This map shows the geographic impact of Etsuro Koyama's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Etsuro Koyama with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Etsuro Koyama more than expected).
This network shows the impact of papers produced by Etsuro Koyama. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Etsuro Koyama. The network helps show where Etsuro Koyama may publish in the future.
Co-authorship network of co-authors of Etsuro Koyama
This figure shows the co-authorship network connecting the top 25 collaborators of Etsuro Koyama.
A scholar is included among the top collaborators of Etsuro Koyama based on the total number of
citations received by their joint publications. Widths of edges
represent the number of papers authors have co-authored together.
Node borders
signify the number of papers an author published with Etsuro Koyama. Etsuro Koyama is excluded from
the visualization to improve readability, since they are connected to all nodes in the network.
Kaneko, Takayuki, Kenji Takasaki, Atsushi Yasuda, et al.. (2010). MTSAT Observation of the Eruption Cloud Occurred at the February 2, 2009 Eruption of Mt. Asama, Central Japan. 55(2). 119–128.2 indexed citations
Aoki, Yosuke, Hidefumi Watanabe, Etsuro Koyama, Jun Oikawa, & Yuichi Morita. (2005). Ground Deformation Associated with the 2004-2005 Unrest of Asama Volcano, Japan(＜Special Section＞The 2004 Eruption of Asama Volcano(2)). 50(6). 575–584.3 indexed citations
8.
Kaminuma, Katsutada, et al.. (1985). Seismic activity of Mount Erebus, Antarctica in 1983-1984. Memoirs of National Institute of Polar Research. Special issue. 37(37). 29–39.1 indexed citations
9.
Ueki, Sadato, et al.. (1984). Seismic activity of Mount Erebus, Antarctica in 1982-1983. Memoirs of National Institute of Polar Research. Special issue. 33(33). 29–40.3 indexed citations
10.
Koyama, Etsuro, et al.. (1983). P Wave Velocity Structure of Asama Volcano.. 28(3). 301–304.3 indexed citations
11.
Minakami, Takeshi, et al.. (1970). 14. The Ebino Earthquake Swarm and the Seismic Activity in the Kirisima Volcanoes, in 1968-1969, Part 4 : Shifts of Seismic Activity from the Kakuto Caldera to Simmoe-dake, Naka-dake and Takatiho-mine. 東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo. 48(2). 205–233.2 indexed citations
Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive
bibliographic database. While OpenAlex provides broad and valuable coverage of the global
research landscape, it—like all bibliographic datasets—has inherent limitations. These include
incomplete records, variations in author disambiguation, differences in journal indexing, and
delays in data updates. As a result, some metrics and network relationships displayed in
Rankless may not fully capture the entirety of a scholar's output or impact.