第2図．A-3地点におけるトレンチ壁面(a) ，およびAs3層準の軟X線写真(b)．
Fig. 2. Tephra layers and tsunami sands interbedded by peat layers on the southwestern wall at A-3 trench site (a) and a radiograph of As3 layer showing graded bedding with lamina (b).