Calculation of coseismic displacement from lidar data in the 2016 Kumamoto, Japan, earthquake

Luis Moya,Wen Liu,Tatsuro Chiba,Fumio Yamazaki

doi:10.5194/nhess-17-143-2017

Abstract

Abstract. The spatial distribution of the coseismic displacements that occurred along the Futagawa fault during the 2016 Kumamoto earthquake of Mw 7.0 was estimated using airborne light detection and ranging (lidar) data. In this study, a pair of digital surface models (DSMs) obtained from the high-density lidar data before and after the mainshock on 16 April 2016 were used. A window matching search approach based on the correlation coefficient between the two DSMs was used to estimate the geodetic displacement in the near-field region. The results showed good agreements with the geodetic displacements calculated from strong-motion acceleration records and coincided with the fault line surveyed by the Geological Survey of Japan.

Highlights

On 14 April 2016, an Mw 6.2 earthquake struck Kumamoto Prefecture, Japan, at 21:26 JST
The coseismic displacements produced during the mainshock of Mw 7.1 of the 2016 Kumamoto earthquake were estimated using two digital surface models (DSMs) acquired by high-resolution lidar flights before and after the mainshock on 16 April
The maximum cross-correlation coefficient was used with a window matching technique between the two DSMs to calculate the coseismic displacement

Summary

Introduction

On 14 April 2016, an Mw 6.2 earthquake struck Kumamoto Prefecture, Japan, at 21:26 JST. The first event was designated as the foreshock and the second one as the mainshock Both the events occurred in the town of Mashiki (with a population of approximately 33 000), which is located to the east of Kumamoto City (with a population of approximately 735 000). Many aftershocks followed these events, and as of 6 September, 4 months after the foreshock, the total number of aftershocks (larger than Mw 3.5) is 272. This number is the largest among the recent inland (crustal) earthquakes in Japan (Japan Meteorological Agency, 2016). A total of 8550 buildings, mostly in Kumamoto Prefecture, were seriously damaged or collapsed, and 50 human lives were lost, mostly because of landslides or the collapse of buildings (Cabinet Office of Japan, 2016)

Methods

Findings

Discussion

Conclusion