Detection and mapping of soil liquefaction in the 2011 Tohoku earthquake using SAR interferometry

Abstract

We have identified areas of soil liquefaction by the analysis of surface changes caused by the 2011 Tohoku earthquake, using synthetic aperture radar (SAR) interferometry in the Kanto region of Japan. Changes in surface scattering properties were evaluated using phase-corrected coherence, computed from the reflective intensity (amplitude) of SAR data. Often, the loss of coherence (decorrelation) is simply considered to represent areas damaged from the disaster. However, temporal decorrelation could also be induced by ordinal surface cover change in addition to disaster damage. Therefore, we use a coherence change threshold to discriminate significant decorrelation caused by soil liquefaction from that produced by ordinal surface cover changes. Moreover, local surface displacements are estimated using phase information from the SAR data. Our results compare favorably with those from surveys of sand boils and aerial photography, showing that surface changes derived from SAR data are associated with soil liquefaction. Our results demonstrate that soil liquefaction occurred mainly near the waterfront along Tokyo Bay and the Tone River, and ground subsidence was widely distributed.

Fusion of Multi-Temporal Interferometric Coherence and Optical Image Data for the 2016 Kumamoto Earthquake Damage Assessment

“…This study thus demonstrates that it is feasible to combine and extend the advantages of two different remote sensing sensors for earthquake damage assessments. The urban damage levels following the 2016 Kumamoto earthquake were obtained from the degree of interferometric coherence of pre-seismic and co-seismic data, and the findings were consistent with the results of previous research reports that mapped the urban damage [11][12][13]15] and liquefaction areas [27] by using interferometric coherence.…”

“…To clarify the change of correlation between damaged areas and low coherence areas such as forests, plantations, and reservoirs, comparisons of pre-disaster and co-disaster interferogram correlations were used to evaluate the change caused by the Kumamoto earthquake. We evaluated buildings damaged by the earthquake [10][11][12] and detected areas of soil liquefaction [27]. The normalized difference (ND) of the coherence change (Equation (2)) was also used to detect damaged areas [9,13]:…”

Earthquake rupture properties of the 2016 Kumamoto earthquake foreshocks (M j 6.5 and M j 6.4) revealed by conventional and multiple-aperture InSAR

“…It is known that liquefaction induces ground subsidence and can be sometimes detected by InSAR (Ishitsuka et al 2012). Liquefaction occurred in some parts of Mashiki town during the earthquake series, yet the timing of liquefaction does not appear to be known.…”

Coseismic and postseismic deformation estimation of the 2011 Tohoku earthquake in Kanto Region, Japan, using InSAR time series analysis and GPS

“…We use the coherence difference method presented by (Ishitsuka, Tsuji, & Matsuoka, 2012) and (Tamura & Li, 2013). The main idea of this approach is to identify the pixels that lost coherence as a result of a certain event.…”