伊豆小笠原弧福徳岡ノ場火山は気象衛星の観測によると2021年8月13日6時頃から噴火を開始し，噴煙高度が16 kmと対流圏界面に達する大規模噴火となった（気象庁火山活動解説資料令和3年8月）．噴煙柱は300 km以上離れた小笠原諸島からも観察された．さらには15日に海上保安庁が実施した航空機からの観察によって，1986年の噴火以来35年ぶりに新島が誕生していることが確認された．また衛星写真から，噴火開始と同時に海面下に変色域が出現し，その後，海面上に軽石が浮上しているのが観察された．

 軽石は多孔質の火山砕屑物である．気泡に空気が入ることによって比重が海水よりも小さくなり，筏（ラフト）のように海面上に長期間浮いて海流や風によって漂流する．この噴火によって発生した軽石ラフトは黒潮反流にのって西に流され，10月以降，大東諸島や琉球諸島に続々と漂着し，海運や漁業に大きな影響を与えている．

 喜界島は奄美大島の東方約20 kmに位置し，新第三系の島尻層群を琉球層群の石灰岩が覆う平坦な島である．島の最高地点（標高約200 m）を構成している百之台のサンゴ化石からは約10万年前の形成年代が報告されており（稲垣・大村，2006），急速な隆起によって島が形成されたことが示唆される．隆起によって形成された複雑な入り江の奥深くまで軽石が入り込んでおり，軽石が長期間滞留することが懸念されている．

（写真・解説：谷　健一郎　2021年10月16日撮影）

 Two evolutionary lineages of the Neoshwagerinidae are recognized in the East Tethys-Panthalassa region in the mid-Permian time. These are the Misellina-Cancellina-Colania-Lepidolina and Misellina-Maklaya-Neoschwagerina-Yabeina evolutionary lineages. They formed distinctly isolated habitats in the Panthalassa region and are named the Colania-Lepidolina and Neoschwagerina-Yabeina territories, respectively. The paleogeographic distribution of the two territories is newly presented with an analysis of the Circum-Pacific accretionary complex combining the fusulinoidean faunas in mid-oceanic paleo-atoll limestones and the timing of their accretion clarified by radiolarian fossils. It is concluded that the Colania-Lepidolina territory expanded into a paleo-equatorial area in mid-Panthalassa with the Neoschwagerina-Yabeina territory at its southern side in the southern hemisphere. In East Paleo-Tethys, South China and Indochina continental blocks which were isolated in equatorial regions throughout the Permian period are striking territories characterized by an extension of the Lepidolina of the Colania-Lepidolina evolutionary lineage. On the Japanese Islands, Kurosegawa, Hida Gaien, South Kitakami and Maizuru belts are also characterized by the occurrence of Lepidolina.

 This study aims to elucidate the mechanisms for sustaining local labor markets in international mountain resorts according to their regional characteristics, focusing on foreign labor. It remains unclear how international mountain resorts, which have recently struggled to secure labor to accommodate a growing number of visiting tourists, have successfully attracted outside labor to sustain local labor markets. In this case study, Whistler is an example of a resort with an imbalance between the supply and demand of labor due to an increase in demand. When analyzing labor market results in this region, a mechanism emerges that includes two processes for supplying external labor. First, the process involving those who are willing to improve their language or professional skills and obtain permanent residence rights through work promotion, changing work, or starting businesses to establish themselves in a community. Second, the process of seasonal workers going abroad with working holiday visas and for recreational purposes. A specific social regulation effect overcomes three mismatches (space, temporal, and skills) and sustains these local labor markets. In other words, the international labor force travels abroad from one market to another when the spatial divergence is resolved. The process of permanent settlement or seasonal stay of workers is enabled by addressing the divergence between temporal elements and skills in these local labor markets.

 At the beginning of the 19^th century Ino Tadataka surveyed almost all of Japan's coastline and its main roads, and mapped them. He made ca. 70,000 magnetic azimuth measurements to perspective objectives such as mountain tops, isolated islands, and offshore rocks. Some of them are indicated on 1/216,000 maps with perspective lines and additional numeric characters. Differences between magnetic azimuth angles described on Ino's map and true azimuth angles measured on current maps show the magnetic deviation at sites. A total of 555 sites and values were obtained across Japan, which were divided over 26 regions. Using 26 region-presentative values chosen statistically to mitigate errors, a magnetic deviation map of Japan at the beginning of 19^th century was compiled.

 The appearance of transnational migrants and the characteristics of ethnic space influenced by the new migrants' residential selection are understood through a case study on Koreans who migrated from the 1980s to the global city of Greater London. The results suggest the following two conclusions. First, Korean migrants in London are highly educated white-collar professionals who aim to study or work in a global city and build international career paths. Their characteristics show that London as a global city stimulates transnational migration, which differs from former labor migration in terms of economic or historic motivations. Second, influenced by the locations of educational institutes, these migrants live in dispersed locations at the central area of the city, or congregate loosely in the suburbs. Because they experience higher education or work in London, they decide their residences according to the locations of their schools or workplaces, instead of living close to other Korean people. Unmarried respondents and married couples without children live in dispersed locations at the central area of the city, while expatriates and married couples with children live in suburban residential areas such as New Malden. In particular, the suburban congregation of Korean migrants is strongly influenced by the educational environments of their children.

 Akaike is a small, temporary pond located about 1 km east of Lake Shoji at the northern foot of Mt. Fuji, which appears following heavy rainfall events. It is widely accepted that the pond is connected to Lake Shoji by groundwater. However, this connection has not yet been evaluated because of a lack of scientific data including water quality and environmental isotopes from both Akaike Pond and Lake Shoji. Major dissolved ion and trace element contents, hydrogen (δD) and oxygen (δ¹⁸O) stable isotope ratios of water, and nitrogen (δ¹⁵N-NO₃) and oxygen (δ¹⁸O-NO₃) stable isotope ratios of nitrate ions were measured in water samples from Akaike Pond, which appeared between July 9th and August 20th in 2020. These data are compared with surface water and rainfall samples collected from the surrounding area to reveal the origin of Akaike Pond. It is found that the δD and δ¹⁸O values of Akaike Pond significantly increased after the late July (21st-28th) rainfall events. Mass balance analysis based on the δD and δ¹⁸O before and after the rainfall indicates that water flowing into Akaike Pond during this period was mainly derived from the immediately preceding rainfall. Major dissolved ion compositions in Akaike Pond show lower Ca²⁺ and HCO₃⁻ concentrations than water samples around the pond. This suggests that water in Akaike Pond appeared in a relatively short period (within a few days) after the heavy rainfall events, without deep underground percolation, which is further supported by δ¹⁸O-NO₃ and trace element composition.

 Developments in geology, historical geology, sedimentology, and paleontology in Japan after the Second World War, from 1945 to 1965 are described. The Geological Society of Japan was reconstructed soon after the war and established the foundations for geological studies. The Tokyo Geographical Society compiled documents on geological research in East Asia before and during the war. The Coal Exploration Advisory Committee (CEAC) and the Petroleum Exploration Advancement Committee (PEAC) made progress on research related to oil and coal. New geological maps were compiled; the nomenclature of strata was formulated; and, regional geologies were summarized. Studies of Precambrian and Paleozoic strata continued to advance, while investigations on the geology of the Mesozoic challenged to establish theories posited before the war. Areas of studies such as “Green tuff,” radiocarbon measurement, tephrochronology, and neotectonics in the Cenozoic strata were opened up. Around 1950, sedimentological themes emerged; the Sedimentology Institute was founded at the University of Tokyo in 1951; and a sedimentology research group was formed in 1957. Research, for example, on recent sediments in Tokyo Bay were started. Soon after the war, the Palaeontological Society of Japan collated data on type species and their descriptions collected since 1868 for the development of palaeontological studies in Japan. Studies on Desmostylus, Naumann elephant, and Metasequoia fossils were launched. Micropaleontology including foraminifera studies made remarkable contributions.

 Geologists, petrologists, geomorphologists, botanists and ecologists often collect samples through field surveys. They are required to obtain permission from the Ministry of the Environment before collecting samples in a special zone and a marine park zone of a national park. For example, permission is necessary for sampling prior to mining minerals or quarrying soil and stones in such zones. A legal procedure is introduced that is required to be followed before taking samples for AMS ¹⁴C dating in Keramashoto National Park, Okinawa.