Yuasa and Hiro located on the west side of Kii Peninsula, western Japan, have been hit by many large tsunamis which were generated about every 100 to 150 years. Sources of all these tsunamis were offshore between Wakayama and Shikoku along the Nankai Trough. Traces of the inundated level on many houses in the two towns caused by the 1946 Nankaido tsunami (Dec. 21, 1946) were surveyed, using the automatic level from Oct. 18 to 23, 1982. The behavior of the 1946 tsunami run-up on land was investigated and compared with the two historical tsunamis of Hoei (Oct. 28, 1707) and Ansei (Dec. 24, 1854). The results of the present survey are as follows: (1) At Yuasa, the inundation heights of the 1946 tsunami were 3.0-3.5 meters above M.S.L. Ground about 3.0 meters above M.S.L. was inundated, so that 450 houses were inundated but hardly any were washed away. At Hiro, the sea wall strongly protected the main part of town from the 1946 tsunami (This bank was constructed just after the 1854 Ansei tsunami from Mr. Goryo Hamaguchi's personal funds). However, the tsunami energy concentrated at the head of bay along the Egami River. The inundation heights locally reached 5 meters (above M.S.L.) or more and 22 persons were killed. (2) According to old documents, the inundation area of the 1707 Hoei tsunami elongated along the Yamada, Hiro and Egami Rivers. Forty-one lives were lost at Yuasa and 192 at Hiro. Inundation heights above M.S.L. were estimated 4-5 meters at Yuasa and 5-6 meters at Hiro. (3) By the 1854 Ansei tsunami, 28 lives were lost at Yuasa and 36 at Him. The patterns of damage at Yuasa and Hiro are similar to those of the 1707 Hoei tsunami. There remain even now traces of the inundation level on a few old houses in both towns. Inundation heights above M.S.L. were 4.0-4.7 meters at Yuasa and 5.0 meters in the center of Hiro town. Ground about 4.0 meters above M.S.L. was inundated, 0.7 to 1 meter higher than that during the 1946 Nankaido tsunami.
雑誌名
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo
巻
58
号
1
ページ
187 - 206
発行年
1983-07-28
ISSN
00408972
書誌レコードID
AN00162258
フォーマット
application/pdf
日本十進分類法
453
出版者
東京大学地震研究所
出版者別名
Earthquake Research Institute, University of Tokyo
7. 和歌山県湯浅・広に遡上した南海道津波の調査 : 1946年南海道および宝永・安政津波について
ji0581007.pdf
(1.81MB)
