Estimating surface displacement in the Hanshin area, Japan, by PS-InSAR analysis using satellite Sentinel-1 data

2021 ◽  
Author(s):  
Yutaro Shigemitsu ◽  
Kazuya Ishitsuka ◽  
Weiren Lin
Keyword(s):  
Fault Zone ◽  
Groundwater Level ◽  
Active Faults ◽  
Surface Displacement ◽  
Sar Interferometry ◽  
Surface Displacements ◽  
Active Segment ◽  
2018 Northern Osaka Earthquake ◽  
Groundwater Level Changes

<p>The 2018 northern Osaka earthquake with a magnitude 6.1 earthquake struck on June 18, 2018 in northern Osaka, causing enormous damage. SAR interferometry using satellite synthetic aperture radar (SAR) data can detect surface displacement distribution over a wide area and is effective for observing surface displacement during an earthquake. On the other hand, it is also important to observe the tendency of long-term surface displacement around active faults on a yearly basis in order to monitor the deformation at and around active faults. In this study, we used persistent scatter SAR interferometry (PS-InSAR) to clarify the recent surface displacement including before and after the 2018 northern Osaka earthquake near the Arima-Takatsuki Fault Zone and the Mt. Rokko active segment, near the epicenter of the earthquake. PS-InSAR analysis is a method that analyzes coherent pixels only, and can extract surface displacements with less noise than the conventional two-pass SAR interferometry. By using Sentinel-1 data, we expect to understand a long-term surface displacement and temporal changes in displacement pattern by comparing with the results using other satellites in previous studies. As a result of our analysis, we found that (i) ground subsidence occurred near the Mt. Rokko active segment, (ii) subsidence or eastward displacement occurred in the eastern part of the Takarazuka GNSS station, (iii) surface displacement in the wedge-shaped area located between the Arima-Takatsuki Fault Zone and the Mt. Rokko active segment is suggested to be caused by groundwater level changes, (iv) groundwater level changes may have caused surface displacement considered to be uplift in the wide area between the Ikoma Fault Zone and Uemachi Fault Zone, and (v) slip of the source fault may have caused surface displacement around the epicenter of the 2018 northern Osaka earthquake. Furthermore, we validated the estimated surface displacements by comparison with GNSS measurements and previous studies. These results suggest that surface displacement near the Arima-Takatsuki fault zone was caused by the 2018 northern Osaka earthquake. In order to reveal the mechanism of surface displacement in the vicinity of the fault, it is necessary to continue to monitor the surface displacement in this area using time-series SAR interferometry.</p><p> </p><p> </p><p>We acknowledge Sentinel-1 data provided from the European Space Agency (ESA) based on the open data policy.</p>

Do active faults’ clay mineral compositions affect whether earthquake ruptures they host will displace the surface?

2021 ◽  
Author(s):  
Selina S. Fenske ◽  
Virginia G. Toy ◽  
Bernhard Schuck ◽  
Anja M. Schleicher ◽  
Klaus Reicherter
Keyword(s):  
Fault Zone ◽  
Clay Mineral ◽  
Active Faults ◽  
Surface Displacement ◽  
Surface Rupture ◽  
Near Surface ◽  
Ground Shaking ◽  
Physical Measurements ◽  
Surface Displacements ◽  
Earthquake Ruptures

<p>The tectonophysical paradigm that earthquake ruptures should not start, or easily propagate into, the shallowest few kilometers of Earth’s crust makes it difficult to understand why damaging surface displacements have occurred during historic events. The paradigm is supported by decades of analyses demonstrating that near the surface, most major fault zones are composed of clay minerals – particularly extraordinarily weak smectites – which most laboratory physical measurements suggest should prevent surface rupture if present. Recent studies of New Zealand’s Alpine Fault Zone (AFZ) demonstrate smectites are absent from some near surface fault outcrops, which may explain why this fault was able to offset the surface locally in past events. The absence of smectites in places within the AFZ can be attributed to locally exceptionally high geothermal gradients related to circulation of meteoric (surface-derived) water into the fault zone, driven by significant topographic gradients. The record of surface rupture of the AFZ is heterogeneous, and no one has yet systematically examined the distribution of segments devoid of evidence for recent displacement. There are significant implications for seismic hazard, which comprises both surface displacements and ground shaking with intensity related to the area of fault plane that ruptures (which will be reduced if ruptures do not reach the surface).  We will present results of new rigorous XRD clay mineral analyses of AFZ principal slip zone gouges that indicate where smectites are present, and consider if these display systematic relationships to surface displacement records. We also plan to apply the same methodology to the Carboneras Fault Zone in Spain, and the infrequent Holocene-active faults in Western Germany.</p>

scholarly journals Diagnosing Subsidence Geohazard at Beijing Capital International Airport, from High-Resolution SAR Interferometry

2020 ◽  
Vol 12 (6) ◽  
pp. 2269 ◽  
Author(s):  
Keren Dai ◽  
Xianlin Shi ◽  
Jisong Gou ◽  
Leyin Hu ◽  
Mi Chen ◽  
...  
Keyword(s):  
High Resolution ◽  
Active Faults ◽  
Sar Interferometry ◽  
Soil Thickness ◽  
International Airport ◽  
The Future ◽  
Over Exploitation ◽  
Compressible Soil ◽  
First Time

Beijing Capital International Airport (BCIA) has suffered from uneven land subsidence since 1935, which affects the smoothness of airport runways and seriously threatens the safety of aircrafts. In this paper, a spaceborne interferometric synthetic aperture radar (InSAR) with high-resolution Cosmo-SkyMed SAR data was utilized at BCIA for the first time to diagnose the subsidence hazard. The results show that subsidence is progressing at BCIA at a maximum rate of 50 mm/year, which is mainly distributed in the northwest side of the airport. It was found that the Shunyi-Liangxiang fault directly traverses Runway2 and Runway3 and causes uneven subsidence, controlling the spatial subsidence pattern to some degree. Four driving factors of subsidence were investigated, namely: the over-exploitation of groundwater, active faults, compressible soil thickness, and aquifer types. For the future sustainable development of BCIA, the influence of Beijing new airport and Beijing Daxing International Airport (BDIA), was analyzed and predicted. It is necessary to take relevant measures to control the uneven subsidence during the initial operation of BDIA and conduct long-term monitoring to ensure the regular safe operation of BCIA. This case demonstrates a remote sensing method of diagnosing the subsidence hazard with high accuracy and non-contact, providing a reliable alternative for the geohazard diagnosis of key infrastructures in the future.

Long-term groundwater level changes and land subsidence in Tianjin, China

2020 ◽  
Author(s):  
Da Ha ◽  
Gang Zheng ◽  
Hugo A. Loáiciga ◽  
Wei Guo ◽  
Haizuo Zhou ◽  
...  
Keyword(s):  
Land Subsidence ◽  
Groundwater Level ◽  
Groundwater Level Changes

scholarly journals Groundwater Hydrograph Decomposition With the HydroSight Model

2021 ◽  
Vol 9 ◽  
Author(s):  
Feihe Kong ◽  
Jinxi Song ◽  
Russell S. Crosbie ◽  
Olga Barron ◽  
David Schafer ◽  
...  
Keyword(s):  
Land Cover ◽  
Groundwater Level ◽  
Groundwater Pumping ◽  
Contribution Rate ◽  
Groundwater Abstraction ◽  
Study Region ◽  
The World ◽  
Groundwater Level Changes ◽  
Over Time

Groundwater, the most important water resource and the largest distributed store of fresh water in the world, supports sustainability of groundwater-dependent ecosystems and resilient and sustainable economy of the future. However, groundwater level decline in many parts of world has occurred as a result of a combination of climate change, land cover change and groundwater abstraction from aquifers. This study investigates the determination of the contributions of these factors to the groundwater level changes with the HydroSight model. The unconfined superficial aquifer in the Gnangara region in Western Australia was used as a case study. It was found that rainfall dominates long-term (1992–2014) groundwater level changes and the contribution rate of rainfall reduced because the rainfall decreased over time. The mean rainfall contribution rate is 77% for climate and land cover analysis and 90% for climate and pumping analysis. Secondly, the increasing groundwater pumping activities had a significant influence on groundwater level and its mean contribution rate on groundwater level decline is -23%. The land cover changes had limited influence on long-term groundwater level changes and the contribution rate is stable over time with a mean of 2%. Results also showed spatial heterogeneity: the groundwater level changes were mainly influenced by rainfall and groundwater pumping in the southern study region, and the groundwater level changes were influenced by the combination of rainfall, land cover and groundwater pumping in the northern study region. This research will assist in developing a quantitative understanding of the influences of different factors on groundwater level changes in any aquifer in the world.

scholarly journals Determination of the Long-Term Ground Surface Displacements Using a PSI Technique—Case Study on Wrocław (Poland)

2020 ◽  
Vol 10 (10) ◽  
pp. 3343
Author(s):  
Piotr Grzempowski ◽  
Janusz Badura ◽  
Wojciech Milczarek ◽  
Jan Blachowski ◽  
Tadeusz Głowacki ◽  
...  
Keyword(s):  
Ground Surface ◽  
Surface Displacement ◽  
Temporal Analysis ◽  
Recent Measurement ◽  
Entire Area ◽  
Surface Displacements ◽  
Spatio Temporal ◽  
Potential Factors ◽  
The City

Wrocław is a major city located in the southwestern part of Poland in an aseismic tectonic fault zone. Slow, long-term, vertical displacements have been observed there from the 1930s based on the levelling network measurements with the use of a precise levelling method. Due to the high cost of classic surveys, these were performed at intervals of several decades and the most recent measurement of ground surface displacement was performed in 1999. The main aim of this study is to determine the ground surface displacements on the area of Wrocław in the 1995–2019 period, the spatio-temporal analysis of deformations and the identification of the potential factors causing these deformations. To determine the ground movements, an advanced PSI technique and data from ERS-2, Envisat, and Sentinel-1 sensors were used. Application of SAR technology for the first time in this area, provided new knowledge about the process of deformation in short time intervals over the entire area of the city. The results verify the hypothesis on the linearity of displacements obtained from historical geodetic observations. The obtained results show that the displacements, which continue to occur in the area of Wrocław have a cyclic character with 4–5 year long period of subsidence and 2–3 year long periods of stabilization or uplift. The displacement trends indicate that the area of the city gradually subsides in relation to the reference area located on the Fore-Sudetic Block.

scholarly journals Glacier–volcano interactions deduced by SAR interferometry

2001 ◽  
Vol 47 (156) ◽  
pp. 58-70 ◽  
Author(s):  
Helgi Björnsson ◽  
Helmut Rott ◽  
Sverrir Gudmundsson ◽  
Andrea Fischer ◽  
Andreas Siegel ◽  
...  
Keyword(s):  
Volcanic Activity ◽  
Surface Displacement ◽  
Vertical Displacement ◽  
Ice Cover ◽  
Sar Interferometry ◽  
Glacier Surface ◽  
Ice Flow ◽  
Radar Images ◽  
Ice Cap ◽  
Surface Displacements

AbstractGlacier-surface displacements produced by geothermal and volcanic activity beneath Vatnajökull ice cap in Iceland are described by field surveys of the surface topography combined with interferograms acquired from repeat-pass synthetic aperture radar images. A simple ice-flow model serves well to confirm the basic interpretation of the observations. The observations cover the period October 1996–January 1999 and comprise: (a) the ice-flow field during the infilling of the depressions created by the subglacial Gjálp eruption of October 1996, (b) the extent and displacement of the floating ice cover of the subglacier lakes of Grímsvötn and the Skaftá cauldrons, (c) surface displacements above the subglacier pathways of the jökulhlaups from the Gjálp eruption site and the Grímsvötn lake, (d) detection of areas of increased basal sliding due to lubrication by water, and (e) detection of spots of temporal displacement that may be related to altering subglacial volcanic activity. At the depression created by the Gjálp eruption, the maximum surface displacement rate away from the radar decreased from 27 cm d−1 to 2 cm d−1 over the period January 1997–January 1999. The observed vertical displacement of the ice cover of Grímsvötn changed from an uplift rate of 50 cm d−1 to sinking of 48 cm d−1, and for Skaftá cauldrons from 2 cm d to 25 cm d−1.

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