Tectonic activity around the Fukul plane and its evaluation

1948年的福井地震对福井平原周围的城镇和村庄造成了严重破坏。此外，本区推定有许多活动断层。然而，对这些断层的详细调查几乎没有进行。然后，为了明确这些断裂的晚平均滑动、古地震活动和本区的构造活动，我们对该区的主要断裂进行了重新考察。本次研究的活动断层有沿越前海岸的断裂带、Sabae断裂带、Kiotoshi断裂带和福井平原及其周围的断裂带。在越前海岸的断群中，最近的一次断层事件发生在17世纪，当时沿海地区抬升了3 ~ 7米。萨别断裂在武府盆地冲积面形成了数米的高差。该断层还形成了向东倾斜的萨拜高地。小野盆地的Kiotoshi断裂，其长度短至3公里，表现出每1000年1.7 ~ 2.3米的高平均滑动。在福井平面，基底向西渐深，有时因断裂而迅速深进几十米，不仅在平面东侧，而且在平面西侧都有活动断裂。如上所示，很明显，在这一地区存在许多活动断层，比以前所假定的要多。为进一步明确福井地区女田—神户构造线的构造活动，有必要继续开展本研究。

The 1948 Fukui earthquake did serious damage to the cities, towns and villages around the Fukui plain.In addition, many active faults are presumed in this area.However, detailed investigations are not almost conducted about these faults.Then, to make clear the average slip late, paleoseismic activity of these faults, and tectonic activity in this area, we reexamined about the major faults of this are.The active faults investigated in this study are the fault group along the Echizen coast, the Sabae fault, the Kiotoshi fault, and the fault group in and around the Fukui plain.About the fault group along the Echizen coast, the most recent fault event was the 17th century, and the coastal area was upheaved 3 to 7meters at that time.The Sabae fault formed the level difference of several meters on alluvial surface in Takefu basin.The fault also formed the Sabae upland which is tilted eastward.The Kiotoshi fault in the Ono basin, the length of this fault is as short as 3 kirometers, shows the high average sliplate as 1.7 to 2.3 meters per 1,000 years.In the Fukui plane, the basement is gets deep toward the west gradually, though sometimes deep rapidly by faults several tens of meters, and not only the eastern side but also the western side of the plane is bordered with active faults.As shown above, it has become clear that many active faults exit in this area more than it is presumed previously.It is necessary to continue this study further to clarified the tectonic activity along the Nugata-Kobe tectonic line in Fukui prefecture.