A distinctive fill top terrace accompanying with thick deposits develops along the Hinokinai River which flows in hills and mountains in north of the Yokote basin, northeastern Honshu island.　The authors analyzed tephra-origin materials in the tephric loess overlying on this terrace and pollen assemblages in the terrace deposits.　The results are followings:1） Pollen assemblages showed that paleovegetation was conifer-riched and deciduous broadleaved mixed forest without Fagus during the depositional period of fill top terrace. 2） Tephric loess analyses showed that this terrace emerged just before the falling of the To-Of tephra （ca. 36 cal ky BP）.　These indicates that the aggradation terrace had formed since the MIS 3 when it’s climate had been little cooler and less precipitation than the Holocene.

　The COVID-19 pandemic has had a significant impact on societies, which has resulted in unprecedented changes in internal migrant patterns.　We conducted a questionnaire survey of single young adults living in Tokyo to investigate the changes in their relocation intentions before and after the pandemic and examine the COVID-19 related factors that may influence their preferences.　The result shows that young adults’ working environment, income, and psychological status were significantly affected by the COVID-19 crisis, and 16.6% of the respondents started to consider moving out of Tokyo.　Teleworking, decreased income, and anxiety about being infected with COVID-19 were positively related to their migration intentions.　The determinants of migration intention differed before and after the COVID-19 pandemic.　In addition, those who started to consider relocating after the pandemic were more likely to have higher incomes, stable jobs, and were more oriented toward metropolitan areas.　Meanwhile, the less educated group was also more likely to develop a migration intention after the outbreak of the COVID-19.　These results suggest that the mechanisms through which new potential migrants were triggered during the pandemic may differ by socioeconomic status.　In promoting migration in the post-COVID-19 era, it is necessary for policymakers to take into account the characteristics of those new potential migrants, and at the same time, to pay attention to the widening social and residential disparities.