Detection and mapping co-seismic deformation induced by a light earthquake (M<5) using C-band SAR data (original) (raw)
Related papers
Earth Science Informatics, 2015
The island of Cephalonia, Western Greece, was struck by two strong seismic events, with magnitudes, ML= 5.8 and ML = 5.7 which occurred on Jan. 26, 2014 and Feb. 3, 2014 respectively. The first event was located near Argostoli's town, whereas the second one was located at the north part of Livadi village. These two strong earthquake events followed by smaller aftershocks provoking extensive crustal movements and structural damage effects. Differential Synthetic Aperture Radar Interferometry (DInSAR) is a powerful remote sensing tool for ground motion monitoring. The last two decades, DInSAR is widely applied to a variety of applications including natural hazards such as earthquakes. In 2007, a high resolution X-band satellite namely TerraSAR-X was launched. Due to its short revisit cycle of 11 days and its short wavelength, there is a good potential to capture faster surface movements. This study refers to the application of the DInSAR using TerraSAR-X strip map data to monitor the co-and post-seismic surface deformation caused by the second earthquake event. Hence, based on the interferometric processing of multiple scenes, several differential interferograms calculated showing the deformation patterns which caused before and after the seismic event. First results show that the main part of the island shows stability or a small uplift whereas the western part shows a significant deformation pattern. Those results permit to identify the local tectonic setting of the study area and investigate the reasons that some of settlements affected more
Mapping InSAR deformation of low and moderate earthquakes
2021
Low-to-moderate magnitude earthquakes often induce small ground displacement. For such events, ground deformation fields detected by SAR interferometry can be masked or not clearly discernible from the fringes distribution because of the presence of error sources, such as atmospheric artifacts and topographic residuals. We show two examples of low-moderate magnitude earthquakes, for which we adopted a new automatic tool for calculating the fringe pattern stemming from seismological data. The tool estimates the extent and the geographic position of the deformation by running a forward model of the seismic source, thus identifying the best SAR frame to be collected and the expected surface effects to better figure-out the outcomes of InSAR processing. We present the Mw 5.7 occurred in Greece and the Mw 5.4 occurred in Zagreb on 21 and 22 March 2020, respectively. For the Greek earthquake, the tool predicted a deformation close to the InSAR product, and gave evidences of atmospheric disturbances, thus providing information for inverse source modelling. The tool in the Zagreb event was used to infer the extent and location of the ground motion, that were used to identify the best SAR pair to be processed, being the SAR frames edge very close to the epicenter.
InSAR based deformation mapping of earthquake using Sentinel 1A imagery
Geocarto International, 2019
Development of Synthetic Aperture Radar (SAR) based satellites provide remedies to major geohazards under critical situations around the world. Sentinel 1A mission with the revisit period of 12 days helps to serve the objective in an effective manner. With the availability of Interferometric Wide Swath (IW) mode, Sentinel 1A mission is capable of monitoring the surface deformation using InSAR techniques. On November 12 th , 2017, an earthquake with a magnitude of 7.3 occurred in the Iran/Iraq border lead to the enormous disaster reaching over 500 victims. The study focuses on measuring the deformation caused due to earthquakes by using Differential SAR Interferometry (DInSAR). VV polarization of Sentinel Data and SRTM DEM are used as an input to GMTSAR for the development of interferogram. Based on the results obtained, it is found that a maximum of 85.1 cm deformation occurred and nearly 1500 km 2 of the area is severely affected.
Proceedings. 2005 IEEE International Geoscience and Remote Sensing Symposium, 2005. IGARSS '05., 2005
A seismic event of magnitude M w =6,0 struck the broader area of Athens on September 7, 1999, causing considerable damages to building and loss of many human lifes. The present study focus on the assessment of different co-seismic interferometric images in terms of magnitude and pattern of deformation recorded, in relation to parameters that could limit the accuracy of the results, such as the baseline, the temporal and spatial decorrelation and the altitude of ambiguity. A total number of six interferograms were produced covering different time span periods. It was noticed that the measurement of deformation as well as its pattern are highly depended on the interferometric pair chosen for the analysis and especially on temporal and spatial decorrelation. Thus the production of multiple co-seismic interferograms in order to constrain any possible misinterpretation is of great importance.
Multi-Temporal InSAR Analysis for Monitoring Ground Deformation in Amorgos Island, Greece
Sensors, 2020
Radar Interferometry is a widely used method for estimating ground deformation, as it provides precision to a few millimeters to centimeters, and at the same time, a wide spatial coverage of the study area. On 9 July 1956, one of the strongest earthquakes of the 20th century in the area of the South Aegean, occurred in Amorgos, with a magnitude of Mw = 7.7. The objective of this research is to map ground deformation in Amorgos island, using InSAR techniques. We conducted a multi-temporal analysis of all available data from 2003 to 2019 by exploiting historical ENVISAT SAR imagery, as well as the dense archive of Sentinel-1 SLC imagery. Persistent Scatterer Interferometry (PS) and Small Baseline Subset (SBAS) methods were implemented. Results of both data-sets indicate a small-scale deformation on the island. A multi-track analysis was implemented on Sentinel-1 data to decompose the line of sight velocities to vertical and horizontal. The central south coast is experiencing horizonta...
Journal of Applied Geophysics, 2009
Co-seismic interferometric analysis was performed to investigate the spatial and temporal evolution of ground deformation related to the aftershock sequence of the Athens 1999 earthquake (M w = 6.0). Differential interferograms (DInSAR) spanning different periods after the main seismic event showed variable ground deformation associated with the evolution of the post-seismic displacement field. Using ERS SAR images, four co-seismic differential interferograms were generated for the period from September to December of 1999, and spanning 16, 32, 67 and 102 days after the occurrence of the main shock. It was found that the cumulative ground deformation detected by DInSAR analysis was exponentially decreasing, following the declining rate of the post-seismic activity. The observed propagation of the ground deformation maxima towards the SE direction is consistent with the presence of clustered aftershock activity to the east of the epicentral area. The aforementioned evolution of deformation was also recognized by the observed expansion of the displacement field to the east.
ASEAN Engineering Journal
On April 22, 2019, an earthquake with a magnitude MW 6.1 struck the municipality of Castillejos in Zambales, the Philippines, and severely affected the province of Pampanga, which caused damage to commercial and residential structures reaching over 40 victims. This paper presents an approach for creating a pixel-based proxy damage assessment and displacement field maps to delineate the extent of ground surface displacements due to an earthquake. Specifically, this paper explored two change detection methods: the interferometric synthetic aperture radar (InSAR) technique and the coherence difference analysis method, using an open-source remote sensing software package and free SAR image data acquired by Sentinel-1 missions. Ground truth data were collected to substantiate the findings of the generated maps after the earthquake. Out of 7 surveyed damaged structures that were included in the National Disaster Risk Reduction and Management Council (NDRRMC) of the Philippines Situational...
Geosciences
We study the surface deformation following a moderate size M5+ earthquake sequence that occurred close to Tyrnavos village (Thessaly, Greece) in March 2021. We adopt the interferometric synthetic aperture radar (InSAR) technique to exploit several pairs of Sentinel-1 acquisitions and successfully retrieve the ground movement caused by the three major events (M5+) of the sequence. The mainshocks occurred at depths varying from ~7 to ~10 km, and are related to the activation of at least three normal faults characterizing the area previously unknown. Thanks to the 6-day repeat time of the Sentinel-1 mission, InSAR analysis allowed us to detect both the surface displacement due to the individual analyzed earthquakes and the cumulative displacement caused by the entire seismic sequence. Especially in the case of a seismic sequence that occurs over a very short time span, it is quite uncommon to be able to separate the surface effects ascribable to the mainshock and the major aftershocks ...