著者

杉戸 信彦 松多 信尚 石黒 聡士 内田 主税 千田 良道 鈴木 康弘

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.124, no.2, pp.157-176, 2015-04-25 (Released:2015-05-14)

参考文献数

15

被引用文献数

5 8

---

Spatial variations of hazards such as strong ground motion and tsunami inundation are a key element for obtaining a geographical understanding of natural disasters. However, detailed distribution of tsunami run-up heights for the devastating tsunami associated with the 2011 off the Pacific coast of Tohoku earthquake is not available. A GIS analysis of tsunami inundation areas is conducted from data collected by the Tsunami Damage Mapping Team and from post-tsunami 2-m mesh and 5-m mesh digital elevation models (DEM) after the Geospatial Information Authority of Japan, in order to produce the Tsunami Run-up Height Map, which includes polygon data of inundation areas with elevation data at each point. Horizontal shifts of orthophotos taken just after the tsunami are corrected using a Helmert transformation. The map covers Iwate Prefecture, Miyagi Prefecture, and the northern part of Fukushima Prefecture continuously at high resolutions, and reveals spatial variations of tsunami run-up heights in detail. These variations are caused by: 1) landforms at each site, such as coastal plains, valleys, bays, and beach ridges, as well as their directions and magnitudes, and 2) source locations, interference, and wavelengths of the tsunami, as implied by a previous study. The map supports examination carried out on source fault models and simulation results of tsunamis from a geographical viewpoint. At the same time, the methodology to produce the map would be useful for systematically revealing run-up height distribution, in addition to inundation areas immediately after future tsunamis.

著者

鈴木 康弘 杉戸 信彦 坂上 寛之 内田 主税 渡辺 満久 澤 祥 松多 信尚 田力 正好 廣内 大助 谷口 薫

出版者

公益社団法人 日本地理学会

雑誌

E-journal GEO (ISSN:18808107)

巻号頁・発行日

vol.4, no.1, pp.37-46, 2009 (Released:2010-02-24)

参考文献数

16

---

活断層の詳細位置・変位地形の形状・平均変位速度といった地理情報は,地震発生予測のみならず,土地利用上の配慮により被害軽減を計るためにも有効な情報である.筆者らは糸魚川-静岡構造線活断層帯に関する基礎データと,活断層と変位地形の関係をビジュアルに表現したグラフィクスとをwebGIS上に取りまとめ,「糸魚川-静岡構造線活断層情報ステーション」としてインターネット公開した.本論文は,被害軽減に資する活断層情報提供システムの構築方法を提示する.これまでに糸魚川-静岡構造線北部および中部について,平均変位速度の詳細な分布を明らかにした.この情報は,断層の地震時挙動の推定や強震動予測を可能にする可能性がある.さらに縮尺1.5万分の1の航空写真を用いた写真測量により,高密度・高解像度DEMを作成した.人工改変により消失している変位地形については,1940年代や1960年代に撮影された航空写真の写真測量により再現し,その形状を計測した.写真測量システムを用いた地形解析によって,断層変位地形に関する高密度な解析が可能となり,数値情報として整備された.

著者

澤 祥 坂上 寛之 隈元 崇 渡辺 満久 鈴木 康弘 田力 正好 谷口 薫 廣内 大助 松多 信尚 安藤 俊人 佐藤 善輝 石黒 聡士 内田 主税

出版者

Japanese Society for Active Fault Studies

雑誌

活断層研究 (ISSN:09181024)

巻号頁・発行日

vol.2006, no.26, pp.121-136, 2006

---

We conducted a tectonic geomorphological survey along the northern part of the Itoigawa-Shizuoka Tectonic Line (ISTL) with support from the Ministry of Education, Culture, Sports, Science and Technology of Japan as one of the intensive survey on ISTL fault system. This survey aims to clarify the detailed distribution of the slip rates of this fault system, which provides the essential data set to predict the coseismic behavior and to estimate the strong ground motion simulation. In order to achieve this purpose, the active fault traces are newly mapped along the northern part of the ISTL through interpretations of aerial photographs archived in the 1940s and 1960s at scales of 1: 10,000 and 1: 20,000, respectively. This aerial photo analysis was also supplemented and reinforced by field observations.<BR>One of the remarkable results by using this data set is a large number of, here 84, photogrammetrically measured landform transections to quantify the tectonic deformations. We could calculate vertical slip rates of the faults at 74 points, based on the estimated ages of terraces (H: 120 kyrs, M: 50-100 kyrs, Ll: 10-20 kyrs, L2: 4-7 kyrs, L3: 1-2 kyrs). The vertical slip rates distributed in the northern part of the study area show 0.2-5.5 mm/yr on the L terraces (less than 20 kyrs) and 0.05-0.9 mm/yr on the M and H terraces (more than 50 kyrs). The vertical slip rates of the faults located in the central and southern part of the study area are 0.2-3.1 mm/yr.