TY - JOUR
T1 - The M7 2016 Kumamoto, Japan, Earthquake
T2 - 3-D Deformation Along the Fault and Within the Damage Zone Constrained From Differential Lidar Topography
AU - Scott, Chelsea P.
AU - Arrowsmith, Ramon
AU - Nissen, Edwin
AU - Lajoie, Lia
AU - Maruyama, Tadashi
AU - Chiba, Tatsuro
N1 - Funding Information:
C. Scott was supported by NSF Postdoctoral Fellowship 1625221 and by the School of Earth and Space Exploration at Arizona State University. E. Nissen and L. Lajoie acknowledge support through the Southern California Earthquake Center through SCEC awards 14101 and 15189. We thank Manoochehr Shirzaei for a discussion on error calculation. Thanks to Koji Okumura for early conversations about the Kumamoto earthquake surface rupture. We additionally thank Yehuda Ben-Zion (Editor), Chris Milliner (reviewer), Michele Cooke (reviewer), and two anonymous reviewers for constructive comments that strengthened the manuscript. We thank the Asia Air Survey Co., Ltd. for providing us with access to the pre-earthquake and postearthquake point cloud lidar data sets. The lidar data sets are available at OpenTopography (http://www.opentopography.org). Our 3-D displacement results are included in a text file in the supporting information. The LIBICP software is available at http://www.cvlibs.net/software/libicp/.
Publisher Copyright:
©2018. American Geophysical Union. All Rights Reserved.
PY - 2018/7
Y1 - 2018/7
N2 - Three-dimensional near-fault coseismic deformation fields from high-resolution differential topography provide new information on the behavior of the shallow fault zone in large surface-rupturing earthquakes. Our work focuses on the 16 April 2016 Mw 7.0 Kumamoto, Japan, earthquake, which ruptured ~40 km of the Futagawa-Hinagu Fault Zone on Kyushu Island with an oblique strike-slip mechanism and surface offset exceeding 2 m. Our differential lidar analysis constrains the structural style of strain accommodation along the primary fault trace and the surrounding damage zone. We show that 36 ± 29% and 62 ± 32% of the horizontal and vertical deformation, respectively, was accommodated off the principal fault trace. The horizontal strains of up to 0.03 suggest that the approximate elastic strain limit was exceeded over a ~250 m width in many locations along the rupture. The inelastic deformation of the fault volume produced the observed distributed deformation at the Earth's surface. We demonstrate a novel approach for calculating 3-D displacement uncertainties, indicating errors of centimeters to a few decimeters for displacements computed over 50 m horizontal windows. Errors correlate with land cover and relief, with flatter agricultural land associated with the highest displacement uncertainty. These advances provide a framework for future analyses of shallow earthquake behavior using differential topography.
AB - Three-dimensional near-fault coseismic deformation fields from high-resolution differential topography provide new information on the behavior of the shallow fault zone in large surface-rupturing earthquakes. Our work focuses on the 16 April 2016 Mw 7.0 Kumamoto, Japan, earthquake, which ruptured ~40 km of the Futagawa-Hinagu Fault Zone on Kyushu Island with an oblique strike-slip mechanism and surface offset exceeding 2 m. Our differential lidar analysis constrains the structural style of strain accommodation along the primary fault trace and the surrounding damage zone. We show that 36 ± 29% and 62 ± 32% of the horizontal and vertical deformation, respectively, was accommodated off the principal fault trace. The horizontal strains of up to 0.03 suggest that the approximate elastic strain limit was exceeded over a ~250 m width in many locations along the rupture. The inelastic deformation of the fault volume produced the observed distributed deformation at the Earth's surface. We demonstrate a novel approach for calculating 3-D displacement uncertainties, indicating errors of centimeters to a few decimeters for displacements computed over 50 m horizontal windows. Errors correlate with land cover and relief, with flatter agricultural land associated with the highest displacement uncertainty. These advances provide a framework for future analyses of shallow earthquake behavior using differential topography.
KW - differential topography
KW - earthquake deformation
KW - faulting mechanics
KW - lidar
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U2 - 10.1029/2018JB015581
DO - 10.1029/2018JB015581
M3 - Article
AN - SCOPUS:85051063691
SN - 2169-9313
VL - 123
SP - 6138
EP - 6155
JO - Journal of Geophysical Research: Solid Earth
JF - Journal of Geophysical Research: Solid Earth
IS - 7
ER -