The request to present an overview of American geography in less than an hour presents an awesome challenge. I am delighted to be here and honored to have this opportunity to reflect on geography in the United States. I regret that I am not able to give this talk in Japanese and hope that by the time I come to Japan again I will have remedied this deficiency! What I offer this afternoon is a personal statement on the status of American geography today. Because this will be a personal viewpoint, it is necessarily selective, partial, and biased, especially so in light of the fact that one of the hallmarks of American geography is its diversity. The thousands of practicing geographers in the U.S. today embody a remarkable variety of philosophical positions, areas of expertise, employment situations, and research and teaching interests.2) I see this diversity as a strength of the discipline, for it opens the way for a continuous influx of new ideas, ensures lively ongoing debates within the field, and increasingly serves to link geography with other disciplines. This is an exciting time in American geography, with both the status of the field and its content undergoing change.
A growing trend in migration studies in Africa is the stronger interest in the contexual analysis of migration in relation to the larger political economies. In this study, migration is viewed as a sign of economic and political change, or a manifestation of people's response to such change. Political ecology as point of view is useful for the purpose of this study with a focus on the Nigerian economy which has experienced unprecedented ups-and-downs since 1970 and therefore provides us a suitable field for study. It has become clear that household or kin group network played an important role in people's migration. It was mobilized in the period of the economic boom of the 1970 s; shifting people from farming to non-farming jobs; encouraging migration from rural areas to urban areas; andd promoting higher education. And after an economic depression, it helped young people find jobs, even in the informal sectors of towns; and to hold unemployed young people in the village. These are some ways in which migration is forcing people to adapt to the rapid economic change.
In this conceptual investigation, a set of hypotheses on potential socio-historical aspects and conditions of the establishment of the urban question are proposed through examining each concept of urban space explicitly or implicitly presupposed within corresponding urban geographical studies. One of the preliminary hypotheses on the relative novelty of the establishment of urban studies and theoretical formulation on the urban question is that this socio-historically specific domain formation as the amalgamation of urban studies and the urban question may have been related to the birth of the modern nation-state as a distinct socio-political and territorial surveillance institution. Urban space, under this institution, is seen as a function concomitant with the degree of its efficiency from the vantage point of social control and/or surveillance. The social scientific discourses on urban space are hence doomed to conceptualize it in its totality until it has become relevant. The general theory of urban space has contributed most effectively to the formation of a socio-historically specific domain of which raison d'etre tends to be taken-for-granted with scarce doubts. From the early Chicago sociologists to not a few of contemporary urbanologists, the main direction of research has been consistently to develop this general theory of urban space, with little concern for the sociohistorically specific conditions for its overall establishment. In reality, this has created an irresolvable tension between seeing urban space socially and seeing social groups spatially, and resulted in a miscellaneous chaotic conceptualization of modern urban space which has, indeed, gradually been formed through the duration of the modern era. Given that this kind of historical specificity surrounds the discursive formation of the urban question and its subsequent domain formation, we may as well redirect our geo-historically sensitive research interests towards the very politico-juridical and administrative processes through which the modern nation state has succeeded in transforming existing historical urban space with its socio-historically and culturally specific social relations, and finally incorporating it as a territorially distinct organizational unit, that is the urban municipal corporation, for its socio-political constitution as well as governance.
This paper focuses on the relationships between time, space and geomorphic environments of the Holocene reef-flat formation. The discussion is based on nine core logs drilled in the Holocene emerged reef-flat of Nishimezaki, Kume Island, the Central Ryukyus. The following results are obtained. The apparent sea-level curve during the period from 7, 500 to 2, 000 Y. B. P. can be divided into three phases on the basis of sea-level rise rates. 1) 7, 500 to 6, 500 Y. B. P.; Sea-level rose rapidly at an approximated rate of 10m/1, 000 yrs. 2) 6, 500 to 5, 000 Y. B. P.; Sea-level rise rate slowed abruptly to less than 3m/1, 000 yrs. Rise rate gradually decreased up to 5, 000 Y.B.P. 3) 5, 000 to 2, 000 Y. B. P.; Stabilization of sea-level. The formational process of the reef-flat topography could be divided into three phases. 1) Initial growth phase; Reef initiation occurred at ca. 7, 500 Y. B. P. The differences of growth fabrics in this phase depend on the direction of driving waves and slopes on the pre-Holocene topography, and the depth variation at that time. 2) Reef-crest growth phase; Vigorous reef growth of autochthonous tabular corals coincides with the slowing down of the sea-level rise rate between 6, 500 to 6, 000 Y. B. P. The spurs or pinnacles located in shallow water and attacked by strong wave action reached the sea-level earlier than those in other locations (e. g. deep water, not under strong wave action). 3) Reef-flat formation phase; This phase coincides with the slow rise and stabilization of sea-level from 6, 000 Y. B. P. The reef-crest ridge is the earliest to reach sea-level. Subsequently, the outer part and inner part of the reef-crest reached the sea-level and formed the reef-flat. Where breaks or interruptions are present in the reef-crest ridge, there is rapid growth of the inner part. In contrast to the sea-level rise rate and the wave direction controlling unilaterally the reef accretion processes, topography is both a result of reef accretion and a factor which controls the subsequent reef accretion.