TY - JOUR
T1 - Coseismic fault zone deformation revealed with differential lidar
T2 - Examples from Japanese Mw ~7 intraplate earthquakes
AU - Nissen, Edwin
AU - Maruyama, Tadashi
AU - Arrowsmith, Ramon
AU - Elliott, John R.
AU - Krishnan, Aravindhan K.
AU - Oskin, Michael E.
AU - Saripalli, Srikanth
N1 - Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2014/11/1
Y1 - 2014/11/1
N2 - We use two recent Japanese earthquakes to demonstrate the rich potential, as well as some of the challenges, of differencing repeat airborne Light Detection and Ranging (lidar) topographic data to measure coseismic fault zone deformation. We focus on densely-vegetated sections of the 14 June 2008 Iwate-Miyagi (Mw 6.9) and 11 April 2011 Fukushima-Hamadori (Mw 7.1) earthquake ruptures, each covered by 2 m-resolution pre-event and 1 m-resolution post-event bare Earth digital terrain models (DTMs) obtained from commercial lidar providers. Three-dimensional displacements and rotations were extracted from these datasets using an adaptation of the Iterative Closest Point (ICP) algorithm. These displacements remain coherent close to surface fault breaks, as well as within dense forest, despite intervals of ~2 years (Iwate-Miyagi) and ~4 years (Fukushima-Hamadori) encompassed by the lidar scenes. Differential lidar analysis is thus complementary to Interferometric Synthetic Aperture Radar (InSAR) and sub-pixel correlation techniques which often break down under conditions of long time intervals, dense vegetation or steep displacement gradients. Although the ICP displacements are much noisier than overlapping InSAR line-of-sight displacements, they still provide powerful constraints on near-surface fault slip. In the Fukushima-Hamadori case, near-fault displacements and rotations are consistent with decreased primary fault slip at very shallow depths of a few tens of meters, helping to account for the large, along-strike heterogeneity in surface offsets observed in the field. This displacement field also captures long-wavelength deformation resulting from the 11 March 2011 Tohoku great earthquake.
AB - We use two recent Japanese earthquakes to demonstrate the rich potential, as well as some of the challenges, of differencing repeat airborne Light Detection and Ranging (lidar) topographic data to measure coseismic fault zone deformation. We focus on densely-vegetated sections of the 14 June 2008 Iwate-Miyagi (Mw 6.9) and 11 April 2011 Fukushima-Hamadori (Mw 7.1) earthquake ruptures, each covered by 2 m-resolution pre-event and 1 m-resolution post-event bare Earth digital terrain models (DTMs) obtained from commercial lidar providers. Three-dimensional displacements and rotations were extracted from these datasets using an adaptation of the Iterative Closest Point (ICP) algorithm. These displacements remain coherent close to surface fault breaks, as well as within dense forest, despite intervals of ~2 years (Iwate-Miyagi) and ~4 years (Fukushima-Hamadori) encompassed by the lidar scenes. Differential lidar analysis is thus complementary to Interferometric Synthetic Aperture Radar (InSAR) and sub-pixel correlation techniques which often break down under conditions of long time intervals, dense vegetation or steep displacement gradients. Although the ICP displacements are much noisier than overlapping InSAR line-of-sight displacements, they still provide powerful constraints on near-surface fault slip. In the Fukushima-Hamadori case, near-fault displacements and rotations are consistent with decreased primary fault slip at very shallow depths of a few tens of meters, helping to account for the large, along-strike heterogeneity in surface offsets observed in the field. This displacement field also captures long-wavelength deformation resulting from the 11 March 2011 Tohoku great earthquake.
KW - Active tectonics
KW - Earthquake deformation
KW - Lidar
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U2 - 10.1016/j.epsl.2014.08.031
DO - 10.1016/j.epsl.2014.08.031
M3 - Article
AN - SCOPUS:84907854606
SN - 0012-821X
VL - 405
SP - 244
EP - 256
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
ER -