中央構造線活断層系 : 伊予断層の変位地形

Fault morphology of the lyo Fault, the Median Tectonic Line Active Fault System

後藤 秀昭

活断層研究

In this paper, we investigated the various fault features of the lyo fault and depicted fault lines or detailed topographic map. The results of this paper are summarized as follows; 1) Distinct evidence of the right-lateral movement is continuously discernible along the lyo fault. 2) Active fault traces are remarkably linear suggesting that the angle of fault plane is high. 3) The lyo fault can be divided into four segments by jogs between left-stepping traces. 4) The mean slip rate is 1.3 ～ 1.6mm/yr. laterally, and is 0.17 ～ 0.2mm/yr. vertically. 5) Offset stream ratio a=D/L, where D is horizontal displacement and L is length of the river upstream from the fault, is 0.55 - 0.09 for the lyo fault. Based on the offset stream ratio, the mean slip rate of the lyo fault is roughly estimated 1 ～ 5mm/yr. and the fault is classified as class A in activity.

中央構造線

活断層

伊予断層

断層変位地形

Median Tectonic Line

active fault

Iyo fault

fault morphology

地理・地誌・紀行 [ 290 ]

日本語

活断層研究会

[ISSN] 0918-1024

[NCID] AN10157356

[URI] http://topo.earth.chiba-u.jp/afr/index.htm