The EERI-GEER aerial reconnaissance of the areas damaged by the 2004 Niigata-ken Chetsu earthquake was performed on October 30, 2004.
The aerial reconnaissance team was composed of J.P. Bardet, University of Southern California; Hirokazu Iemura, Kyoto University; and Charles Scawthorn, Kyoto University.
The jet airplane and the helicopter, which were used by the reconnaissance team, were provided by Asahi Shimbun, Japan's leading national newspaper.
We thank Yasuda Tomoki, staff writer at Asahi Shimbun for his contribution and organization of the flyover. We are indebted to Hirokazu Iemura for planning and organizing this aerial reconnaissance and for his great hospitality during the earthquake reconnaissance.

Figures 1and 2 shows the complete flight path, and the flight path right over the earthquake areas. The helicopter flight lasted about 90 minutes. It started at Niigata to the North, followed the Shinano River toward Sanjo and the Shinkansen railway track to the South, and covered Nagaoka, the mountains areas to the East, Kawaguchi, Ojiya, and returned and finally ended in Niigata. Figures 3-7 provide some logistic information. Figures 8-14, 125, and 126 show the Niigata area as viewed from an aircraft. Figure 15 represents the location of Figures 16 to 124, which are the main observations on the earthquake.

Figure 1. Flight path of the helicopter reconnaissance of earthquake affected areas on October 30, 2004.

Figure 2. Close-up view of the helicopter flight path during the October 30, 2004, flyover.

Figure 3. Asahi, the newspaper company, provided a jet aircraft to fly the aerial reconnaissance team from Tokyo to Niigata (10/29/2004 5:51:22 PM).

Figure 4. Arrival in Niigata airport of two members of the helicopter reconnaissance team (J.P. Bardet, left and Charles Scawthorn, right) (10/29/2004 6:48:52 PM).

Figure 5. GPS unit used to georeference video and camera through a common time (10/30/2004 1:00:19 PM, N37.95350 E139.11079).

Figure 6. Helicopter pilot takingoff from the Niigata airport (10/30/2004 1:07:10 PM, N37.95618 E139.11584).

Figure 7. The reconnaissance team communicated using headphones during the helicopter flight (10/30/2004 1:07:20 PM, N37.95627 E139.11349).

Figure 8. The downtown of Niigata City has been developed since the 1964 Niigata earthquake (10/30/2004 1:09:30 PM, N37.92768 E139.05679).

Figure 9. The Shinano River in Niigata is crossed by many bridges; its flow is regulated by flood control gates. (10/30/2004 1:09:47 PM, N37.91940 E139.05240).

Figure 10. Niigata is located in the flat and open alluvial deposit of the Shinano River (10/30/2004 1:16:25 PM, N37.69402 E138.95059).

Figure 11. Rice is a common agriculture in Niigata; habitations are concentrated to preserve the agricultural land (10/30/2004 1:16:54 PM, N37.67610 E138.94417).

Figure 12. The Shinano River flows in large meanders which has swept the plain through geological times (10/30/2004 1:17:02 PM, N37.67115 E138.94238).

Figure 13. No apparent damage to the highway bridge and its abutment along Shinano River (10/30/2004 1:17:28 PM, N37.65508 E138.93661).

Figure 14. Nagaoka City and Japanese Railways (JR) station at Nagaoka (10/30/2004 1:22:44 PM, N37.45868 E138.86334).

Figure 15. Location of Figures.

Figure 16. The Shin-Estu railway line passes under the Jo-Etsu Shinkansen viaduct in Nagaoka (10/30/2004 1:23:10 PM, N37.44249 E138.85757).

Figure 17. No apparent damage at the intersection of highway 17 and Shinkansen viaduct (10/30/2004 1:24:09 PM, N37.40871 E138.85220).

Figure 18. The Shinkansen, which was headed toward Niigata, derailed as a result of the earthquake on October 23, 2004. It is reported to have started derailing 1.6 km to the South, 400 m after emerging from a tunnel. (10/30/2004 1:24:41 PM, N37.39454 E138.85110).

Figure 19. View of the last car of the Shinkansen which derailed. The last car was the most inclined of all cars (10/30/2004 1:25:01 PM, N37.38783 E138.84904).

Figure 20. The last car of the Shinkansen leaned on its side in the center gutter of the elevated viaduct (10/30/2004 1:25:09 PM, N37.38745 E138.84593).

Figure 21. The derailed Shinkansen viewed from the Southwest (10/30/2004 1:25:15 PM, N37.38816 E138.84407).

Figure 22. View of the central part of the Shinkansen; it has a total of ten cars including the end cars (10/30/2004 1:25:28 PM, N37.39172 E138.84241).

Figure 23. The derailed Shinkansen viewed from the Southeast (10/30/2004 1:25:38 PM, N37.39444 E138.84334).

Figure 24. The tunnel portal through which the Shinkansen emerged. The Shinkansen was reported to derail 400 m after the portal (10/30/2004 1:26:29 PM, N37.38620 E138.85664).

Figure 25. To the East of Ojiya, the hillsides have been graded in terraces and are covered with ponds to raise golden carps (10/30/2004 1:27:38 PM, N37.36286 E138.87637).

Figure 26. A shallow landslide denuded the vegetation cover of a steep slope (10/30/2004 1:27:40 PM, N37.36222 E138.87700).

Figure 27. View of the same landslide from a location slightly to the East (10/30/2004 1:27:44 PM, N37.36086 E138.87791).

Figure 28. The landslide initiated from a terrace to the top and cut the road (10/30/2004 1:28:05 PM, N37.35518 E138.88464).

Figure 29. Close view of the same landslide (10/30/2004 1:28:10 PM, N37.35425 E138.88669).

Figure 30. Close view of the top part of the landslide; it cut sharply through a pond which discharged its contents (10/30/2004 1:28:17 PM, N37.35242 E138.88896).

Figure 31. Ground cracking at the corner of a pond at the top of the landslide (10/30/2004 1:28:24 PM, N37.35024 E138.89072).

Figure 32. The slope and ponds just to the South of the landslide did not fail during the earthquake (10/30/2004 1:28:57 PM, N37.33714 E138.89554).

Figure 33. The road was washed away as its basement was taken by a landslide (10/30/2004 1:29:17 PM, N37.32910 E138.89560).

Figure 34. Not all slopes failed during the earthquake, as shown in this view which displays no sign of damage from the helicopter (10/30/2004 1:30:04 PM, N37.32146 E138.88367).

Figure 35. The landslide failed a corner of the pond which leaked its contents (10/30/2004 1:30:19 PM, N37.32490 E138.88249).

Figure 36. Circular echelon failure in losely compacted ground (10/30/2004 1:30:53 PM, N37.32982 E138.88931).

Figure 37. The landslide blocked the road and destroyed houses on its path (10/30/2004 1:31:12 PM, N37.33204 E138.89330).

Figure 38. The debris of these landslides converged into one flow (10/30/2004 1:31:33 PM, N37.33614 E138.89439).

Figure 39. The hillside was covered by several slides of various size (10/30/2004 1:31:58 PM, N37.34077 E138.89795).

Figure 40. Some landsides blocked the streams and water accumulated into lakes behind these natural dams (10/30/2004 1:32:52 PM, N37.35239 E138.90892).

Figure 41. Debris flow into the recently formed lake (10/30/2004 1:33:44 PM, N37.34606 E138.92348).

Figure 42. The S-shaped road was destroyed in may parts (10/30/2004 1:34:10 PM, N37.33931 E138.92509).

Figure 43. Landslides originated from both sides of the road and blocked the stream. They crushed the structure protecting the road from avalanches and rock falls (10/30/2004 1:34:18 PM, N37.33769 E138.92342).

Figure 44. Close view of the crushed structure through which water seeped (10/30/2004 1:34:24 PM, N37.33730 E138.92177).

Figure 45. The asphat pavement fell down about 30 meters into the stream just in front the white car (10/30/2004 1:34:46 PM, N37.34026 E138.91632).

Figure 46. Landslide debris covered the S-shaped road (10/30/2004 1:35:36 PM, N37.34050 E138.92180).

Figure 47. Slope failure of a terrace with a pond (10/30/2004 1:36:21 PM, N37.34239 E138.92282).

Figure 48. Debris flow on a steep slope (10/30/2004 1:36:58 PM, N37.34318 E138.91719).

Figure 49. A road section with extensive damage due to landsliding (10/30/2004 1:38:13 PM, N37.34021 E138.92027).

Figure 50. Another road section with extensive damage due to landsliding (10/30/2004 1:38:32 PM, N37.33515 E138.92259).

Figure 51. A building close to the edge of a landslide (10/30/2004 1:38:41 PM, N37.33279 E138.92160).

Figure 52. Half of the building collapsed after the earthquake (10/30/2004 1:39:18 PM, N37.33185 E138.91299).

Figure 53. Damage to S-shaped road and nearby building (10/30/2004 1:39:02 PM, N37.32957 E138.91650).

Figure 54. Another view of the same building (10/30/2004 1:39:38 PM, N37.33578 E138.91533).

Figure 55. The building surrounding by landslide and raising water (10/30/2004 1:39:51 PM, N37.33539 E138.91849).

Figure 56. The structure and the road were damaged by landsliding (10/30/2004 1:40:06 PM, N37.33202 E138.91959).

Figure 57. Example of landslides that diverted and blocked the course of the stream (10/30/2004 1:41:55 PM, N37.33119 E138.91750).

Figure 58. The building was damaged and flooded (10/30/2004 1:42:15 PM, N37.32625 E138.91769).

Figure 59. Flooded village (10/30/2004 1:42:25 PM, N37.32376 E138.91765).

Figure 60. The road disappears under landslide debris and water (10/30/2004 1:42:37 PM, N37.32076 E138.91704).

Figure 61. The landslide head scarp was close to buildings at the top (10/30/2004 1:42:41 PM, N37.31979 E138.91663).

Figure 62. The landslide blocked the course of the river and destroyed the road (10/30/2004 1:43:10 PM, N37.31855 E138.90958).

Figure 63. The road was washed out by landsliding (10/30/2004 1:43:37 PM, N37.32484 E138.90919).

Figure 64. Flooding of a smalll village due to formation of natural dams by lansliding (10/30/2004 1:44:00 PM, N37.32716 E138.91406).

Figure 65. The debris of a landslide blocked the road (10/30/2004 1:44:40 PM, N37.31746 E138.91925).

Figure 66. The debris of a landslide crossed the road and blocked it (10/30/2004 1:44:46 PM, N37.31565 E138.91930).

Figure 67. The access road to the village was damaged and blocked in several locations by landslides (10/30/2004 1:44:54 PM, N37.31332 E138.91833).

Figure 68. The lower road was floodded by the water accumulated behind natural dams formed by landslides, and the upper road partially dropped down into the newly formed lake (10/30/2004 1:45:00 PM, N37.31172 E138.91730).

Figure 69. From the distance, the bridge appears to have performed well whereas the access road was flooded (10/30/2004 1:45:16 PM, N37.30806 E138.91383).

Figure 70. The abutment of the bridges failed (10/30/2004 1:45:51 PM, N37.30214 E138.90620).

Figure 71. The road in front the building was completely washed out (10/30/2004 1:46:02 PM, N37.30228 E138.90314).

Figure 72. The debris from the landslide completely covered the rods (10/30/2004 1:46:11 PM, N37.30395 E138.90160).

Figure 73. A patch of tree remains standing almost intact while the ground beneath it slided laterally, blocked the stream, and covered the road on the other bank (10/30/2004 1:46:28 PM, N37.30786 E138.90228).

Figure 74. The road on each side of the bridge was cut by two different landslides (10/30/2004 1:47:00 PM, N37.31100 E138.90858).

Figure 75. Overall view of the landslide (10/30/2004 1:47:10 PM, N37.30910 E138.91020).

Figure 76. The landslide toe ramped up against the slope on the other side of the road, which tilted the trees on the landslide mass (10/30/2004 1:47:59 PM, N37.30166 E138.90282).

Figure 77. The landslide mass moved laterally, without much deforming the ground surface (10/30/2004 1:48:24 PM, N37.30641 E138.90263).

Figure 78. Head scarp of the landslide showing a translational failure mode on a inclined bedding (10/30/2004 1:48:38 PM, N37.30696 E138.90640).

Figure 79. Head scarp of the landslide showing a translational failure mode on a inclined bedding (10/30/2004 1:48:48 PM, N37.30566 E138.90877).

Figure 80. There were many lanslides in steep slopes (10/30/2004 1:49:28 PM, N37.29621 E138.90694).

Figure 81. Ground instability on a steep slope (10/30/2004 1:49:39 PM, N37.29362 E138.90681).

Figure 82. Blue tarps and sand bags to cover and stabilize a ground failure of the bridge abutment (10/30/2004 1:52:24 PM, N37.25594 E138.93268).

Figure 83. Ground settlement on each side of the drainage channel passing beneath the roads (10/30/2004 1:53:44 PM, N37.24394 E138.93904).

Figure 84. Blue tarps covering the bridge abutment indicate abutment settlement and local ground failure (10/30/2004 1:54:15 PM, N37.25067 E138.92960).

Figure 85. In spite of numerous landslides, there were no apparent damage to power line tower due to landslides (10/30/2004 1:55:03 PM, N37.25759 E138.91159).

Figure 86. Small landslide on a steep slope revealed by the absence of ground cover (10/30/2004 1:55:12 PM, N37.25868 E138.90770).

Figure 87. Recent patches of asphalt indicate that the bridge abutments has settled during the earthquake (10/30/2004 1:56:00 PM, N37.26646 E138.88879).

Figure 88. The landslide debris flowed on the roof of the structure designed for rock fall and debri (10/30/2004 1:56:17 PM, N37.26612 E138.88254).

Figure 89. The Shinkansen railway track is on an heavy bridge while its neighboring railway track of a local line is on a light steel bridge (10/30/2004 1:56:50 PM, N37.26548 E138.87692).

Figure 90. The reinfored concrete piers of the Shinkansen bridge were damaged, whereas the light steel bridge of the adjacent railway line was undamaged (10/30/2004 1:57:12 PM, N37.26743 E138.88316).

Figure 91. Damaged pier of Shinkansen bridge (10/30/2004 1:59:04 PM, N37.26489 E138.88097).

Figure 92. Damaged pier of Shinkansen bridge indicated by complete circumferential spalling of concrete and exposure of rebars (10/30/2004 1:59:08 PM, N37.26421 E138.88144).

Figure 93. The landslide debris blocked a local railway line (10/30/2004 2:01:24 PM, N37.26036 E138.88904).

Figure 94. The landslide completely blocked the road (10/30/2004 2:02:37 PM, N37.26578 E138.87996).

Figure 95. Differential ground deformation and failure around the portal of the tunnel of a local railway line (10/30/2004 2:03:34 PM, N37.25892 E138.88130).

Figure 96. Ground failure on each side of the portal of the tunnel destroyed a small road (10/30/2004 2:03:38 PM, N37.25946 E138.88182).

Figure 97. A building fell into the Ueno River due to slope failure (10/30/2004 2:05:44 PM, N37.25825 E138.86485).

Figure 98. Slope failure along the bank of the Ueno River (10/30/2004 2:05:47 PM, N37.25832 E138.86349).

Figure 99. Debris of a building on the road probably caused by slope stability (10/30/2004 2:05:57 PM, N37.25899 E138.85892).

Figure 100. The Ueno River flows in meanders which had moved with time across its alluvial plain (10/30/2004 2:07:16 PM, N37.27569 E138.82828).

Figure 101. The Ueno River erodes its bank and creates slope instability, which were were exacerbated by the earthquake (10/30/2004 2:07:40 PM, N37.28193 E138.81992).

Figure 102. Landslides on steep slopes were easily detectable by the absence of vegetation along the debris corridor (10/30/2004 2:08:14 PM, N37.29008 E138.80513).

Figure 103. The bridge abutment settled and cracked longitudinally (10/30/2004 2:08:37 PM, N37.29702 E138.79643).

Figure 104. A single instance of collapsed building at the corner of an road intersection (10/30/2004 2:09:47 PM, N37.31060 E138.80553).

Figure 105. The white rock slide is located along the Shinano River. Several persons were reported to have died at this location (10/30/2004 2:13:02 PM, N37.34142 E138.83176).

Figure 106. The white rock slide viewed from the North (10/30/2004 2:13:04 PM, N37.34115 E138.83246).

Figure 107. The white rock slide (10/30/2004 2:14:06 PM, N37.32781 E138.82578).

Figure 108. The white rock slide (10/30/2004 2:14:12 PM, N37.32852 E138.82336).

Figure 109. The white rock slide (10/30/2004 2:14:20 PM, N37.33042 E138.82060).

Figure 110. The white rock slide (10/30/2004 2:14:33 PM, N37.33483 E138.81870).

Figure 111. At some locations, the downstream surface of levees were covered with blue tarp, in addition to the crest, indicating cracking on the downstream surface (10/30/2004 2:15:41 PM, N37.35457 E138.83012).

Figure 112. The tarps did not continuously cover the levee crest, indicating that the levees had been partially damaged. (10/30/2004 2:18:08 PM, N37.35694 E138.82269).

Figure 113. Several kilometers of levee along the Shinano River were covered by blue tarp (10/30/2004 2:18:30 PM, N37.36223 E138.81854).

Figure 114. Kilometers of levee along the Shinano River were covered by blue tarp (10/30/2004 2:19:08 PM, N37.37154 E138.81451).

Figure 115. No apparent damage to the tower close to the levees (10/30/2004 2:19:24 PM, N37.37623 E138.81485).

Figure 116. Blue tarps on top of levees along the Shinano River indicated that the levees had undergone some cracking on the crest. These tarps were used to prevent rainwater from infiltrating the levees. (10/30/2004 2:20:27 PM, N37.37931 E138.81343).

Figure 117. Ground cracking and sand boils in agricultural land located close to the Shinano River (10/30/2004 2:23:00 PM, N37.37527 E138.82539).

Figure 118. Closer view of ground cracking next to building (10/30/2004 2:23:12 PM, N37.37610 E138.82324).

Figure 119. Ground cracking and sand boils in agricultural land located close to the Shinano River (10/30/2004 2:23:15 PM, N37.37672 E138.82312).

Figure 120. Closer view of ground cracking next to building (10/30/2004 2:23:29 PM, N37.37794 E138.82500).

Figure 121. Ground cracking and sand boils in agricultural land located close to the Shinano River (10/30/2004 2:23:41 PM, N37.37667 E138.82568).

Figure 122. Liquefaction-induced sand boils and ground cracking next to building (10/30/2004 2:24:24 PM, N37.37797 E138.82407).

Figure 123. Liquefaction-induced settlement and cracking in front of building (10/30/2004 2:24:30 PM, N37.37772 E138.82510).

Figure 124. Settlement of bridge abutments indicated by recent asphalt repairs at the connection between bridge and abutments (10/30/2004 2:25:33 PM, N37.37561 E138.82666).

Figure 125. View of Niigata City where no damage was reported after the earthquake (10/30/2004 2:42:34 PM, N37.86597 E138.98602).

Figure 126. Another view of Niigata City where no damage was reported after the earthquake (10/30/2004 2:43:12 PM, N37.88888 E138.99384).