher in primary school in 1898 and then obtained teaching certificate of geography for middle school in 1909. Working as a teacher at a middle school, he devoted his time to research work on geography, improvement and enrichment of geography teaching. He became one of leaders in the field of geography and its teaching in Japan before he died in the Atomic Bomb attack in Hiroshima in 1945. His main cotributions in geography teaching are 'Human Geography (Jinbunchirigaku Kogi (1) (2))', 'Method and teaching material for primary geography education (Gutaika-seru Shogakuchirikyozai-to Kyojuho)' and 'Some aspects on geography education (Chirikyoiku-no Shomondai)'. Changes in aspect and method of his geography teaching through his books and articles are summarized as the table below, from which we restore a part of transition of geography teaching in Japan before the World War II. [table]

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Around Cape Ashizuri, evidences for former sea levels are recognized as notch, wave cut bench and calcareous remains of organisms living in tidal zone. This paper aims to clalify coseismic crustal movement during Holocene based on geomorphological and biological sea-level indicators around Cape Ashizuri. Based on vertical distribution of former sea level indicators, four former sea levels are distinguished at Cape Ashizuri, i.e. I:4.7m, II:3.5m, III:2.0m, IV:unknown in height. These former sea levels are aged as I:around 4800 y.B.P., II:at least 2730 to 2430 y.B.P., III:around 1770 y.B.P., IV:unknown by means of radiocarbon dating. The earthquakes having caused these abrupt drops of former sea levels are named event 1 to event 4 in counter chronological order. Event 2 to event 4 occurred at 1770 to O y.B.P. , 2430 to 1770 y.B.P., 4800 to 2730 y.B.P. respectively. Judging from radiocarbon ages and distribution of amount of uplift, earthquakes (event 4 and event 3) in Ashizuri region could be correlated to earthquakes (event 6 and event 4) in Muroto region (Maemoku, 1988) respectively. These earthquakes are assumed not to be interplate, but to be intraplate ones.

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