InSAR deformation monitoring

The paper presents an overview of the results of diagnostic and monitoring activities carried out in the last years through satellite radar interferometry (2011-2016) and in situ measurements (2017-2019) in the historical city of Gubbio, Italy. The study is aimed at contributing to understanding the potential of remote sensing technologies in measuring complex deformation phenomena in historic buildings, such as those caused by soil-structural interaction and earthquakes, considering the monumental Consoli Palace and the Town Walls as case studies. The research activities have been carried out within the European HERACLES project, funded in the framework of Horizon (2020) and aimed at proposing novel diagnostic monitoring solutions for enhancing heritage resilience against various types of hazards. Particular attention is focused on the cross-correlation of the outputs of satellite radar interferometry and in-situ structural monitoring data aimed at achieving engineering meaningful results supporting decision making and proactive interventions.

Regions of temperate oceanic climate have historically represented a challenge for the application of satellite-based multi-temporal SAR interferometry. The landscapes of such regions are commonly characterized by extensive, seasonally-variable vegetation coverage that can cause low temporal coherence and limit the detection capabilities of SAR imagery as acquired, for instance, by previous ERS-1/2 and ENVISAT missions. In this work, we exploited the enhanced resolution in space and time of the recently deployed Sentinel-1A/B SAR satellites to detect and monitor ground motions occurring in two study areas in the Republic of Ireland. The first, is a ~1800 km2 area spanning the upland karst of the Clare Burren and the adjacent mantled lowland karst of east Galway. The second, is an area of 100 km2 in Co. Meath spanning an active mine site. The available datasets, consisting of more than 100 images acquired in both ascending and descending orbits from April 2015 to March 2018, were pro...

Özet;
Karapınar, Türkiye'nin tarımsal ve ekonomik açıdan önemli bir üretim bölgesi olan Konya Kapalı Havzasının merkezinde yer almaktadır. Bölgede, iklim özellikleri ile uyuşmayan yüksek miktarda su tüketimine sahip yoğun tarım faaliyetlerinin gerçekleştirilmesi, iklim değişikliği etkileri, bölgedeki yeraltı su kaynaklarının giderek azalıyor olması, yeraltından çekilen suyun yağışlar ile geri beslenememesi doğal yaşamı ve tarımın geleceğini tehdit altına almaktadır. Bu parametrelere Karapınar'ın jeolojik yapısı da eklendiği zaman bölgede zemin çökmeleri ve obruk oluşumları gibi çevresel sorunlar ortaya çıkmaktadır. Doktora tez çalışması kapsamında, Karapınar ve çevresindeki yaşanan bu sorunların kontrol altına alınabilmesi ve bölgede yapılacak olan planlama çalışmalarına kaynak oluşturabilecek verilerin ve haritaların oluşturulması hedeflenmiştir. Çalışmalar envanter verilerinin temini, arazi örtüsü/kullanımı değişimleri, InSAR uygulaması ve Obruk Duyarlılık Haritası (ODH) üretimi olmak üzere dört aşamada gerçekleştirilmiştir. İlk olarak, bölgede mevcut tüm obruklara (301) ait envanter verisi toplanmış ve bu verinin Fusion Tables hizmetleri ile web tabanlı sistem üzerinden paylaşılmasının alt yapısı oluşturulmuştur. Daha sonra 29 yıllık (1987-2016) periyotta meydana gelen arazi örtüsü/kullanımı değişimleri belirlenmiş ve bu değişikliğin yeraltı suyu ve yağışlar ile olan ilişkileri ortaya konmuştur. InSAR uygulaması başlığı altında, Karapınar ve çevresine ait belirli periyotlar ile elde edilen Cosmo-SkyMed (2016), Sentinel-1 (2014-2017) uydu verilerinden oluşan toplam 37 adet SAR görüntüsü ile deformasyon analizi gerçekleştirilmiştir. Bu kapsamda yıllık -55 mm'ye kadar zemin çökmeleri tespit edilmiştir. Ayrıca X band Cosmo-SkyMed verileri ile çalışma sahası içerinde bulunan alüvyonel bölgelerde tarım faaliyetlerine bağlı olarak gözlemlenen çökmeler net bir şekilde belirlenmiştir. Son olarak, muhtemel obruk alanlarının belirlenebilmesi için jeoloji, yükseklik, eğim, bakı, arazi kullanımı/örtüsü, yeraltı suyu seviye(YSS) değişimi, kuyu yoğunluğu, Faya Olan Uzaklık (FOU), Drenaja Olan Uzaklık (DOU), Karstik yapı oluşturabilecek birim kalınlığı, yağış, PH gibi temel parametrelere ek olarak bölgenin deformasyon haritasının bir faktör olarak dahil edildiği çalışma sonucunda Obruk Duyarlılık Haritası (ODH) üretilmiştir. Elde edilen sonuç haritasının bölgede oluşan güncel obruklar ile yüksek uyuşum gösterdiği belirlenmiştir.

Abstract;
Karapinar is Turkey's agricultural and economically important production region and located in the middle of Konya Closed Basin. In the region, the natural life and the future of agriculture are threatened by the fact that underground water resources are gradually diminishing, the realization of intensive agricultural activities that are incompatible with climate characteristics and have high water consumption, climate change effects. In addition to all these parameters, when considering the geological structure of Karapinar, it reveals environmental problems such as land subsidence and sinkhole formation in the region. In this doctoral thesis, controlling these problems in Karapinar and its surrounding, obtaining data which can be sources for planning studies of the region and creating maps from that data has been worked. For this purpose, four studies were carried out, such as supplying the inventory data, Land Use/Land Cover (LULC) changing, application of InSAR and production of sinkhole susceptibility map. Firstly, inventory data of 301 sinkholes, which were not revealed by any study before, have been collected. Thus, this study has created a substructure to share these inventory data with using Fusion Tables services. Afterward, LULC changes of 29 years (1987-2016) and its relation to groundwater, and precipitation are revealed. Under the title of InSAR application, totally 37 SAR images belonging to Cosmo-SkyMed (2016) and Sentinel-1(2014-2017) satellites acquired for Karapınar and its surroundings with certain periods were detected and -55 mm/year land subsidence was noticed. Furthermore, land subsidence due to agricultural activities was clearly observed in the alluvial regions located in the study area with X band Cosmo-SkyMed data. Finally, a sinkhole susceptibility map was produced to determine the potential sinkhole areas including basic parameters such as geology, elevation, slope, aspect, LULC, groundwater level change, well density, distance to faults, distance to drainage, water-soluble rock thickness, precipitation, PH and also, deformation map of the Region was added as a factor. It has been determined that the obtained result map shows high agreement with the current sinkholes in the region.

Studi tentang pemantauan penurunan permukaan tanah sangat penting untuk mitigasi bencana. Dalam penelitian ini menggunakan 33 data synthetic aperture radar (SAR) Sentinel-1A yang digabungkan sehingga menghasilkan atmospheric phase screen (APS) kemudian dilakukan analisis multi-temporal sehingga menghasilkan interferometry SAR (InSAR) time series mulai dari Oktober 2014 hingga Maret 2017 dan April 2017 hingga September 2018 dengan threshold 0,8. InSAR time series dapat mengetahui gejala penurunan permukaan tanah secara cepat dan praktis. Kecepatan penurunan permukaan tanah di lapangan panasbumi Ulubelu terbesar -10 mm/tahun dengan rata-rata -2,9 mm/tahun (Oktober 2014 - Maret 2017) dan -3,3 mm/tahun (April 2017 - September 2018) dalam radius 10 km dengan titik pusat X=453.558,26 m, Y=9.412.437,83 m, Zona 48 S. Penurunan ini didominasi karena pengaruh alamiah akibat pemadatan batuan teralterasi. Selain itu, struktur geologi berupa patahan dan perbedaan litologi serta pembebanan permukaan juga mempengaruhi penurunan permukaan tanah. Daerah yang mengalami penurunan permukaan tanah berada di pemukiman Pekon Muara Dua, Pekon Pagar Alam, Pekon Karang Rejo dan Pekon Gunung Tiga. Dari data pembanding anomali 4D microgravity (Juli 2012 - September 2013) terdapat korelasi antara anomali rendah dengan daerah yang mengalami penurunan permukaan tanah.

This paper presents an analysis of the integration between interferometric and intensity-offset tracking-based SAR remote sensing for landslide hazard mitigation in the Italian Alps. Despite the advantages of Synthetic Aperture Radar Interferometry (InSAR) methods for quantifying landslide deformation, some limitations remain. The temporal decorrelation, the 1-D Line Of Sight (LOS) observation restriction, the high velocity rate and the multi-directional movement properties make it difficult to monitor accurately complex landslides in areas covered by vegetation. Therefore, complementary and integrated approaches, such as offset tracking-based techniques, are needed to overcome these InSAR limitations for monitoring ground surface deformations. As sub-pixel offset tracking is highly sensitive to data spatial resolution, the latest generations of SAR sensors, such as TerraSAR-X and COSMO-SkyMed, open interesting perspective for a more accurate hazard assessment. In this paper, we consider high-resolution X-band data acquired by the COSMO-SkyMed (CSK) constellation for Permanent Scatterers Interferometry (PSI), Multi-Aperture Interferometry (MAI) and offset tracking processing. We analyze the offset tracking techniques considering area and feature-based matching algorithms to evaluate their applicability to CSK data by improving sub-pixel offset estimations. To this end, PSI and MAI are used for extracting LOS and azimuthal displacement components. Then, four well-known area-based and five feature-based matching algorithms (taken from computer vision) are applied to 16 X-band corner reflectors. Results show that offset estimation accuracy can be considerably improved up to less than 3% of the pixel size using the combination of the different feature-based detectors and descriptors. A sensitivity analysis of these techniques applied to CSK data to monitor complex landslides in the Italian Alps provides indications on advantages and disadvantages of each of them.

Active deformation zones on the earth surface continue to threaten the life in the past, present and the future. The
main two of these disasters are earthquake and landslide that are the reason of most human loss. The geological
and multi-disciplinary research related to these kinds of disasters that occurred in the early 20th century has
gained further momentum with events that affect people's lives significantly. Thanks to scientific andtechnological advances, different kinds of studies have led to new insights to the earth sciences. Among these
studies especially in the last decades, Interferometric Synthetic Aperture Radar (InSAR) technique has become
an effective geodetic method for determining surface deformation. This technique determines deformation rate
from various surface movements using radar images. From the point of view of examining spatial distribution of
surface deformations, we search for landslides in our country. Many urban areas in Turkey are affected by
landslides. For example, in Denizli, Babadag town center and close surroundings, various landslides have been
observed. We examined landslides which are located in Gundogdu district. Gundogdu landslide is significant for
our study due to the density of the residential area. From the previous studies a movement about 4-10 cm per
year is determined.
In this study, it is aimed to detect amount and direction of horizontal movement occurred in Babadag Gundogdu
district based on InSAR technique. This study shows that the deformations are still developing in the different
parts of Babadag and its surroundings. For mapping deformations through interferograms, ALOS PALSAR radar
images were delivered from the European Space Agency under Category-1 project (Project ID: 14218) and some
image pairs were created to examine the surface deformations within the study area. The interferograms which
were processed with the sarproz software showed high coherence, and the surface deformations were interpreted
using these interferograms.
Keywords: Landslide, InSAR, Babadağ (Gündoğdu), ALOS PALSAR

Gempa Padang pada tanggal 30 September 2009 dengan kekuatan Mw 7.6 yang berpusat pada pesisir pantai barat Sumatera, merupakan salah satu bentuk gempa akibat patahan naik (thrust fault) pada kedalaman sekitar 80 kilometer. Kejadian ini sejak beberapa tahun lalu telah dianalisis dengan metode Interferometric Synthetic Aperture Radar (InSAR) tetapi belum memberikan hasil yang mengindikasikan terjadinya perubahan permukaan akibat gempa ini. Penelitian ini menggunakan perangkat lunak bebas terbuka (open source software) GMTSAR untuk mengolah data satelit ALOS-PALSAR terkait dengan waktu kejadian gempa. Metode yang digunakan adalah dengan melakukan proses pemfokusan data SAR, transformasi koordinat ke sistem radar menggunakan infromasi orbit yang teliti, image alignment, interferome dan phase unwrapping menggunakan algoritma SNAPHU. Berbeda dengan hasil sebelumnya yang dipublikasikan oleh Geographical Survey Institute (GSI) Jepang yang tidak mendeteksi perubahan permukaan dengan metode InSAR, penelitian ini mampu mendeteksi terjadinya perubahan permukaan yang ditandai dengan perubahan fase pada arah pemantauan satelit (line of sight) sekitar 8 cm.

Landslide is one of the natural hazards that pose maximum threat for human lives and property in mountainous regions. Mitigation and prediction of this phenomenon can be done through the detection of landslide-susceptible areas. Therefore, an appropriate landslide analysis is needed in order to map and consequently understand the characteristic of this disaster. One of the recent popular remote sensing techniques in deformation analysis is the differential interferometric synthetic aperture radar which is popularly known as DInSAR. Due to the mass vegetation condition in Malaysia, a long-wavelength synthetic aperture radar (∼24 cm) is required in order to be able to penetrate through the forests and reach the bare land. For that reason, ALOS PALSAR HH imagery was used in this study to derive a deformation map of the Gunung Pass area located in the tropical forest of the Cameron Highlands, Malaysia. In this study, the ascending orbit ALOS PALSAR images were acquired in September 2008, January 2009 and December 2009. Subsequently the displacement measurements of the study site (Gunung Pass) were calculated. The accuracy of the result was evaluated through its comparison with ground truth data using the R2 and root mean square error (RMSE) methods. The resulted deformation map showed the landslide locations in the study area from interpretation of the results with 0.84 R2 and 0.151 RMSE. The DInSAR precision was 11.8 cm which proved the efficiency of the proposed method in detecting landslides in a tropical country like Malaysia. It is highly recommended to use the proposed method for any other deformation studies.

The growing volume of synthetic aperture radar (SAR) imagery acquired by satellite constellations creates novel opportunities and opens new challenges for interferometric SAR (InSAR) applications to observe Earth's surface processes and geohazards. In this paper, the Parallel Small BAseline Subset (P-SBAS) advanced InSAR processing chain running on the Geohazards Exploitation Platform (GEP) is trialed to process two unprecedentedly big stacks of Copernicus Sentinel-1 C-band SAR images acquired in 2014-2020 over a coastal study area in southern Italy, including 296 and 283 scenes in ascending and descending mode, respectively. Each stack was processed in the GEP in less than 3 days, from input SAR data retrieval via repositories, up to generation of the output P-SBAS datasets of coherent targets and their displacement histories. Use-cases of long-term monitoring of land subsidence at the Capo Colonna promontory (up-2.3 cm/year vertical and-1.0 cm/year east-west rate), slow-moving landslides and erosion landforms, and deformation at modern coastal protection infrastructure in the city of Crotone are used to: (i) showcase the type and precision of deformation products outputting from P-SBAS processing of big data, and the deriva-ble key information to support value-adding and geological interpretation; and (ii) discuss potential and challenges of big data processing using cloud/grid infrastructure.

Remote sensing using satellite-based Interferometric Synthetic Aperture Radar (InSAR) provides a unique opportunity for monitoring slope deformation during the assessment of large open pit slope kinematics. This case study presents the results of an integrated numerical modelling-monitoring investigation of a large open pit slope at Bingham Canyon Mine, Utah, USA. Development of the pit slope geomechanical model involved the use of a two-dimensional finite-discrete element code incorporating a discrete fracture network. The analysis of mapping data from mine reports provided a solid foundation to understand the joint fabric and develop a discrete fracture network, which was imported into the numerical model and explicitly simulated. This approach proved successful in analysing slope deformation through combined brittle fracture and sliding along non-daylighting shear zones, previously identified through subsurface monitoring. Development of kinematic release along the shear zones was simulated by a combination of internal deformation, intact rock bridge fracture and shearing within the assumed joint network. To simulate ongoing slope deformation, the key driving factors had to be considered with several simulations incorporating the potential seasonal effect of a perched aquifer. A major outcome from the study was the development of techniques to interpret InSAR data and comparison of the results with mine-based geodetic monitoring. This provides a valuable future constraint for geomechanical modelling of large pit slopes directly incorporating the key aspects of the slope deformation mechanisms.

Satellite interferometric synthetic aperture radar (InSAR) monitoring campaigns were performed on the archaeological heritage of the Roman Forum, Palatino and Oppio Hills in the centre of Rome, Italy, to test the capabilities of persistent scatterer interferometry techniques for the preventive diagnosis of deformation threatening the structural stability of archaeological monuments and buried structures. ERS-1/2 and RADARSAT-1/2 SAR images were processed with the permanent scatterers InSAR (PSInSAR) and SqueeSAR approaches, and the identified measurement points (MP) were radar-interpreted to map the conservation criticalities in relation to the local geohazard factors and active deterioration processes. The multi-temporal reconstruction of past/recent instability events based on the MP deformation time series provided evidences of stabilization for the Domus Tiberiana as a consequence of recent restoration works, as well as of persistent deformation for the Temple of Magna Mater on the Palatino Hill and the structures of the Baths of Trajan on the Oppio Hill. Detailed time series analysis was also exploited to back monitor and understand the nature of the 2010 collapse that occurred close to Nero's Golden House, and to establish an early-stage warning procedure useful to preventively detect potential instability.

Displacement maps from multitemporal InSAR (MTI) are usually noisy and fragmented. Thresholding on ensemble coherence is a common practice for identifying radar scatterers that are less affected by decorrelation noise. Thresholding on coherence might, however, cause loss of information over the areas undergoing more complex deformation scenarios. If the discrepancies in the areas of moderate coherence share similar behavior, it appears important to take into account their spatial correlation for correct inference. The information over low-coherent areas might then be used in a similar way the coherence is used in thematic mapping applications such as change detection. We propose an approach based on data mining and statistical procedures for mitigating the impact of outliers in MTI results. Our approach allows for minimization of outliers in final results while preserving spatial and statistical dependence among observations. Tests from monitoring slope failures and undermined areas performed in this work have shown that this is beneficial: 1) for better evaluation of low-coherent scatterers that are commonly discarded by the standard thresholding procedure, 2) for tackling outlying observations with extremes in any variable, 3) for improving spatial densities of standard persistent scatterers, 4) for the evaluation of areas undergoing more complex deformation scenarios, and 5) for the visualization purposes.

Using InSAR (Interferometric Synthetic Aperture Radar) data collected from the newly operational Sentinel-1A satellite, I measured coseismic and post-seismic displacements caused by the August 2014 Napa Valley earthquake in the San Francisco Bay Area, California. By combining these measurements with GPS data and further InSAR data from Cosmo-Skymed, I performed slip dislocation modelling using a new, combined direct inversion method that takes advantage of overlapping acquisition times from different datasets to disentangle early postseismic displacements on the fault plane at depth from the overwhelming coseismic slip. This resulted in a temporally precise model that allowed the temporal evolution of deformation on the fault plane to be studied from day 1 of the event. This work contributed towards a paper by Wright et al. (in prep.) and expands upon it by adding detail to early postseismic fault activity. This improved the constraints on, and reduced assumptions relating to, the modelling of a time constant to the temporal evolution of slip on fault patches. This work is among the first to be undertaken using Sentinel-1A and provides important information on seismic hazard by increasing the scientific knowledge base on early postseismic fault activity and the distribution of aftershocks following an event in the San Francisco Bay area. This is a region with a 63% probability of >M6.7 earthquake by 2036 (Field et al., 2009) and over 7 million inhabitants (U.S. Census Bureau, 2010).

In Japan, several cities endured severe damage due to soil liquefaction phenomenon, which was developed in association with the massive shaking of the 2011 Tohoku earthquake. Measuring soil lique-faction deformations was not an easy task, mainly because of the total loss of signal coherence in the affected regions. In this paper, we present our approach to estimate the deformations associated with soil liquefaction using interferometric synthetic aperture radar techniques. We use a stack of coseismic inter-ferograms to identify the reliable pixels in the damaged areas using permanent scatterers technique. Then, we estimate and remove the preseismic mean velocity and DEM error components. Finally, we identify the liquefaction deformation component using least squares inversion and spatial phase filtering. We test the performance of the proposed approach using synthetic data, simulating the effects of soil liquefaction. The simulation results show a RMSE of the liquefaction deformation of 5.23 mm. After that, we estimate the deformation associated with soil liquefaction in Urayasu city, Japan, using ALOS–PALSAR data. The proposed approach allows a prompt estimation of the liquefaction deformation by utilizing the SAR images archives with only one postseismic SAR image.

We greatly appreciate the thoughtful comments by Andrew Sowter and Francesca Cigna [1] on our paper [2]. Unfortunately, we overlooked the ISBAS acronym during the revision process of the article. Therefore, we would suggest to use the acronym of ESBAS (Enhanced Small BAseline Subset) for our method presented in Vajedian et al. [2]

ABSTRACT

With the help of space geodesy techniques such as InSAR (Interferometric synthetic aperture radar) and GNSS (Global navigation satellite system), a number of models have been developed for the physical properties and rheology of upper crust and other layers of the lithosphere. These models are also used in InSAR studies for interseismic period in order to approach earthquake predictions. However, large earthquakes that release total strains in any fault segment occur over a period of several hundred to several thousand years, while deformation observations, which usually span a maximum period about ten years, represent a very small time interval in a complete earthquake cycle. To use these short-term deformation observations in seismic hazards, better models of how the fault zones deform in space and time are needed. Consequently, InSAR studies focusing on the deformations around the main segments and other structural elements in the tectonic basins and fault zones, also addressing the relationship between the observed deformations and the behavior of these structural elements, may be very important in terms of earthquake predictions. In this respect, we aimed in our paper to associate the tectonic characteristics of the Erzincan basin, a part of the North Anatolian Fault (NAF) zone, with the deformation clusters determined by the InSAR technique. To do this, instead of modern usage of InSAR technique in which hundreds of interferograms are calculated, we preferred its old-school usage which allows us to evaluate deformation areas in terms of structural geology by a few interferograms focused into the basin.

In the last century, two destructive earthquakes happened in the Erzincan tectonic subsidence basin (1939, M: 7.8 - 8.2 and 1992, M:6.8). Previous studies suggest that the basin forms as a result of pull-apart type opening along the NAF zone. The Ovacık Fault (OF) activity widens the basin. In the east of the basin, there is a seismic gap zone extending for at least 75 km along the NAF. This seismic gap is thought to be made up of two main segments which are the nearly 22 km long Sansa in the west and the 53 km long Yedisu in the east.

In our study we compared the deformation areas, observed on the interferogram generated by Differential SAR interferometry (DInSAR) technique from the ERS-1 satellite SAR data, acquired in the postseismic period of 2.5 years between 1993-1995 following the March 13 1992 earthquake in Erzincan (M: 6.8), with the structural aspects of the basin. Interferometric deformation findings were observed on tectonic zones near the boundaries of Erzincan plain. The amounts of displacements corresponding subsidence in vertical components of direction are higher around the northern boundary of the basin than those on the southern boundary. Along the northern boundary of the basin and the NAF zone, the deformations that occur in the northwest and north of Erzincan city have lower slip rates relative to deformations in the east and northeast. This sheds light on the development of transpressive zones and push-up structures in the relatively slower northwestern part while both areas collapse together. On the interferogram, deformation clusters are not observed in the eastern part of the Erzincan basin. Therefore, as it approaches the seismic gap zone towards the east of the basin, the NAF segment is thought to exhibit a behavior with lower slip rates.

We have also shortly mentioned a quaint and venerable, a so said science-antique, field report (Stchepinsky et al., 1940) established under very harsh conditions that comprises 185 km long surface rupture mapping of the 1939 Erzincan earthquake (M: 8.0) between Ekşisu (Erzincan) and Bahçe village (Koyulhisar, Sivas).

ÖZ

InSAR (İnterferometrik Sentez Açılımlı Radar) ve GNSS (Küresel Navigasyon Uydu Sistemi) gibi uzay jeodezisi tekniklerinin sağladığı verilerle üst kabuk ve litosferin diğer katmanlarının fiziksel özellikleri ve reolojisine yönelik çok sayıda model geliştirilmiştir. Bu modeller yine deprem tahminlerine yaklaşımda bulunmak üzere intersismik döneme yönelik InSAR çalışmalarında kullanılmaktadır. Ancak herhangi bir fay segmentinde gerilimleri boşaltan büyük depremler, birkaç yüz ile birkaç bin yıllık bir süre aralığında meydana gelirken, genellikle en çok on yıllık bir zaman aralığını kapsayan deformasyon gözlemleri tam bir deprem çevriminde oldukça küçük bir zaman aralığını temsil ederler. Bu kısa süreli deformasyon gözlemlerini sismik tehlikede kullanmak için, fay zonlarının uzayda ve zamanda nasıl deforme olduğuna dair daha iyi modellere ihtiyaç duyulur. Dolayısıyla, tektonik havzalar ve fay zonlarındaki ana segmentler ile diğer yapısal unsurlar etrafındaki deformasyonlara odaklanan ve aynı zamanda gözlemlenen deformasyonlar ile bu yapısal unsurların arasındaki ilişkiyi de ele alan InSAR çalışmaları, deprem tahminleri açısından oldukça önem arz edebilir. Bu bağlamda makalemizde, Kuzey Anadolu Fayı (KAF) üzerinde bulunan Erzincan havzasının tektonik özelliklerini, InSAR ile belirlenmiş deformasyon alanları ile birlikte ele alarak değerlendirmeyi düşündük. Buna yönelik olarak, InSAR tekniğinin çok büyük alanları ve yüzlerce interferogram analizini kapsayan modern kullanımı yerine, havza içine odaklanmış az sayıda interferogramla belirlenen deformasyon alanlarının yapısal jeoloji açısından değerlendirildiği başlangıçtaki eski usül kullanımını tercih ettik.

Erzincan tektonik çökme havzasında son yüzyılda iki yıkıcı deprem meydana gelmiştir (1939, M: 7.8 - 8.2 ve 1992, M:6.8). Önceki çalışmalar, havzanın KAF zonu boyunca çek-ayır tipinde bir açılmanın sonucu olarak oluştuğunu göstermektedir. Ovacık fayı (OF) aktivitesi havzayı genişletmektedir. Havzanın doğusunda KAF boyunca en az 75 km uzanan bir sismik boşluk zonu bulunmaktadır. Bu sismik boşluk hattının, batıda yaklaşık 22 km uzunluğundaki Sansa ve doğuda yaklaşık 53 km uzunluğundaki Yedisu olmak üzere, iki ana segmentten meydana geldiği düşünülmektedir.
Çalışmamızda, 13 Mart 1992 tarihindeki Erzincan depremi (M = 6.8) sonrasındaki yaklaşık 2.5 yıllık postsismik bir dönem (1993-1995) için, ERS-1 uydusunun SAR verilerinden Farksal İnterferometrik SAR (DInSAR) tekniği ile üretilen bir interferogramda belirlenen deformasyon alanlarını, havzanın yapısal jeoloji unsurlarıyla karşılaştırdık. İnterferometrik deformasyon bulguları Erzincan ovasının kenarlarına yakın tektonik hatlar üzerinde belirginleşmişlerdir. Dikey yön bileşenlerinde çökmeye karşılık gelen yerdeğiştirme miktarları, havzanın kuzey kenarı çevresinde, güney kenarındakilerden daha yüksektir. Havzanın kuzey kenarı ve KAF zonu boyunca, Erzincan kent merkezinin kuzeybatısı ve kuzeyinde gelişen deformasyonlar, doğusu ve kuzeydoğusunda gelişen deformasyonlara göreceyle daha düşük hız ve seviyelerdedir. Bu, her iki alanın birlikte çökerlerken, göreceyle daha yavaş çöken kuzeybatı kesiminde transpresif zonların ve push-up yapılarının gelişmesine ışık tutmaktadır. İnterferogramda, Erzincan ovasının yaklaşık doğu çıkışından itibaren deformasyon gelişimi gözlenmemektedir. Bu nedenle havzanın doğusuna doğru ilerlerken sismik boşluk zonuna yaklaştıkça, KAF segmentinin daha düşük kayma miktarlarına sahip olan bir davranış sergilediği düşünülmüştür.

Çalışmamızda ayrıca, 1939 Erzincan depreminin (M: 8.0) Ekşisu (Erzincan) - Bahçe Köyü (Koyulhisar, Sivas) arasında 185 km uzunluğundaki yüzey kırığı haritalamasını içeren, oldukça zor şartlar altında üretilmiş hayranlık ve saygı uyandıran bilim-antik özellikteki eski bir saha raporuna (Stchepinsky vd., 1940) kısaca yer verilmiştir.

After two decades of existence of SAR satellites, their data processed by interferometric techniques (InSAR) allows a sensitive detection of terrain movements. Various projects have risen towards detection of landslide activity and thus possibility of early warning based on SAR data. The ability of InSAR techniques to detect a slope stability is limited and depends on an orientation of slope, a rate of movement, ratio of vegetation cover and temporal and spatial resolution of SAR images. This paper presents common issues found in past projects of the team of authors observing landslides using available satellite SAR data processed by various InSAR techniques. It is demonstrated that in some cases the basic differential InSAR combining two images only provides more valuable information compared to advanced multi-temporal InSAR techniques. The paper aims at providing guidelines for maximally successful detection of landslide activity and to introduce pros and cons of the InSAR as a me...

Land surface displacement caused by landslides is among the most damaging phenomena in northern Morocco. In this paper, we measure ground deformation in the Chefchaouen area which is a zone characterized by geological formations and structurally complex losses that promote instability (landslide, mudflow, block falls, etc.) leading to slow to extremely slow deformation phenomena, which require an interferometric study, using the DinSAR (dif-ferential interferometric synthetic Aperture Radar) technique with sentinel 1 images in bance C, which is a powerful tool for the detection and analysis of interferences and monitoring of ground deformations. We worked on four areas of the study area. Its points are provided by the direction of the roads, which generates Interferograms and then deformation maps with precision in mm/year.

In this article, satellite radar data are analysed to control the deformation of the buildings of Murcia City (SE Spain) affected by subsidence. This phenomenon has occurred as a result of groundwater overexploitation in drought periods, and special attention is paid to the most recent drought which occurred between 2005 and 2008. In the first part of this work, the study area is presented followed by a description of the characteristics and effects of subsidence on the buildings of the urban area. Persistent scatterer interferometry is used to process a satellite base radar dataset measuring the temporal and the spatial evolution of subsidence. These results are analysed with respect to several factors that control subsidence mechanisms: water table decrease, thickness of the compressible layer and the type of foundation of the buildings. To validate these results, a detailed structural damage analysis of several buildings is presented. According to the results presented in this work, it may be concluded that damage of buildings is triggered by soil consolidation due to groundwater overexploitation, demonstrating that the inclusion of this technique can be particularly interesting in structural monitoring framework of civil infrastructures, as a complementary tool to control subsidence damage.

The Methana volcano in Greece belongs to the western part of the Hellenic Volcanic Arc, where the African and Eurasian tectonic plates converge at a rate of approximately 3 cm/year. While volcanic hazard in Methana is considered low, the neotectonic basin constituting the Saronic Gulf area is seismically active and there is evidence of local geothermal activity. Monitoring is therefore crucial to characterize any activity at the volcano that could impact the local population. This study aims to detect surface deformation in the whole Methana peninsula based on a long stack of 99 Sentinel-1 C-band Synthetic Aperture Radar (SAR) images in interferometric wide swath mode acquired in March 2015–August 2019. A Multi-Temporal Interferometric SAR (MT-InSAR) processing approach is exploited using the Interferometric Point Target Analysis (IPTA) method, involving the extraction of a network of targets including both Persistent Scatterers (PS) and Distributed Scatterers (DS) to augment the mo...

In this study, regarding the shallow earthquake (Mw=6.6) on July 21, 2017 between Kos (Greece) and Bodrum (Turkey), InSAR technique is used to determine relative vertical displacements. Data was acquired from ESA’s website. The model is built by geodetic data from Sentinel 1B interferograms, processed by SNAP software. Step by step processes were explained. Surface deformation reached about 10 cm at Bodrum vicinity. Results were compared with other published studies.

volcano dome InSAR time series deformation infrared degassing and cooling Colima Dome building activity is common at many volcanoes and due to the gravitational instability, a dome represents one of the most hazardous volcanic phenomena. Shallow volcanic processes as well as rheological and structural changes of the dome affecting the fluid transport have been linked to transitions in eruptive activity. Also, hydrothermal alteration may affect the structural integrity of the dome, increasing the potential for collapse. However, mapping the deformation and details of fluid escape at the summit of steep sloped volcanoes and integrating these with other types of data is challenging due to difficult access and poor coverage. Here we present for the first time the near-vertical and near-horizontal surface deformation field of a quiescent summit dome and the relationships with degassing and topographic patterns. Our results are derived from high resolution satellite radar interferometry (InSAR) time series based on a year of TerraSAR-X SpotLight acquisitions and Structure from Motion (SfM) processing of overflight infrared data at Volcán de Colima, Mexico. The identified deformation is dominated by localized heterogeneous subsidence of the summit dome exceeding rates of 15 cm/yr, and strongly decreasing over the year 2012, up to the renewal of explosive and extrusive activity in early 2013. We tentatively attribute the deformation to the degassing, cooling and contraction of the dome and shallow conduit material. We also find that the results strongly differ depending on the chosen InSAR time series method, which potentially overprints the true physical complexities of small scale, shallow deformation processes. The combined interpretation of the deformation and infrared data reveals a complex spatial relationship between the degassing pathways and the deformation. While we observe no deformation across the crater rim fumaroles, discontinuities in the deformation field are more commonly observed around the dome rim fumaroles and occasionally on the dome upper surface. We propose that the deformation pattern is also linked to processes controlling the fumarole formation and distribution (topography, permeability and volcanic activity), and the lack of direct relationships may be explained by how the influence of these processes varies across the volcanic summit. The presented work provides a new approach for safely monitoring the activity and stability of internal dome structures, as well as for constraining and validating models of dome degassing pathways and densification processes.

We present a method for inferring time-dependent three-component surface deformation fields given a set of geodetic images of displacements collected from multiple viewing geome-tries. Displacements are parameterized in time with a dictionary of displacement functions. The algorithm extends an earlier single-component (i.e., single line of sight) framework for time-series analysis to three spatial dimensions using combinations of multitemporal, multigeometry interferometic synthetic aperture radar (InSAR) and/or pixel offset (PO) maps. We demonstrate this method with a set of 101 pairs of azimuth and range PO maps generated for a portion of the Rutford Ice Stream, West Antarctica, derived from data collected by the COSMO-SkyMed satellite constellation. We compare our results with previously published InSAR mean velocity fields and selected GPS time series and show that our resulting three-component surface displacements resolve both secular motion and tidal variability. Index Terms— 3-D analysis, ocean tides, pixel offsets (POs), Rutford ice stream (RIS), synthetic aperture radar (SAR), time-series analysis.

We propose a methodology using interferometric synthetic aperture radar (InSAR) time series analysis and a
single GPS station to estimate the coseismic and postseismic crustal deformations in the Kanto region, Japan,
which has been affected by the 2011 Tohoku earthquake. The proposed methodology depends on choosing a
proper deformation trend(s) to accurately describe the earthquake deformation signature by studying the
deformation time series of a single GPS station. The modeled deformation trend is subtracted from the
unwrapped phase maps to separate the main deformation signature fromthe imposed errors. Some deformation
components, not described by the model(s), will leak to the residual phase maps which will be subjected to
temporal and spatial filtering. The final corrected unwrapped phasemaps are estimated by restoring themodeled
deformation trend to the filtered residual phase maps and finally the deformation time series is estimated using
a least squares technique. The proposed methodology was designed to retrieve complex and fine surface
deformations in areas that have been affected by large dominating deformation signatures and contain at a least
single GPS station. The methodology was tested using Envisat-ASAR C-band images and validation was carried
out using GPS stations resulting in a mean RMS error of 6.9 mm. The estimated deformation time series shows a
differential postseismic deformation pattern that can be attributed to an off Boso peninsula motion triggered by
the 2011 Tohoku earthquake.