Electronic Supplement to
Surficial Slip and Rupture Geometry on the Beichuan Fault near Hongkou during the Mw 7.9 Wenchuan Earthquake, China
by
Jing Liu-Zeng, Li Wen, Jie Sun, Zhihui Zhang, Guyue Hu, Xiucheng Xing, Lingsen Zeng and Qiang Xu
Selected field photographs of the 2008
surface rupture in the southern section.
Figures S1, S2, S3 are annotated field photos, showing evidence of surface ruptures at key locations south of Hongkou.
Then, selected field photographs with short descriptions of surface rupture near Hongkou, grouped in four sections, from southwest to northeast, the Shenxigou, Miaoba, Gaoyuan,
and Bajioa Miao sections, respectively.
Figure S1. Evidence of co-seismic surface rupture at Yingxiu.
a) is a post-earthquake air photo of Yingxiu (modified from Fu et al., 2008), showing the locations of photos (b-f).
b) The scarp to the west of the Yinxiu high terrace remnants and on T1 terrace. It is a gentle warp of 2.2 m high over 24 m-wide fault zone. Looking north.
c) Surface rupture offset the concrete road at the Minjiang river west bank (point 239), also cut through multiple levels of terraces, at
the location coinciding with a pre-existing geomorphic cumulative scarp. Looking southwest. On the eastern bank of the river, the concrete wall shows the
right-lateral horizontal offset (d), across a broad zone of en echelon cracks (e). Looking south.
f) Toward the northeast, the fault entered a dry tributary
valley, causing extensive collapses along the southern steeply-slope valley wall, but without clear geomorphic scarps.
a) is a post-earthquake air photo of Yingxiu (modified from Fu et al., 2008), showing the locations of photos (b-f).
b) The scarp to the west of the Yinxiu high terrace remnants and on T1 terrace. It is a gentle warp of 2.2 m high over 24 m-wide fault zone. Looking north.
c) Surface rupture offset the concrete road at the Minjiang river west bank (point 239), also cut through multiple levels of terraces, at
the location coinciding with a pre-existing geomorphic cumulative scarp. Looking southwest. On the eastern bank of the river, the concrete wall shows the
right-lateral horizontal offset (d), across a broad zone of en echelon cracks (e). Looking south.
f) Toward the northeast, the fault entered a dry tributary
valley, causing extensive collapses along the southern steeply-slope valley wall, but without clear geomorphic scarps.
Figure S2. Evidence of co-seismic surface rupture at Xuankou.
Several lines of evidence argue for a tectonic origin of the ground deformation seen at the Guxi village, Xuankou. The deformation zone, which passed through multiple houses and farm plots, occured in the relatively flat part of the valley, rather than on steep slopes. Along the deformation zone, a variety of deformation occurred, including a) monoclinal scarp (looking south) and b) warping of 18 m in width cut through corn fields with roughly east-west-striking and southeast-side-up. Looking northeast. c) A moletrack-like N38E-trending crack with southeast-side-up vertical separation of 0.2-0.4 m. Looking northeast. d) a house foundation moved ~10 cm southward, looking northeast. e) Inside the house, the kitchen floor was deformed with elongated bulge and hearth being tilted and cracked. In addition, local residents told that the fissuring and warping of their yards, houses and ground surface appeared to increase incrementally with occurrences of felt-sized aftershocks (post-seismic deformation?).
Several lines of evidence argue for a tectonic origin of the ground deformation seen at the Guxi village, Xuankou.
The deformation zone, which passed through multiple houses and farm plots, occured in the relatively flat part of the valley,
rather than on steep slopes. Along the deformation zone, a variety of deformation occurred, including a) monoclinal scarp (looking south) and b)
warping of 18 m in width cut through corn fields with roughly east-west-striking and southeast-side-up. Looking northeast.
c) A moletrack-like N38E-trending crack with southeast-side-up vertical separation of 0.2-0.4 m. Looking northeast.
d) a house foundation moved ~10 cm southward, looking northeast. e) Inside the house, the kitchen floor was deformed with elongated bulge and hearth being tilted and cracked.
In addition, local residents told that the fissuring and warping of their yards, houses and ground surface appeared to increase incrementally
with occurrences of felt-sized aftershocks (post-seismic deformation?).
Figure S3. Distributed surface rupture zone at the eastern end of the Shenxi Gou section.
A fault-perpendicular paved road shows that the fault zone consisted of at least 3-4 branches, among which two had relatively large vertical separations of 1.2 m and 1.5 m, and the other two with nominal vertical separation of less than 0.2 m each. Photos (a-c) were taken at different positions to show lateral variation of the fault scarp. View locations and direction for a through c are shown in the mapview sketch of fault zone.
A fault-perpendicular paved road shows that the fault zone consisted of at least 3-4 branches,
among which two had relatively large vertical separations of 1.2 m and 1.5 m, and the other two with nominal
vertical separation of less than 0.2 m each. Photos (a-c) were taken at different positions to show lateral variation of the fault scarp. View locations and direction for a through c are shown in the mapview sketch of fault zone.
Selected field photographs of the surface rupture in the Hongkou area
Selected field photographs, shown in four sections, from southwest to northeast with short descriptions.
(a) In the Shenxi Gou section
(b) In the Miaoba section
(c) In the Gaoyuan section
(d) In the Bajiao Miao section
References
Fu,B., P. Shi and Z. Zhang (2008). Spatial characteristics of the surface rupture produced by the Ms 8.0
Wenchuan earthquake using high-resolution remote sensing imagery, Acta Geologica Sinica, 82:1679-1687.