Iwao Yasuda, Hasshu Co, Ltd, Tokyo, Japan (http://www.hasshu.co.jp) performed an aerial reconnaissance of the earthquake damage on October 25, 2004 using a fixed wing aircraft. The present report in English presents the pictures and maps of Hasshu Co. The information in this report is the courtesy of Hasshu Co. Ltd, which should be fully acknowledged. The collaboration of M. Hamada, Waseda University, is also acknowledged.

The location of the aerial photographs are given in Figures A, B, C, D and E. Figure A  is divided into four quadrants: the Northwest, Northeast, Southeast and Northeast quadrants. Each quadrant is 7.5 km in the East-West direction and 10 km in the North-South direction. The Northwest quadrant (Figure B) includes the eastern part of the city of Nagaoka. The Southwest quadrant (Figure D) covers the Shinano River, and part of Ojiya City. The Southeast quadrant (Figure E) covers Yamakoshi village and the Imo river. .

Figure A. Orientation map of the aerial reconnaissance of Iwao Yasuda, Hasshu Co, Ltd, Tokyo, Japan.

Figure B. Orientation map of the aerial reconnaissance of Iwao Yasuda, Hasshu Co, Ltd, Tokyo, Japan.

Figure C. Location of Figures 1 to 4 (Northeast quadrant of Figure B).

Figure 1. Three small landslides blocking or deviating the course of the stream..

Figure 2. Road blocked by the debris of a landslide on a steep cutslope. No debris flowed on the structure at the lower left corner of the photograph.

Figure 3. Landslide reclaiming part of the agricultural terrace. .

Figure 4. Landslides in the far distance above the village. The road appears free of debris and the village undamaged.

Figure D. Location of Figures 5 to 11 (Northwest quadrant of Figure B). The Northwest quadrant covers the eastern part of the city of Nagaoka.

Figure 5. The road was damaged after the earthquake.

Figure 6. The smaller landslide covered the road, whereas the larger landslide removed the road and trees..

Figure 7. The landslide cut the upper road and covered the lower road..

Figure 8. A large landslide, the head scarp of which cut the road and forest. The landslide displaced a road, and covered another road..

Figure 9. Fan-shaped landslide clearly visible from the green agricultural field..

Figure 10. Debris flow into a stream channel.

Figure 11. Overview of a village which shows no damage. The concrete structure above the village protects it from debris flows and fast floods originating from the mountains. .

Figure D. Location of Figures 12 to 33 (Southwest quadrant of Figure B). The Southwest quadrant covers the Shinano River and the eastern part of Ojiya City..

Figure 12. A landslide lowered a section of the road.

Figure 13. Landslide lowered a section of the terrace and cut through a pond.

Figure 14. The White Rock slide along the Shinano River.

Figure 15. Another view of the White Rock slide along the Shinano River.

Figure 16. Two adjacent landslides blocked the highway..

Figure 17. View of the area just to the east of the White Rock slide.

Figure 18. View of the area to the east of Figure 17. No damage detectable from the aircraft.

Figure 19. Small landslides 1.5 km to the east of the White Rock slide.

Figure 20. Debris flow into an existing debris channel.

Figure 21. Another view of Figure 20.

Figure 22. Landslide originating high above the road and cutting it .

Figure 23. Other view of Figure 22.

Figure 24. Other view of Figure 22.

Figure 25. Landslide covering ponds and a small road.

Figure 26. A pond cracked and discharged its water onto the road.

Figure 27. The road was covered by mud and small debris originating from failure in the hill.

Figure 28. Landslide removed ground and ballast material beneath the railway track.

Figure 29. Local deformation of railway track.

Figure 30. Landslide cut the highway and removed ground and ballast material beneath the railway track.

Figure 31. Slope failure destroying railway track along Shinano River.

Figure 32. A small valley that was severely damaged. More detail can be found in the reconnaissance report of November 2..

Figure 33. A section of the road collapsed. The cable parapet remains hanging on the side of the road.

Figure F. Location of Figures 34 to 56 (Southeast quadrant of Figure B). The Southeast quadrant covers Yamakoshi villa.

Figure 34. Small failures in the man-made terraces in a steep terrain.

Figure 35. Landslide adjacent to portal of tunnel. Mud and small debris left on the road. More detail can be found in the reconnaissance report of November 2..

Figure 36. Road destroyed at several locations by landslides.

Figure 37. Another view of Figure 36.

Figure 38. Another view of Figure 36.

Figure 39. Debris flow washing out road on its path.

Figure 40. Another view of Figure 39.

Figure 41. Road destroyed by several landslides.

Figure 42. Landslides taking out part of a road and blocking the stream below. A small lake is formed upstream of this natural dam, which may fail catastrophically in the future.

Figure 43. Toe of a large landslide covering the road. The trees to the right of the road are inclined and are located on the landslide.

Figure 44. Same landslide as in Figure 43. The head scrap is at the lower right corner of the photograph.

Figure 45. Road washed out in several locations.

Figure 46. Denudation of vegetation cover from a steep slope and failure of ponds that released their contents on sloping ground.

Figure 47. Slope failure covering road.

Figure 48. Another view of Figure 47.

Figure 49. An unstable area with failure and cracking of man made terraces.

Figure 50. Another view of Figure 49.

Figure 51. Road damaged at various locations due to landslides and failure of its fill base.

Figure 52. Road destroyed by landslide.

Figure 53. Another view of Figure 52.

Figure 54. Steep slope with ground cover failure.

Figure 55. Road cracked in the foreground, and landslide in the background. The landslide took away the road and a building.

Figure 56. Landslide destroying S-shape road and blocking flow of stream below. A natural dam is formed..