日本地球惑星科学連合2018年大会

講演情報

[EJ] ポスター発表

セッション記号 S (固体地球科学) » S-SS 地震学

[S-SS09] 地殻変動

2018年5月20日(日) 10:45 〜 12:15 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:落 唯史(国立研究開発法人産業技術総合研究所 地質調査総合センター 活断層・火山研究部門)、大園 真子(北海道大学大学院理学研究院附属地震火山研究観測センター)

[SSS09-P09] Estimation of block boundaries around the Izu Peninsula based on GNSS data using hierarchical and non-hierarchical cluster analyses

渡邊 識2、*三井 雄太1 (1.静岡大学理学部地球科学科、2.元・静岡大学理学部地球科学科)

キーワード:GNSS、伊豆半島、ブロック境界

The purpose of this research is to estimate the block boundaries around the Izu Peninsula based on GNSS horizontal data, as an application of cluster analysis following recent studies (e.g., Simpson et al., 2012; Savage, 2018). Using F3 solution of the GNSS data by Geographical Survey Institute, we obtain displacement rates for 2 years, 3 years, and 5 years during 2005-2010. We perform cluster analyses of the displacement rate data into 3 divisions by the Ward method of a hierarchical method and the k-means method of a non-hierarchical method, and plot the results on maps. On the basis of the Delaunay triangulation algorithm, each observation point was connected. Then we mark lines of which endpoints are classified in a different cluster, and stack them to estimate the locations of the block boundaries. The block boundary goes north along the Suruga Trough and joins the Darumayama fault zone in the western part of the Izu Peninsula. It crosses the Izu peninsula eastward and separates Izu Oshima from the Izu peninsula. The block boundary also extends northward toward the Hakone volcano along the eastern Izu volcano group and Tanna fault.