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Sample records for ground deformation monitoring

  1. Space-based monitoring of ground deformation

    Science.gov (United States)

    Nobakht Ersi, Fereydoun; Safari, Abdolreza; Gamse, Sonja

    2016-07-01

    Ground deformation monitoring is valuable to understanding of the behaviour of natural phenomena. Space-Based measurement systems such as Global Positioning System are useful tools for continuous monitoring of ground deformation. Ground deformation analysis based on space geodetic techniques have provided a new, more accurate, and reliable source of information for geodetic positioning which is used to detect deformations of the Ground surface. This type of studies using displacement fields derived from repeated measurments of space-based geodetic networks indicates how crucial role the space geodetic methods play in geodynamics. The main scope of this contribution is to monitor of ground deformation by obtained measurements from GPS sites. We present ground deformation analysis in three steps: a global congruency test on daily coordinates of permanent GPS stations to specify in which epochs deformations occur, the localization of the deformed GPS sites and the determination of deformations.

  2. Monitoring of Deformation in Ground Before and After Tunnel Excavation

    Science.gov (United States)

    Eren, Mehmet; Hilmi Erkoç, Muharrem

    2017-04-01

    As population increase in metropolitan city, we need transportation and transmission tunnel. In this context, the engineers and administors attach impotance to building and planning underground-tunnel. Moreover, we must at regular intervals monitoring to deformation in underground-tunnel for quality and safety. Firstly, a deformation monitoring network is designed as perpendicular to the tunnel main axis. Secondly, the prescribed number of deformation measurements must be made. Finally, the deformation analysis is evaluated and its results is interpreted. This study investigates how deformation in monitoring network during and after tunnel excavate change.For this purpose, a deformation monitoring network of 18 object point and 4 reference point was established. Object points networks was designed steeply to the tunnel main axis as 3 cross section. Each cross section consisted of 3 point left, 2 point right and 1 point at the flowing line. Initial conditional measurement was made before tunnel excavation. Then the deformation measurement was made 5 period (1 period measured after tunnel excavate). All data sets were adjusted according to free adjustment method. The results from the investigation considering the tunnel line, a symmetrical subsidence was observed. The following day of tunnel excavation, we were observed %68 per of the total deformation. At the end of the last period measurements, %99 per of the total deformation was detected. Keywords: Tunnel, Deformation, Subsidence, Excavation

  3. Application of Distributed Optical Fiber Sensing Technique in Monitoring the Ground Deformation

    Directory of Open Access Journals (Sweden)

    Jin Liu

    2017-01-01

    Full Text Available The monitoring of ground deformation is important for the prevention and control of geological disaster including land subsidence, ground fissure, surface collapse, and landslides. In this study, a distributed optical fiber sensing technique based on Brillouin Optical Time-Domain Analysis (BOTDA was used to monitor the ground deformation. The principle behind the BOTDA is first introduced, and then laboratory calibration test and physical model test were carried out. Finally, BOTDA-based monitoring of ground fissure was carried out in a test site. Experimental results show that the distributed optical fiber can measure the soil strain during ground deformation process, and the strain curve responded to the soil compression and tension region clearly. During field test in Wuxi City, China, the ground fissures deformation area was monitored accurately and the trend of deformation can also be achieved to forecast and warn against the ground fissure hazards.

  4. Geodetic network design for InSAR: Application to ground deformation monitoring

    NARCIS (Netherlands)

    Mahapatra, P.S.

    2015-01-01

    For the past two decades, interferometric synthetic aperture radar (InSAR) has been used to monitor ground deformation with subcentimetric precision from space. But the applicability of this technique is limited in regions with a low density of naturally-occurring phase-coherent radar targets, e.g.

  5. Ground Surface Deformation around Tehran due to Groundwater Recharge: InSAR Monitoring.

    Science.gov (United States)

    Gourmelen, N.; Peyret, M.; Fritz, J. F.; Cherry, J.

    2003-04-01

    Tehran is located on an active tectonic and seismic zone. The surface deformation monitoring provides a powerful tool for getting a better understanding of faults kinematics and mechanisms. Used in conjunction with GPS networks, InSAR (Interferometric Synthetic Aperture Radar) provides dense and precise deformation measurements which are essential for mapping complex heterogeneous deformation fields. Moreover, urban and arid areas preserve interferometric phase coherence. The archived acquisitions of ERS that span 9 months between September 1998 and June 1999 reveal wide areas of surface uplift (by as much as 9 cm). This vertical deformation (gradual in time) has probably no tectonic meaning but is rather the ground response to ground water recharge. These zones are all located dowstream of large alluvial fans like the one of Karaj. The variation of effective stress caused by intersticial water draining could explain such surface deformation. It can also be noticed that some faults act as boundary for these deformation zones and fluid motion. The understanding of this deformation is relevant for groundwater monitoring and urban developement management. It is also necessary for discriminating it from tectonic deformation that also occurs on this zone. Due to the lack of attitude control of satellite ERS-2 since February 2001, the last images acquired could not be combined with the former acquisitions. Nevertheless, we expect to be able to enrich our set of images in order to map tectonic deformation on a longer period and to monitor in a more continuous way the deformation due to groundwater evolution. This would allow to quantify the permanent and reversible part of this signal.

  6. Deformation Monitoring of Waste-Rock-Backfilled Mining Gob for Ground Control

    Science.gov (United States)

    Zhao, Tongbin; Zhang, Yubao; Zhang, Zhenyu; Li, Zhanhai; Ma, Shuqi

    2017-01-01

    Backfill mining is an effective option to mitigate ground subsidence, especially for mining under surface infrastructure, such as buildings, dams, rivers and railways. To evaluate its performance, continual long-term field monitoring of the deformation of backfilled gob is important to satisfy strict public scrutiny. Based on industrial Ethernet, a real-time monitoring system was established to monitor the deformation of waste-rock-backfilled gob at −700 m depth in the Tangshan coal mine, Hebei Province, China. The designed deformation sensors, based on a resistance transducer mechanism, were placed vertically between the roof and floor. Stress sensors were installed above square steel plates that were anchored to the floor strata. Meanwhile, data cables were protected by steel tubes in case of damage. The developed system continually harvested field data for three months. The results show that industrial Ethernet technology can be reliably used for long-term data transmission in complicated underground mining conditions. The monitoring reveals that the roof subsidence of the backfilled gob area can be categorized into four phases. The bearing load of the backfill developed gradually and simultaneously with the deformation of the roof strata, and started to be almost invariable when the mining face passed 97 m. PMID:28475168

  7. Deformation Monitoring of Waste-Rock-Backfilled Mining Gob for Ground Control.

    Science.gov (United States)

    Zhao, Tongbin; Zhang, Yubao; Zhang, Zhenyu; Li, Zhanhai; Ma, Shuqi

    2017-05-05

    Backfill mining is an effective option to mitigate ground subsidence, especially for mining under surface infrastructure, such as buildings, dams, rivers and railways. To evaluate its performance, continual long-term field monitoring of the deformation of backfilled gob is important to satisfy strict public scrutiny. Based on industrial Ethernet, a real-time monitoring system was established to monitor the deformation of waste-rock-backfilled gob at -700 m depth in the Tangshan coal mine, Hebei Province, China. The designed deformation sensors, based on a resistance transducer mechanism, were placed vertically between the roof and floor. Stress sensors were installed above square steel plates that were anchored to the floor strata. Meanwhile, data cables were protected by steel tubes in case of damage. The developed system continually harvested field data for three months. The results show that industrial Ethernet technology can be reliably used for long-term data transmission in complicated underground mining conditions. The monitoring reveals that the roof subsidence of the backfilled gob area can be categorized into four phases. The bearing load of the backfill developed gradually and simultaneously with the deformation of the roof strata, and started to be almost invariable when the mining face passed 97 m.

  8. MetaSensing's FastGBSAR: ground based radar for deformation monitoring

    Science.gov (United States)

    Rödelsperger, Sabine; Meta, Adriano

    2014-10-01

    The continuous monitoring of ground deformation and structural movement has become an important task in engineering. MetaSensing introduces a novel sensor system, the Fast Ground Based Synthetic Aperture Radar (FastGBSAR), based on innovative technologies that have already been successfully applied to airborne SAR applications. The FastGBSAR allows the remote sensing of deformations of a slope or infrastructure from up to a distance of 4 km. The FastGBSAR can be setup in two different configurations: in Real Aperture Radar (RAR) mode it is capable of accurately measuring displacements along a linear range profile, ideal for monitoring vibrations of structures like bridges and towers (displacement accuracy up to 0.01 mm). Modal parameters can be determined within half an hour. Alternatively, in Synthetic Aperture Radar (SAR) configuration it produces two-dimensional displacement images with an acquisition time of less than 5 seconds, ideal for monitoring areal structures like dams, landslides and open pit mines (displacement accuracy up to 0.1 mm). The MetaSensing FastGBSAR is the first ground based SAR instrument on the market able to produce two-dimensional deformation maps with this high acquisition rate. By that, deformation time series with a high temporal and spatial resolution can be generated, giving detailed information useful to determine the deformation mechanisms involved and eventually to predict an incoming failure. The system is fully portable and can be quickly installed on bedrock or a basement. The data acquisition and processing can be fully automated leading to a low effort in instrument operation and maintenance. Due to the short acquisition time of FastGBSAR, the coherence between two acquisitions is very high and the phase unwrapping is simplified enormously. This yields a high density of resolution cells with good quality and high reliability of the acquired deformations. The deformation maps can directly be used as input into an Early

  9. Long-range ground deformation monitoring by InSAR analysis

    Directory of Open Access Journals (Sweden)

    S. Rokugawa

    2015-11-01

    Full Text Available InSAR (Interferometric Synthetic Aperture Radar analysis is an effective technique to map 3-dimensional surface deformation with high spatial resolution. The aim of this study was to evaluate the capability of InSAR analysis when applied to ground monitoring of an environmental disaster. We performed a time series InSAR analysis using ENVISAT/ASAR and ALOS/PALSAR data and commercial software to investigate subsidence around the Kanto District of Japan. We also investigated techniques for efficient early detection of landslides in Kyushu using time series analysis that incorporated synthetic aperture radar (SAR images. ENVISAT/ASAR data acquired from 2003–2010 and ALOS/PALSAR data acquired from 2006–2011 were used to detect poorly expressed geomorphological deformation by conducting time series analyses of periodically acquired SAR data. In addition, to remove noise caused by geographical feature stripes or phase retardation, we applied median filtering, histogram extraction processing, and clarification of the displacement with a Laplacian filter. The main functions of the InSAR time series analysis are the calculation of phase differences between two images and the inversion with smoothness constraint for the estimation of deformation along the line of sight. The results enabled us to establish criteria for the selection of suitable InSAR data pairs, and provided the final error estimation of the derived surface deformation. The results of the analysis in the Kanto District suggested that localized areas of uplift and subsidence have occurred at irregular intervals in this area. Furthermore, the method offers the possibility of early warning of environmental disasters such as landslide and abrupt subsidence. Our results confirm the effectiveness of InSAR analysis for the monitoring of ground deformation over wide areas via the detection of localized subsidence and landslides.

  10. PSP SAR interferometry monitoring of ground and structure deformations in the archeological site of Pompeii

    Science.gov (United States)

    Costantini, Mario; Francioni, Elena; Paglia, Luca; Minati, Federico; Margottini, Claudio; Spizzichino, Daniele; Trigila, Alessandro; Iadanza, Carla; De Nigris, Bruno

    2016-04-01

    The "Major Project Pompeii" (MPP) is a great collective commitment of different institututions and people to set about solving the serious problem of conservation of the largest archeological sites in the world. The ancient city of Pompeii with its 66 hectares, 44 of which are excaveted, is divided into 9 regiones (district), subdivided in 118 insulae (blocks) and almost 1500 domus (houses), and is Unesco site since 1996. The Italian Ministry for Heritage and Cultural Activities and Tourism (MiBACT) and Finmeccanica Group have sealed an agreement whereby the Finmeccanica Group will donate innovative technologies and services for monitoring and protecting the archaeological site of Pompeii. Moreover, the Italian Institute for Environment Protection and Research (ISPRA) - Geological Survey of Italy, was also involved to support the ground based analysis and interpretation of the measurements provided by the industrial team, in order to promote an interdisciplinary approach. In this work, we will focus on ground deformation measurements obtained by satellite SAR interferometry and on their interpretation. The satellite monitoring service is based on the processing of COSMO-SkyMed Himage data by the e-Geos proprietary Persistent Scatterer Pair (PSP) SAR interferometry technology. The PSP technique is a proven SAR interferometry method characterized by the fact of exploiting in the processing only the relative properties between close points (pairs) in order to overcome atmospheric artifacts (which are one of the main problems of SAR interferometry). Validations analyses showed that this technique applied to COSMO-SkyMed Himage data is able to retrieve very dense (except of course on vegetated or cultivated areas) millimetric deformation measurements with sub-metric localization. By means of the COSMO-SkyMed PSP SAR interferometry processing, a historical analysis of the ground and structure deformations occurred over the entire archaeological site of Pompeii in the

  11. Integrated monitoring system for ground deformation hazard assessment in Telese Terme (Benevento province, Italy)

    Science.gov (United States)

    Tessitore, S.; Castiello, G.; Fedi, M.; Florio, G.; Fuschini, V.; Ramondini, M.; Calcaterra, D.

    2012-04-01

    TeleseTerme plain is characterized by a very articulated stratigraphy (levels of travertine, fluvial-marshy and pyroclastic deposits), that allows the occurrence of underground water circulation with overlapping aquifers. These aquifers are locally in pressure and, because of chemical characteristics and physical properties of the water, they may activate processes of accelerated travertine's corrosion; the consequence is the formation of cavity along the ground water's preferential flow paths, and the activation of subsidence and sinkholes phenomena. In particular test area includes two zones, where in 2002 and 2006 occurred two sinkholes events, classified as "piping sinkholes". The hazard evaluation was carried out trhought an integrated monitoring system, based on "traditional" techniques conduced "in situ", as geological-geomorphological and geophysical (microgravity) surveys, integrated by the most innovative techniques of Remote sensing interferometry(Advanced DInSAR Interferometry Techniques). The last allow to evaluate the ground deformation, characterized by a predominantvertical component (typical deformation of sinkholes and subsidence phenomena), and are well suited to operate a continuous and long monitoring ofvery extended areas. Through an initial analysis of the Permanent Scatterers available in the Telese municipality, we found the envelopes of the areal that contain PS with negative and positive mean velocities; these velocities showed the presence of a possible phenomenon of subsidence detected by ERS and ENVISAT satellites. Through interferometric processing of ENVISAT images, the soil deformations of 2002-2010 year sare evaluated and compared with the data obtainedby survey took "in situ" during the same period. The knowledge of the deformation's evolution of the area made it possible to organize a more focused future monitoring through traditional techniques of relief (with the help of geophysical methodologies). Since the zone affected by

  12. Geophysical Monitoring of Ground Surface Deformation Associated with a Confined Aquifer Storage and Recovery Operation

    Science.gov (United States)

    Bonneville, Alain; Heggy, Essam; Strickland, Christopher; Normand, Jonathan; Dermond, Jeffrey; Fang, Yilin; Sullivan, Charlotte

    2015-08-01

    One important issue in the storage of large volumes of fluids, mainly water and CO2, in the deep subsurface is to determine the resulting field-scale-induced displacements and consequences of overpressures on the mechanical integrity of the storage reservoir and surroundings. A quantifiable estimation of displacement can be made by combining the robust, cost-effective, and repeatable geophysical techniques of micro-gravimetry, differential global positioning system (DGPS), and differential synthetic aperture radar interferometry (DInSAR). These techniques were field tested and evaluated for the first time on an active large-volume aquifer storage and recovery (ASR) project in Pendleton, Oregon, USA, where three ASR wells are injecting up to 1.9 million m3 year-1 into basalt aquifers to a depth of about 150 m. Injection and recovery of water at the wells are accompanied by significant gravity anomalies and vertical deformation of the ground surface localized to the immediate surroundings of the injection wells as evidenced by DGPS and gravity measurements collected in 2011. At a larger scale, and between 2011 and 2013, DInSAR monitoring of the Pendleton area shows sub- centimetric deformation in the western part of the city and close to the injection locations associated with ASR cycle. Deformations are found to be temporally out phased with the injection and recovery events due to complex groundwater flow. A numerical simulation of the effect of the water injection gives results in good agreement with the observations and confirms the validity of the approach, which could be deployed in similar geological contexts to look at the mechanical effects of water and gas injections.

  13. PSP SAR interferometry monitoring of ground and structure deformations applied to archaeological sites

    Science.gov (United States)

    Costantini, Mario; Francioni, Elena; Trillo, Francesco; Minati, Federico; Margottini, Claudio; Spizzichino, Daniele; Trigila, Alessandro; Iadanza, Carla

    2017-04-01

    Archaeological sites and cultural heritage are considered as critical assets for the society, representing not only the history of region or a culture, but also contributing to create a common identity of people living in a certain region. In this view, it is becoming more and more urgent to preserve them from climate changes effect and in general from their degradation. These structures are usually just as precious as fragile: remote sensing technology can be useful to monitor these treasures. In this work, we will focus on ground deformation measurements obtained by satellite SAR interferometry and on the methodology adopted and implemented in order to use the results operatively for conservation policies in a Italian archaeological site. The analysis is based on the processing of COSMO-SkyMed Himage data by the e-GEOS proprietary Persistent Scatterer Pair (PSP) SAR interferometry technology. The PSP technique is a proven SAR interferometry technology characterized by the fact of exploiting in the processing only the relative properties between close points (pairs) in order to overcome atmospheric artefacts (which are one of the main problems of SAR interferometry). Validations analyses [Costantini et al. 2015] settled that this technique applied to COSMO-SkyMed Himage data is able to retrieve very dense (except of course on vegetated or cultivated areas) millimetric deformation measurements with sub-metric localization. Considering the limitations of all the interferometric techniques, in particular the fact that the measurement are along the line of sight (LOS) and the geometric distortions, in order to obtain the maximum information from interferometric analysis, both ascending and descending geometry have been used. The ascending analysis allows selecting measurements points over the top and, approximately, South-West part of the structures, while the descending one over the top and the South-East part of the structures. The interferometric techniques needs

  14. SqueeSAR™ and GPS ground deformation monitoring of Santorini Volcano (1992-2012): Tectonic implications

    Science.gov (United States)

    Lagios, E.; Sakkas, V.; Novali, F.; Bellotti, F.; Ferretti, A.; Vlachou, K.; Dietrich, V.

    2013-05-01

    The Santorini Volcanic Complex (SVC) has been in a dormant state for the last 60 years until January 2011 when upward influx of magma reawakened the volcano with intense radial ground deformation and inter-caldera seismicity that lasted until January 2012 but declined afterwards. This paper aims to study the ground deformation and the inferred tectonic implications of the SVC for the period 1992-2012 mainly based on the SqueeSAR™ technique and DGPS campaign results of our local network which incorporates available data on Internet from several continuous GPS stations established on the island. The spatial deformation of the SVC during the quiet period 1992-2010 was deduced by joint analysis of ERS1 and 2 and ENVISAT. It was found that the intra caldera Palaea Kammeni shield volcano was being uplifted (2-3 mm/yr) with increasing rate, whilst the adjacent Nea Kammeni shield volcano was being subsided (up to 6 mm/yr) with increasing rate. The rest of the SVC showed a velocity field varying from - 1 to + 2 mm/yr, indicating a rather linear deformation during that period. The results from the GPS network are in full agreement with the SqueeSAR results. Based on the results of SqueeSAR analysis of 12 ENVISAT images, and DGPS/CGPS data to end 2012, the deformation for the unrest period 2011-2012 was non-linear being characterized by strong radial deformation in the northern part of the caldera (50-120 mm/yr), and accelerating values (> 130 mm/yr2). Combined GPS/SqueeSAR Mogi modeling indicated a source located north of Nea Kammeni at a shallow depth. However, a progressively decreasing rate in deformation was noted at most GPS/CGPS station components after January 2012, indicating magma settlement consistent with the constantly decreasing rate of the inter-caldera seismicity. The faulting features seem to have a key role in the evolution of the deformation, which continues up the end 2012, but at a very low level.

  15. SqueeSARTM & GPS Ground Deformation Monitoring (1992-2012) of Santorini Volcano (Greece)

    Science.gov (United States)

    Lagios, E.; Sakkas, V.; Novali, F.; Vlachou, K.; Bellotti, F.; Giannico, C.

    2012-12-01

    The Santorini Volcanic Complex (SVC) - consisting of the islands of Thera, Therassia, Aspronisi and the two Kammenis (Palea & Nea Kammeni) - is one of the largest Quaternary volcanic centers in the Aegean located in the central part of the Hellenic Volcanic Arc. The complex has been in a quiet state the last 60 years, until January 2011 when the volcano reawakened, starting producing earthquakes in the caldera region of magnitudes up to 3, and showing an intense radial ground deformation. The seismicity in the caldera lasted until Jan. 2012 while afterwards, a decline in the seismicity rate started taking place. In the following, a two decade (1992-2012) ground deformation of the SVC is presented based on (i) the SqueeSAR technique (an advanced Permanent Scatterer (PS) Interferometric technique) and (ii) GPS campaign measurement results of our local network, including the continuous GPS (CGPS) stations established on the island. The spatial deformation of Santorini Volcano during the "quiet" period 1992-2010 was deduced by joint analysis of ERS1&2 and ENVISAT radar images of ascending and descending orbital geometry. This period, considering also the acceleration field of the PS, Palea Kammeni was getting uplifted (2-3 mm/yr), characterized by an increasing rate of uplift, whilst the adjacent Nea Kammeni was subsided (up to -3 mm/yr) with increasing rates. These two islets exhibit a different type of vertical motion. The rest of the area showed a LOS velocity field varying from -1 to +2 mm/yr and sub-millimeter acceleration field values, indicating a linear deformation during that period. Combining ascending and descending radar data, the vertical and horizontal (E-W) components of the velocity field were determined, where several deformation patterns were identified: The two main faulting zones, the Columbo and the Kammeni zones at the northern and central part, the Alpine basement at the SE part of Thera, and a pattern associated with the graben basin at its SE

  16. Monitoring and analysis of ground temperature and deformation within Qinghai-Tibet Highway subgrade in permafrost region

    Institute of Scientific and Technical Information of China (English)

    YaHu Tian; YuPeng Shen; WenBing Yu; JianHong Fang

    2015-01-01

    In order to study the stability of the Qinghai-Tibet Highway embankment at Chumaerhe in the permafrost region of northwest China, the ground temperature and deformation at different depths were monitored under the left and right shoulders of the embankment where thermosyphons were set up only on the left shoulder. Based on the monitored data, characteristics of ground temperature and deformation of the left and right shoulders are analyzed and discussed. The results show that the start time of freezing or thawing of the seasonal active layer was about one to two months later than that of the embankment body itself. The stability of each shoulder was mainly controlled by the settlement of different soil layers, whereas frost heave of soil had scarcely any effect on the stability of the embankment. For the left shoulder, the settlement was mainly influenced by the seasonal active layer and then by the embankment body itself, due to freeze-thaw cycles which may change the soil properties; however, the permafrost layer remained fairly stable. For the right shoulder, creep of the warm permafrost layer was the main influence factor on its stability, followed by settlement of embankment body itself, and finally settlement of the seasonal active layer. Compared with the deformation of the left shoulder, the permafrost layer under the right shoulder was less stable, which indicates that the thermosyphons had a significantly positive effect on the stability of warm permafrost.

  17. Stress Changes and Deformation Monitoring of Longwall Coal Pillars Located in Weak Ground

    Science.gov (United States)

    Yu, Bin; Zhang, Zhenyu; Kuang, Tiejun; Liu, Jinrong

    2016-08-01

    Coal pillar stability is strongly influenced by the site-specific geological and geotechnical conditions. Many geological structures such as faults, joints, or rock intrusions can be detrimental to mining operations. In order to evaluate the performance of coal pillars under weak roof degraded by igneous rock intrusion, stress and deformation monitoring was conducted in the affected tailgate areas of Nos. 8208 and 8210 longwalls in Tashan coal mine, Shanxi Province, China. The measurements in the 8208 longwall tailgate showed that the mining-induced stresses in 38-m-wide coal chain pillars under the overburden depth of 300-500 m started to increase at about 100 m ahead of the 8208 longwall working face and reached its peak level at approximately 50 m ahead of the longwall face. The peak stress of 9.16 MPa occurred at the depth of 8-9 m into the pillar from the tailgate side wall. In comparison, disturbance of the headgate block pillar area was negligible, indicating the difference of abutment pressure distribution between the tailgate and headgate sites where the adjacent unmined longwall block carried most of the overburden load. However, when the longwall face passed the headgate monitoring site by 360-379 m, the pillar stress increased to a peak value of 21.4 MPa at the pillar depth of 13 m from the gob side mainly due to stress redistribution in the chain pillar. In contrast to the headgate, at the tailgate side, the adjacent goaf was the dominant triggering factor for high stress concentrations in the chain pillar. Convergence measurements in the tailgate during longwall mining further indicated the evolution characteristics of coal pillar deformation, clearly showing that the gateroad deformation is mainly induced by the longwall extraction it serves. When predicting the future pillar loads from the monitored data, two stress peaks appeared across the 38-m-wide tailgate coal pillar, which are separated by the lower stress area within the pillar center. This

  18. Geometric Aspects of Ground Augmentation of Satellite Networks for the Needs of Deformation Monitoring

    Science.gov (United States)

    Protaziuk, Elżbieta

    2016-06-01

    Satellite measurements become competitive in many tasks of engineering surveys, however, in many requiring applications possibilities to apply such solutions are still limited. The possibility to widely apply satellite technologies for displacements measurements is related with new challenges; the most important of them relate to increasing requirements concerning the accuracy, reliability and continuity of results of position determination. One of the solutions is a ground augmentation of satellite network, which intention is to improve precision of positioning, ensure comparable accuracy of coordinates and reduce precision fluctuations over time. The need for augmentation of GNSS is particularly significant in situations: where the visibility of satellites is poor because of terrain obstacles, when the determined position is not precise enough or a satellites constellation does not allow for reliable positioning. Ground based source/sources of satellite signal placed at a ground, called pseudosatellites, or pseudolites were intensively investigated during the last two decades and finally were developed into groundbased, time-synchronized transceivers, that can transmit and receive a proprietary positioning signal. The paper presents geometric aspects of the ground based augmentation of the satellite networks using various quality measures of positioning geometry, which depends on access to the constellation of satellites and the conditions of the observation environment. The issue of minimizing these measures is the key problem that allows to obtain the position with high accuracy. For this purpose, the use of an error ellipsoid is proposed and compared with an error ellipse. The paper also describes the results of preliminary accuracy analysis obtained at test area and a comparison of various measures of the quality of positioning geometry.

  19. 2D and 3D Ground Penetrating Radar monitoring of a reinforced concrete asphalt plate affected by mechanical deformation.

    Science.gov (United States)

    Bavusi, M.; Dumoulin, J.; Loperte, A.; Rizzo, E.; Soldovieri, F.

    2012-04-01

    The main facility of Hydrogeosite Laboratory of the Italian National Research Council (Marsico Nuovo, CNR) is a 3m x 7m x 10m reinforced concrete pool filled by siliceous sand designed for hydrologic experiments. One of its peculiarities is the possibility to vary the water table depth by using a proper hydraulic system [1]. In the framework of the FP7 ISTIMES project (Integrated System for Transport Infrastructure surveillance and Monitoring by Electromagnetic Sensing), a 3m x 3m layered structure has been purposely built and placed in the pool of the Hydrogeosite Laboratory with the aim to carry out a long term monitoring, by using jointly several electromagnetic sensing technologies, during two different phases simulating the rising of the water table and a mechanical solicitation. Several layers composed the structure from the top to the bottom, such as: 5 cm of asphalt; 5-10 cm of reinforced concrete; 20-25 cm of conglomerate, 55 cm of sand. Moreover, in the sand layer, three (metallic and plastic) pipes of different size were buried to simulate utilities. Ground Penetrating Radar (GPR) surveys were performed by using a the GSSI SIR 3000 system equipped with 400 MHz and 1500 MHz central frequency antennas. Surveys carried out by means of 400 MHz antenna allowed to detect and localize the three pipes (one in plastic and two in metal) and to investigate the effects of the sand water content on their radar signature. Surveys carried out by using 1500 MHz antenna were focused to characterize the shallower layers of the structure. The Hydrogeosite experiment consisted in following stages: • Arising of a water table by infiltration from the bottom; • Water gravity infiltration condescendingly; • Infiltration by peristaltic pump in the very shallow layers of the structure; • Water table drawdown; • Mechanical structure deformation; • Asphalt plate restoration after mechanical solicitation. After each stage a series of GPR surveys was performed. Moreover

  20. The unrest of the San Miguel volcano (El Salvador, Central America): installation of the monitoring network and observed volcano-tectonic ground deformation

    Science.gov (United States)

    Bonforte, Alessandro; Hernandez, Douglas Antonio; Gutiérrez, Eduardo; Handal, Louis; Polío, Cecilia; Rapisarda, Salvatore; Scarlato, Piergiorgio

    2016-08-01

    On 29 December 2013, the Chaparrastique volcano in El Salvador, close to the town of San Miguel, erupted suddenly with explosive force, forming a column more than 9 km high and projecting ballistic projectiles as far as 3 km away. Pyroclastic density currents flowed to the north-northwest side of the volcano, while tephras were dispersed northwest and north-northeast. This sudden eruption prompted the local Ministry of Environment to request cooperation with Italian scientists in order to improve the monitoring of the volcano during this unrest. A joint force, made up of an Italian team from the Istituto Nazionale di Geofisica e Vulcanologia and a local team from the Ministerio de Medio Ambiente y Recursos Naturales, was organized to enhance the volcanological, geophysical and geochemical monitoring system to study the evolution of the phenomenon during the crisis. The joint team quickly installed a multiparametric mobile network comprising seismic, geodetic and geochemical sensors (designed to cover all the volcano flanks from the lowest to the highest possible altitudes) and a thermal camera. To simplify the logistics for a rapid installation and for security reasons, some sensors were colocated into multiparametric stations. Here, we describe the prompt design and installation of the geodetic monitoring network, the processing and results. The installation of a new ground deformation network can be considered an important result by itself, while the detection of some crucial deforming areas is very significant information, useful for dealing with future threats and for further studies on this poorly monitored volcano.

  1. The 2011 volcanic crisis at El Hierro (Canary Islands): monitoring ground deformation through tiltmeter and gravimetric observations

    Science.gov (United States)

    Arnoso, J.; Montesinos, F. G.; Benavent, M.; Vélez, E. J.

    2012-04-01

    and shallow earthquakes happened, producing in some cases large tilt variations of tens of µrad. By other side, in 2003 we established a control gravity network that was measured again in 2004 and 2008. After the beginning of the eruption on October 2011, we have carried out gravity measurements in various points of the network as well as other new points to attain more accurate control of the possible variations of gravity or/and altitude. Gravity data are still under study although some results about observed gravity changes could reflect the ground deformations pattern according to tiltmeter records and GPS measurements, or a change in the subsurface mass distribution as consequence of the new emplacement the magmatic material in the area with volcanic and seismic activity.

  2. Monitoring of ground surface deformation in mining area with InSAR technique%利用InSAR技术监测矿区地表形变

    Institute of Scientific and Technical Information of China (English)

    朱建军; 邢学敏; 胡俊; 李志伟

    2011-01-01

    The application status and research progress of InSAR technique in the monitoring of the ground surface deformation in mining area were introduced. Firstly, the advantages of D-InSAR technique were analyzed by comparing to the traditional surveying methods. Then, the limitations of D-InSAR in the mining deformation detection were described. According to the limitations of the traditional D-InSAR method, the advanced InSAR technique, e.g., small baseline subset (SBAS), permanent scatterer (PS) and corner reflector (CR) techniques were discussed. Using real mining subsidence monitoring as example, the characteristics and application status of those advanced InSAR techniques were studied, and the key problems still existing in the current research were summarized. Finally, it is indicated that the development trend of InSAR monitoring surface deformation in mining area is the combination of advanced InSAR and high-resolution SAR images.%介绍了InSAR技术在矿区地表形变监测中的应用现状及进展,分析了D-InSAR技术相比于传统测量手段的优势,并指出其在矿区地表形变监测中的不足.针对传统D-InSAR技术的局限性,重点讨论了短基线(SBAS)、永久散射体(PS)和角反射器(CR)等高级差分干涉技术,并结合矿区沉降监测实例,分析了其特点与应用现状,讨论了现有研究中仍存在的问题.高级InSAR技术和高分辨率SAR影像的结合将是矿区地表形变监测的发展趋势.

  3. The unrest of S. Miguel volcano (El Salvador, CA): installation of the monitoring network and observed volcano-tectonic ground deformation

    Science.gov (United States)

    Bonforte, A.; Hernandez, D.; Gutiérrez, E.; Handal, L.; Polío, C.; Rapisarda, S.; Scarlato, P.

    2015-10-01

    On 29 December 2013, the Chaparrastique volcano in El Salvador, close to the town of S. Miguel, erupted suddenly with explosive force, forming a more than 9 km high column and projecting ballistic projectiles as far as 3 km away. Pyroclastic Density Currents flowed to the north-northwest side of the volcano, while tephras were dispersed northwest and north-northeast. This sudden eruption prompted the local Ministry of Environment to request cooperation with Italian scientists in order to improve the monitoring of the volcano during this unrest. A joint force made up of an Italian team from the Istituto Nazionale di Geofisica e Vulcanologia and a local team from the Ministerio de Medio Ambiente y Recursos Naturales was organized to enhance the volcanological, geophysical and geochemical monitoring system to study the evolution of the phenomenon during the crisis. The joint team quickly installed a multi-parametric mobile network comprising seismic, geodetic and geochemical sensors, designed to cover all the volcano flanks from the lowest to the highest possible altitudes, and a thermal camera. To simplify the logistics for a rapid installation and for security reasons, some sensors were co-located into multi-parametric stations. Here, we describe the prompt design and installation of the geodetic monitoring network, the processing and results. The installation of a new ground deformation network can be considered an important result by itself, while the detection of some crucial deforming areas is very significant information, useful for dealing with future threats and for further studies on this poorly monitored volcano.

  4. Activation of the SIGRIS monitoring system for ground deformation mapping during the Emilia 2012 seismic sequence, using COSMO-SkyMed InSAR data

    Directory of Open Access Journals (Sweden)

    Stefano Salvi

    2012-10-01

    designed to provide the DPC with value-added information products in the different phases of the seismic cycle. During earthquake emergencies, its goal is to rapidly provide decision-support products, such as validated ground-displacement maps and seismic source models. This study reports the details of the activation of the SIGRIS system in the case of the Emilia sequence. It provides a description of the COSMO-SkyMed datasets and processing procedures, as well as selected interferometric results for the coseismic and post-seismic ground deformation. […

  5. Monitoring Ground Deformation Using Persistent Scatters Interferometry (PSI) and Small Baselines (SBAS) Techniques Integrated in the ESA RSS Service: The Case Study of Valencia, Rome and South Sardinia

    Science.gov (United States)

    Delgado, Manuel J.; Cuccu, Roberto; Rivolta, Giancarlo

    2015-05-01

    This work is focused on the infrastructure monitoring of areas which had experienced significant urbanization and therefore, also an increase of the exploitation of natural resources. Persistent Scatters Interferometry (PS-InSAR) and Small Baselines (SBAS) approaches are applied to three study areas for which large datasets of SAR images are available in ascending and descending modes to finally deploy deformation maps of different buildings and infrastructures. Valencia, Rome and South Sardinia areas have been selected for this study, having experienced an increase of the exploitation of natural resources in parallel with their urban expansion. Moreover, Rome is a very special case, where Cultural Heritage permeating the city and its surroundings would suggest the necessity of a tool for monitoring the stability of the different sites. This work wants to analyse the potential deformation that had occurred in these areas during the period 1992 to 2010, by applying Persistent Scatters Interferometry to ESA ERS SAR and Envisat ASAR data.

  6. Ground deformation monitoring using RADARSAT-2 DInSAR-MSBAS at the Aquistore CO2 storage site in Saskatchewan (Canada)

    OpenAIRE

    M. Czarnogorska; Samsonov, S.; White, D.

    2014-01-01

    The research objectives of the Aquistore CO2 storage project are to design, adapt, and test non-seismic monitoring methods for measurement, and verification of CO2 storage, and to integrate data to determine subsurface fluid distributions, pressure changes and associated surface deformation. Aquistore site is located near Estevan in Southern Saskatchewan on the South flank of the Souris River and west of the Boundary Dam Power Station and the historical part of Estevan coal mine in s...

  7. SAR Interferometric Analysis Of Ground Deformation At Santorini Volcano (Greece)

    Science.gov (United States)

    Papageorgiou, Elena; Foumelis, Michael; Parcharidis, Issaak

    2012-01-01

    The core of the present study builds on ground deformation monitoring by SAR Interferometry at Santorini Volcanic Complex (Greece). Dataset used for this case study, include the entire archive of ERS SAR and ENVISAT ASAR data for both ascending and descending orbits covering almost two decades of observations (1992-2010). Deformation signals of millimeter-level accuracy were retrieved from both SAR and ASAR datasets, by way of the Interferometric Stacking technique. The linear rate of differential phases and the corresponding errors were estimated by averaging the unwrapped differential interferograms. Subsequently, vertical deformation rates were calculated by the combination of LOS measurements in ascending and descending acquisition geometries. The observed ground deformation shows mainly subsidence in the central part of Santorini Caldera, at Nea Kammeni Island, equal to -5.1 ±0.7 mm/yr, and -6.3 ±1.2 mm/yr for the periods 1992-2000 and 2003-2010 respectively, while both signs of movements (uplift and subsidence) of lower scale magnitude were recognized elsewhere on the volcano. In fact, higher deformation rates for the period after 2003 (ranging between -4.6 mm/yr and 5.6 mm/yr), compared to the lower values of the period 1992-2000 (from -1.7 mm/yr to 2.7 mm/yr), indicate increase in the undergoing deformation of the volcanic complex. Finally, this work presents an attempt to obtain integrated interferometric results of ground deformation from both ERS and ENVISAT sensors in order to allow future investigations on the deformation sources of the volcanic complex, which could be further exploited in the volcanic hazard and risk assessment.

  8. Monitoring on Xi'an Ground Fissures Deformation with TerraSAR-X Data%采用TerraSAR-X数据监测西安地裂缝形变

    Institute of Scientific and Technical Information of China (English)

    赵超英; 张勤; 朱武; Lu Zhong

    2012-01-01

    Owing to the fine resolution of TerraSAR-X data provided since 2007,this paper applied 6 TerraSAR data(strip mode) during 3rd Dec.2009 to 23rd Mar.2010 to detect and monitor the active fissures over Xi'an region.Three themes have been designed for high precision detection and monitoring of Xi'an-Chang'an fissures,as small baseline subsets(SBAS) to test the atmospheric effects of differential interferograms pair stepwise,2-pass differential interferogram with very short baseline perpendicular to generate the whole deformation map with 44 days interval,and finally,corner reflector(CR) technique was used to closely monitor the relative deformation time series between two CRs settled crossing two ground fissures.Results showed that TerraSAR data are a good choice for small-scale ground fissures detection and monitoring,while special considerations should be taken for their great temporal and baseline decorrelation.Secondly,ground fissures in Xi'an were mostly detected at the joint section of stable and deformable regions.Lastly,CR-InSAR had potential ability to monitor relative deformation crossing fissures with millimeter precision.%基于3m分辨率的TerraSAR-X数据对覆盖西安地区的活动地裂缝进行了定位与监测研究。数据为2009-12-03~2010-03-23共6景Strip模式数据。实验结果显示,高分辨率TerraSAR数据是监测地裂缝很好的数据源,但为了获取高精度的监测成果还需要特别考虑时间和基线去相干因素。二轨法监测结果显示,活动地裂缝往往出现在稳定区域与形变区域的转折部位,而采用人工角反射器技术可以监测出mm量级的地裂缝相对形变信息。

  9. Experimental modelling of ground deformation associated with shallow magma intrusions

    Science.gov (United States)

    Galland, O.

    2012-04-01

    Active volcanoes experience ground deformation as a response to the dynamics of underground magmatic systems. The analysis of ground deformation patterns may provide important constraints on the dynamics and shape of the underlying volcanic plumbing systems. Nevertheless, these analyses usually take into account simplistic shapes (sphere, dykes, sills) and the results cannot be verified as the modelled systems are buried. In this contribution, I will present new results from experimental models of magma intrusion, in which both the evolution of ground deformation during intrusion and the shape of the underlying intrusion are monitored in 3D. The models consisted of a molten vegetable oil, simulating low viscosity magma, injected into cohesive fine-grained silica flour, simulating the brittle upper crust; oil injection resulted is sheet intrusions (dykes, sills and cone sheets). The initial topography in the models was flat. While the oil was intruding, the surface of the models slightly lifted up to form a smooth relief, which was mapped through time. After an initial symmetrical development, the uplifted area developed asymmetrically; at the end of the experiments, the oil always erupted at the steepest edge of the uplifted area. After the experiment, the oil solidified, the intrusion was excavated and the shape of its top surface mapped. The comparison between the uplifted zone and the underlying intrusions showed that (1) the complex shapes of the uplifted areas reflected the complex shapes of the underlying intrusions, (2) the time evolution of the uplifted zone was correlated with the evolution of the underlying intrusion, and (3) the early asymmetrical evolution of the uplifted areas can be used to predict the location of the eruption of the oil. The experimental results also suggest that complex intrusion shapes (inclined sheet, cone sheet, complex sill) may have to be considered more systematically in analyses of ground deformation patterns on volcanoes.

  10. Research on monitoring system for slope deformation

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-sheng; ZHANG Xue-zhuang; WANG Ai-gong

    2007-01-01

    The monitoring system for slope deformation which bases on Leica (TCA series)was researched and developed. This system consists of electronic total stations, high precision thermometer, digital barometer, photoelectric frequency adjustor and other related instruments and data collection and processing software. The system can monitor a series of targets automatically to obtain accurate data of distance at predetermined time, besides,it can timely display targets' coordinates and deformation value, velocity, etc. in graph as well. To compare of the results of different monitoring time, we can find the problems of mine slope deformation rapidly and accurately.

  11. 3D geodetic monitoring slope deformations

    Directory of Open Access Journals (Sweden)

    Weiss Gabriel

    1996-06-01

    Full Text Available For plenty of slope failures that can be found in Slovakia is necessary and very important their geodetic monitoring (because of their activity, reactivisations, checks. The paper gives new methodologies for these works, using 3D terrestrial survey technologies for measurements in convenient deformation networks. The design of an optimal type of deformation model for various kinds of landslides and their exact processing with an efficient testing procedure to determine the kinematics of the slope deformations are presented too.

  12. Regional ground deformation and its controlling measures in China

    Science.gov (United States)

    Zhou, Zhifang; Zhu, Haisheng; Huang, Yong

    2006-12-01

    With the development of construction of China Cities, there exist a lot of environmental geological problems involved in the geofracture, land subsidence, collapse, landslide, devolution, mudrock flow, floating sand, piping and soft ground deformation. Of big cities whose population is over one million in China, about 30 cities appears the land subsidence region. Other cities locate in the regions of collapse yellow earth or expand soil of strong swell-shrink charasteristic, soft ground and karst. In the paper, the cause and hazard of regionality ground deformation is summed up. The causes of regional land deformation caused by the natural geological effect and activities of human being are analyzed. According to the length of deformation course and endanger of society, economy and life, land deformation involves three types, that is, the delay, rapid and break land deformation. And the concrete countermeasure and method are provided.

  13. On application of D-InSAR technique in ground deformation monitoring%D-InSAR 技术在地面变形监测中的应用

    Institute of Scientific and Technical Information of China (English)

    陈雷

    2016-01-01

    描述了 D-InSAR 技术的相关原理,分析了差分干涉测量的整个处理流程,并根据伊朗巴姆地区地震前后的地面形变情况,利用 ENVISAT 雷达数据,获取了 SAR 影像的干涉条纹,通过两轨差分干涉测量方法得到实验区域的地面沉降数据,验证了合成孔径雷达差分干涉测量技术在地表变形监测方面的可行性。%The article describes the relevant principles D-InSAR technique,and analyzes the entire process flow differential interferometry meas-urements. And according to surface deformation Bam earthquake in Iran before and after the use of ENVISAT radar data acquired SAR influence of the interference fringes and using two rail differential interferometry experiments obtained ground subsidence data area. Verify that the differen-tial synthetic aperture radar interferometry technique in measuring the feasibility of surface deformation monitoring applications.

  14. Ground tilt monitoring at Phlegraean Fields (Italy: a methodological approach

    Directory of Open Access Journals (Sweden)

    C. Del Gaudio

    2003-06-01

    Full Text Available Among geodetic methods used for monitoring ground deformation in volcanic areas, tiltmetry represents the most rapid technique and therefore it is used by almost all the volcanological observatories in the world. The deformation of volcanic building is not only the result of endogenous causes (i.e. dykes injection or magma rising, but also non-tectonic environmental factors. Such troubles cannot be removed completely but they can be reduce. This article outlines the main source of errors affecting the signals recorded by Phlegraean tilt, network, such as the dependence of the tilt response on temperature and to the thermoelastic effect on ground deformation. The analytical procedure used to evaluate about such errors and their reduction is explained. An application to data acquired from the tilt network during two distinct phases of ground uplift and subsidence of the Phlegraean Fields is reported.

  15. Detection of ground deformation at the Neapolitan volcanic area (Southern Italy)

    Science.gov (United States)

    Bottiglieri, M.; Falanga, M.; Tammaro, U.; de Martino, P.; Obrizzo, F.; Godano, C.; Pingue, F.

    2009-04-01

    The correct definition of the background level of ground deformation is a very important aspect in geodetic monitoring of volcanic areas. Indeed, it could allow a fast identification of an anomalous deformation trend that evolves towards an eruptive event. It is interesting confirm that any ground deformation modifies the distribution of the time series amplitude so significantly that this behaviour could be used as the marker of an effective source driven deformation. As an example, we analyse the site position time series of Neapolitan Volcanic Continuous GPS (NeVoCGPS) network operating on three volcanic active districts (Somma-Vesuvius volcano, Campi Flegrei Calder and Ischia Island) in a densely inhabited area, recorded during the period 2001-2007. These GPS time series reveal a very peculiar behaviour. When a clear deformation is observed, the amplitude distribution evolves from a gaussian to a bivariate gaussian distribution. This behaviour can be characterized by evaluating the kurtosis. The time series for all stations have been modelled with a fifth order polynomial fit. This represents the deformation history. Indeed, when this polynomial is subtracted from the time series, the distributions become again gaussian. A simulation of the deformation time evolution reveals that the amplitude distribution evolves towards a non gaussian behaviour if the ground deformation starts at 2/3 of the time series duration.

  16. Complex Deformation Monitoring over the Linfen–Yuncheng Basin (China with Time Series InSAR Technology

    Directory of Open Access Journals (Sweden)

    Cheng-sheng Yang

    2016-03-01

    Full Text Available The Linfen–Yuncheng basin is an area prone to geological disasters, such as surface subsidence, ground fissuring, fault activity, and earthquakes. For the purpose of disaster prevention and mitigation, Interferometric Synthetic Aperture Radar (InSAR was used to map ground deformation in this area. After the ground deformation characteristics over the Linfen–Yuncheng basin were obtained, the cross-correlations among regional ground subsidence, fault activity, and underground water level were analyzed in detail. Additionally, an area of abnormal deformation was found and examined. Through time series deformation monitoring and mechanism inversion, we found that the abnormal deformation was related mainly to excessive groundwater exploitation.

  17. Rockslide deformation monitoring with fiber optic strain sensors

    Directory of Open Access Journals (Sweden)

    J. R. Moore

    2010-02-01

    Full Text Available With micro-strain resolution and the capability to sample at rates of 100 Hz and higher, fiber optic (FO strain sensors offer exciting new possibilities for in-situ landslide monitoring. Here we describe a new FO monitoring system based on long-gauge fiber Bragg grating sensors installed at the Randa Rockslide Laboratory in southern Switzerland. The new FO monitoring system can detect sub-micrometer scale deformations in both triggered-dynamic and continuous measurements. Two types of sensors have been installed: (1 fully embedded borehole sensors and (2 surface extensometers. Dynamic measurements are triggered by sensor deformation and recorded at 100 Hz, while continuous data are logged every 5 min. Deformation time series for all sensors show displacements consistent with previous monitoring. Accelerated shortening following installation of the borehole sensors is likely related to long-term shrinkage of the grout. A number of transient signals have been observed, which in some cases were large enough to trigger rapid sampling. The combination of short- and long-term observation offers new insight into the deformation process. Accelerated surface crack opening in spring is shown to have a diurnal trend, which we attribute to the effect of snowmelt seeping into the crack void space and freezing at night to generate pressure on the crack walls. Controlled-source tests investigated the sensor response to dynamic inputs, which compared an independent measure of ground motion against the strain measured across a surface crack. Low frequency signals were comparable but the FO record suffered from aliasing, where undersampling of higher frequency signals generated spectral peaks not related to ground motion.

  18. a Novel Instrument to Monitor Lanslides Deformation

    Science.gov (United States)

    Pasuto, A.; Mantovani, M.; Schenato, L.; Scherneck, H.

    2013-12-01

    Landslides are more widespread than any other geological event and have high ranking among the natural disasters in terms of casualties and economical damages. Deforestation and constructions of new settlements and infrastructures, as direct consequences of population growth, and the increasing frequency of extreme meteorological events, due to the global climatic changing, could lead to a more severe impact of landslides on human life and activities in the next future. Risk reduction generally comes through countermeasures, both structural and non-structural, that directly act on the developing process or tend to reduce the effects on the fabric of the city and of the environment. Nevertheless countermeasures have often shown their flimsiness especially if they are carried out on disruptions hard to stabilize for their dimensions, kinematics and morpho-evolutive conditions. In these cases there are basically two options: the relocation of the element at risk or the surveillance of the evolution of the instability process by means of a monitoring system. Monitoring therefore represents a powerful tool in both the surveillance of the territory and the management of the emergencies coming from geo-hydrological hazard. In this study we propose the development and testbedding of a novel, low-cost wireless smart sensor network for remote monitoring of land surface deformations. The purpose is to create a flexible and scalable monitoring system in order to overcome some of the limitations of the existing devices and to strongly reduce the costs. The system consists in a master station that works as a control and measuring unit, and a series of sensors (motes) placed over the unstable areas. The master station transmits a microwave signal and receives the response from each mote measuring their relative position and inferring any deformation occurred between successive interrogations. Moreover the motes can work as bridges so that even those that are not directly visible

  19. Ground-Water Protection and Monitoring Program

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P.E.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the ground-water protection and monitoring program strategy for the Hanford Site in 1994. Two of the key elements of this strategy are to (1) protect the unconfined aquifer from further contamination, and (2) conduct a monitoring program to provide early warning when contamination of ground water does occur. The monitoring program at Hanford is designed to document the distribution and movement of existing ground-water contamination and provides a historical baseline for evaluating current and future risk from exposure to the contamination and for deciding on remedial action options.

  20. Monitoring and analysis of dam deformations Sherman Island hydroelectric development

    Energy Technology Data Exchange (ETDEWEB)

    Rohde, M.W.; Asce, A.M. [Coler & Colantonio, Inc., Norwell, MA (United States); Zuccolotto, J.M. [Niagara Mohawak Power Corporation, Syracuse, NY (United States)

    1995-12-31

    A modern integrated deformation monitoring program established for a reconstructed buttress dam is presented. A brief overview of the monitoring program will be provided along with discussions on equipment calibration aspects, how to assess the quality of the observation data, methods used to verify stability of the deformation network and to establish a trend of the deformations, how to develop deformation models which accurately reflect the spatial and temporal motions of the structure, including an investigation into the use of the Global Positioning System (GPS) for monitoring the deformations.

  1. 40 CFR 265.91 - Ground-water monitoring system.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Ground-water monitoring system. 265.91... DISPOSAL FACILITIES Ground-Water Monitoring § 265.91 Ground-water monitoring system. (a) A ground-water monitoring system must be capable of yielding ground-water samples for analysis and must consist of: (1...

  2. Nuclear ground-state masses and deformations: FRDM(2012)

    CERN Document Server

    Moller, P; Ichikawa, T; Sagawa, H

    2015-01-01

    We tabulate the atomic mass excesses and binding energies, ground-state shell-plus-pairing corrections, ground-state microscopic corrections, and nuclear ground-state deformations of 9318 nuclei ranging from $^{16}$O to $A=339$. The calculations are based on the finite-range droplet macroscopic model and the folded-Yukawa single-particle microscopic model. Relative to our FRDM(1992) mass table in {\\sc Atomic Data and Nuclear Data Tables} [{\\bf 59} 185 (1995)], the results are obtained in the same model, but with considerably improved treatment of deformation and fewer of the approximations that were necessary earlier, due to limitations in computer power. The more accurate execution of the model and the more extensive and more accurate experimental mass data base now available allows us to determine one additional macroscopic-model parameter, the density-symmetry coefficient $L$, which was not varied in the previous calculation, but set to zero. Because we now realize that the FRDM is inaccurate for some high...

  3. Comparison of Small Baseline Interferometric SAR Processors for Estimating Ground Deformation

    Directory of Open Access Journals (Sweden)

    Wenyu Gong

    2016-04-01

    Full Text Available The small Baseline Synthetic Aperture Radar (SAR Interferometry (SBI technique has been widely and successfully applied in various ground deformation monitoring applications. Over the last decade, a variety of SBI algorithms have been developed based on the same fundamental concepts. Recently developed SBI toolboxes provide an open environment for researchers to apply different SBI methods for various purposes. However, there has been no thorough discussion that compares the particular characteristics of different SBI methods and their corresponding performance in ground deformation reconstruction. Thus, two SBI toolboxes that implement a total of four SBI algorithms were selected for comparison. This study discusses and summarizes the main differences, pros and cons of these four SBI implementations, which could help users to choose a suitable SBI method for their specific application. The study focuses on exploring the suitability of each SBI module under various data set conditions, including small/large number of interferograms, the presence or absence of larger time gaps, urban/vegetation ground coverage, and temporally regular/irregular ground displacement with multiple spatial scales. Within this paper we discuss the corresponding theoretical background of each SBI method. We present a performance analysis of these SBI modules based on two real data sets characterized by different environmental and surface deformation conditions. The study shows that all four SBI processors are capable of generating similar ground deformation results when the data set has sufficient temporal sampling and a stable ground backscatter mechanism like urban area. Strengths and limitations of different SBI processors were analyzed based on data set configuration and environmental conditions and are summarized in this paper to guide future users of SBI techniques.

  4. Observations of coupled seismicity and ground deformation at El Hierro Island (2011-2014)

    Science.gov (United States)

    Gonzalez, P. J.

    2015-12-01

    New insights into the magma storage and evolution at oceanic island volcanoes are now being achieved using remotely sensed space geodetic techniques, namely satellite radar interferometry. Differential radar interferometry is a technique tracking, at high spatial resolution, changes in the travel-time (distance) from the satellites to the ground surface, having wide applications in Earth sciences. Volcanic activity usually is accompanied by surface ground deformation. In many instances, modelling of surface deformation has the great advantage to estimate the magma volume change, a particularly interesting parameter prior to eruptions. Jointly interpreted with petrology, degassing and seismicity, it helps to understand the crustal magmatic systems as a whole. Current (and near-future) radar satellite missions will reduce the revisit time over global sub-aerial volcanoes to a sub-weekly basis, which will increase the potential for its operational use. Time series and filtering processing techniques of such streaming data would allow to track subsurface magma migration with high precision, and frequently update over vast areas (volcanic arcs, large caldera systems, etc.). As an example for the future potential monitoring scenario, we analyze multiple satellite radar data over El Hierro Island (Canary Islands, Spain) to measure and model surface ground deformation. El Hierro has been active for more than 3 years (2011 to 2014). Initial phases of the unrest culminated in a submarine eruption (late 2011 - early 2012). However, after the submarine eruption ended, its magmatic system still active and affected by pseudo-regular energetic seismic swarms, accompanied by surface deformation without resumed eruptions. Such example is a great opportunity to understand the crustal magmatic systems in low magma supply-rate oceanic island volcanoes. This new approach to measure surface deformation processes is yielding an ever richer level of information from volcanology to

  5. Theory and Practice of the SSDM for GPS Deformation Monitoring

    Institute of Scientific and Technical Information of China (English)

    L(U) Wei-cai; XU Shao-quan

    2006-01-01

    Global Positioning System technique is widely used to monitor the deformations of all kinds of buildings and constructions. According to the characteristics of the high precise GPS deformation monitoring, the theory and practice of the SSDM (Similar Single-Difference Methodology) for GPS deformation monitoring are introduced synthetically from the background, the essential mathematic model,the error sources and control measures, the monitoring schemes and the software development. Some arguments are also given in the form of reference literatures. Based on the first period observation results of the GPS monitor network, SSDM solves the monitoring points' deformation values at a single epoch from carrier phases directly, without needing to solve baseline vectors and network adjustment. The SSDM avoids the troublesome problem of detecting and repairing cycle slips, and can be used in static and dynamic deformation monitoring. In the SSDM, the unknown parameters have no relation to the numbers of satellites. If the number of synchronous satellites between stations is not less than two, the monitoring point's deformation information can be solved easily.

  6. 40 CFR 257.22 - Ground-water monitoring systems.

    Science.gov (United States)

    2010-07-01

    ... operator. When physical obstacles preclude installation of ground-water monitoring wells at the relevant... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Ground-water monitoring systems. 257... Waste Disposal Units Ground-Water Monitoring and Corrective Action § 257.22 Ground-water......

  7. Characterization of Ground Deformation above AN Urban Tunnel by Means of Insar Time Series Analysis

    Science.gov (United States)

    Ferretti, A.; Iannacone, J.; Falorni, G.; Berti, M.; Corsini, A.

    2013-12-01

    Ground deformation produced by tunnel excavation in urban areas can cause damage to buildings and infrastructure. In these contexts, monitoring systems are required to determine the surface area affected by displacement and the rates of movement. Advanced multi-image satellite-based InSAR approaches are uniquely suited for this purpose as they provide an overview of the entire affected area and can measure movement rates with millimeter precision. Persistent scatterer approaches such as SqueeSAR™ use reflections off buildings, lampposts, roads, etc to produce a high-density point cloud in which each point has a time series of deformation spanning the period covered by the imagery. We investigated an area of about 10 km2 in North Vancouver, (Canada) where the shaft excavation of the Seymour-Capilano water filtration plant was started in 2004. As part of the project, twin tunnels in bedrock were excavated to transfer water from the Capilano Reservoir to the treatment plant. A radar dataset comprising 58 images (spanning March 2001 - June 2008) acquired by the Radarsat-1 satellite and covering the period of excavation was processed with the SqueeSAR™ algorithm (Ferretti et al., 2011) to assess the ground deformation caused by the tunnel excavation. To better characterize the deformation in the time and space domains and correlate ground movement with excavation, an in-depth time series analysis was carried out. Berti et al. (2013) developed an automatic procedure for the analysis of InSAR time series based on a sequence of statistical tests. The tool classifies time series into six distinctive types (uncorrelated; linear; quadratic; bilinear; discontinuous without constant velocity; discontinuous with change in velocity) which can be linked to different physical phenomena. It also provides a series of descriptive parameters which can be used to characterize the temporal changes of ground motion. We processed the movement time series with PSTime to determine the

  8. Game model of safety monitoring for arch dam deformation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Arch dam deformation is comprehensively affected by water pressure,temperature,dam’s structural behavior and material properties as well as other factors.Among them the water pressure and temperature are external factors(source factors) that cause dam deformation,and dam’s structural behavior and material properties are the internal factors of deformation(resistance factors).The dam deformation is the result of the mutual game playing between source factors and resistance factors.Therefore,resistance factors of structure and materials that reflect resistance character of arch dam structure are introduced into the traditional model,where structure factor is embodied by the flexibility coefficient of dam body and the maximum dam height,and material property is embodied by the elastic modulus of dam.On the basis of analyzing the correlation between dam deformation and resistance factors,the game model of safety monitoring for arch dam deformation is put forward.

  9. Ground Surface Deformations Near a Fault-Bounded Groundwater Aquifer

    Science.gov (United States)

    Lipovsky, B.; Funning, G. J.; Ferretti, A.

    2011-12-01

    Geodetic data often reveal the presence of groundwater aquifers that are bounded by faults (Schmidt and Bürgmann, 2003; Galloway and Hoffmann, 2007; Bell et al., 2008). Whereas unrestricted groundwater aquifers exhibit a radially symmetric pattern of uplift with diffuse boundaries, aquifers that are bounded by faults have one or more sharp, linear boundaries. Interferometric synthetic aperture (InSAR) data, due to their high spatial density, are particularly well suited to observe fault bounded aquifers, and the Santa Clara Aquifer in the San Francisco Bay Area, California, constitutes an excellent example. The largest ground surface displacements in the Bay Area are due to the inflation of the Santa Clara aquifer, and InSAR data plainly show that the Santa Clara aquifer is partitioned by the Silver Creek fault. This study first develops a general model of the displacements at the surface of the Earth due to fluid diffusion through a buried permeable boundary such as a fault zone. This model is compared to InSAR data from the Silver Creek fault and we find that we are able to infer fault zone poromechanical properties from InSAR data that are comparable to in situ measurements. Our theoretical model is constrained by several geological and hydrological observations concerning the structure of fault zones. Analytical solutions are presented for the ground surface displacements due to a perfectly impermeable fault zone. This end-member family of models, however, does not fit the available data. We therefore make allowance for an arbitrarily layered, variably permeable, one-dimensional fault zone. Time-dependent ground surface deformations are calculated in the Laplace domain using an efficient semi-analytic method. This general model is applicable to other poroelastic regimes including geothermal and hydrocarbon systems. We are able to estimate fault zone hydraulic conductivity by comparing theoretical ground surface displacements in a permeable fault zone to

  10. 40 CFR 258.51 - Ground-water monitoring systems.

    Science.gov (United States)

    2010-07-01

    ... preclude installation of ground-water monitoring wells at the relevant point of compliance at existing... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Ground-water monitoring systems. 258... CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Ground-Water Monitoring and Corrective Action § 258.51...

  11. Piezoelectric nanoribbons for monitoring cellular deformations

    Science.gov (United States)

    Nguyen, Thanh D.; Deshmukh, Nikhil; Nagarah, John M.; Kramer, Tal; Purohit, Prashant K.; Berry, Michael J.; McAlpine, Michael C.

    2012-09-01

    Methods for probing mechanical responses of mammalian cells to electrical excitations can improve our understanding of cellular physiology and function. The electrical response of neuronal cells to applied voltages has been studied in detail, but less is known about their mechanical response to electrical excitations. Studies using atomic force microscopes (AFMs) have shown that mammalian cells exhibit voltage-induced mechanical deflections at nanometre scales, but AFM measurements can be invasive and difficult to multiplex. Here we show that mechanical deformations of neuronal cells in response to electrical excitations can be measured using piezoelectric PbZrxTi1-xO3 (PZT) nanoribbons, and we find that cells deflect by 1 nm when 120 mV is applied to the cell membrane. The measured cellular forces agree with a theoretical model in which depolarization caused by an applied voltage induces a change in membrane tension, which results in the cell altering its radius so that the pressure remains constant across the membrane. We also transfer arrays of PZT nanoribbons onto a silicone elastomer and measure mechanical deformations on a cow lung that mimics respiration. The PZT nanoribbons offer a minimally invasive and scalable platform for electromechanical biosensing.

  12. Monitoring Crustal Deformations with Radar Interferometry:A Review

    Institute of Scientific and Technical Information of China (English)

    刘国祥; 丁晓利; 黄丁发

    2004-01-01

    The crustal movements, probably motivating earthquakes, are considered as one of the main geodynamic sources. The quantitative measurements of ground surface deformations are vital for studying mechanisms of the buried faults or even estimating earthquake potential. A new space-geodetic technology, synthetic aperture radar interferometry (InSAR), can be applied to detect such large-area deformations, and has demonstrated some prominent advantages. This paper reviews the capacity and limitations of InSAR, and summarises the existing applications including some of our results in studying the earthquake-related crustal motions.Finally it gives the outlook for the future development of InSAR.

  13. Ground Deformation Extraction Using Visible Images and LIDAR Data in Mining Area

    Science.gov (United States)

    Hu, Wenmin; Wu, Lixin

    2016-06-01

    Recognition and extraction of mining ground deformation can help us understand the deformation process and space distribution, and estimate the deformation laws and trends. This study focuses on the application of ground deformation detection and extraction combining with high resolution visible stereo imagery, LiDAR observation point cloud data and historical data. The DEM in large mining area is generated using high-resolution satellite stereo images, and ground deformation is obtained through time series analysis combined with historical DEM data. Ground deformation caused by mining activities are detected and analyzed to explain the link between the regional ground deformation and local deformation. A district of covering 200 km2 around the West Open Pit Mine in Fushun of Liaoning province, a city located in the Northeast China is chosen as the test area for example. Regional and local ground deformation from 2010 to 2015 time series are detected and extracted with DEMs derived from ZY-3 images and LiDAR point DEMs in the case study. Results show that the mean regional deformation is 7.1 m of rising elevation with RMS 9.6 m. Deformation of rising elevation and deformation of declining elevation couple together in local area. The area of higher elevation variation is 16.3 km2 and the mean rising value is 35.8 m with RMS 15.7 m, while the deformation area of lower elevation variation is 6.8 km2 and the mean declining value is 17.6 m with RMS 9.3 m. Moreover, local large deformation and regional slow deformation couple together, the deformation in local mining activities has expanded to the surrounding area, a large ground fracture with declining elevation has been detected and extracted in the south of West Open Pit Mine, the mean declining elevation of which is 23.1 m and covering about 2.3 km2 till 2015. The results in this paper are preliminary currently; we are making efforts to improve more precision results with invariant ground control data for validation.

  14. Real-time GNSS volcano deformation monitoring (Invited)

    Science.gov (United States)

    Lisowski, M.; Langbein, J. O.; Hudnut, K. W.

    2013-12-01

    We present comparisons of the precision obtained from several alternative real-time GNSS processing methods, and show how offsets caused by snow and ice on an antenna can be automatically identified in real time using signal-to-noise ratio (SNR) data. We monitor ground deformation using continuous GNSS stations installed on several volcanoes in the Cascade Range and elsewhere, and many of these stations transmit high-rate (1s) data in real-time. We examine real-time, high-rate station position solutions obtained with two implementations of centralized RTNet (GPS Solutions, Inc.) processing, and find that the precision is roughly the same for ambiguity-fixed network solutions and for ambiguity-fixed precise point position solutions (PPPAR). The PPPAR method uses satellite clock corrections provided by GPS Solutions from a network of Plate Boundary Observatory (PBO) stations in western Oregon. The precision of network solutions that include GPS and GLONASS data is similar to the GPS-only solutions, except at stations with a relatively poor view of the sky. An alternative method of processing the real-time GPS data uses clock corrections transmitted directly to the receiver, which then autonomously calculates and transmits positions. We will compare our RTNet results with autonomous point position solutions calculated using Trimble's CenterPoint RTX corrections. RTX performance in repeated, controlled, large antenna-motion tests by USGS and UNAVCO indicates that it meets requirements of USGS volcano-monitoring applications; more thorough testing and performance checks on an ongoing basis would be desirable. GNSS antennas on volcanoes often become temporarily coated with ice or buried by snow in the winter. In these situations, signal delays introduce an apparent offset in the monitoring station's position. We address this problem by implementing in real time a technique developed by Kristine Larson that uses changes in the signal-to-noise ratio (SNR) of GNSS signals

  15. Eruptive history, seismic activity and ground deformations at Mt. Vesuvius, Italy

    Energy Technology Data Exchange (ETDEWEB)

    Bonasia, V. (Dipt. di Geofisica e Vulcanologia, Universita di Napoli (Italy)); Del Pezzo, E.; Pingue, F.; Scandone, R.; Scarpa, R. (Osservatorio Vesuviano, Napoli (Italy))

    Mt. Vesuvius is an active volcano characterized by a quiescent state of activity since April 1944. The high density of population in this region, combined with the past volcanic history, makes it potentially one of the most dangerous in the world. This paper reports all the results on the seismic and ground deformation monitoring performed during the last 13 years. The present seismic activity is characterized by a moderate level of microearthquakes, about 1 event/day, which is presently monitored at OVO station, magnitude threshold 1.7. These microearthquakes exhibit a clustering tendency, following a generalized Poisson process, with the grouped events distributed according to Riemann statistics. Horizontal and vertical distance measurements around this volvanic region have not shown any significant deformation, during the last 7 years, in agreement with the present low seismic activity. The eruptive history and structural framework indicate a possible triggering mechanism for eruptions in the seismic episodes of the neighbouring mountain chain, but further complexities in the feeding system make any simple correlation between eruptions and regional strain release processes difficult.

  16. On InSAR Ambiguity Resolution For Deformation Monitoring

    Science.gov (United States)

    Teunissen, P.

    2006-01-01

    Integer carrier phase ambiguity resolution is the key to fast and highprecision satellite positioning and navigation. It applies to a great variety of current and future models of GPS, modernized GPS and Galileo. It also applies to stacked radar interferometry for deformation monitoring, see e.g. [Hanssen, et al, 2001]. In this contribution we apply the integer least-squares' principle to the rank defect model of stacked InSAR carrier phase data. We discuss two ways of dealing with the rank defect for ambiguity resolution. One is based on the use of a priori data, the other is based on the use of an interval constraint on the deformation rate.

  17. Implementing ground surface deformation tools to characterize field-scale properties of a fractured aquifer during a short hydraulic test

    Science.gov (United States)

    Schuite, Jonathan; Longuevergne, Laurent; Bour, Olivier; Boudin, Frédérick; Durand, Stéphane

    2016-04-01

    In naturally fractured reservoirs, fluid flow is governed by the structural and hydromechanical properties of fracture networks or conductive fault zones. In order to ensure a sustained exploitation of resources or to assess the safety of underground storage, it is necessary to evaluate these properties. As they generally form highly heterogeneous and anisotropic reservoirs, fractured media may be well characterized by means of several complementary experimental methods or sounding techniques. In this framework, the observation of ground deformation has been proved useful to gain insight of a fractured reservoir's geometry and hydraulic properties. Commonly, large conductive structures like faults can be studied from surface deformation from satellite methods at monthly time scales, whereas meter scale fractures have to be examined under short-term in situ experiments using high accuracy intruments like tiltmeters or extensometers installed in boreholes or at the ground's surface. To the best of our knowledge, the feasability of a field scale (~ 100 m) characterization of a fractured reservoir with geodetic tools in a short term experiment has not yet been addressed. In the present study, we implement two complementary ground surface geodetic tools, namely tiltmetry and optical leveling, to monitor the deformation induced by a hydraulic recovery test at the Ploemeur hydrological observatory (France). Employing a simple purely elastic modeling approach, we show that the joint use of time constraining data (tilt) and spatially constraining data (vertical displacement) makes it possible to evaluate the geometry (dip, root depth and lateral extent) and the storativity of a hydraulically active fault zone, in good agreement with previous studies. Hence we demonstrate that the adequate use of two complementary ground surface deformation methods offer a rich insight of large conductive structure's properties using a single short term hydraulic load. Ground surface

  18. Characteristics of Multipath Effects in GPS Dynamic Deformation Monitoring

    Institute of Scientific and Technical Information of China (English)

    HUANG Shengxiang; JIN Xiangsheng; YANG Baocen

    2006-01-01

    The multipath has long been considered a major error source in GPS applications. The characteristics of the GPS signal multipath effects are analyzed, based on which an experiment that considers the characteristics of dynamic deformation monitoring has been carried out. The solution results of observation data in two successive days are processed by a method, which combines the wavelet filtering and the differential correction between two successive days. The research demonstrates that the multipath errors have stronger repeatability on successive days; after significantly mitigating the influence of multipath effects, the accuracy of three-dimensional positioning for GPS dynamic deformation monitoring can attain the mm level, an obvious accuracy improving particularly in vertical component. The characteristics of GPS signal multipath, the experimental scheme and the qualitative and quantitative analysis of results are detailed.

  19. Deformation Monitoring of Retrofitted Short Concrete Columns with Laser Sensor

    Science.gov (United States)

    Avsar, E. Ö.; Celik, M. F.; Binbir, E.; Arslan, A. E.; Çokkeçeci, D.; Seker, D. Z.; Pala, S.

    2016-06-01

    This paper presents one of the applications of monitoring mechanical tests carried out in Construction Materials Laboratory of Istanbul Technical University. In Turkey, as in many countries, large amount of existing buildings exposed to seismic hazard, therefore various analytical and experimental studies are being conducted to contribute to the solution of the problem. One of the new generation retrofitting techniques is to strength the structural members by using Fiber Reinforcing Polymer (FRP). This study summarize the results of monitoring of deformations short concrete column samples under the incremental compression load. In this study, result of two rectangular short columns are given. One of them was tested as a reference sample, the other sample were tested after strengthening by PET reinforced polymer composite materials. Besides conventional displacement and strain measurement systems, laser scanning method was used to get three dimensional deformed shape of sample at each selected steps.

  20. Monitoring Building Deformation with InSAR: Experiments and Validation.

    Science.gov (United States)

    Yang, Kui; Yan, Li; Huang, Guoman; Chen, Chu; Wu, Zhengpeng

    2016-12-20

    Synthetic Aperture Radar Interferometry (InSAR) techniques are increasingly applied for monitoring land subsidence. The advantages of InSAR include high accuracy and the ability to cover large areas; nevertheless, research validating the use of InSAR on building deformation is limited. In this paper, we test the monitoring capability of the InSAR in experiments using two landmark buildings; the Bohai Building and the China Theater, located in Tianjin, China. They were selected as real examples to compare InSAR and leveling approaches for building deformation. Ten TerraSAR-X images spanning half a year were used in Permanent Scatterer InSAR processing. These extracted InSAR results were processed considering the diversity in both direction and spatial distribution, and were compared with true leveling values in both Ordinary Least Squares (OLS) regression and measurement of error analyses. The detailed experimental results for the Bohai Building and the China Theater showed a high correlation between InSAR results and the leveling values. At the same time, the two Root Mean Square Error (RMSE) indexes had values of approximately 1 mm. These analyses show that a millimeter level of accuracy can be achieved by means of InSAR technique when measuring building deformation. We discuss the differences in accuracy between OLS regression and measurement of error analyses, and compare the accuracy index of leveling in order to propose InSAR accuracy levels appropriate for monitoring buildings deformation. After assessing the advantages and limitations of InSAR techniques in monitoring buildings, further applications are evaluated.

  1. Monitoring of Huaihe DikeDeformation Caused by Mining

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on a large number of data gathered through monitoring and surveying, this paper gives modifica-tion and calculation formulas of the movement and deformation of the dike slope. The variation of subsidence andhorizontal movement in the dike interior is analyzed. And from the geological condition of the dike, the interrela-tion between the subsidence, horizontal movement and the stratum structure and the basic laws are discussed.

  2. A Study of Ground Deformation in the Guangzhou Urban Area with Persistent Scatterer Interferometry

    Directory of Open Access Journals (Sweden)

    Qing Zhao

    2009-01-01

    Full Text Available TheInterferometric Point Target Analysis (IPTA technique and Advanced Synthetic Aperture Radar (ASAR images acquired over Hong Kong from 2007–2008 were used to detect ground deformation in the urban area of Guangzhou city in South China. A ground deformation rate map with scattered distribution of point targets shows the maximum subsidence (rise rate as high as -26 to -20 mma-1 (16–21 mma-1, implying that the study area is an active zone for ground deformation. Based on the point target map, a contour ground deformation rate map is generated. The map shows three major subsidence zones located in the middle-west, the east, and the southwest of the study area, respectively. All the six ground collapse accidents that occurred in 2007–2008 fall within the subsidence zones, qualitatively validating the IPTA results. Ground subsidence and geological conditions on Datansha Island are examined. The results indicate that the local geological conditions, such as limestone Karst geomorphology as well as silt layers characterized by high water content, high void ratio, high compressibility, low bearing capacity and low shear strength, and underground engineering projects are responsible for ground subsidence and ground collapse accidents occurred there.

  3. A study of ground deformation in the guangzhou urban area with persistent scatterer interferometry.

    Science.gov (United States)

    Zhao, Qing; Lin, Hui; Jiang, Liming; Chen, Fulong; Cheng, Shilai

    2009-01-01

    The Interferometric Point Target Analysis (IPTA) technique and Advanced Synthetic Aperture Radar (ASAR) images acquired over Hong Kong from 2007-2008 were used to detect ground deformation in the urban area of Guangzhou city in South China. A ground deformation rate map with scattered distribution of point targets shows the maximum subsidence (rise) rate as high as -26 to -20 mma(-1) (16-21 mma(-1)), implying that the study area is an active zone for ground deformation. Based on the point target map, a contour ground deformation rate map is generated. The map shows three major subsidence zones located in the middle-west, the east, and the southwest of the study area, respectively. All the six ground collapse accidents that occurred in 2007-2008 fall within the subsidence zones, qualitatively validating the IPTA results. Ground subsidence and geological conditions on Datansha Island are examined. The results indicate that the local geological conditions, such as limestone Karst geomorphology as well as silt layers characterized by high water content, high void ratio, high compressibility, low bearing capacity and low shear strength, and underground engineering projects are responsible for ground subsidence and ground collapse accidents occurred there.

  4. In-situ monitoring of deformation of clayey and volcanic sequences in the lacustrine plain of Iztapalapa, Mexico City

    Science.gov (United States)

    Carreon-Freyre, D.; Cerca, M.; Barrientos, B.; Gutierrez, R.; Blancas, D.

    2012-12-01

    Major cities of Central Mexico with lowering of land elevation problems are located in inter-volcanic and fault bounded basins within the central Trans-Mexican Volcanic Belt (TMVB). The most representative and studied case of ground deformation is Mexico City, where the Iztapalapa Municipality presents the highest population density. This area is located over the geological contact between the "Sierra de Santa Catarina" volcanic range and a lacustrine plain. Filling of lacustrine basins includes silty and clayey sediments as well as pyroclastic deposits (coarse and fine grained) and volcanic rocks layers. We used Ground Penetrating Radar (GPR) and MASW prospection to evaluate contrasts in the physical properties of fine grained soils and identify geometry of the deformational features and implemented a mechanical system for in situ monitoring in fractured sites. Deformational features in this basin reflect an interplay between the geological history (depositional conditions), load history, seismic activity, and faulting. Plastic mechanical behaviour predominates in these clayey sediments and differential deformation locally triggers brittle fracturing and/or subsidence of the surface. In this work we present the results of monitoring and characterization of ground deformation and fracturing in different sequences, our results show a dynamic interplay between the mechanisms of ground fracturing and the stress history of sedimentary sequences. Relating the mechanical behaviour of the studied sequences with variations of physical and geological properties should be taken into account to estimate land level lowering and risk of fracturing for urban development planning.

  5. Integrating ALOS-2 and Sentinel-1 InSAR data for systematic volcano deformation monitoring

    Science.gov (United States)

    Hickey, James; Biggs, Juliet; Ebmeier, Susanna; Parker, Amy

    2016-04-01

    The recent launches of the Sentinel-1 and ALOS-2 satellites provide a wealth of new Interferometric Synthetic Aperture Radar (InSAR) data for Earth observation purposes. We exploit these data for volcano deformation monitoring with a particular focus on Latin America, which is nominated as a priority target area under the Committee on Earth Observation Satellites volcano pilot program. By conducting an integrated survey that employs both Sentinel-1 and ALOS-2 we are able to achieve previously unprecedented levels of spatial and temporal resolution and combat decorrelation arising from vegetation cover. Latin America is an ideal target region as it has a diversity of geographic volcano locations (e.g., dense rainforest to high-altitude deserts), as well as abundant and varied volcanic activity. The numerous local volcano observatories can also directly benefit from this additional InSAR data when integrating it alongside ground-based observations. To further facilitate this impact we are directing our data outputs to a global volcano deformation database in near-real-time to provide a first-order access point for observatory staff and research scientists in need of satellite-derived ground-deformation results. We will draw upon a selection of case studies within Latin America to demonstrate our approach and how it can enhance volcano monitoring and eruption forecasting efforts.

  6. Correlation study between ground motion intensity measure parameters and deformation demands for bilinear SDOF systems

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The correlation between ground motion intensity measures (IM) and single-degree-of-freedom (SDOF) deformation demands is described in this study. Peak ground acceleration (APG), peak ground velocity (VPG), peak ground displacement (DPG), spectral acceleration at the first-mode period of vibration [As(T1)] and ratio of VPG to APG are used as IM parameters, and the correlation is characterized by correlation coefficients ρ. The numerical results obtained by nonlinear dynamic analyses have shown good correlation between As(T1) or VPG and deformation demands. Furthermore, the effect of As(T1) and VPG as IM on the dispersion of the mean value of deformation demands is also investigated for SDOF systems with three different periods T=0.3 s, 1.0 s, 3.0 s respectively.

  7. Design and Implementation of a Modern Automatic Deformation Monitoring System

    Science.gov (United States)

    Engel, Philipp; Schweimler, Björn

    2016-03-01

    The deformation monitoring of structures and buildings is an important task field of modern engineering surveying, ensuring the standing and reliability of supervised objects over a long period. Several commercial hardware and software solutions for the realization of such monitoring measurements are available on the market. In addition to them, a research team at the University of Applied Sciences in Neubrandenburg (NUAS) is actively developing a software package for monitoring purposes in geodesy and geotechnics, which is distributed under an open source licence and free of charge. The task of managing an open source project is well-known in computer science, but it is fairly new in a geodetic context. This paper contributes to that issue by detailing applications, frameworks, and interfaces for the design and implementation of open hardware and software solutions for sensor control, sensor networks, and data management in automatic deformation monitoring. It will be discussed how the development effort of networked applications can be reduced by using free programming tools, cloud computing technologies, and rapid prototyping methods.

  8. A Feasible Approach for Improving Accuracy of Ground Deformation Measured by D-InSAR

    Institute of Scientific and Technical Information of China (English)

    CHANG Zhan-qiang; GONG Hui-li; ZHANG Jing-fa; GONG Li-xia

    2007-01-01

    D-InSAR is currently one of the most popular research tools in the field of Microwave Remote Sensing. It is unrivaled in its aspect of measuring ground deformation due to its advantages such as high resolution, continuous spatial-coverage and dynamics. However, there are still a few major problems to be solved urgently as a result of the intrinsic complexity of this technique. One of the problems deals with improving the accuracy of measured ground deformation. In this paper, various factors affecting the accuracy of ground deformation measured by D-InSAR are systematically analyzed and investigated by means of the law of measurement error propagation. At the same time, we prove that the ground deformation error not only depends on the errors of perpendicular baselines as well as the errors of the interferometric phase for topographic pair and differential pair, but also on the combination of the relationship of perpendicular baselines for topographic pairs and differential pairs. Furthermore, a feasible approach for improving the accuracy of measured ground deformation is proposed, which is of positive significance in the practical application of D-InSAR.

  9. A New GPS System for Continuous Deformation Monitoring

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper presents a multi-antenna GPS based system developed for localcontinuous deformation monitoring. Due to a large number of points that needs to be monitored,the standard approaches of using permanent GPS receiver arrays will cause high cost. Iteventually becomes the limiting factor for large-scale use of GPS in these application areas.Multi-antenna GPS system allows a number of GPS antennas to be linked to one GPS receiverby a specially designed electronic component, i.e. the so-called GPS multi-antenna switch(GMS), The receiver takes data sequentially from each of the antennas attached to thereceiver. A distinctive advantage of the approach is that one GPS receiver can be used tomonitor more than one point. The cost per monitored point (i. e. the expenses of hardware)istherefore significantly reduced.

  10. Joint Terrestrial and Aerial Measurements to Study Ground Deformation: Application to the Sciara Del Fuoco at the Stromboli Volcano (Sicily

    Directory of Open Access Journals (Sweden)

    Alessandro Bonforte

    2016-05-01

    Full Text Available The 2002–2003 Stromboli eruption triggered the failure of part of the Sciara del Fuoco slope, which generated a tsunami that struck the island and the northern coastline of Sicily. The Sciara del Fuoco is a very steep slope where all lava flows from the craters’ emplacement; most lateral eruptions usually take place from fissures propagating in this sector of the volcano. The eruption went on to produce a lava field that filled the area affected by the landslide. This in turn led to further instability, renewing the threat of another slope failure and a potentially related tsunami. This work describes a new joint approach, combining surveying data and aerial image correlometry methods, to study the motion of this unstable slope. The combination has the advantage of very precise surveying measurements, which can be considered the ground truth to constrain the very-high-resolution aerial photogrammetric data, thereby obtaining highly detailed and accurate ground deformation maps. The joint use of the two methods can be very useful to obtain a more complete image of the deformation field for monitoring dangerous and/or rather inaccessible places. The proposed combined methodology improves our ability to study and assess hazardous processes associated with significant ground deformation.

  11. GNSS Monitoring of Deformation within heavy civil infrastructure

    Science.gov (United States)

    Montillet, Jean-Philippe; Melbourne, Timothy; Szeliga, Walter; Schrock, Gavin

    2015-04-01

    The steady increase in precision simultaneous with the decreasing of continuous GPS monitoring has enabled the deployment of receivers for a host of new activities. Here we discuss the precision obtained from several multi-station installations operated over a five-year period on several heavy civil-engineered structures, including two earthen-fill dams and subsiding highway overpass damaged by seismic shaking. In the past 5 years, the Cascadia Hazards Institute (Pacific Northwest Geodetic Array) at Central Washington University together with the Washington department of public utilities (Land Survey) have been monitoring several structures around Seattle area including two dams (Howard Hansen and Tolt). One aim of this study is to test the use of continuous GNSS in order to detect any deformations due to rapid pool level rises or to monitor the safety of a structure when an Earthquake strikes it. In this study, data is processed using Real Time Kinematic GPS with short baseline (d GPS daily position (PPP). However, multipath is the most limiting factor on accuracy for very precise positioning applications with GPS. It is very often present indoors and outdoors, especially in narrow valleys with a limited view of the sky. As a result, multipath can amount to an error of a few centimetres. Unfortunately, the accuracy requirements of precision deformation monitoring are generally at the sub centimetre level, which is presently a big challenge on an epoch-by-epoch basis with regular, carrier phase techniques. Thus, it needs to be properly mitigated. In this study, several stations are set up on the dams (4 stations on the Tolt reservoir and 10 stations on the Howard Hansen dam), and spatial filtering can then be used to mitigate multipath. In addition, several signal processing techniques are also investigated (i.e. Empirical mode decomposition, sidereal filtering, adaptive filtering). RTK GPS should allow to monitor rapid deformations, whereas GPS daily position is

  12. Use of global navigation satellite systems for monitoring deformations of water-development works

    Energy Technology Data Exchange (ETDEWEB)

    Kaftan, V. I. [Russian Academy of Sciences, Geophysical Center (Russian Federation); Ustinov, A. V. [JSC Institut Gidropreoekt (Russian Federation)

    2013-05-15

    The feasibility of using global radio-navigation satellite systems (GNSS) to improve functional safety of high-liability water-development works - dams at hydroelectric power plants, and, consequently, the safety of the population in the surrounding areas is examined on the basis of analysis of modern publications. Characteristics for determination of displacements and deformations with use of GNSS, and also in a complex with other types of measurements, are compared. It is demonstrated that combined monitoring of deformations of the ground surface of the region, and engineering and technical structures is required to ensure the functional safety of HPP, and reliable metrologic assurance of measurements is also required to obtain actual characteristics of the accuracy and effectiveness of GNSS observations.

  13. Effect of Passive Pile on 3D Ground Deformation and on Active Pile Response

    OpenAIRE

    Bingxiang Yuan; Rui Chen; Jun Teng; Tao Peng; Zhongwen Feng

    2014-01-01

    Using a series of model tests, this study investigated the effect of a passive pile on 3D ground deformation around a laterally loaded pile and on that laterally loaded pile’s response in sand. The active pile head was subjected to lateral loads, and the passive pile was arranged in front of the active pile. In the model tests, the distance between the two pile centers was set to zero (i.e., a single pile test), 2.5, 4, and 6 times the pile width (B). The 3D ground surface deformations around...

  14. Ub-library of Atomic Masses and Nuclear Ground States Deformations (CENPL.AMD)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The atomic mass is one of basic data of a nuclear. There are the atomic masses in all nuclear reaction model formulas and motion equations. For any reaction calculations atomic masses are basic data for getting binding energies or Q-values. In some applications, it is important also to have atomic masses even for exotic nuclei quite far from the valley of stability. In addition, nuclear ground state deformations and abundance values are also requisite in the nuclear data calculations. For this purpose, A data file on atomic masses and nuclear ground states deformations (AMD) were constructed, which

  15. Ground-water monitoring sites for Carson Valley, Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains the monitoring sites where water levels were collected and used to develop a spatial ground-water data base in Carson Valley, west-central...

  16. Hanford Site ground-water monitoring for 1994

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P.E.; Thorne, P.D.; Luttrell, S.P. [and others

    1995-08-01

    This report presents the results of the Ground-Water Surveillance Project monitoring for calendar year 1994 on the Hanford Site, Washington. Hanford Site operations from 1943 onward produced large quantities of radiologic and chemical waste that have impacted ground-water quality on the Site. Monitoring of water levels and ground-water chemistry is performed to track the extent of contamination and trends in contaminant concentrations. The 1994 monitoring was also designed to identify emerging ground-water quality problems. The information obtained is used to verify compliance with applicable environmental regulations and to evaluate remedial actions. Data from other monitoring and characterization programs were incorporated to provide an integrated assessment of Site ground-water quality. Additional characterization of the Site`s geologic setting and hydrology was performed to support the interpretation of contaminant distributions. Numerical modeling of sitewide ground-water flow also supported the overall project goals. Water-level monitoring was performed to evaluate ground-water flow directions, to track changes in water levels, and to relate such changes to changes in site disposal practices. Water levels over most of the Hanford Site continued to decline between June 1993 and June 1994. These declines are part of the continued response to the cessation of discharge to U Pond and other disposal facilities. The low permeability in this area which enhanced mounding of waste-water discharge has also slowed the response to the reduction of disposal.

  17. Somma-Vesuvius ground deformation over the last glacial cycle

    Science.gov (United States)

    Marturano, Aldo; Aiello, Giuseppe; Barra, Diana

    2013-04-01

    Vertical ground movements at Somma-Vesuvius during the last glacial cycle have been inferred from micropalaeontological and petrochemical analyses of rock samples from boreholes drilled at the archaeological sites of Herculaneum and Pompeii as well as on the apron of the volcano and the adjacent Sebeto and Sarno Valleys. Opposing movements occurred during the periods preceding and following the Last Glacial Maximum (LGM). The uplift began 20 ka ago with marine deposits rising several tens of metres up to 25 m a.s.l., recovering previous subsidence which occurred during the Late glacial period, suggesting a strict connection between volcano-tectonic and glacial cycles. Here we present the analysis of deposits predating the LGM, which confirms subsidence of the Campanian Plain where Mt. Somma-Vesuvius is located, shows variable surface loading effects and highlights the volcano-tectonic stages experienced by the volcano. The self-balancing mechanism of the volcanic system, evolving towards an explosive, subaerial activity 60 ka ago, is testified to by a large ground oscillation in phase with sea level change during the last glacial cycle.

  18. Coupled reservoir-geomechanical analysis of CO2 injection and ground deformations at In Salah, Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Rutqvist, J.; Vasco, D.W.; Myer, L.

    2009-11-01

    In Salah Gas Project in Algeria has been injecting 0.5-1 million tonnes CO{sub 2} per year over the past five years into a water-filled strata at a depth of about 1,800 to 1,900 m. Unlike most CO{sub 2} storage sites, the permeability of the storage formation is relatively low and comparatively thin with a thickness of about 20 m. To ensure adequate CO{sub 2} flow-rates across the low-permeability sand-face, the In Salah Gas Project decided to use long-reach (about 1 to 1.5 km) horizontal injection wells. In an ongoing research project we use field data and coupled reservoir-geomechanical numerical modeling to assess the effectiveness of this approach and to investigate monitoring techniques to evaluate the performance of a CO{sub 2}-injection operation in relatively low permeability formations. Among the field data used are ground surface deformations evaluated from recently acquired satellite-based inferrometry (InSAR). The InSAR data shows a surface uplift on the order of 5 mm per year above active CO{sub 2} injection wells and the uplift pattern extends several km from the injection wells. In this paper we use the observed surface uplift to constrain our coupled reservoir-geomechanical model and conduct sensitivity studies to investigate potential causes and mechanisms of the observed uplift. The results of our analysis indicates that most of the observed uplift magnitude can be explained by pressure-induced, poro-elastic expansion of the 20 m thick injection zone, but there could also be a significant contribution from pressure-induced deformations within a 100 m thick zone of shaly sands immediately above the injection zone.

  19. Application of Time Series Insar Technique for Deformation Monitoring of Large-Scale Landslides in Mountainous Areas of Western China

    Science.gov (United States)

    Qu, T.; Lu, P.; Liu, C.; Wan, H.

    2016-06-01

    Western China is very susceptible to landslide hazards. As a result, landslide detection and early warning are of great importance. This work employs the SBAS (Small Baseline Subset) InSAR Technique for detection and monitoring of large-scale landslides that occurred in Li County, Sichuan Province, Western China. The time series INSAR is performed using descending scenes acquired from TerraSAR-X StripMap mode since 2014 to get the spatial distribution of surface displacements of this giant landslide. The time series results identify the distinct deformation zone on the landslide body with a rate of up to 150mm/yr. The deformation acquired by SBAS technique is validated by inclinometers from diverse boreholes of in-situ monitoring. The integration of InSAR time series displacements and ground-based monitoring data helps to provide reliable data support for the forecasting and monitoring of largescale landslide.

  20. Deformation Monitoring of Motorway Underpasses Using Laser Scanning Data

    Science.gov (United States)

    Puente, I.; González-Jorge, H.; Riveiro, B.; Arias, P.

    2012-07-01

    The motorway Ourense - Celanova will become the next years in one of the main roads of inland Galicia (northwest region of Spain) that will connect quickly with the cities of Northern Portugal. This highway is projected as a public - private partnership between the regional government of Xunta de Galicia and the construction companies Copasa SA and Extraco SA. There are currently under construction the 19 km of this road and presents a number of structures as viaducts, overpasses and underpasses. The viaducts are part of the main road, allowing passage of the vehicles at conventional speed. Overpasses are mainly used in the connection of the highway with secondary roads. Moreover, the underpasses are better suited for the passage of wildlife animals, persons or agricultural machinery. The underpass arch-shape structures used for this project consist of two reinforced concrete voussoirs placed on two small concrete walls. For each set of voussoirs there are three joining points, two between the walls and the voussoirs and one between the both voussoirs at the top of the structure. These underpasses suffer significant mechanical stress during construction, because during the backfilling process asymmetric loads are applied to both sides. Thus, it is very important the monitoring of the structure using geodetic techniques as total stations, levels or laser scanners The underpass selected for this study is located at the kilometric point 4.9 of the highway, with a total length of 50.38 m, maximum span of 13.30 m and rise of 7.23 m. Voussoirs has a thickness of 0.35 m and a length of 2.52 m. The small lateral walls exhibit a height of 2.35 m and thickness of 0.85 m. The underpass presents a slope of approximately 4 % and the maximum height of the backfill over the top of the structure is 3.80 m. The foundation consists of a concrete slab arch-shape (curvature opposite the main arch) with a thickness of 0.7 m. The geodetic technology used for the deformation monitoring

  1. Assessment of radar interferometry performance for ground subsidence monitoring due to underground mining

    Energy Technology Data Exchange (ETDEWEB)

    Ng, A.H.M.; Chang, H.C.; Ge, L.L.; Rizos, C.; Omura, M. [Cooperative Research Centre for Spatial Information, Carlton, Vic. (Australia)

    2009-07-01

    This paper describes the results from the recently launched SAR satellites for the purpose of subsidence monitoring over underground coal mine sites in the state of New South Wales, Australia, using differential interferometric synthetic aperture radar (DInSAR) technique. The quality of the mine subsidence monitoring results is mainly constrained by noise due to the spatial and temporal decorrelation between the interferometric pair and the phase discontinuities in the interferogram. This paper reports oil the analysis of the impact of these two factors on the performance of DInSAR for monitoring ground deformation. Simulations were carried out prior to real data analyses. SAR data acquired using different operating frequencies, for example, X-, C- and L-band, from the TerraSAR-X, ERS-1/2, ENVISAT, JERS-1 and ALOS satellite missions, were examined. The simulation results showed that the new satellites ALOS, TerraSAR-X and COSMO-SkyMed perform much better than the satellites launched before 2006. ALOS and ENVISAT satellite SAR images with similar temporal coverage were searched for the test site. The ALOS PALSAR DInSAR results have been compared to DInSAR results obtained from ENVISAT ASAR data to investigate the performance of both satellites for ground subsidence monitoring. Strong phase discontinuities and decorrelation have been observed in almost all ENVISAT interferograms and hence it is not possible to generate the displacement maps without errors. However these problems are minimal in ALOS PALSAR interferograms due to its spatial resolution and longer wavelength. Hence ALOS PALSAR is preferred for ground subsidence monitoring in areas covered by vegetation and where there is a high rate ground deformation.

  2. A Blind Test Experiment in Volcano Geodesy: a Benchmark for Inverse Methods of Ground Deformation and Gravity Data

    Science.gov (United States)

    D'Auria, Luca; Fernandez, Jose; Puglisi, Giuseppe; Rivalta, Eleonora; Camacho, Antonio; Nikkhoo, Mehdi; Walter, Thomas

    2016-04-01

    The inversion of ground deformation and gravity data is affected by an intrinsic ambiguity because of the mathematical formulation of the inverse problem. Current methods for the inversion of geodetic data rely on both parametric (i.e. assuming a source geometry) and non-parametric approaches. The former are able to catch the fundamental features of the ground deformation source but, if the assumptions are wrong or oversimplified, they could provide misleading results. On the other hand, the latter class of methods, even if not relying on stringent assumptions, could suffer from artifacts, especially when dealing with poor datasets. In the framework of the EC-FP7 MED-SUV project we aim at comparing different inverse approaches to verify how they cope with basic goals of Volcano Geodesy: determining the source depth, the source shape (size and geometry), the nature of the source (magmatic/hydrothermal) and hinting the complexity of the source. Other aspects that are important in volcano monitoring are: volume/mass transfer toward shallow depths, propagation of dikes/sills, forecasting the opening of eruptive vents. On the basis of similar experiments already done in the fields of seismic tomography and geophysical imaging, we have devised a bind test experiment. Our group was divided into one model design team and several inversion teams. The model design team devised two physical models representing volcanic events at two distinct volcanoes (one stratovolcano and one caldera). They provided the inversion teams with: the topographic reliefs, the calculated deformation field (on a set of simulated GPS stations and as InSAR interferograms) and the gravity change (on a set of simulated campaign stations). The nature of the volcanic events remained unknown to the inversion teams until after the submission of the inversion results. Here we present the preliminary results of this comparison in order to determine which features of the ground deformation and gravity source

  3. Application and Evaluation of ALOS PALSAR Data for Monitoring of Mining Induced Surface Deformations Using Interferometric Techniques

    Science.gov (United States)

    Walter, Diana; Wegmuller, Urs; Spreckels, Volker; Busch, Wolfgang

    2008-11-01

    The main objective of the projects "Determination of ground motions in mining areas by interferometric analyses of ALOS data" (ALOS ADEN 3576, ESA) and "Monitoring of mining induced surface deformation" (ALOS-RA-094, JAXA) is to evaluate PALSAR data for surface deformation monitoring, using interferometric techniques. We present monitoring results of surface movements for an active hard coal colliery of the German hard coal mining company RAG Deutsche Steinkohle (RAG). Underground mining activities lead to ground movements at the surface with maximum subsidence rates of about 10cm per month for the test site. In these projects the L-band sensor clearly demonstrates the good potential for deformation monitoring in active mining areas, especially in rural areas. In comparison to C-band sensors we clearly observe advantages in resolving the high deformation gradients that are present in this area and we achieve a more complete spatial coverage than with C-band. Extensive validation data based on levelling data and GPS measurements are available within RAǴs GIS based database "GeoMon" and thus enable an adequate analysis of the quality of the interferometric results. Previous analyses confirm the good accuracy of PALSAR data for deformation monitoring in mining areas. Furthermore, we present results of special investigations like precision geocoding of PALSAR data and corner reflector analysis. At present only DInSAR results are obtained due to the currently available number of PALSAR scenes. For the future we plan to also apply Persistent Scatterer Interferometry (PSI) using longer series of PALSAR data.

  4. A preliminary study on surface ground deformation near shallow foundation induced by strike-slip faulting

    Science.gov (United States)

    Wong, Pei-Syuan; Lin, Ming-Lang

    2016-04-01

    According to investigation of recent earthquakes, ground deformation and surface rupture are used to map the influenced range of the active fault. The zones of horizontal and vertical surface displacements and different features of surface rupture are investigated in the field, for example, the Greendale Fault 2010, MW 7.1 Canterbury earthquake. The buildings near the fault rotated and displaced vertically and horizontally due to the ground deformation. Besides, the propagation of fault trace detoured them because of the higher rigidity. Consequently, it's necessary to explore the ground deformation and mechanism of the foundation induced by strike-slip faulting for the safety issue. Based on previous study from scaled analogue model of strike-slip faulting, the ground deformation is controlled by material properties, depth of soil, and boundary condition. On the condition controlled, the model shows the features of ground deformation in the field. This study presents results from shear box experiment on small-scale soft clay models subjected to strike-slip faulting and placed shallow foundations on it in a 1-g environment. The quantifiable data including sequence of surface rupture, topography and the position of foundation are recorded with increasing faulting. From the result of the experiment, first en echelon R shears appeared. The R shears rotated to a more parallel angle to the trace and cracks pulled apart along them with increasing displacements. Then the P shears crossed the basement fault in the opposite direction appears and linked R shears. Lastly the central shear was Y shears. On the other hand, the development of wider zones of rupture, higher rising surface and larger the crack area on surface developed, with deeper depth of soil. With the depth of 1 cm and half-box displacement 1.2 cm, en echelon R shears appeared and the surface above the fault trace elevated to 1.15 mm (Dv), causing a 1.16 cm-wide zone of ground-surface rupture and deformation

  5. Removal of systematic seasonal atmospheric signal from interferometric synthetic aperture radar ground deformation time series

    Science.gov (United States)

    Samsonov, Sergey V.; Trishchenko, Alexander P.; Tiampo, Kristy; González, Pablo J.; Zhang, Yu; Fernández, José

    2014-09-01

    Applying the Multidimensional Small Baseline Subset interferometric synthetic aperture radar algorithm to about 1500 Envisat and RADARSAT-2 interferograms spanning 2003-2013, we computed time series of ground deformation over Naples Bay Area in Italy. Two active volcanoes, Vesuvius and Campi Flegrei, are located in this area in close proximity to the densely populated city of Naples. For the first time, and with remarkable clarity, we observed decade-long elevation-dependent seasonal oscillations of the vertical displacement component with a peak-to-peak amplitude of up to 3.0 cm, substantially larger than the long-term deformation rate (Vesuvius previously observed by geodetic techniques.

  6. Hanford Site ground-water monitoring for 1993

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P.E.; Luttrell, S.P.; Evans, J.C. [and others

    1994-09-01

    This report presents the results of the Ground-Water Surveillance Project monitoring for calendar year 1993 on the Hanford Site, Washington. Hanford Site operations from 1943 onward produced large quantities of radiological and chemical waste that have impacted ground-water quality on the Site. Monitoring of water levels and ground-water chemistry is performed to track the extent of contamination and trends in contaminant concentrations. The 1993 monitoring was also designed to identify emerging ground-water quality problems. The information obtained is used to verify compliance with applicable environmental regulations and to evaluate remedial actions. Data from other monitoring and characterization programs were incorporated to provide an integrated assessment of Site ground-water quality. Additional characterization of the Site`s geologic setting and hydrology was performed to support the interpretation of contaminant distributions. Numerical modeling of sitewide ground-water flow also supported the overall project goals. Water-level monitoring was performed to evaluate ground-water flow directions, to track changes in water levels, and to relate such changes to changes in site disposal practices. Water levels over most of the Hanford Site continued to decline between June 1992 and June 1993. The greatest declines occurred in the 200-West Area. These declines are part of the continued response to the cessation of discharge to U Pond and other disposal facilities. The low permeability in this area which enhanced mounding of waste-water discharge has also slowed the response to the reduction of disposal. Water levels remained nearly constant in the vicinity of B Pond, as a result of continued disposal to the pond. Water levels measured from wells in the unconfined aquifer north and east of the Columbia River indicate that the primary source of recharge is irrigation practices.

  7. Control technology and coordination deformation mechanism of rise entry group with high ground stress

    Institute of Scientific and Technical Information of China (English)

    Li Qingfeng; Zhu Quanqu

    2012-01-01

    Based on engineering practices of Wuyang Coal Mine,we carried out X-ray diffract researches on No.3 coal; and the rocks of its roof and floor by XRD meter,and simulated the interactive effect of the surrounding rock deformation by FLAC2D5.0 numerical simulation software under the condition of different tunneling method of multimine roadway in parallel.The internal structures of the surrounding rocks of 76 belt roadway were monitored by borehole observation instruments; and then,we analyzed the reason of failure and deformation of surrounding rocks of several rise entry,and proposed the technical measures for controlling interactive effect of several rise entry surrounding rock deformation at last.For the thickness seam rise roadway,two conclusions were drawn:one is that the co-deformation among roadway groups mainly reflecton that both shear failure and deformation in coal pillar among roadways have decreased the width of pillar core region and clamping action of coal pillar to roof strata,increased the actual span of roof strata,intensified the flexural failure of roof strata and prized the bed separation of roof deep rock strata.The other conclusion is that the factors controlling the interactive deformation among roadways is obvious when appropriate re-adjustment in construction sequence of the tunneling of multimine parallel roadways because the construction sequence among roadways also has great effects on deformation of the surrounding rock in roadway.

  8. Multi-parameter numerical simulation of dynamic monitoring of rock deformation in deep mining

    Institute of Scientific and Technical Information of China (English)

    Li Juanjuan; Hu Mingshun; Ding Enjie; Kong Wei; Pan Dongming; Chen Shenen

    2016-01-01

    The level of deformation development of surrounding rocks is a vital predictor to evaluate impending coal mine disasters and it is important to establish accurate measurements of the deformed status to ensure coal mine safety. Traditional deformation monitoring methods are mostly based on single parameter, in this paper, multiple approaches are integrated: firstly, both electric and elastic models are established, from which electric field distribution and seismic wave recording are calculated and finally, the resistivity profiles and source position information are determined using inversion methods, from which then the deformation and failure of mine floor are evaluated. According to the inversion results of both electric and seismic field signals, multiple-parameter dynamic monitoring of surrounding rock deformation in deep mine can be performed. The methodology is validated using numerical simulation results which shows that the multi-parameter dynamic monitoring methods have better results for surrounding rock deformation in deep mine monitoring than single parameter methods.

  9. Analysis of recent surface deformation at Ischia Island Volcano (South Italy) via multi-platform monitoring systems

    Science.gov (United States)

    Manzo, Mariarosaria; De Martino, Prospero; Castaldo, Raffaele; De Luca, Claudio; Dolce, Mario; Scarpato, Giovanni; Tizzani, Pietro; Zinno, Ivana; Lanari, Riccardo

    2017-04-01

    Ischia Island is a densely populated volcanic area located in the North-Western sector of the Gulf of Napoli (South Italy), whose activity is characterized by eruptions (the last one occurred in 1302 A.D.), earthquakes (the most disastrous ones occurred in 1881 and in 1883), fumarolic-hydrothermal manifestations and ground deformation. In this work we carry out the surface deformation time-series analysis occurring at the Island by jointly exploiting data collected via two different monitoring systems. In particular, we take advantage from the large amount of periodic and continuous geodetic measurements collected by the GPS (campaign and permanent) stations deployed on the Island and belonging to the INGV-OV monitoring network. Moreover, we benefit from the large, free and open archive of C-band SAR data acquired over the Island by the Sentinel-1 constellation of the Copernicus Program, and processed via the advanced Differential SAR Interferometry (DInSAR) technique referred to as Small BAseline Subset (SBAS) algorithm [Berardino et al., 2002]. We focus on the 2014-2017 time period to analyze the recent surface deformation phenomena occurring on the Island, thus extending a previous study, aimed at investigating the temporal evolution of the ground displacements affecting the Island and limited to the 1992-2003 time interval [Manzo et al., 2006]. The performed integrated analysis provides relevant spatial and temporal information on the Island surface deformation pattern. In particular, it reveals a rather complex deformative scenario, where localized phenomena overlap/interact with a spatially extended deformation pattern that involves many Island sectors, with no evidence of significant uplift phenomena. Moreover, it shows a good agreement and consistency between the different kinds of data, thus providing a clear picture of the recent dynamics at Ischia Island that can be profitably exploited to deeply investigate the physical processes behind the observed

  10. Ground Source Heat Pump in Heating System with Electronics Monitoring

    Directory of Open Access Journals (Sweden)

    NEAMŢU Ovidiu

    2013-10-01

    Full Text Available The monitoring system is implemented for a ground coupled heat pump in heating/ system. The borehole heat exchangers – which are 150 m long - are filled with a mixture of water and ethilene glycol calledbrine. Metering and monitoring energy consumption is achieved for: heat pump, circulation pumps, additional electrical heating, hot air ventilation systems, control systems with sensors: analog and smart sensors. Instantaneous values are stored in a local computer.

  11. Application of the spatial data mining module in analysis of mining ground deformation factors

    Directory of Open Access Journals (Sweden)

    Jan Blachowski

    2013-09-01

    Full Text Available Spatial data mining methods for example those based on artificial neural networks (ANN allow extraction of information from databases and detection of otherwise hidden patterns occurring in these data and in consequence acquiring new knowledge on the analysed phenomena or processes. One of these techniques is the multivariate statistical analysis, which facilitates identification of patterns otherwise difficult to observe. In the paper an attempt of applying self-organising maps (SOM to explore and analyse spatial data related to studies of ground subsidence associated with underground mining has been described. The study has been carried out on a selected part of a former underground coal mining area in SW Poland with the aim to analyse the influence of particular ground deformation factors on the observed subsidence and the relationships between these factors. The research concerned the uppermost coal panels and the following factors: mining system, time of mining activity and inclination, thickness and depth below the ground of the exploited coal panels. It has been found that the exploratory spatial data analysis can be used to identify relationships in multidimensional data related to mining induced ground subsidence. The proposed approach may be found useful in identification of areas threatened by mining related subsidence and in creating scenarios of developing deformation zones and therefore aid spatial development of mining grounds.

  12. Ground deformation in La Palma (Canary Islands) detected using Stacking Radar Interferometry

    Science.gov (United States)

    Fernandez, J.; Gonzalez, P. J.; Tiampo, K. F.; Perlock, P. A.; Camacho, A. G.

    2007-12-01

    Ground deformation in ocean volcanic islands can reveal deep accommodation of strain at depth due to very different mechanisms. Nowadays, volcano-tectonics and its relation to volcanic activity is a very open research field. Using InSAR measurements, we are able to detect transient and/or persistent patterns of deformation in this kind of volcanic environments. We have studied an 8-year period (1992-2000) using ERS-1/2 SAR images over the island of La Palma, Canary Islands. First, single interferograms have not shown significant deformation over several cycles (or fringes), and second, La Palma is located in a tropical area so interferometric phase measurements would be greatly affected with the existence of tropospheric water vapour and dense vegetation. In order to mitigate those effects, we use a total number of 48 interferogram to obtain a stacked (average) velocity map of the surface deformation covering most of the island, where coherence is preserved. We found two areas of deformation. First, a subsidence signal around 5-6 mm/yr is located in the southern tip of the island in the area of 1971-Teneguia volcano (a recent cinder cone and lava flows). Second, a broader subsidence area around 3-4 mm/yr is located covering the western of the Cumbre Vieja volcano. We present preliminar modelling results about the causative sources. Ground deformation using InSAR is an important tool to reveal the actual state of strain at the surface in an oceanic volcanic island and using jointly with mathematical modelling is able to infer useful information about deep processes in and below the volcanic edifice.

  13. A proposed ground-water quality monitoring network for Idaho

    Science.gov (United States)

    Whitehead, R.L.; Parliman, D.J.

    1979-01-01

    A ground water quality monitoring network is proposed for Idaho. The network comprises 565 sites, 8 of which will require construction of new wells. Frequencies of sampling at the different sites are assigned at quarterly, semiannual, annual, and 5 years. Selected characteristics of the water will be monitored by both laboratory- and field-analysis methods. The network is designed to: (1) Enable water managers to keep abreast of the general quality of the State 's ground water, and (2) serve as a warning system for undesirable changes in ground-water quality. Data were compiled for hydrogeologic conditions, ground-water quality, cultural elements, and pollution sources. A ' hydrologic unit priority index ' is used to rank 84 hydrologic units (river basins or segments of river basins) of the State for monitoring according to pollution potential. Emphasis for selection of monitoring sites is placed on the 15 highest ranked units. The potential for pollution is greatest in areas of privately owned agricultural land. Other areas of pollution potential are residential development, mining and related processes, and hazardous waste disposal. Data are given for laboratory and field analyses, number of site visits, manpower, subsistence, and mileage, from which costs for implementing the network can be estimated. Suggestions are made for data storage and retrieval and for reporting changes in water quality. (Kosco-USGS)

  14. Preliminary results of continuous GPS monitoring of surface deformation at the Aquistore underground CO2 storage site

    Science.gov (United States)

    Craymer, M. R.; Henton, J. A.; Piraszewski, M.; Silliker, J.; Samsonov, S. V.

    2013-12-01

    Aquistore is a demonstration project for the underground storage of CO2 at a depth of ~3350 m near Estevan, Saskatchewan, Canada. An objective of the project is to design, adapt, and test non-seismic monitoring methods that have not been systematically utilized to date for monitoring CO2 storage projects, and to integrate the data from these various monitoring tools to obtain quantitative estimates of the change in subsurface fluid distributions, pressure changes and associated surface deformation. Monitoring methods being applied include satellite-, surface- and wellbore-based monitoring systems and comprise natural- and controlled-source electromagnetic methods, gravity monitoring, GPS, synthetic aperture radar interferometry (InSAR), tiltmeter array analysis, and chemical tracer studies. Here we focus on the GPS monitoring of surface deformation. Five of the planned thirteen GPS monitoring stations were installed in November 2012 and results subsequently processed on a weekly basis. The first GPS results prior to CO2 injection have just been determined using both precise point positioning (PPP) and baseline processing with the Bernese GPS Software. The time series of the five sites are examined, compared and analysed with respect to monument stability, seasonal signals and estimates of expected regional ground motion. The individual weekly network solutions are combined together in a cumulative 4D network solution to provide a preliminary local velocity field in the immediately vicinity of the injection well. The results are compared to those from InSAR.

  15. Design of Deformation Monitoring System for Volcano Mitigation

    Science.gov (United States)

    Islamy, M. R. F.; Salam, R. A.; Munir, M. M.; Irsyam, M.; Khairurrijal

    2016-08-01

    Indonesia has many active volcanoes that are potentially disastrous. It needs good mitigation systems to prevent victims and to reduce casualties from potential disaster caused by volcanoes eruption. Therefore, the system to monitor the deformation of volcano was built. This system employed telemetry with the combination of Radio Frequency (RF) communications of XBEE and General Packet Radio Service (GPRS) communication of SIM900. There are two types of modules in this system, first is the coordinator as a parent and second is the node as a child. Each node was connected to coordinator forming a Wireless Sensor Network (WSN) with a star topology and it has an inclinometer based sensor, a Global Positioning System (GPS), and an XBEE module. The coordinator collects data to each node, one a time, to prevent collision data between nodes, save data to SD Card and transmit data to web server via GPRS. Inclinometer was calibrated with self-built in calibrator and tested in high temperature environment to check the durability. The GPS was tested by displaying its position in web server via Google Map Application Protocol Interface (API v.3). It was shown that the coordinator can receive and transmit data from every node to web server very well and the system works well in a high temperature environment.

  16. Monitoring of ground water aquifer by electrical prospecting; Denki tansaho ni yoru chikasui monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Ushijima, K. [Kyushu University, Fukuoka (Japan)] [Faculty of Engineering (Japan)

    1997-12-01

    This paper describes three case studies for monitoring ground water aquifers by electrical prospecting. An example in the Hofu plain, Yamaguchi Prefecture is presented, where the ground water environment has been monitored for more than 30 years from the viewpoint of hydrology. Then, transition from the fresh ground water to sea water is evaluated by a sharp boundary as salt-water wedges through the field survey in a coastal area of a large city for a short term using vertical electrical prospecting. Moreover, streaming potential measurements are described to grasp the real-time behavior of ground water flow. From the long-term monitoring of ground water aquifer, it was found that the variation of ground water streaming can be evaluated by monitoring the long-term successive change in the resistivity of ground water aquifer. From the vertical electrical prospecting, water quality can be immediately judged through data analysis. From the results of streaming potential measurements and vertical electrical prospecting using Schlumberger method, streaming behavior of ground water in the area of spring water source can be estimated by determining three-dimensional resistivity structure. 17 refs., 15 figs.

  17. Liquefaction, ground oscillation, and soil deformation at the Wildlife Array, California

    Science.gov (United States)

    Holzer, T.L.; Youd, T.L.

    2007-01-01

    Excess pore-water pressure and liquefaction at the Wildlife Liquefaction Array in 1987 were caused by deformation associated with both high-frequency strong ground motion and 5.5-second-period Love waves. The Love waves produced large (???1.5%) cyclic shear strains well after the stronger high-frequency ground motion abated. These cyclic strains generated approximately from 13 to 35% of the excess pore-water pressure in the liquefied layer and caused excess pore-water pressures ultimately to reach effective overburden stress. The deformation associated with the Love waves explains the "postearthquake" increase of pore-water pressure that was recorded at the array. This explanation suggests that conventional methods for predicting liquefaction based on peak ground acceleration are incomplete and may need to consider cyclic strains associated with long-period surface waves. A post-earthquake survey of an inclinometer casing indicated permanent shear strain associated with lateral spreading primarily occurred in the upper part of the liquefied layer. Comparison of cone penetration test soundings conducted after the earthquake with pre-earthquake soundings suggests sleeve friction increased. Natural lateral variability of the liquefied layer obscured changes in tip resistance despite a ???1% reduction in volume. The large oscillatory motion associated with surface waves explains ground oscillation that has been reported at some liquefaction sites during earthquakes.

  18. 40 CFR Appendix Ix to Part 264 - Ground-Water Monitoring List

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Ground-Water Monitoring List IX... Pt. 264, App. IX Appendix IX to Part 264—Ground-Water Monitoring List Ground-Water Monitoring List... species in the ground water that contain this element are included. 3 CAS index names are those used in...

  19. Role of the interface between distributed fibre optic strain sensor and soil in ground deformation measurement

    Science.gov (United States)

    Zhang, Cheng-Cheng; Zhu, Hong-Hu; Shi, Bin

    2016-11-01

    Recently the distributed fibre optic strain sensing (DFOSS) technique has been applied to monitor deformations of various earth structures. However, the reliability of soil deformation measurements remains unclear. Here we present an integrated DFOSS- and photogrammetry-based test study on the deformation behaviour of a soil foundation model to highlight the role of strain sensing fibre–soil interface in DFOSS-based geotechnical monitoring. Then we investigate how the fibre–soil interfacial behaviour is influenced by environmental changes, and how the strain distribution along the fibre evolves during progressive interface failure. We observe that the fibre–soil interfacial bond is tightened and the measurement range of the fibre is extended under high densities or low water contents of soil. The plastic zone gradually occupies the whole fibre length when the soil deformation accumulates. Consequently, we derive a theoretical model to simulate the fibre–soil interfacial behaviour throughout the progressive failure process, which accords well with the experimental results. On this basis, we further propose that the reliability of measured strain can be determined by estimating the stress state of the fibre–soil interface. These findings may have important implications for interpreting and evaluating fibre optic strain measurements, and implementing reliable DFOSS-based geotechnical instrumentation.

  20. Evaluating Topographic Effects on Ground Deformation: Insights from Finite Element Modeling

    Science.gov (United States)

    Ronchin, Erika; Geyer, Adelina; Martí, Joan

    2015-07-01

    Ground deformation has been demonstrated to be one of the most common signals of volcanic unrest. Although volcanoes are commonly associated with significant topographic relief, most analytical models assume the Earth's surface as flat. However, it has been confirmed that this approximation can lead to important misinterpretations of the recorded surface deformation data. Here we perform a systematic and quantitative analysis of how topography may influence ground deformation signals generated by a spherical pressure source embedded in an elastic homogeneous media and how these variations correlate with the different topographic parameters characterizing the terrain form (e.g., slope, aspect, curvature). For this, we bring together the results presented in previous published papers and complement them with new axisymmetric and 3D finite element (FE) model results. First, we study, in a parametric way, the influence of a volcanic edifice centered above the pressure source axis. Second, we carry out new 3D FE models simulating the real topography of three different volcanic areas representative of topographic scenarios common in volcanic regions: Rabaul caldera (Papua New Guinea) and the volcanic islands of Tenerife and El Hierro (Canary Islands). The calculated differences are then correlated with a series of topographic parameters. The final aim is to investigate the artifacts that might arise from the use of half-space models at volcanic areas due to diverse topographic features (e.g., collapse caldera structures, prominent central edifices, large landslide scars).

  1. Ground deformation detection of the greater area of Thessaloniki (Northern Greece using radar interferometry techniques

    Directory of Open Access Journals (Sweden)

    D. Raucoules

    2008-07-01

    Full Text Available In the present study SAR interferometric techniques (stacking of conventional interferograms and Permanent Scatterers, using images from satellites ERS-1 and 2, have been applied to the region of Thessaloniki (northern Greece. The period covered by the images is 1992–2000. Both techniques gave good quantitative and qualitative results. The interferometric products were used to study ground surface deformation phenomena that could be related to the local tectonic context, the exploitation of underground water and sediments compaction.

    The city of Thessaloniki shows relatively stable ground conditions. Subsidence in four locations, mainly in the area surrounding the city of Thessaloniki, has been detected and assessed. Two of the sites (Sindos-Kalochori and Langadhas were already known from previous studies as subsiding areas, using ground base measurements. On the contrary the other two sites in the northern suburbs of Thessaloniki (Oreokastro and in the south-east (airport area were unknown as areas of subsidence. A further investigation based on fieldwork is needed in these two areas. Finally, an attempt to interpret the observed deformation, according to the geological regime of the area and its anthropogenic activities, has been carried out.

  2. Ground deformation near Gada ‘Ale Volcano, Afar, observed by radar interferometry

    Science.gov (United States)

    Amelung, Falk; Oppenheimer, Clive; Segall, P.; Zebker, H.

    2000-10-01

    Radar interferometric measurements of ground-surface displacement using ERS data show a change in radar range, corresponding to up to 12 cm of subsidence near Gada ‘Ale volcano in northern Afar, Ethiopia, that occurred between June 1993 and May 1996. This is the area of lowest topography within the Danakil Depression (-126 m). Geodetic inverse modeling and geological evidence suggest a volcanic origin of the observed deformation; it was probably caused by a combined process of magma withdrawal from a larger reservoir and normal faulting. There is no evidence of subaerial eruption. This is the only identifiable deformation event during June 1993-October 1997 in the 80 km long Erta ‘Ale volcanic range, indicating surprising inactivity elsewhere in the range.

  3. Seismic Monitoring System Calibration Using Ground Truth Database

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Winston; Wagner, Robert

    2002-12-22

    Calibration of a seismic monitoring system remains a major issue due to the lack of ground truth information and uncertainties in the regional geological parameters. Rapid and accurate identification of seismic events is currently not feasible due to the absence of a fundamental framework allowing immediate access to ground truth information for many parts of the world. Precise location and high-confidence identification of regional seismic events are the primary objectives of monitoring research in seismology. In the Department of Energy Knowledge Base (KB), ground truth information addresses these objectives and will play a critical role for event relocation and identification using advanced seismic analysis tools. Maintaining the KB with systematic compilation and analysis of comprehensive sets of geophysical data from various parts of the world is vital. The goal of this project is to identify a comprehensive database for China using digital seismic waveform data that are currently unavailable. These data may be analyzed along with ground truth information that becomes available. To date, arrival times for all regional phases are determined on all events above Mb 4.5 that occurred in China in 2000 and 2001. Travel-time models are constructed to compare with existing models. Seismic attenuation models may be constructed to provide better understanding of regional wave propagation in China with spatial resolution that has not previously been obtained.

  4. Anthropogenic and natural ground deformation in the Hengill geothermal area, Iceland

    Science.gov (United States)

    Juncu, Daniel; Árnadóttir, Thóra; Hooper, Andy; Gunnarsson, Gunnar

    2017-04-01

    We investigate crustal deformation due to the extraction of water and steam from a high-enthalpy geothermal reservoir; a common occurrence, yet not well understood. The cause of this deformation can be a change in pressure or in temperature in the reservoir, both of which can be caused by extraction or injection of geothermal fluids. Our study area, the Hengill mountains in SW Iceland, is an active volcanic center and a plate triple junction that hosts two power plants producing geothermal energy. This combination of natural and anthropogenic processes causes a complex displacement field at the surface. We analyze geodetic data—Global Navigation Satellite System and Interferometric Synthetic Aperture Radar—to obtain the surface velocity field, which we then simulate using an inverse modeling approach. This way we are able to untangle the deformation signal and find that plate motion and a deep contracting body can explain the broad scale signal in the area. Local deformation near the two power plants, Hellisheidi and Nesjavellir, can be explained by extraction of geothermal fluids. We estimate reservoirs extending from 0.6 to 3.0 km depth at Hellisheidi, and 1.0 to 3.0 km depth at Nesjavellir for observed pressure decrease rates of 0.25 MPa/yr and 0.1 MPa/yr, respectively. We find that the main cause for the subsidence in the geothermal area is the observed pressure drawdown. This means that surface deformation could be used to constrain reservoir pressure models and improve their performance, which could make surface deformation measurements a valuable tool in reservoir monitoring.

  5. 2000 Squaw Creek National Wildlife Refuge Amphibian Deformity Monitoring Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In 1997 the Region 3 Assistant Regional Director (ARD) requested that all staffed field stations conduct amphibian deformity surveys. The purpose of these surveys...

  6. 2001 Squaw Creek National Wildlife Refuge Amphibian Deformity Monitoring Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In 1997 the Region 3 Assistant Regional Director (ARD) requested that all staffed field stations conduct amphibian deformity surveys. The purpose of these surveys...

  7. 2002 Squaw Creek National Wildlife Refuge Amphibian Deformity Monitoring Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In 1997 the Region 3 Assistant Regional Director (ARD) requested that all staffed field stations conduct amphibian deformity surveys. The purpose of these surveys...

  8. 2003 Squaw Creek National Wildlife Refuge Amphibian Deformity Monitoring Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In 1997 the Region 3 Assistant Regional Director (ARD) requested that all staffed field stations conduct amphibian deformity surveys. The purpose of these surveys...

  9. Applications of FBG-based sensors to ground stability monitoring

    Institute of Scientific and Technical Information of China (English)

    An-Bin Huang; Chien-Chih Wang; Jui-Ting Lee; Yen-Te Ho

    2016-01-01

    Over the past few decades, many optical fiber sensing techniques have been developed. Among these available sensing methods, optical fiber Bragg grating (FBG) is probably the most popular one. With its unique capabilities, FBG-based geotechnical sensors can be used as a sensor array for distributive (profile) measurements, deployed under water (submersible), for localized high resolution and/or dif-ferential measurements. The authors have developed a series of FBG-based transducers that include inclination, linear displacement and gauge/differential pore pressure sensors. Techniques that involve the field deployment of FBG inclination, extension and pore-pressure sensor arrays for automated slope stability and ground subsidence monitoring have been developed. The paper provides a background of FBG and the design concepts behind the FBG-based field monitoring sensors. Cases of field monitoring using the FBG sensor arrays are presented, and their practical implications are discussed.

  10. The Rover Environmental Monitoring Station Ground Temperature Sensor: A Pyrometer for Measuring Ground Temperature on Mars

    OpenAIRE

    2010-01-01

    We describe the parameters that drive the design and modeling of the Rover Environmental Monitoring Station (REMS) Ground Temperature Sensor (GTS), an instrument aboard NASA’s Mars Science Laboratory, and report preliminary test results. REMS GTS is a lightweight, low-power, and low cost pyrometer for measuring the Martian surface kinematic temperature. The sensor’s main feature is its innovative design, based on a simple mechanical structure with no moving parts. It includes an in-flight cal...

  11. Numerical models for ground deformation and gravity changes during volcanic unrest: simulating the hydrothermal system dynamics of a restless caldera

    Science.gov (United States)

    Coco, A.; Gottsmann, J.; Whitaker, F.; Rust, A.; Currenti, G.; Jasim, A.; Bunney, S.

    2016-04-01

    Ground deformation and gravity changes in restless calderas during periods of unrest can signal an impending eruption and thus must be correctly interpreted for hazard evaluation. It is critical to differentiate variation of geophysical observables related to volume and pressure changes induced by magma migration from shallow hydrothermal activity associated with hot fluids of magmatic origin rising from depth. In this paper we present a numerical model to evaluate the thermo-poroelastic response of the hydrothermal system in a caldera setting by simulating pore pressure and thermal expansion associated with deep injection of hot fluids (water and carbon dioxide). Hydrothermal fluid circulation is simulated using TOUGH2, a multicomponent multiphase simulator of fluid flows in porous media. Changes in pore pressure and temperature are then evaluated and fed into a thermo-poroelastic model (one-way coupling), which is based on a finite-difference numerical method designed for axi-symmetric problems in unbounded domains.Informed by constraints available for the Campi Flegrei caldera (Italy), a series of simulations assess the influence of fluid injection rates and mechanical properties on the hydrothermal system, uplift and gravity. Heterogeneities in hydrological and mechanical properties associated with the presence of ring faults are a key determinant of the fluid flow pattern and consequently the geophysical observables. Peaks (in absolute value) of uplift and gravity change profiles computed at the ground surface are located close to injection points (namely at the centre of the model and fault areas). Temporal evolution of the ground deformation indicates that the contribution of thermal effects to the total uplift is almost negligible with respect to the pore pressure contribution during the first years of the unrest, but increases in time and becomes dominant after a long period of the simulation. After a transient increase over the first years of unrest

  12. Numerical models for ground deformation and gravity changes during volcanic unrest: simulating the hydrothermal system dynamics of an active caldera

    Directory of Open Access Journals (Sweden)

    A. Coco

    2015-08-01

    Full Text Available Ground deformation and gravity changes in active calderas during periods of unrest can signal an impending eruption and thus must be correctly interpreted for hazard evaluation. It is critical to differentiate variation of geophysical observables related to volume and pressure changes induced by magma migration from shallow hydrothermal activity associated with hot fluids of magmatic origin rising from depth. In this paper we present a numerical model to evaluate the thermo-poroelastic response of the hydrothermal system in a caldera setting by simulating pore pressure and thermal expansion associated with deep injection of hot fluids (water and carbon dioxide. Hydrothermal fluid circulation is simulated using TOUGH2, a multicomponent multiphase simulator of fluid flows in porous media. Changes in pore pressure and temperature are then evaluated and fed into a thermo-poroelastic model (one-way coupling, which is based on a finite-difference numerical method designed for axi-symmetric problems in unbounded domains. Based on data for the Campi Flegrei caldera (Italy, a series of simulations assess the influence of fluid injection rates and mechanical properties on the hydrothermal system, uplift and gravity. Heterogeneities in hydrological and mechanical properties associated with the presence of ring faults are a key determinant of the fluid flow pattern and consequently the geophysical observables. Peaks (in absolute value of uplift and gravity change profiles computed at the ground surface are located close to injection points (namely at the centre of the model and fault areas. Temporal evolution of the ground deformation indicates that the contribution of thermal effects to the total uplift is almost negligible with respect to the pore pressure contribution during the first years of the unrest, but increases in time and becomes dominant after a long period of the simulation. After a transient increase over the first years of unrest, gravity

  13. Online Monitoring Volume Deformation of Cement-based Materials in Multiple Enviroments

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Comparing and analyzing some volume deformation measuring means for cement-based materials at home and abroad, a continuous online monitor of cement-based material volume deformation in multiple environments is developed. The device is designed based on the environmental simulation technology, micro-distance measuring technology of laser and eddy current, and transmission agent online monitoring the deformation of multi-group samples. This device can be used widely, such as glass, ceramics, walling material, and so on, with high precision, low testing cost, and intellectualization.

  14. APPLICATION OF THE ROOF DISTURBANCETO MONITORING AND PREDICTINGTHE GROUND PRESSURE

    Institute of Scientific and Technical Information of China (English)

    付国彬; 钱鸣高

    1992-01-01

    Based on study of the influence of main roof fracture on ground pressure,this paper considered the immediate roof as a semi-infinite long beam on a Winkler elastic foundation. In the model the coal seam is the foundation and the pressure caused by rnian roof deflection is the load.Having solved the model and analyzed relevant factors,the authors indicate that the disturbance caused by the breakage of the mian roof can be observed in both gates of iongwaii face and explain why it can be. The paper points out that the applicability of the method to obtain the disturbance information by measuring the loads on supports is wider than that by measuring the roof convergence rate. The results are useful for monitoring and predicting ground pressure.

  15. Mapping ground surface deformation using temporarily coherent point SAR interferometry: Application to Los Angeles Basin

    Science.gov (United States)

    Zhang, L.; Lu, Zhiming; Ding, X.; Jung, H.-S.; Feng, G.; Lee, C.-W.

    2012-01-01

    Multi-temporal interferometric synthetic aperture radar (InSAR) is an effective tool to detect long-term seismotectonic motions by reducing the atmospheric artifacts, thereby providing more precise deformation signal. The commonly used approaches such as persistent scatterer InSAR (PSInSAR) and small baseline subset (SBAS) algorithms need to resolve the phase ambiguities in interferogram stacks either by searching a predefined solution space or by sparse phase unwrapping methods; however the efficiency and the success of phase unwrapping cannot be guaranteed. We present here an alternative approach - temporarily coherent point (TCP) InSAR (TCPInSAR) - to estimate the long term deformation rate without the need of phase unwrapping. The proposed approach has a series of innovations including TCP identification, TCP network and TCP least squares estimator. We apply the proposed method to the Los Angeles Basin in southern California where structurally active faults are believed capable of generating damaging earthquakes. The analysis is based on 55 interferograms from 32 ERS-1/2 images acquired during Oct. 1995 and Dec. 2000. To evaluate the performance of TCPInSAR on a small set of observations, a test with half of interferometric pairs is also performed. The retrieved TCPInSAR measurements have been validated by a comparison with GPS observations from Southern California Integrated GPS Network. Our result presents a similar deformation pattern as shown in past InSAR studies but with a smaller average standard deviation (4.6. mm) compared with GPS observations, indicating that TCPInSAR is a promising alternative for efficiently mapping ground deformation even from a relatively smaller set of interferograms. ?? 2011.

  16. Ground-penetrating radar: A tool for monitoring bridge scour

    Science.gov (United States)

    Anderson, N.L.; Ismael, A.M.; Thitimakorn, T.

    2007-01-01

    Ground-penetrating radar (GPR) data were acquired across shallow streams and/or drainage ditches at 10 bridge sites in Missouri by maneuvering the antennae across the surface of the water and riverbank from the bridge deck, manually or by boat. The acquired two-dimensional and three-dimensional data sets accurately image the channel bottom, demonstrating that the GPR tool can be used to estimate and/or monitor water depths in shallow fluvial environments. The study results demonstrate that the GPR tool is a safe and effective tool for measuring and/or monitoring scour in proximity to bridges. The technique can be used to safely monitor scour at assigned time intervals during peak flood stages, thereby enabling owners to take preventative action prior to potential failure. The GPR tool can also be used to investigate depositional and erosional patterns over time, thereby elucidating these processes on a local scale. In certain instances, in-filled scour features can also be imaged and mapped. This information may be critically important to those engaged in bridge design. GPR has advantages over other tools commonly employed for monitoring bridge scour (reflection seismic profiling, echo sounding, and electrical conductivity probing). The tool doesn't need to be coupled to the water, can be moved rapidly across (or above) the surface of a stream, and provides an accurate depth-structure model of the channel bottom and subchannel bottom sediments. The GPR profiles can be extended across emerged sand bars or onto the shore.

  17. Application of terrestrial laser scanning for detection of ground surface deformation in small mud volcano (Murono, Japan)

    Science.gov (United States)

    Hayakawa, Yuichi S.; Kusumoto, Shigekazu; Matta, Nobuhisa

    2016-07-01

    We perform terrestrial laser scanning (TLS) to detect changes in surface morphology of a mud volcano in Murono, north-central Japan. The study site underwent significant deformation by a strong earthquake in 2011, and the surface deformation has continued in the following years. The point cloud datasets were obtained by TLS at three different times in 2011, 2013 and 2014. Those point clouds were aligned by cloud-based registration, which minimizes the closest point distance of point clouds of unchanged ground features, and the TLS-based point cloud data appear to be suitable for detecting centimeter-order deformations in the central domain of the mud volcano, as well as for measurements of topographic features including cracks of paved ground surface. The spatial patterns and accumulative amount of the vertical deformation during 2011-2014 captured by TLS correspond well with those previously reported based on point-based leveling surveys, supporting the validity of TLS survey.

  18. First Results of Continuous GPS Monitoring of Surface Deformation at the Aquistore Underground CO2 Storage Site

    Science.gov (United States)

    Craymer, M. R.; Ferland, R.; Piraszewski, M.; Samsonov, S. V.; Czarnogorska, M.

    2014-12-01

    Aquistore is a demonstration project for the underground storage of CO2 at a depth of ~3350 m near Estevan, Saskatchewan, Canada. An objective of the project is to design, adapt, and test non-seismic monitoring methods that have not been systematically utilized to date for monitoring CO2 storage projects, and to integrate the data from these various monitoring tools to obtain quantitative estimates of the change in subsurface fluid distributions, pressure changes and associated surface deformation. Monitoring methods being applied include satellite-, surface- and wellbore-based monitoring systems and comprise natural- and controlled-source electromagnetic methods, gravity monitoring, GPS, synthetic aperture radar interferometry (InSAR), tiltmeter array analysis, and chemical tracer studies. Here we focus on the GPS monitoring of surface deformation. Five GPS monitoring stations were installed in 2012 and another six in 2013, some collocated on top of InSAR retroreflectors. The GPS data from these stations have been processed on a weekly basis in both baseline processing mode using the Bernese GPS Software and precise point positioning mode using CSRS-PPP. Here we present the first complete results with 1-2 years of data at all sites prior to CO2 injection. The time series of these sites are examined, compared and analysed with respect to monument stability, seasonal signals and estimates of expected regional ground motion. The individual weekly network solutions have also been combined together in a cumulative 4D network solution to provide a preliminary local velocity field in the immediately vicinity of the injection well. These results are also compared to those obtained independently from InSAR, in particular the direct comparison of GPS and InSAR at the retroreflectors.

  19. The coseismic ground deformations of the 1997 Umbria-Marche earthquakes: a lesson for the development of new GPS networks

    Directory of Open Access Journals (Sweden)

    E. Serpelloni

    2008-06-01

    Full Text Available After the occurrence of the two main shocks Mw=5.7 (00.33 GMT and Mw=6.0 (09:40 GMT on September 26, 1997, which caused severe damages and ground cracks in a wide area of the Umbria Marche region, the Istituto Nazionale di Geofisica in cooperation with the Istituto Geografico Militare Italiano set out to detect the coseismic ground deformation and reoccupied the available geodetic monuments placed across the epicentral area, belonging to the first order Italian GPS network IGM95 and to the Tyrgeonet network. The comparison between the pre and post-earthquakes coordinate set, the latter obtained from the surveys performed in the early days of October 1997 in the Umbria Marche earthquake area, showed maximum displacements values at the closest stations to the epicentres, up to 14.0±1.8 and 24.0±3.0 cm in the horizontal and vertical components, respectively. The availability of the IGM95 stations allowed geodetic data to be translated into relevant geophysical results. For the first time in Italy, the evaluation of post-earthquake coordinates at 13 vertices provided the estimation of a significant deformation field associated with a seismic sequence. Unfortunately, the same actions could not be applied to the October 14, 1997, Mw=5.6 Sellano earthquake, whose epicentre was located a few tens of km south of the previous ones, due to a lack of available geodetic vertices of Tyrgeonet and IGM95 networks in the surroundings of the epicentral zone. This fact, which prevented the estimation of coseismic deformation and seismic source modelling for this earthquake, clarified the need to set up tailor made GPS networks devoted to geophysical applications, able to capture a possible coseismic signal, but also interseismic and post-seismic signals, at the surface of the Earth’s crust at the scale of the expected magnitudes and fault length. Here we show and discuss the development of the Discrete GPS and Continuous GPS (CGPS networks in

  20. Development of a 3D modeling algorithm for tunnel deformation monitoring based on terrestrial laser scanning

    Directory of Open Access Journals (Sweden)

    Xiongyao Xie

    2017-03-01

    Full Text Available Deformation monitoring is vital for tunnel engineering. Traditional monitoring techniques measure only a few data points, which is insufficient to understand the deformation of the entire tunnel. Terrestrial Laser Scanning (TLS is a newly developed technique that can collect thousands of data points in a few minutes, with promising applications to tunnel deformation monitoring. The raw point cloud collected from TLS cannot display tunnel deformation; therefore, a new 3D modeling algorithm was developed for this purpose. The 3D modeling algorithm includes modules for preprocessing the point cloud, extracting the tunnel axis, performing coordinate transformations, performing noise reduction and generating the 3D model. Measurement results from TLS were compared to the results of total station and numerical simulation, confirming the reliability of TLS for tunnel deformation monitoring. Finally, a case study of the Shanghai West Changjiang Road tunnel is introduced, where TLS was applied to measure shield tunnel deformation over multiple sections. Settlement, segment dislocation and cross section convergence were measured and visualized using the proposed 3D modeling algorithm.

  1. Ground Deformation At Uturuncu Volcano, Bolivia: Insights From Finite Element Analysis

    Science.gov (United States)

    Hickey, J.; Gottsmann, J.; del Potro, R.

    2011-12-01

    This study focuses on a Finite Element Analysis of large-scale ground deformation at Uturuncu volcano in the Altiplano-Puna region of southern Bolivia, for the period 19th May 1996 to 24th December 2000. The amplitude of the line-of-sight displacement from InSAR is 7.4 cm, with a wavelength of around 80 km for that period. We present a series of forward models that explain the observed ground displacement using COMSOL Multiphysics and accounting for both homogeneous and heterogeneous crustal mechanics. The source geometry is approximated using spherical, prolate and oblate source shapes. Crustal heterogeneity is constrained by published seismic velocity profiles that indicate the presence of a large low-velocity body at depths of 17 km below the surface. We deduce that the observed uplift is best explained by a single prolate source, in an heterogeneous medium, centred between 16.1 and 18.9 km below local elevation, with a semi-major axis of 5.2 - 9.8 km, semi-minor axes of 2.9 - 5.5 km and a uniform pressure change of between 5.6 and 29.1 MPa, as determined by bootstrapping of the best-fitting models at 90% confidence. This model can be interpreted to reflect pressurisation, at very modest levels, of a magma chamber within the Altiplano-Puna Magma Body. Further efforts to explore the sensitivity of the model fits to the required source excess pressures are obtained by first-order approximations of varying Poisson ratio with depth, host rock viscoelasticity and source multiplicity. We find that such mechanisms play a primary role in explaining the observed deformation at Uturuncu. However, to further constrain the most likely causative source parameters the full three-dimensional displacement field is required.

  2. Model experimental research on deformation and subsidence characteristics of ground and wall rock due to mining under thick overlying terrane

    Energy Technology Data Exchange (ETDEWEB)

    Weizhong Ren; Chengmai Guo; Ziqiang Peng; Yonggang Wang [Chinese Academy of Sciences, Wuhan (China). Institute of Rock and Soil Mechanics

    2010-06-15

    Based on the prototype of a mine, a physical simulation test is conducted. The characteristics of the deformation and failure of the ground surface and the wall rock around a goaf, as well as the creep behavior of the wall rock deformation and the failure mechanism, are analyzed. The simulation test has greatly improved our understanding on the wall rock's deformation and failure characteristics. For the first time, digital close-range photogrammetry was used to measure the displacements in a sectional model test. The measurements by this technique agreed very well with those obtained by other methods, such as using dial gauges.

  3. Monitoring the subsurface with quasi-static deformation

    Energy Technology Data Exchange (ETDEWEB)

    Sneider, Roel; Spetzler, Hartmut

    2013-09-06

    This project consisted of three sub-projects that are all aimed at monitoring the subsurface with geophysical methods. The objectives of these sub-projects are: to investigate the use of seismic waves for remote monitoring of temperature changes in the Yucca Mountain nuclear repository; to investigate the use of measured changes in the tidal tilt as a diagnostic for the infiltration of fluids in the subsurface; and to extract the electrostatic response from dynamic field fluctuations.

  4. Sequential data assimilation strategies for utilizing ground deformation data to assess rapidly evolving magma reservoirs

    Science.gov (United States)

    Gregg, P. M.; Pettijohn, J. C.; Zhan, Y.

    2015-12-01

    Classic inversion and joint inversion schemes for analyzing ground deformation data are limited in their ability to provide model forecasts and track the temporal dynamics of a volcano experiencing unrest. Sequential data assimilation techniques, such as the Ensemble Kalman Filter (EnKF; Evensen, 1994), estimate the instantaneous state of a dynamic system in a time-forward fashion by updating the model of a system whenever observations become available. The EnKF method uses a Markov Chain Monte Carlo approach to estimate the covariance matrix in the Kalman filter and also tracks model parameters concurrently at a fraction of the computational cost of the Kalman filter (Kalman, 1960) and Extended Kalman Filter (Schmidt, 1966). In this investigation, we build upon Gregg and Pettijohn (2015) to test the performance of the EnKF for assimilating multiple, disparate ground deformation datasets (InSAR, GPS, leveling, and EDM) to provide model forecasts of a volcano exhibiting rapid variations in surface deformation. Specifically, the EnKF is applied to a hypothetical volcano experiencing both inflation and deflation to determine how quickly the EnKF is able to respond to changes in the magma chamber source given a particular set of surface observations. Of interest is how the EnKF responds to limitations imposed by the spatial and temporal resolution of the observations as well as data uncertainties. A series of synthetic tests is run to compare EnKF functionality with individual and multiple dataset assimilation. As the EnKF is model-independent, we test the performance of the EnKF with both time-forward viscoelastic finite element models as well as classic elastic analytical models. References: Evensen, G. (1994), Sequential data assimilation with a nonlinear quasi-geostrophic model using Monte Carlo methods to forecast error statistics, JGR, doi:10.1029/94jc00572. Gregg, P. M., and Pettijohn, J. C. (2015), A multi-data stream assimilation framework for the assessment

  5. Phantom-based ground-truth generation for cerebral vessel segmentation and pulsatile deformation analysis

    Science.gov (United States)

    Schetelig, Daniel; Säring, Dennis; Illies, Till; Sedlacik, Jan; Kording, Fabian; Werner, René

    2016-03-01

    Hemodynamic and mechanical factors of the vascular system are assumed to play a major role in understanding, e.g., initiation, growth and rupture of cerebral aneurysms. Among those factors, cardiac cycle-related pulsatile motion and deformation of cerebral vessels currently attract much interest. However, imaging of those effects requires high spatial and temporal resolution and remains challenging { and similarly does the analysis of the acquired images: Flow velocity changes and contrast media inflow cause vessel intensity variations in related temporally resolved computed tomography and magnetic resonance angiography data over the cardiac cycle and impede application of intensity threshold-based segmentation and subsequent motion analysis. In this work, a flow phantom for generation of ground-truth images for evaluation of appropriate segmentation and motion analysis algorithms is developed. The acquired ground-truth data is used to illustrate the interplay between intensity fluctuations and (erroneous) motion quantification by standard threshold-based segmentation, and an adaptive threshold-based segmentation approach is proposed that alleviates respective issues. The results of the phantom study are further demonstrated to be transferable to patient data.

  6. A new PPP algorithm for deformation monitoring with single-frequency receiver

    Indian Academy of Sciences (India)

    Yanli Zheng; Rui Zhang; Shengfeng Gu

    2014-12-01

    Considering the applications of deformation monitoring, PPP (precise point positioning) with singlefrequency (SF) receivers has the advantages of stand-alone, absolute positioning and cost efficiency. However, the existing SF PPP methods can be hardly implemented for deformation monitoring directly due to their limited precision of submeter level. For this purpose, an innovative approach is presented in this paper with several improvements to the existing approaches: firstly, the SEID (Satellite-specific Epoch-differenced Ionospheric Delay) model is adopted in SF kinematic PPP to handle the ionospheric delays for SF receivers embedded in networks of dual-frequency (DF) receivers; secondly, according to the dynamic characteristic of the monitor station, a combination of kinematic PPP and sliding window based static PPP algorithm is adopted. To confirm the availability of the algorithm for deformation monitoring with SF receiver, a seismic experiment is carried out on an earthquake simulation platform. Comparable positioning precision with 1.5 cm for horizontal and 2.2 cm for vertical is achieved by SF PPP with respect to RTK (real-time kinematic) solution. The new deformation monitoring algorithm with SF receiver can be treated as an effective and low cost way to realize some types of geological hazard monitoring in a wide range.

  7. 30 CFR 75.902 - Low- and medium-voltage ground check monitor circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Low- and medium-voltage ground check monitor... Medium-Voltage Alternating Current Circuits § 75.902 Low- and medium-voltage ground check monitor circuits. On or before September 30, 1970, low- and medium-voltage resistance grounded systems shall...

  8. 40 CFR 264.97 - General ground-water monitoring requirements.

    Science.gov (United States)

    2010-07-01

    ... FACILITIES Releases From Solid Waste Management Units § 264.97 General ground-water monitoring requirements. The owner or operator must comply with the following requirements for any ground-water monitoring... 40 Protection of Environment 25 2010-07-01 2010-07-01 false General ground-water...

  9. Surface Deformation Monitoring in Permafrost Regions of Tibetan Plateau Based on Alos Palsar Data

    Science.gov (United States)

    Chen, L. M.; Qiao, G.; Lu, P.

    2017-09-01

    The permafrost region of Qinghai-Tibet Plateau is widely distributed with the freeze/thaw processes that cause surface structural damage. The differential interferometry synthetic aperture radar (DInSAR) can detect large scale surface deformation with high precision, thus can be used to monitor the freeze/thaw processes of frozen soil area. In this paper, the surface deformation pattern of Qinghai-Tibet railway was analyzed by using the PALSAR 1.0 raw data of the ALOS satellite (L band) and 90m resolution SRTM DEM data, with the help of two-pass DInSAR method in GAMMA software, and the differential interferograms and deformation maps were obtained accordingly. Besides, the influence of temperature, topography and other factors on deformation of frozen soil were also studied. The following conclusions were obtained: there is a negative correlation between deformation and temperature, and there is a delay between the deformation change and that of temperature; deformation and elevation are positively correlated; the permafrost deformation is also affected by solar radiation that could form variable amplitude variation.

  10. Monitoring Bridge Deformation in the Czech Republic with Sentinel-1 Data

    Science.gov (United States)

    Hlavacova, Ivana; Kolomaznik, Jan; Lazecky, Milan

    2016-08-01

    In the Czech republic, as well as in other areas, the bridges are of various age and various condition. It seems that more problems can be found on recently- built bridges, but this is due to the fact that the old ones are usually not monitored in such a detail or not at all. The aim of monitoring bridges is to find possible deformations before the deformations get large/significant to endanger the people and/or traffic. However, there are more deformation causes of the bridges, and most of them are reversible, such as thermal dilation, bending with load etc. The problem is to recognize these components from the irreversible deformations, and one needs a large dataset, covering at least 18 month data (to separate the thermal dilation component from the linear deformation component). The direction of the irreversible movements can be arbitrary, and due to the easily accessible Sentinel-1 data, we try to monitor the bridge from various directions.For improving the accuracy we plan to make experiment with corner reflectors to enhance the intensity, and therefore to lower the standard deviation of the movement, however this experiment will be evaluated in future.Our project monitors few bridges in the Czech republic, of various length and age.

  11. Centimeter Cosmo-Skymed Range Measurements for Monitoring Ground Displacements

    Science.gov (United States)

    Fratarcangeli, F.; Nascetti, A.; Capaldo, P.; Mazzoni, A.; Crespi, M.

    2016-06-01

    The SAR (Synthetic Aperture Radar) imagery are widely used in order to monitor displacements impacting the Earth surface and infrastructures. The main remote sensing technique to extract sub-centimeter information from SAR imagery is the Differential SAR Interferometry (DInSAR), based on the phase information only. However, it is well known that DInSAR technique may suffer for lack of coherence among the considered stack of images. New Earth observation SAR satellite sensors, as COSMO-SkyMed, TerraSAR-X, and the coming PAZ, can acquire imagery with high amplitude resolutions too, up to few decimeters. Thanks to this feature, and to the on board dual frequency GPS receivers, allowing orbits determination with an accuracy at few centimetres level, the it was proven by different groups that TerraSAR-X imagery offer the capability to achieve, in a global reference frame, 3D positioning accuracies in the decimeter range and even better just exploiting the slant-range measurements coming from the amplitude information, provided proper corrections of all the involved geophysical phenomena are carefully applied. The core of this work is to test this methodology on COSMO-SkyMed data acquired over the Corvara area (Bolzano - Northern Italy), where, currently, a landslide with relevant yearly displacements, up to decimeters, is monitored, using GPS survey and DInSAR technique. The leading idea is to measure the distance between the satellite and a well identifiable natural or artificial Persistent Scatterer (PS), taking in account the signal propagation delays through the troposphere and ionosphere and filtering out the known geophysical effects that induce periodic and secular ground displacements. The preliminary results here presented and discussed indicate that COSMO-SkyMed Himage imagery appear able to guarantee a displacements monitoring with an accuracy of few centimetres using only the amplitude data, provided few (at least one) stable PS's are available around the

  12. DEFORMATION MONITORING OF MATERIALS UNDER STRESS IN LABORATORY EXPERIMENTS

    Directory of Open Access Journals (Sweden)

    D. Skarlatos

    2016-06-01

    Full Text Available Photogrammetry is a valid alternative solution to linear variable differential transformer (LVDT measurements in structural testing in laboratory conditions. Although the use of LVDTs boasts a high degree of accuracy, on the other hand it is limiting as it offers measurements between two points and it thus might be unable to capture localized deformations and strains over a bigger area of a structural specimen. In this aspect photogrammetry seems to offer certain advantages. Commercial solutions provide limited testing envelopes, while on the other hand, the wide range on new materials need more versatile techniques. Based on the need to develop an in-house photogrammetric toolbox to support several structural and material experiments in the department Advanced Pore Morphology (APM aluminium foam specimens developed at Fraunhofer IFAM in Germany and cured at CUT, were tested under monotonic compressive load. Data acquisition, analysis and results, along with lessons learnt from the process are presented in this work.

  13. Development and Field Testing of a Multi- Antenna GPS System for Deformation Monitoring

    Institute of Scientific and Technical Information of China (English)

    Ding Xiao-li; Huang Ding-fa; Yin Jian-hua; Chen Yong-qi; C. K. Lau; Yang Yu-wen; Sun Yong-rong; Chen Wu; He Xiu-feng

    2003-01-01

    GPS has become an important technology for monitoring deformations of structures and the crust of the Earth. A limiting factor for large-scale use of GPS in such applications is however its high hardware cost. For automatic monitoring of deformations, each point to be monitored needs equipped with a set of GPS instruments. This makes many applications such as routine monitoring of landslides too expensive in most cases. A multi-antenna GPS system has been developed and tested aiming at significantly reducing the cost of GPS when used for monitoring deformations of objects such as slopes. The system uses special hardware and software to allow one GPS receiver to be used with a number of GPS antennas. One set of such equipment can therefore be used to monitor a number of points. The system normally reduces the cost of GPS hardware by a number of folds. Besides, such a system design also eases the tasks of data communication, management and system control. This paper describes the design and system configurations of the multi-antenna GPS system that has been developed by the research team. The system consists of integrated hardware and software components for data acquisition, transmission, processing, analysis and visualization. Integration of the GPS system with conventional slope monitoring systems will also be discussed in brief.

  14. Calculating e-flow using UAV and ground monitoring

    Science.gov (United States)

    Zhao, C. S.; Zhang, C. B.; Yang, S. T.; Liu, C. M.; Xiang, H.; Sun, Y.; Yang, Z. Y.; Zhang, Y.; Yu, X. Y.; Shao, N. F.; Yu, Q.

    2017-09-01

    Intense human activity has led to serious degradation of basin water ecosystems and severe reduction in the river flow available for aquatic biota. As an important water ecosystem index, environmental flows (e-flows) are crucial for maintaining sustainability. However, most e-flow measurement methods involve long cycles, low efficiency, and transdisciplinary expertise. This makes it impossible to rapidly assess river e-flows at basin or larger scales. This study presents a new method to rapidly assessing e-flows coupling UAV and ground monitorings. UAV was firstly used to calculate river-course cross-sections with high-resolution stereoscopic images. A dominance index was then used to identify key fish species. Afterwards a habitat suitability index, along with biodiversity and integrity indices, was used to determine an appropriate flow velocity with full consideration of the fish spawning period. The cross-sections and flow velocity values were then combined into AEHRA, an e-flow assessment method for studying e-flows and supplying-rate. To verify the results from this new method, the widely used Tennant method was employed. The root-mean-square errors of river cross-sections determined by UAV are less than 0.25 m, which constitutes 3-5% water-depth of the river cross-sections. In the study area of Jinan city, the ecological flow velocity (VE) is equal to or greater than 0.11 m/s, and the ecological water depth (HE) is greater than 0.8 m. The river ecosystem is healthy with the minimum e-flow requirements being always met when it is close to large rivers, which is beneficial for the sustainable development of the water ecosystem. In the south river channel of Jinan, the upstream flow mostly meets the minimum e-flow requirements, and the downstream flow always meets the minimum e-flow requirements. The north of Jinan consists predominantly of artificial river channels used for irrigation. Rainfall rarely meets the minimum e-flow and irrigation water requirements

  15. Fiber-Reinforced Rocks Akin to Roman Concrete Help Explain Ground Deformation at Campi Flegrei Caldera

    Science.gov (United States)

    Vanorio, Tiziana; Kanitpanyacharoen, Waruntorn

    2016-04-01

    The caldera of Campi Flegrei is one of the active hydrothermal systems of the Mediterranean region experiencing notable unrest episodes in a densely populated area. During the last crisis of 1982-1984, nearly 40,000 people were evacuated for almost two years from the main town of Pozzuoli, the Roman Puteoli, due to the large uplifts (~2 m over two years) and the persistent seismic activity. The evacuation severely hampered the economy and the social make-up of the community, which included the relocation of schools and commercial shops as well as the harbor being rendered useless for docking. Despite the large uplifts, the release of strain appears delayed. Seismicity begins and reaches a magnitude of 4.0 only upon relatively large uplifts (~ 70-80 cm) contrary to what is generally observed for calderas exhibiting much lower deformation levels. Over and above the specific mechanism causing the unrest and the lack of identification of a shallow magmatic reservoir (concrete. The formation of fibrous minerals by intertwining filaments confers shear and tensile strength to the caprock, contributing to its ductility and increased resistance to fracture. The importance of the findings reported in this study lies not only on the fibrous and compositionally nature of the caprock but also on its possible physicochemical deterioration. Given the P-T-XCO2 conditions regulating the decarbonation reactions, the influx of new fluids into the Campi Flegrei system lowers the temperature of the decarbonation reaction and dilutes the existing CO2, thus triggering additional CO2, methane, and steam to form. As these gases rise toward the surface, the natural cement layer halts them, leading to pore pressure increase and subsequent ground deformations.

  16. The Rover Environmental Monitoring Station Ground Temperature Sensor: A Pyrometer for Measuring Ground Temperature on Mars

    Directory of Open Access Journals (Sweden)

    Miguel Ramos

    2010-10-01

    Full Text Available We describe the parameters that drive the design and modeling of the Rover Environmental Monitoring Station (REMS Ground Temperature Sensor (GTS, an instrument aboard NASA’s Mars Science Laboratory, and report preliminary test results. REMS GTS is a lightweight, low-power, and low cost pyrometer for measuring the Martian surface kinematic temperature. The sensor’s main feature is its innovative design, based on a simple mechanical structure with no moving parts. It includes an in-flight calibration system that permits sensor recalibration when sensor sensitivity has been degraded by deposition of dust over the optics. This paper provides the first results of a GTS engineering model working in a Martian-like, extreme environment.

  17. Signature of magmatic processes in ground deformation signals from Phlegraean Fields (Italy)

    Science.gov (United States)

    Bagagli, Matteo; Montagna, Chiara Paola; Longo, Antonella; Papale, Paolo

    2016-04-01

    Ground deformation signals such as dilatometric and tiltmetric ones, are nowadays well studied from the vulcanological community all over the world. These signals can be used to retrieve information on volcanoes state and to study the magma dynamics in their plumbing system. We compared synthetic signals in the Very Long Period (VLP, 10-2 - 10-1 Hz) and Ultra Long Period (ULP, 10-4 - 10-2 Hz) bands obtained from the simulation of magma mixing in shallow reservoirs ([3],[4]) with real data obtained from the dilatometers and tiltmeters network situated in the Phlegraean Fields near Naples (Italy), in order to define and constrain the relationships between them. Analyses of data from the October 2006 seismic swarm in the area show that the frequency spectrum of the synthetics is remarkably similar to the transient present in the real signals. In depth studies with accurated techniques for spectral analysis (i.e wavelet transform) and application of this method to other time windows have identified in the bandwidth around 10-4Hz (between 1h30m and 2h45m) peaks that are fairly stable and independent from the processing carried out on the full-band signal. These peaks could be the signature of ongoing convection at depth. It is well known that re-injection of juvenile magmas can reactivate the eruption dynamics ([1],[2]), thus being able to define mixing markers and detect them in the ground deformation signals is a relevant topic in order to understand the dynamics of active and quiescent vulcanoes and to eventually improve early-warning methods for impending eruptions. [1] Arienzo, I. et al. (2010). "The feeding system of Agnano-Monte Spina eruption (Campi Flegrei, Italy): dragging the past into present activity and future scenarios". In: Chemical Geology 270.1, pp. 135-147. [2] Bachmann, Olivier and George Bergantz (2008). "The magma reservoirs that feed supereruptions". In: Elements 4.1, pp. 17-21. [3] Longo, Antonella et al. (2012). "Magma convection and mixing

  18. CENTIMETER COSMO-SKYMED RANGE MEASUREMENTS FOR MONITORING GROUND DISPLACEMENTS

    Directory of Open Access Journals (Sweden)

    F. Fratarcangeli

    2016-06-01

    Full Text Available The SAR (Synthetic Aperture Radar imagery are widely used in order to monitor displacements impacting the Earth surface and infrastructures. The main remote sensing technique to extract sub-centimeter information from SAR imagery is the Differential SAR Interferometry (DInSAR, based on the phase information only. However, it is well known that DInSAR technique may suffer for lack of coherence among the considered stack of images. New Earth observation SAR satellite sensors, as COSMO-SkyMed, TerraSAR-X, and the coming PAZ, can acquire imagery with high amplitude resolutions too, up to few decimeters. Thanks to this feature, and to the on board dual frequency GPS receivers, allowing orbits determination with an accuracy at few centimetres level, the it was proven by different groups that TerraSAR-X imagery offer the capability to achieve, in a global reference frame, 3D positioning accuracies in the decimeter range and even better just exploiting the slant-range measurements coming from the amplitude information, provided proper corrections of all the involved geophysical phenomena are carefully applied. The core of this work is to test this methodology on COSMO-SkyMed data acquired over the Corvara area (Bolzano – Northern Italy, where, currently, a landslide with relevant yearly displacements, up to decimeters, is monitored, using GPS survey and DInSAR technique. The leading idea is to measure the distance between the satellite and a well identifiable natural or artificial Persistent Scatterer (PS, taking in account the signal propagation delays through the troposphere and ionosphere and filtering out the known geophysical effects that induce periodic and secular ground displacements. The preliminary results here presented and discussed indicate that COSMO-SkyMed Himage imagery appear able to guarantee a displacements monitoring with an accuracy of few centimetres using only the amplitude data, provided few (at least one stable PS’s are

  19. Ground Water Monitoring Using Laser Fluorescence And Fiber Optics

    Science.gov (United States)

    Chudyk, Wayne; Pohlig, Kenneth; Rico, Nicola; Johnson, Gregory

    1989-01-01

    In-situ measurement of aromatic ground water contaminants, including the benzene, ethylbenzene, toluene, and xylenes (BTEX) fraction of gasoline, has been demonstrated using fiber optic systems. A prototype field instrument has shown that this method has advantages over traditional sampling and analysis. Problems encountered and solved include coupling of the laser energy into to fiber, sensor design, and detector configuration to optimize instrument sensitivity. The effects of sensor length, corresponding to well depth, on limits of detection are presented. Effects of potential interferences, including external fluorescence quenchers, are discuss-ed. The resolution of complex mixtures is addressed, with modifications to the detector shown to be effective in separation of groups of contaminants. Instrument design considerations include the need for portability, ruggedness at field sites, and ease of operation. The modular instrument design used is shown to help solve these potential problems, while maintaining analytical sensitivity and reproducibility. Modular optical system design has also shown to be useful when modifications are made. Changes in the detector as well as provisions for multiple laser sources have allowed a flexible system to be configured to meet analytical demands as they arise. Sensor design considerations included high ultraviolet transmission, physical flexibility, resistance to breakage, and resistance to chemical and/or biological fouling. The approach to these problem areas is presented, as well as discussion of the methods used to minimize effects of fiber solarization. Results of testing the field portable prototype are presented for a variety of typical ground water analysis sites, illustrating the usefulness of this new technology in environmental monitoring.

  20. Somma Vesuvius volcano: ground deformations from CGPS observations (2001-2012

    Directory of Open Access Journals (Sweden)

    Umberto Tammaro

    2013-11-01

    Full Text Available This paper is a contribution to the evaluation of ground deformations at Somma-Vesuvius volcano by means GPS measurements from 2001 to 2012. In this study we use a dataset from nine continuous GPS stations of the Neapolitan Volcanoes Continuous GPS network (NeVoCGPS, which covers the Neapolitan volcanic area, and is operated by the Istituto Nazionale di Geofisica e Vulcanologia. The GPS data processing is performed by the Bernese software v. 5.0. The results of the data processing show that the dynamics of the Somma-Vesuvio volcano, between 2001 and 2012, is characterized by a general subsidence, with maximum values on the Gran Cono at BKNO (−11.7 ± 0.65 mm/year and BKE1 (−4.92 ± 0.36 mm/year stations. The subsidence decrease from the crater down to the coast and the horizontal displacements are concentrated in Gran Cono area, the youngest part of the volcano. The parameters of the principal strain components indicate that Somma-Vesuvius is affected by a predominant contraction phase, which is concentrated in the areas with the greatest altitudes.

  1. Remote and terrestrial ground monitoring techniques integration for hazard assessment in mountain areas

    Science.gov (United States)

    Chinellato, Giulia; Kenner, Robert; Iasio, Christian; Mair, Volkmar; Mosna, David; Mulas, Marco; Phillips, Marcia; Strada, Claudia; Zischg, Andreas

    2014-05-01

    In high mountain regions the choice of appropriate sites for infrastructure such as roads, railways, cable cars or hydropower dams is often very limited. In parallel, the increasing demand for supply infrastructure in the Alps induces a continuous transformation of the territory. The new role played by the precautionary monitoring in the risk governance becomes fundamental and may overcome the modeling of future events, which represented so far the predominant approach to these sort of issues. Furthermore the consequence of considering methodologies alternative to those more exclusive allow to reduce costs and increasing the frequency of measurements, updating continuously the cognitive framework of existing hazard condition in most susceptible territories. The scale factor of the observed area and the multiple purpose of such regional ordinary surveys make it convenient to adopt Radar Satellite-based systems, but they need to be integrated with terrestrial systems for validation and eventual early warning purposes. Significant progress over the past decade in Remote Sensing (RS), Proximal Sensing and integration-based sensor networks systems now provide technologies, that allow to implement monitoring systems for ordinary surveys of extensive areas or regions, which are affected by active natural processes and slope instability. The Interreg project SloMove aims to provide solutions for such challenges and focuses on using remote sensing monitoring techniques for the monitoring of mass movements in two test sites, in South Tyrol (Italy) and in Grisons Canton (Switzerland). The topics faced in this project concern mass movements and slope deformation monitoring techniques, focusing mainly on the integration of multi-temporal interferometry, new generation of terrestrial technologies for differential digital terrain model elaboration provided by laser scanner (TLS), and GNSS-based topographic surveys, which are used not only for validation purpose, but also for

  2. 3-D Ground Displacement Monitoring of very fast-moving Landslides in Emergency Scenario

    Science.gov (United States)

    Casu, Francesco; Manconi, Andrea; Bonano, Manuela; De Luca, Claudio; Elefante, Stefano

    2014-05-01

    On December 3rd, 2013, a large and fast-moving landslide phenomena, which occurred in South-West of Montescaglioso town (southern Italy) after some days of intense raining, caused ground displacements on the order of several meters. The mass wasting involved an important freeway connection disrupting more than 500 meters of the route and some isolated buildings. In this work we present a case study of application of SAR remote sensing techniques for retrieving ground displacement field in a landslide emergency scenario. To this aim, thanks to the availability of ascending and descending COSMO-SkyMed (CSK) satellite acquisitions, we first applied the DInSAR technique (Massonnet et al., 1993) to both datasets, for generating differential interferograms across the investigated event. In particular, two data pairs (one ascending and one descending) involving pre- and post-event epochs and approximately spanning the same time interval were identified. Unfortunately, the DInSAR analysis produced unsatisfactory results, because of the excessive phase noise within the area of interest, mainly related to the fast-moving deformation pattern (several meters) and also to the presence of vegetation. To overcome the above mentioned limitations, the amplitude-based Pixel Offset (PO) technique (Fialko and Simons, 2001) was applied to the previous identified CSK data pairs. In this case, the PO technique allowed us to retrieve the projection of the surface displacements across and along the satellite's track (range and azimuth, respectively) for both the ascending and descending orbits. Then, by properly combining these 2-D maps of the measured surface movements, we also retrieved the 3-D ground deformation pattern, i.e. the North, East and Vertical displacement components. The ground displacements have a main SSE component, with values exceeding 10 meters. Moreover, large subsidence values were identified in those areas experiencing the largest damages, as well as a clear uplift

  3. Ground-based Space Weather Monitoring with LOFAR

    Science.gov (United States)

    Wise, Michael; van Haarlem, Michiel; Lawrence, Gareth; Reid, Simon; Bos, Andre; Rawlings, Steve; Salvini, Stef; Mitchell, Cathryn; Soleimani, Manuch; Amado, Sergio; Teresa, Vital

    As one of the first of a new generation of radio instruments, the International LOFAR Telescope (ILT) will provide a number of unique and novel capabilities for the astronomical community. These include remote configuration and operation, dynamic real-time processing and system response, and the ability to provide multiple simultaneous streams of data to a community whose scientific interests run the gamut from lighting in the atmospheres of distant planets to the origins of the universe itself. The LOFAR (LOw Frequency ARray) system is optimized for a frequency range from 30-240 MHz and consists of multiple antenna fields spread across Europe. In the Netherlands, a total 36 LOFAR stations are nearing completion with an initial 8 international stations currently being deployed in Germany, France, Sweden, and the UK. Digital beam-forming techniques make the LOFAR system agile and allow for rapid repointing of the telescope as well as the potential for multiple simultaneous observations. With its dense core array and long interferometric baselines, LOFAR has the potential to achieve unparalleled sensitivity and spatial resolution in the low frequency radio regime. LOFAR will also be one of the first radio observatories to feature automated processing pipelines to deliver fully calibrated science products to its user community. As we discuss in this presentation, the same capabilities that make LOFAR a powerful tool for radio astronomy also provide an excellent platform upon which to build a ground-based monitoring system for space weather events. For example, the ability to monitor Solar activity in near real-time is one of the key scientific capabilities being developed for LOFAR. With only a fraction of its total observing capacity, LOFAR will be able to provide continuous monitoring of the Solar spectrum over the entire 10-240 MHz band down to microsecond timescales. Autonomous routines will scan these incoming spectral data for evidence of Solar flares and be

  4. Proceedings of the 2011 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marvin A. [Editor; Patterson, Eileen F. [Editor; Sandoval, Marisa N. [Editor

    2011-09-13

    These proceedings contain papers prepared for the Monitoring Research Review 2011: Ground-Based Nuclear Explosion Monitoring Technologies, held 13-15 September, 2011 in Tucson, Arizona. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), National Science Foundation (NSF), and other invited sponsors. The scientific objectives of the research are to improve the United States' capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  5. Proceedings of the 29th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marvin A. [Editor; Benson, Jody [Editor; Patterson, Eileen F. [Editor

    2007-09-25

    These proceedings contain papers prepared for the 29th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 25-27 September, 2007 in Denver, Colorado. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  6. Proceedings of the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marv A [Los Alamos National Laboratory; Aguilar-chang, Julio [Los Alamos National Laboratory; Arrowsmith, Marie [Los Alamos National Laboratory; Arrowsmith, Stephen [Los Alamos National Laboratory; Baker, Diane [Los Alamos National Laboratory; Begnaud, Michael [Los Alamos National Laboratory; Harste, Hans [Los Alamos National Laboratory; Maceira, Monica [Los Alamos National Laboratory; Patton, Howard [Los Alamos National Laboratory; Phillips, Scott [Los Alamos National Laboratory; Randall, George [Los Alamos National Laboratory; Revelle, Douglas [Los Alamos National Laboratory; Rowe, Charlotte [Los Alamos National Laboratory; Stead, Richard [Los Alamos National Laboratory; Steck, Lee [Los Alamos National Laboratory; Whitaker, Rod [Los Alamos National Laboratory; Yang, Xiaoning [Los Alamos National Laboratory

    2008-09-23

    These proceedings contain papers prepared for the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 23-25 September, 2008 in Portsmouth, Virginia. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States’ capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  7. Proceedings of the 2010 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marvin A [Editor; Patterson, Eileen F [Editor

    2010-09-21

    These proceedings contain papers prepared for the Monitoring Research Review 2010: Ground-Based Nuclear Explosion Monitoring Technologies, held 21-23 September, 2010 in Orlando, Florida,. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, National Science Foundation (NSF), Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  8. Proceedings of the 2009 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marv A [Los Alamos National Laboratory; Aguilar - Chang, Julio [Los Alamos National Laboratory; Anderson, Dale [Los Alamos National Laboratory; Arrowsmith, Marie [Los Alamos National Laboratory; Arrowsmith, Stephen [Los Alamos National Laboratory; Baker, Diane [Los Alamos National Laboratory; Begnaud, Michael [Los Alamos National Laboratory; Harste, Hans [Los Alamos National Laboratory; Maceira, Monica [Los Alamos National Laboratory; Patton, Howard [Los Alamos National Laboratory; Phillips, Scott [Los Alamos National Laboratory; Randall, George [Los Alamos National Laboratory; Rowe, Charlotte [Los Alamos National Laboratory; Stead, Richard [Los Alamos National Laboratory; Steck, Lee [Los Alamos National Laboratory; Whitaker, Rod [Los Alamos National Laboratory; Yang, Xiaoning ( David ) [Los Alamos National Laboratory

    2009-09-21

    These proceedings contain papers prepared for the Monitoring Research Review 2009: Ground -Based Nuclear Explosion Monitoring Technologies, held 21-23 September, 2009 in Tucson, Arizona,. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Test Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States’ capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  9. Spatio-temporal evolution of aseismic ground deformation in the Mexicali Valley (Baja California, Mexico) from 1993 to 2010, using differential SAR interferometry

    Science.gov (United States)

    Sarychikhina, O.; Glowacka, E.

    2015-11-01

    Ground deformation in Mexicali Valley, Baja California, Mexico, the southern part of the Mexicali-Imperial valley, is influenced by active tectonics and human activity, mainly that of geothermal fluid extraction in the Cerro Prieto Geothermal Field. Significant ground deformation, mainly subsidence (~ 18 cm yr-1), and related ground fissures cause severe damage to local infrastructure. The technique of Differential Synthetic Aperture Radar Interferometry (DInSAR) has been demonstrated to be a very effective remote sensing tool for accurately measuring the spatial and temporal evolution of ground displacements over broad areas. In present study ERS-1/2 SAR and ENVISAT ASAR images acquired between 1993 and 2010 were used to perform a historical analysis of aseismic ground deformation in Mexicali Valley, in an attempt to evaluate its spatio-temporal evolution and improve the understanding of its dynamic. For this purpose, the conventional 2-pass DInSAR was used to generate interferograms which were used in stacking procedure to produce maps of annual aseismic ground deformation rates for different periods. Differential interferograms that included strong co-seismic deformation signals were not included in the stacking and analysis. The changes in the ground deformation pattern and rate were identified. The main changes occur between 2000 and 2005 and include increasing deformation rate in the recharge zone and decreasing deformation rate in the western part of the CPGF production zone. We suggested that these changes are mainly caused by production development in the Cerro Prieto Geothermal Field.

  10. Landslide monitoring using multitemporal terrestrial laser scanning for ground displacement analysis

    Directory of Open Access Journals (Sweden)

    Maurizio Barbarella

    2015-07-01

    Full Text Available In the analysis of the temporal evolution of landslides and of related hydrogeological hazards, terrestrial laser scanning (TLS seems to be a very suitable technique for morphological description and displacement analysis. In this note we present some procedures designed to solve specific issues related to monitoring. A particular attention has been devoted to data georeferencing, both during survey campaigns and while performing statistical data analysis. The proper interpolation algorithm for digital elevation model generation has been chosen taking into account the features of the landslide morphology and of the acquired datasets. For a detailed analysis of the different dynamics of the hillslope, we identified some areas with homogeneous behaviour applying in a geographic information system (GIS environment a sort of rough segmentation to the grid obtained by differentiating two surfaces. This approach has allowed a clear identification of ground deformations, obtaining detailed quantitative information on surficial displacements. These procedures have been applied to a case study on a large landslide of about 10 hectares, located in Italy, which recently has severely damaged the national railway line. Landslide displacements have been monitored with TLS surveying for three years, from February 2010 to June 2012. Here we report the comparison results between the first and the last survey.

  11. Applications of state estimation in multi-sensor information fusion for the monitoring of open pit mine slope deformation

    Institute of Scientific and Technical Information of China (English)

    FU Hua; LIU Yin-ping; XIAO Jian

    2008-01-01

    The traditional open pit mine slope deformation monitoring system can not use the monitoring information coming from many monitoring points at the same time,can only using the monitoring data coming from a key monitoring point, and that is to say it can only handle one-dimensional time series. Given this shortage in the monitoring,the multi-sensor information fusion in the state estimation techniques would be introduced to the slope deformation monitoring system, and by the dynamic characteristics of deformation slope, the open pit slope would be regarded as a dynamic goal, the condition monitoring of which would be regarded as a dynamic target tracking. Distributed Information fusion technology with feedback was used to process the monitoring data and on this basis Klman filtering algorithms was introduced, and the simulation examples was used to prove its effectivenes.

  12. 30 CFR 77.902 - Low- and medium-voltage ground check monitor circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Low- and medium-voltage ground check monitor... OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.902 Low- and medium-voltage ground check monitor circuits. On and after September 30, 1971, three-phase low- and...

  13. 40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.

    Science.gov (United States)

    2010-07-01

    ... Rule § 141.402 Ground water source microbial monitoring and analytical methods. (a) Triggered source water monitoring—(1) General requirements. A ground water system must conduct triggered source water... State, systems must submit for State approval a triggered source water monitoring plan that identifies...

  14. Ground-based monitoring of solar radiation in Moldova

    Science.gov (United States)

    Aculinin, Alexandr; Smicov, Vladimir

    2010-05-01

    Integrated measurements of solar radiation in Kishinev, Moldova have been started by Atmospheric Research Group (ARG) at the Institute of Applied Physics from 2003. Direct, diffuse and total components of solar and atmospheric long-wave radiation are measured by using of the radiometric complex at the ground-based solar radiation monitoring station. Measurements are fulfilled at the stationary and moving platforms equipped with the set of 9 broadband solar radiation sensors overlapping wavelength range from UV-B to IR. Detailed description of the station can be found at the site http://arg.phys.asm.md. Ground station is placed in an urban environment of Kishinev city (47.00N; 28.56E). Summary of observation data acquired at the station in the course of short-term period from 2004 to 2009 are presented below. Solar radiation measurements were fulfilled by using CM11(280-3000 nm) and CH1 sensors (Kipp&Zonen). In the course of a year maximum and minimum of monthly sums of total radiation was ~706.4 MJm-2 in June and ~82.1MJm-2 in December, respectively. Monthly sums of direct solar radiation (on horizontal plane) show the maximum and minimum values of the order ~456.9 MJm-2 in July and ~25.5MJm-2 in December, respectively. In an average, within a year should be marked the predominance of direct radiation over the scattered radiation, 51% and 49%, respectively. In the course of a year, the percentage contribution of the direct radiation into the total radiation is ~55-65% from May to September. In the remaining months, the percentage contribution decreases and takes the minimum value of ~ 28% in December. In an average, annual sum of total solar radiation is ~4679.9 MJm-2. For the period from April to September accounts for ~76% of the annual amount of total radiation. Annual sum of sunshine duration accounts for ~2149 hours, which is of ~ 48% from the possible sunshine duration. In an average, within a year maximum and minimum of sunshine duration is ~ 304 hours in

  15. Above-ground antineutrino detection for nuclear reactor monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Sweany, M.; Brennan, J.; Cabrera-Palmer, B.; Kiff, S.; Reyna, D.; Throckmorton, D.

    2015-01-01

    Antineutrino monitoring of nuclear reactors has been demonstrated many times (Klimov et al., 1994 [1]; Bowden et al., 2009 [2]; Oguri et al., 2014 [3]), however the technique has not as of yet been developed into a useful capability for treaty verification purposes. The most notable drawback is the current requirement that detectors be deployed underground, with at least several meters-water-equivalent of shielding from cosmic radiation. In addition, the deployment of liquid-based detection media presents a challenge in reactor facilities. We are currently developing a detector system that has the potential to operate above ground and circumvent deployment problems associated with a liquid detection media: the system is composed of segments of plastic scintillator surrounded by {sup 6}LiF/ZnS:Ag. ZnS:Ag is a radio-luminescent phosphor used to detect the neutron capture products of {sup 6}Li. Because of its long decay time compared to standard plastic scintillators, pulse-shape discrimination can be used to distinguish positron and neutron interactions resulting from the inverse beta decay (IBD) of antineutrinos within the detector volume, reducing both accidental and correlated backgrounds. Segmentation further reduces backgrounds by identifying the positron's annihilation gammas, a signature that is absent for most correlated and uncorrelated backgrounds. This work explores different configurations in order to maximize the size of the detector segments without reducing the intrinsic neutron detection efficiency. We believe that this technology will ultimately be applicable to potential safeguards scenarios such as those recently described by Huber et al. (2014) [4,5].

  16. Splitting of ISGMR strength in the light-mass nucleus $^{24}$Mg due to ground-state deformation

    CERN Document Server

    Gupta, Y K; Matta, J T; Patel, D; Peach, T; Hoffman, J; Yoshida, K; Itoh, M; Fujiwara, M; Hara, K; Hashimoto, H; Nakanishi, K; Yosoi, M; Sakaguchi, H; Terashima, S; Kishi, S; Murakami, T; Uchida, M; Yasuda, Y; Akimune, H; Kawabata, T; Harakeh, M N

    2015-01-01

    The isoscalar giant monopole resonance (ISGMR) strength distribution in $^{24}$Mg has been determined from background-free inelastic scattering of 386-MeV $\\alpha$ particles at extreme forward angles, including 0$^{\\circ}$. The ISGMR strength distribution has been observed for the first time to have a two-peak structure in a light-mass nucleus. This splitting of ISGMR strength is explained well by microscopic theory in terms of the prolate deformation of the ground state of $^{24}$Mg.

  17. Numerical models for ground deformation and gravity changes during volcanic unrest: simulating the hydrothermal system dynamics of an active caldera

    OpenAIRE

    Coco, A.; Gottsmann, J.; F. Whitaker; Rust, A; G. Currenti; A. Jasim; S. Bunney

    2015-01-01

    Ground deformation and gravity changes in active calderas during periods of unrest can signal an impending eruption and thus must be correctly interpreted for hazard evaluation. It is critical to differentiate variation of geophysical observables related to volume and pressure changes induced by magma migration from shallow hydrothermal activity associated with hot fluids of magmatic origin rising from depth. In this paper we present a nu...

  18. Monitoring Crustal Deformation by GPS and InSAR in the Three Gorge Area

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The on-going Three Gorges Project (TGP) aims to build one of the largest hydropower stations in the world. Previous investigations have concluded that the reservoir is likely to induce medium-to-intense earthquakes. 23 GPS stations have been established to maintain a geodetic and seismological monitoring network around the reservoir to monitor seismicity and crustal deformation, and to facilitate mitigation activities in case an intense earthquake occurs. The velocity of GPS site was derived from 3 repeated GPS surveys. Meanwhile, another effort has been made to investigate the feasibility of application of satellite interferometric synthetic aperture radar (InSAR) techniques in detecting crustal deformation possibly caused by impoundment of the Three Gorges Reservoir. It has been made to derive digital elevation models (DEM) using European Remote Sensing (ERS) synthetic aperture radar (SAR) imagery. Pairs of ERS SAR images in raw format are processed to generate digital elevation models. This effort will help us evaluate the accuracy of the InSAR techniques for further derivation of background deformation patterns and future detection of reservoir-induced crustal deformation in the area.

  19. Monitoring microstructural evolution in-situ during cyclic deformation by high resolution reciprocal space mapping

    DEFF Research Database (Denmark)

    Diederichs, Annika Martina; Thiel, Felix; Fischer, Torben

    2017-01-01

    is gained by in-situ monitoring of the microstructural evolution during cyclic deformation. By HRRSM, a large number of individual subgrains can be resolved within individual grains in the bulk of polycrystalline specimens and their fate, their individual orientation and elastic stresses, tracked during...... different loading regimes as tension and compression. With this technique, the evolution of dislocation structures in selected grains was followed during an individual load cycle....

  20. Linear friction weld process monitoring of fixture cassette deformations using empirical mode decomposition

    Science.gov (United States)

    Bakker, O. J.; Gibson, C.; Wilson, P.; Lohse, N.; Popov, A. A.

    2015-10-01

    Due to its inherent advantages, linear friction welding is a solid-state joining process of increasing importance to the aerospace, automotive, medical and power generation equipment industries. Tangential oscillations and forge stroke during the burn-off phase of the joining process introduce essential dynamic forces, which can also be detrimental to the welding process. Since burn-off is a critical phase in the manufacturing stage, process monitoring is fundamental for quality and stability control purposes. This study aims to improve workholding stability through the analysis of fixture cassette deformations. Methods and procedures for process monitoring are developed and implemented in a fail-or-pass assessment system for fixture cassette deformations during the burn-off phase. Additionally, the de-noised signals are compared to results from previous production runs. The observed deformations as a consequence of the forces acting on the fixture cassette are measured directly during the welding process. Data on the linear friction-welding machine are acquired and de-noised using empirical mode decomposition, before the burn-off phase is extracted. This approach enables a direct, objective comparison of the signal features with trends from previous successful welds. The capacity of the whole process monitoring system is validated and demonstrated through the analysis of a large number of signals obtained from welding experiments.

  1. InSAR Monitoring of Surface Deformation in Alberta's Oil Sands

    Science.gov (United States)

    Pearse, J.; Singhroy, V.; Li, J.; Samsonov, S. V.; Shipman, T.; Froese, C. R.

    2013-05-01

    Alberta's oil sands are among the world's largest deposits of crude oil, and more than 80% of it is too deep to mine, so unconventional in-situ methods are used for extraction. Most in situ extraction techniques, such as Steam-Assisted Gravity Drainage (SAGD), use steam injection to reduce the viscosity of the bitumen, allowing it to flow into wells to be pumped to the surface. As part of the oil sands safety and environmental monitoring program, the energy regulator uses satellite radar to monitor surface deformation associated with in-situ oil extraction. The dense vegetation and sparse infrastructure in the boreal forest of northern Alberta make InSAR monitoring a challenge; however, we have found that surface heave associated with steam injection can be detected using traditional differential InSAR. Infrastructure and installed corner reflectors also allow us to use persistent scatterer methods to obtain time histories of deformation at individual sites. We have collected and processed several tracks of RADARSAT-2 data over a broad area of the oil sands, and have detected surface deformation signals of approximately 2-3 cm per year, with time series that correlate strongly with monthly SAGD steam injection volumes.

  2. Delineating shallow Neogene deformation structures in northeastern Pará State using Ground Penetrating Radar

    Directory of Open Access Journals (Sweden)

    Dilce F. Rossetti

    2003-06-01

    Full Text Available The geological characterization of shallow subsurface Neogene deposits in northeastern Pará State using Ground Penetrating Radar (GPR revealed normal and reverse faults, as well as folds, not yet well documented by field studies. The faults are identified mostly by steeply-dipping reflections that sharply cut the nearby reflections causing bed offsets, drags and rollovers. The folds are recognized by reflections that are highly undulating, configuring broad concave and convex-up features that are up to 50 m wide and 80 to 90 ns deep. These deformation structures are mostly developed within deposits of Miocene age, though some of the faults might continue into younger deposits as well. Although the studied GPR sections show several diffractions caused by trees, differential degrees of moisture, and underground artifacts, the structures recorded here can not be explained by any of these ''noises''. The detailed analysis of the GPR sections reveals that they are attributed to bed distortion caused by brittle deformation and folding. The record of faults and folds are not widespread in the Neogene deposits of the Bragantina area. These GPR data are in agreement with structural models, which have proposed a complex evolution including strike-slip motion for this area from the Miocene to present.A caracterização geológica de depósitos neógenos ocorrentes em sub-superfície rasa no nordeste do Estado do Pará, usando Radar de Penetração no Solo (GPR, revelou a presença de falhas normais e reversas, bem como dobras, ainda não documentadas em estudos de campo prévios. As falhas são identificadas por reflexões inclinadas que cortam bruscamente reflexões vizinhas, causando freqüentes deslocamentos de camadas. As dobras são reconhecidas por reflexões fortemente ondulantes, configurando feições côncavas e convexas que medem até 50 m de amplitude e 80 a 90 m de profundidade. Estas estruturas deformacionais desenvolvem-se, principalmente

  3. Near real-time monitoring of surface deformation at Long Valley Caldera, California (Invited)

    Science.gov (United States)

    Ji, K.; Llenos, A. L.; Herring, T.

    2013-12-01

    Continuous monitoring of volcanic activity enables us to detect changes from usual activity, issue alerts of impending eruptions and thereby reduce volcanic risk. We have developed a near real-time monitoring tool for surface deformation: the Targeted Projection Operator (TPO). TPO is simple, fast, and easily applied whenever new data are available. With Global Positioning System (GPS) data, we have used TPO for continuous monitoring of surface deformation in the Long Valley Caldera (LVC) region in eastern California. TPO projects GPS position time series onto a target spatial pattern and obtains the amplitude of the projection at each epoch. For this, we assume that a deformation event (i.e., an inflationary or deflationary event) has the same spatial pattern as past events but with possibly different amplitude. This assumption is reasonable for the recent quiet phase in LVC because the 2007-2009 inflation is similar to the 2009-2010 deflation with respect to the deformation pattern. We selected horizontal pattern of the 2009-2010 event along which the GPS data are projected to recover the time-varying amplitudes. Large changes in amplitude imply changes in strength of the event. An anomalous change can be detected by comparing with amplitudes during relatively quiet time periods. Growing misfits between the TPO spatial pattern and the spatial variations of the GPS pattern, indicate changes in the deformation mechanism which can then be explored to assess whether potentially new mechanisms are developing. So far this has not been the case for LVC; the current spatial patterns of deformation match the shape deduced for the 2007-2009 inflation event. TPO shows that LVC has experienced inflation since late 2011 although the rate briefly slowed down in May and October 2012 and has started to slow again since June 2013. The rate of this event is about four times faster than the 2007-2009 inflation event and is consistent with a Mogi source located beneath the resurgent

  4. Research and Practice on the Crustal Deformation Mobile Monitoring Network Layout in the Hydropower Station Reservoir Area

    Institute of Scientific and Technical Information of China (English)

    Shang Hong; Liu Tianhai; Zhang Jincheng; Zhang Chengqiang; Yu Haisheng; Sun Baicheng; Yang Huaining; Du Xiaoxia

    2010-01-01

    According to the construction project of the crustal deformation mobile monitoring network in the cascade hydropower stations built in the lower reaches of Jinsha River,this paper analyzes the design ideas and layout principles of crustal deformation mobile monitoring used in the monitoring of reservoir induced earthquakes.This paper introduces three types of monitoring networks used in the Xiluodu reservoir and Xiangjiaba reservoir,as well as the work already undertaken,in order to provide a kind of reference for the reiated engineering construction and comprehensive monitoring of reservoir induced earthquakes.

  5. Modulation of the thermo-rheological properties of the crust beneath Ischia Island (Southern Italy) on the ground deformation pattern

    Science.gov (United States)

    Castaldo, Raffaele; Gola, Gianluca; Santilano, Alessandro; De Novellis, Vincenzo; Pepe, Susi; Manzo, Mariarosaria; Manzella, Adele; Tizzani, Pietro

    2017-04-01

    We present a model able to simulate the physical process responsible for the long-term ground deformation of Ischia Island Volcano (Southern Italy) by considering the role of the thermo-rheological properties of the crust. To this aim, we develop and implement in a Finite Element (FE) environment an innovative approach that integrates and homogenizes a large amount of data derived from several and different observation techniques (i.e, geological, geophysical and remote sensing). In detail, the main steps of the proposed approach are: (i) the generation of a 3D geological model of the crust beneath the Island by merging the available geological and geophysical information; (ii) the optimization of a 3D thermal model by exploiting the thermal measurements available in literature; (iii) the definition of the 3D B/D (Brittle/Ductile) transition by using the temperature distribution of the crust and the physical information of the rocks; (iv) the optimization of the ground deformation velocity model (that takes into account the rheological stratification) by considering the spatial and temporal information detected via satellite multi-orbit C-Band SAR (Synthetic Aperture Radar) measurements acquired during the 1992-2010 time period. The achieved results allow investigating the physical process responsible for the observed ground deformation pattern. In particular, they reveal how the rheology modulates the spatial and temporal evolution of long-term subsidence phenomenon, highlighting a coupling effect of the viscosities of the rocks and the gravitational loading of the volcano edifice. Moreover, the achieved results provide a very detailed and realistic image of the subsurface crust of the Ischia Island Volcano in order to study the ongoing deformation phenomena.

  6. Rapid dike intrusion into Sakurajima volcano on August 15, 2015, as detected by multi-parameter ground deformation observations

    Science.gov (United States)

    Hotta, Kohei; Iguchi, Masato; Tameguri, Takeshi

    2016-04-01

    We present observations of ground deformation at Sakurajima in August 2015 and model the deformation using a combination of GNSS, tilt and strain data in order to interpret a rapid deformation event on August 15, 2015. The pattern of horizontal displacement during the period from August 14 to 16, 2015, shows a WNW-ESE extension, which suggests the opening of a dike. Using a genetic algorithm, we obtained the position, dip, strike length, width and opening of a dislocation source based on the combined data. A nearly vertical dike with a NNE-SSW strike was found at a depth of 1.0 km below sea level beneath the Showa crater. The length and width are 2.3 and 0.6 km, respectively, and a dike opening of 1.97 m yields a volume increase of 2.7 × 106 m3. 887 volcano-tectonic (VT) earthquakes beside the dike suggest that the rapid opening of the dike caused an accumulation of strain in the surrounding rocks, and the VT earthquakes were generated to release this strain. Half of the total amount of deformation was concentrated between 10:27 and 11:54 on August 15. It is estimated that the magma intrusion rate was 1 × 106 m3/h during this period. This is 200 times larger than the magma intrusion rate prior to one of the biggest eruptions at the summit crater of Minami-dake on July 24, 2012, and 2200 times larger than the average magma intrusion rate during the period from October 2011 to March 2012. The previous Mogi-type ground deformation is considered to be a process of magma accumulation in preexisting spherical reservoirs. Conversely, the August 2015 event was a dike intrusion and occurred in a different location to the preexisting reservoirs. The direction of the opening of the dike coincides with the T-axes and direction of faults creating a graben structure.

  7. GB-SAR Experiment On Deformation Extraction And System Error Analysis

    Science.gov (United States)

    Qu, Shibo; Wang, Yanping; Tan, Weixian; Hong, Wen

    2010-10-01

    Ground Based Synthetic Aperture Radar (GB-SAR) provides a new method to monitoring deformation in relative small region. In this paper, we present the GB-SAR imaging geometry and analyze the interferometric phase for the purpose of deformation monitoring. Deformation monitoring error sources are also analyzed through sensitivity equations, including frequency instability and its influence on interferometric phase and deformation extraction, incident angle and monitoring distance. At last, a deformation monitoring experiment is carry out using ASTRO (Advanced Scannable Two-dimensional Rail Observation system), a GB-SAR system constructed by Institute of Electronics Chinese Academy of Sciences (IECAS). The deformation monitoring results show good consistent with metal objects' movement.

  8. Surface deformation time-series analysis at Ischia Island (South Italy) carried out via multi-platform monitoring systems

    Science.gov (United States)

    Manzo, Mariarosaria; Del Gaudio, Carlo; De Martino, Prospero; Ricco, Ciro; Tammaro, Umberto; Castaldo, Raffaele; Tizzani, Pietro; Lanari, Riccardo

    2014-05-01

    Ischia Island, located at the North-Western corner of the Gulf of Napoli (South Italy), is a volcanic area, whose state of activity is testified from eruptions (the last one occurred in 1302), earthquakes (the most disastrous in 1881 and 1883), hydrothermal manifestations and ground deformation. In this work we present the state of the art of the Ischia Island ground deformation phenomena through the joint analysis of data collected via different monitoring methodologies (leveling, GPS, and Differential SAR Interferometry) during the last twenty years. In particular, our analysis benefits from the large amount of periodic and continuous geodetic measurements collected by the 257 leveling benchmarks and the 20 (17 campaign and 3 permanent) GPS stations deployed on the island. Moreover, it takes advantage from the large archives of C-band SAR data (about 300 ascending and descending ERS-1/2 and ENVISAT images) acquired over the island since 1992 and the development of the advanced Differential SAR Interferometry (DInSAR) technique referred to as Small BAseline Subset (SBAS). The latter, allows providing space-time information on the ground displacements measured along the radar line of sight (LOS), and thanks to the availability of multi-orbit SAR data, permits to discriminate the vertical and east-west components of the detected displacements. Our integrated analysis reveals a complex deformative scenario; in particular, it identifies a spatially extended subsidence pattern, which increases as we move to higher heights, with no evidence of any uplift phenomena. This broad effect involve the Northern, Eastern, Southern and South-Western sectors of the island where we measure velocity values not exceeding -6 mm/year; moreover, we identify a more localized phenomenon affecting the North-Western area in correspondence to the Fango zone, where velocity values up to -10 mm/year are retrieved. In addition, our study shows a migration of the Eastern sector of the island

  9. Deformation Monitoring of Geomechanical Model Test and Its Application in Overall Stability Analysis of a High Arch Dam

    Directory of Open Access Journals (Sweden)

    Baoquan Yang

    2015-01-01

    Full Text Available Geomechanical model testing is an important method for studying the overall stability of high arch dams. The main task of a geomechanical model test is deformation monitoring. Currently, many types of deformation instruments are used for deformation monitoring of dam models, which provide valuable information on the deformation characteristics of the prototype dams. However, further investigation is required for assessing the overall stability of high arch dams through analyzing deformation monitoring data. First, a relationship for assessing the stability of dams is established based on the comprehensive model test method. Second, a stability evaluation system is presented based on the deformation monitoring data, together with the relationships between the deformation and overloading coefficient. Finally, the comprehensive model test method is applied to study the overall stability of the Jinping-I high arch dam. A three-dimensional destructive test of the geomechanical model dam is conducted under reinforced foundation conditions. The deformation characteristics and failure mechanisms of the dam abutments and foundation were investigated. The test results indicate that the stability safety factors of the dam abutments and foundation range from 5.2 to 6.0. These research results provide an important scientific insight into the design, construction, and operation stages of this project.

  10. Design and Testing of the Strain Transducer for Measuring Deformations of Pipelines Operating in the Mining-deformable Ground Environment

    Directory of Open Access Journals (Sweden)

    Gawedzki Waclaw

    2015-10-01

    Full Text Available Design and laboratory test results of the strain transducer intended for monitoring and assessing stress states of pipelines sited in mining areas are presented in this paper. This transducer allows measuring strains of pipelines subjected to external forces - being the mining operations effect. Pipeline strains can have a direct influence on a tightness loss and penetration of the transported fluid into the environment. The original strain gauge transducer was proposed for performing measurements of strains. It allows measuring circumferential strains and determining the value and direction of the main longitudinal strain. This strain is determined on the basis of measuring component longitudinal strains originating from axial forces and the resultant bending moment. The main purpose of investigations was the experimental verification of the possibility of applying the strain transducer for measuring strains of polyethylene pipelines. The obtained results of the transducer subjected to influences of tensile and compression forces are presented and tests of relaxation properties of polyethylene are performed.

  11. Development of AN Open-Source Automatic Deformation Monitoring System for Geodetical and Geotechnical Measurements

    Science.gov (United States)

    Engel, P.; Schweimler, B.

    2016-04-01

    The deformation monitoring of structures and buildings is an important task field of modern engineering surveying, ensuring the standing and reliability of supervised objects over a long period. Several commercial hardware and software solutions for the realization of such monitoring measurements are available on the market. In addition to them, a research team at the Neubrandenburg University of Applied Sciences (NUAS) is actively developing a software package for monitoring purposes in geodesy and geotechnics, which is distributed under an open source licence and free of charge. The task of managing an open source project is well-known in computer science, but it is fairly new in a geodetic context. This paper contributes to that issue by detailing applications, frameworks, and interfaces for the design and implementation of open hardware and software solutions for sensor control, sensor networks, and data management in automatic deformation monitoring. It will be discussed how the development effort of networked applications can be reduced by using free programming tools, cloud computing technologies, and rapid prototyping methods.

  12. Development of Laser Scanner for Full Cross-Sectional Deformation Monitoring of Underground Gateroads.

    Science.gov (United States)

    Yang, Qianlong; Zhang, Zhenyu; Liu, Xiaoqian; Ma, Shuqi

    2017-06-07

    The deformation of underground gateroads tends to be asymmetric and complex. Traditional instrumentation fails to accurately and conveniently monitor the full cross-sectional deformation of underground gateroads. Here, a full cross-sectional laser scanner was developed, together with a visualization software package. The developed system used a polar coordinate measuring method and the full cross-sectional measurement was shown by 360° rotation of a laser sensor driven by an electrical motor. Later on, the potential impact of gateroad wall flatness, roughness, and geometrical profile, as well as coal dust environment on the performance of the developed laser scanner will be evaluated. The study shows that high-level flatness is favorable in the application of the developed full cross-sectional deformation monitoring system. For a smooth surface of gateroad, the sensor cannot receive reflected light when the incidence angle of laser beam is large, causing data loss. Conversely, the roughness surface shows its nature as the diffuse reflection light can be received by the sensor. With regards to coal dust in the measurement environment, fine particles of floating coal dust in the air can lead to the loss of measurement data to some extent, due to scattering of the laser beam.

  13. Sentinel-1 and ground-based sensors for a continuous monitoring of the Corvara landslide kinematic (South Tirol, Italy)

    Science.gov (United States)

    Schlögel, Romy; Darvishi, Mehdi; Cuozzo, Giovanni; Kofler, Christian; Rutzinger, Martin; Zieher, Thomas; Toschi, Isabella; Remondino, Fabio

    2017-04-01

    Sentinel-1 mission allows us to have Synthetic Aperture Radar (SAR) acquisitions over large areas every 6 days with spatial resolution of 20 m. This new open-source generation of satellites has enhanced the capabilities for continuously studying earth surface changes. Over the past two decades, several studies have demonstrated the potential of Differential Synthetic Aperture Radar Interferometry (DInSAR) for detecting and quantifying land surface deformation. DInSAR limitations and challenges are linked to the SAR properties and the field conditions (especially in Alpine environments) leading to spatial and temporal decorrelation of the SAR signal. High temporal decorrelation can be caused by changes in vegetation (particularly in non-urban areas), atmospheric conditions or high ground surface velocity. In this study, kinematics of the complex and vegetated Corvara landslide, situated in Val Badia (South Tirol, Italy), are monitored by a network of 3 permanent and 13 monthly Differential Global Positioning System (DGPS) stations. The slope displacement rates are found to be highly unsteady and reach several meters a year. This analysis focuses on evaluating the limitations of Sentinel-1 imagery processed with Small Baseline Subset (SBAS) technique in comparison to ground-based measurements for assessing the landslide kinematic linked to meteorological conditions. Selecting some particular acquisitions, coherence thresholds and unwrapping processes gives various results in terms of reliability and accuracy supporting the understanding of the landslide velocity field. The evolution of the coherence and phase signals are studied according to the changing field conditions and the monitored ground-based displacements. DInSAR deformation maps and residual topographic heights are finally compared with difference of high resolution Digital Elevation Models at local scale. This research is conducted within the project LEMONADE (http://lemonade.mountainresearch.at) funded

  14. Masses, Deformations and Charge Radii--Nuclear Ground-State Properties in the Relativistic Mean Field Model

    CERN Document Server

    Geng, L S; Meng, J

    2005-01-01

    We perform a systematic study of the ground-state properties of all the nuclei from the proton drip line to the neutron drip line throughout the periodic table employing the relativistic mean field model. The TMA parameter set is used for the mean-field Lagrangian density, and a state-dependent BCS method is adopted to describe the pairing correlation. The ground-state properties of a total of 6969 nuclei with $Z,N\\ge 8$ and $Z\\le 100$ from the proton drip line to the neutron drip line, including the binding energies, the separation energies, the deformations, and the rms charge radii, are calculated and compared with existing experimental data and those of the FRDM and HFB-2 mass formulae. This study provides the first complete picture of the current status of the descriptions of nuclear ground-state properties in the relativistic mean field model. The deviations from existing experimental data indicate either that new degrees of freedom are needed, such as triaxial deformations, or that serious effort is ne...

  15. Monitored Natural Attenuation For Inorganic Contaminants In Ground Water - Technical Issues

    Science.gov (United States)

    Remediation of ground water contaminated with radionuclides may be achieved using attenuation-based technologies. These technologies may rely on engineered processes (e.g., bioremediation) or natural processes (e.g., monitored natural attenuation) within the subsurface. In gene...

  16. Squeezing red blood cells on an optical waveguide to monitor cell deformability during blood storage.

    Science.gov (United States)

    Ahluwalia, Balpreet Singh; McCourt, Peter; Oteiza, Ana; Wilkinson, James S; Huser, Thomas R; Hellesø, Olav Gaute

    2015-01-07

    Red blood cells squeeze through micro-capillaries as part of blood circulation in the body. The deformability of red blood cells is thus critical for blood circulation. In this work, we report a method to optically squeeze red blood cells using the evanescent field present on top of a planar waveguide chip. The optical forces from a narrow waveguide are used to squeeze red blood cells to a size comparable to the waveguide width. Optical forces and pressure distributions on the cells are numerically computed to explain the squeezing process. The proposed technique is used to quantify the loss of blood deformability that occurs during blood storage lesion. Squeezing red blood cells using waveguides is a sensitive technique and works simultaneously on several cells, making the method suitable for monitoring stored blood.

  17. Measuring structure deformations of a composite glider by optical means with on-ground and in-flight testing

    Science.gov (United States)

    Bakunowicz, Jerzy; Święch, Łukasz; Meyer, Ralf

    2016-12-01

    In aeronautical research experimental data sets of high quality are essential to verify and improve simulation algorithms. For this reason the experimental techniques need to be constantly refined. The shape, movement or deformation of structural aircraft elements can be measured implicitly in multiple ways; however, only optical, correlation-based techniques are able to deliver direct high-order and spatial results. In this paper two different optical metrologies are used for on-ground preparation and the actual execution of in-flight wing deformation measurements on a PW-6U glider. Firstly, the commercial PONTOS system is used for static tests on the ground and for wind tunnel investigations to successfully certify an experimental sensor pod mounted on top of the test bed fuselage. Secondly, a modification of the glider is necessary to implement the optical method named image pattern correlation technique (IPCT), which has been developed by the German Aerospace Center DLR. This scientific technology uses a stereoscopic camera set-up placed inside the experimental pod and a stochastic dot matrix applied to the area of interest on the glider wing to measure the deformation of the upper wing surface in-flight. The flight test installation, including the preparation, is described and results are presented briefly. Focussing on the compensation for typical error sources, the paper concludes with a recommended procedure to enhance the data processing for better results. Within the presented project IPCT has been developed and optimized for a new type of test bed. Adapted to the special requirements of the glider, the IPCT measurements were able to deliver a valuable wing deformation data base which now can be used to improve corresponding numerical models and simulations.

  18. Ground-water monitoring compliance plan for the Hanford Site Solid Waste Landfill

    Energy Technology Data Exchange (ETDEWEB)

    Fruland, R.M.

    1986-10-01

    Washington state regulations required that solid waste landfill facilities have ground-water monitoring programs in place by May 27, 1987. This document describes the well locations, installation, characterization studies and sampling and analysis plan to be followed in implementing the ground-water monitoring program at the Hanford Site Solid Waste Landfill (SWL). It is based on Washington Administrative Code WAC 173-304-490. 11 refs., 19 figs., 4 tabs.

  19. Hanford Site ground-water monitoring for July through December 1987

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.C.; Dennison, D.I.; Bryce, R.W.; Mitchell, P.J.; Sherwood, D.R.; Krupka, K.M.; Hinman, N.W.; Jacobson, E.A.; Freshley, M.D.

    1988-12-01

    The Pacific Northwest Laboratory monitors ground-water quality at the Hanford Site for the US Department of Energy to assess the impact of Site operations on the environment. Work undertaken between July and December 1987 included monitoring ground-water elevations across the Site, monitoring hazardous chemicals and radionuclides in ground water, geochemical evaluations of unconfined ground-water data, and calibration of ground-water flow and transport models. Water levels continued to rise in areas receiving increased recharge (e.g., beneath B Pond) and decline in areas where the release of water to disposal facilities has been terminated (e.g., U Pond). The major areas of ground-water contamination defined by monitoring activities are (1) carbon tetrachloride in the 200-West Area; (2) cyanide in and north of the 200-East and 200-West Areas; (3) hexavalent chromium contamination in the 100-B, 100-D, 100-F, 100-H, 100-K, and 200-West Areas; (4) chlorinated hydrocarbons in the vicinity of the Central Landfill and 300 Area; (5) uranium in the 100-F, 100-H, 200-West, and 300 Areas; and (6) tritium and nitrate across the Site. The MINTEQ geochemical code was used to identify chemical reactions that may be affecting the concentrations of dissolved hazardous chemicals in the unconfined ground water. Results indicate that many cations are present mainly as dissolved carbonate complexes and that a majority of the ground-water samples are in near equilibrium with carbonate minerals (e.g., calcite, dolomite, otavite).

  20. Deformation monitoring at Nevado del Ruiz, Colombia - October 1985 - March 1988

    Science.gov (United States)

    Banks, N.G.; Carvajal, C.; Mora, H.; Tryggvason, E.

    1990-01-01

    Deformation studies began at Nevado del Ruiz 23 days before the devastating 13 November 1985 eruption, at least 12 months after precursory seismicity and fumarolic activity began. The late start in geodetic monitoring, limited number of stations in the pre-eruption network, and inconsistent patterns in the observed deformation limit conclusions about intrusive activity in the months and weeks prior to the eruption. However, the data require that the magma source of the devastating eruption was either deeper than 7 km or, if shallow, recovered the same volume and position within one week of the eruption. Geodetic monitoring resumed 1 week after the eruption and, by April 1986, included 11 tilt-leveling stations, 38 EDM lines, and 7 short leveling lines - a network capable of detecting emplacement or movement of magma volumes as small as 3 MCM (3 ?? 106 m3) to a depth of 2-3 km (using a point-source model), 10 MCM to 7 km, 50 MCM to 10 km, and 200 MCM to 15 km beneath Ruiz. In addition, 4 telemetered tiltmeters provided the capability of detecting, in real time, the fairly rapid ascent of much smaller magma bodies. Stations established to detect instability of the summit ice cap after the eruption were discontinued in early 1986. The data collected from the geodetic networks have higher than normal variance but demonstrate that little or no cumulative deformation of Ruiz occurred from October 1985 through March 1988. Thus, little, if any, magma intruded above 5 km beneath the summit during or after the 13 November 1985 eruption. This lack of significant intrusive activity agrees with the surprisingly low seismic energy release under Ruiz and makes direct degassing of a large batholith an improbable explanation of the large sulfur flux to date at Ruiz. Part of the variance in the geodetic data results from real but noncumulative deformation that may in part be pressure-buffered by a fairly large geothermal water-gas mixture for which abundant physical evidence exists

  1. Integrated inversion of ground deformation and magnetic data at Etna volcano using a genetic algorithm technique

    Directory of Open Access Journals (Sweden)

    G. Ganci

    2007-06-01

    Full Text Available Geodetic and magnetic investigations have been playing an increasingly important role in studies on Mt. Etna eruptive processes. During ascent, magma interacts with surrounding rocks and fluids, and inevitably crustal deformation and disturbances in the local magnetic field are produced. These effects are generally interpreted separately from each other and consistency of interpretations obtained from different methods is qualitatively checked only a posteriori. In order to make the estimation of source parameters more robust we propose an integrated inversion from deformation and magnetic data that leads to the best possible understanding of the underlying geophysical process. The inversion problem was formulated following a global optimization approach based on the use of genetic algorithms. The proposed modeling inversion technique was applied on field data sets recorded during the onset of the 2002-2003 Etna flank eruption. The deformation pattern and the magnetic anomalies were consistent with a piezomagnetic effect caused by a dyke intrusion propagating along the NE direction.

  2. Splitting of ISGMR strength in the light-mass nucleus 24Mg due to ground-state deformation

    Directory of Open Access Journals (Sweden)

    Y.K. Gupta

    2015-09-01

    Full Text Available The isoscalar giant monopole resonance (ISGMR strength distribution in 24Mg has been determined from background-free inelastic scattering of 386-MeV α particles at extreme forward angles, including 0∘. The ISGMR strength distribution has been observed for the first time to have a two-peak structure in a light-mass nucleus. This splitting of ISGMR strength is explained well by microscopic theory in terms of the prolate deformation of the ground state of 24Mg.

  3. Use of Terrestrial Laser Scanning Technology for Long Term High Precision Deformation Monitoring

    Science.gov (United States)

    Vezočnik, Rok; Ambrožič, Tomaž; Sterle, Oskar; Bilban, Gregor; Pfeifer, Norbert; Stopar, Bojan

    2009-01-01

    The paper presents a new methodology for high precision monitoring of deformations with a long term perspective using terrestrial laser scanning technology. In order to solve the problem of a stable reference system and to assure the high quality of possible position changes of point clouds, scanning is integrated with two complementary surveying techniques, i.e., high quality static GNSS positioning and precise tacheometry. The case study object where the proposed methodology was tested is a high pressure underground pipeline situated in an area which is geologically unstable. PMID:22303152

  4. New Algorithm Model for Processing Generalized Dynamic Nonlinear Data Derived from Deformation Monitoring Network

    Institute of Scientific and Technical Information of China (English)

    LIN Xiangguo; LIANG Yong

    2005-01-01

    The processing of nonlinear data was one of hot topics in surveying and mapping field in recent years.As a result, many linear methods and nonlinear methods have been developed.But the methods for processing generalized nonlinear surveying and mapping data, especially for different data types and including unknown parameters with random or nonrandom, are seldom noticed.A new algorithm model is presented in this paper for processing nonlinear dynamic multiple-period and multiple-accuracy data derived from deformation monitoring network.

  5. Anthropogenic and natural ground deformation in the Hengill geothermal area, Iceland

    Science.gov (United States)

    Juncu, D.; Árnadóttir, Th.; Hooper, A.; Gunnarsson, G.

    2017-01-01

    We investigate crustal deformation due to the extraction of water and steam from a high-enthalpy geothermal reservoir; a common occurrence, yet not well understood. The cause of this deformation can be a change in pressure or in temperature in the reservoir, both of which can be caused by extraction or injection of geothermal fluids. Our study area, the Hengill mountains in SW Iceland, is an active volcanic center and a plate triple junction that hosts two power plants producing geothermal energy. This combination of natural and anthropogenic processes causes a complex displacement field at the surface. We analyze geodetic data—Global Navigation Satellite System and Interferometric Synthetic Aperture Radar—to obtain the surface velocity field, which we then simulate using an inverse modeling approach. We focus on the deformation around the geothermal power plants but need to model the regional tectonic and volcanic deformation as well, because the signals are overlapping. We find that plate motion and a deep contracting body can explain the broad scale signal in the area. Local deformation near the two power plants, Hellisheidi and Nesjavellir, can be explained by extraction of geothermal fluids. We estimate reservoirs extending from 0.6 to 3.0 km depth at Hellisheidi, and 1.0 to 3.0 km depth at Nesjavellir for observed pressure decrease rates of 0.25 MPa/yr and 0.1 MPa/yr, respectively. We find that the main cause for the subsidence in the geothermal area is the observed pressure drawdown.

  6. New results on ground deformation in the Upper Silesian Coal Basin (southern Poland) obtained during the DORIS Project (EU-FP 7)

    Science.gov (United States)

    Graniczny, Marek; Colombo, Davide; Kowalski, Zbigniew; Przyłucka, Maria; Zdanowski, Albin

    2015-11-01

    mines. The presence of bentonite deposits in the Saturn coal mine can also have influence on the ground surface uplift. Analysis of interferometric L and X-band data in Upper Silesia has enabled observation and monitoring of the underground mining front for several months. It was indicated by the example from the Halemba-Wirek coal mine. Analysis of the TerraSAR-X dataset processed by SqueeSAR algorithms proved to be the most effective for this purpose. X-band persistent scatterer interferometry (PSI) time series can help to indentify small seemingly negligible movements and are successfully supplemented by fringes when displacement becomes significant. Differential interferograms from the L-band dataset detect similar displacement values but, thanks to longer wavelength, are characterized by better coherence, especially in the middle of the subsidence trough. Results on ground deformation proved that ground motion above abandoned mines continues long after their closure. Therefore, existing regulations stating that abandoned mines are considered fully safe five years after mine closure should change. Moreover, it should be emphasised that construction in these areas should be avoided due to existing potential risks.

  7. Lifetime measurements of the first 2+ states in 104,106Zr: Evolution of ground-state deformations

    Directory of Open Access Journals (Sweden)

    F. Browne

    2015-11-01

    Full Text Available The first fast-timing measurements from nuclides produced via the in-flight fission mechanism are reported. The lifetimes of the first 2+ states in 104,106Zr nuclei have been measured via β-delayed γ-ray timing of stopped radioactive isotope beams. An improved precision for the lifetime of the 21+ state in 104Zr was obtained, τ(21+=2.90−20+25 ns, as well as a first measurement of the 21+ state in 106Zr, τ(21+=2.60−15+20 ns, with corresponding reduced transition probabilities of B(E2;21+→0g.s.+=0.39(2 e2b2 and 0.31(1 e2b2, respectively. Comparisons of the extracted ground-state deformations, β2=0.39(1 (104Zr and β2=0.36(1 (106Zr with model calculations indicate a persistence of prolate deformation. The data show that 104Zr is the most deformed of the neutron-rich Zr isotopes measured so far.

  8. Recent Ground Deformation around the Northern Part of Lake Nasser, Aswan, Egypt Using GPS and InSAR

    Science.gov (United States)

    Saleh, Mohamed; Masson, Frederic

    2017-04-01

    The rate of seismic activity around the Lake Nasser was rapidly increased after the creation of the High Dam. The largest earthquake recorded in this area was the November 14, 1981, with magnitude ML5.6 at Kalabsha fault, 60 km southwest of Aswan High Dam. Due to the great importance of this region, many attempts were made to constrain the ground deformation around the northern part of Nasser Lake using GPS data. Due to the sparse spatial resolution of the GPS stations in this region, the achieved results need more verification. Therefore, we are using about 15 years of campaign data collected from the local geodetic network around the northern part of the Lake in addition to 34 SAR scenes, covering the time span from 2002 to 2010, to better constrain the ground deformation of this area. The processing of the GPS data was carried out using GAMIT/GLOBK whereas, the NSBAS technique was applied to the SAR scenes. Combining the results from both GPS and InSAR analysis may help to better understand the geodynamical behavior of such an important region in Egypt for the safety of human and vital national constructions.

  9. Coseismic ground deformation of the 6 April 2009 L'Aquila earthquake (central Italy, Mw6.3)

    Science.gov (United States)

    Boncio, P.; Pizzi, A.; Brozzetti, F.; Pomposo, G.; Lavecchia, G.; Di Naccio, D.; Ferrarini, F.

    2010-03-01

    We provide field data of coseismic ground deformation related to the 6 April Mw 6.3 L'Aquila normal faulting earthquake. Three narrow fracture zones were mapped: Paganica-Colle Enzano (P-E), Mt. Castellano-Mt. Stabiata (C-S) and San Gregorio (SG). These zones define 13 km of surface ruptures that strike at 130-140°. We mapped four main types of ground deformation (free faces on bedrock fault scarps, faulting along synthetic splays and fissures with or without slip) that are probably due to the near-surface lithology of the fault walls and the amount of slip that approached the surface coseismically. The P-E and C-S zones are characterized by downthrow to the SW (up to 10 cm) and opening (up to 12 cm), while the SG zone is characterized only by opening. Afterslip throw rates of 0.5-0.6 mm/day were measured along the Paganica fault, where paleoseismic evidence reveals recurring paleo-earthquakes and post-24.8 kyr slip-rate ≥ 0.24 mm/yr.

  10. Long-term monitoring of geodynamic surface deformation using SAR interferometry

    Science.gov (United States)

    Gong, Wenyu

    Synthetic Aperture Radar Interferometry (InSAR) is a powerful tool to measure surface deformation and is well suited for surveying active volcanoes using historical and existing satellites. However, the value and applicability of InSAR for geodynamic monitoring problems is limited by the influence of temporal decorrelation and electromagnetic path delay variations in the atmosphere, both of which reduce the sensitivity and accuracy of the technique. The aim of this PhD thesis research is: how to optimize the quantity and quality of deformation signals extracted from InSAR stacks that contain only a low number of images in order to facilitate volcano monitoring and the study of their geophysical signatures. In particular, the focus is on methods of mitigating atmospheric artifacts in interferograms by combining time-series InSAR techniques and external atmospheric delay maps derived by Numerical Weather Prediction (NWP) models. In the first chapter of the thesis, the potential of the NWP Weather Research & Forecasting (WRF) model for InSAR data correction has been studied extensively. Forecasted atmospheric delays derived from operational High Resolution Rapid Refresh for the Alaska region (HRRR-AK) products have been compared to radiosonding measurements in the first chapter. The result suggests that the HRRR-AK operational products are a good data source for correcting atmospheric delays in spaceborne geodetic radar observations, if the geophysical signal to be observed is larger than 20 mm. In the second chapter, an advanced method for integrating NWP products into the time series InSAR workflow is developed. The efficiency of the algorithm is tested via simulated data experiments, which demonstrate the method outperforms other more conventional methods. In Chapter 3, a geophysical case study is performed by applying the developed algorithm to the active volcanoes of Unimak Island Alaska (Westdahl, Fisher and Shishaldin) for long term volcano deformation

  11. Monitoring of the Earth's surface deformation in the area of water dam Zarnowiec

    Science.gov (United States)

    Mojzes, Marcel; Wozniak, Marek; Habel, Branislav; Macak, Marek

    2017-04-01

    Mathematical and physical research directly motivates geodetic community which can provide very accurate measurements for testing of the proposed models Earth's surface motion near the water dams should be monitored due to the security of the area. This is a process which includes testing of existing models and their physical parameters. Change of the models can improve the practical results for analyzing the trends of motion in the area of upper reservoir of water dam Zarnowiec. Since 1998 Warsaw University of Technology realized a research focused on the horizontal displacements of the upper reservoir of water dam Zarnowiec. The 15 selected control points located on the upper reservoir crown of the water dam were monitored by classical distance measurements. It was found out that changes in the object's geometry occur due to the variation of the water level. The control measurements of the changes in the object's geometry occurring during the process of emptying and filling of the upper reservoir of water dam were compared with the deformations computed using improved Boussinesqués method programmed in the software MATLAB and ANSYS for elastic and isotropic half space as derivation of suitable potentials extended to the loaded region. The details and numerical results of this process are presented This presentation was prepared within the project "National Centre for Diagnostic of the Earth's Surface Deformations in the Area of Slovakia", ITMS code: 26220220108.

  12. A detection-level hazardous waste ground-water monitoring compliance plan for the 200 areas low-level burial grounds and retrievable storage units

    Energy Technology Data Exchange (ETDEWEB)

    1987-02-01

    This plan defines the actions needed to achieve detection-level monitoring compliance at the Hanford Site 200 Areas Low-Level Burial Grounds (LLBG) in accordance with the Resource Conservation and Recovery Act (RCRA). Compliance will be achieved through characterization of the hydrogeology and monitoring of the ground water beneath the LLBG located in the Hanford Site 200 Areas. 13 refs., 20 figs.

  13. The Long-Term Settlement Deformation Automatic Monitoring System for the Chinese High-Speed Railway

    Directory of Open Access Journals (Sweden)

    Xu Wang

    2015-01-01

    Full Text Available The Beijing-Shanghai high-speed railway is one of the milestones of China’s high-speed railway development and its security plays a significant role in China’s economic and social development. However, the evaluation methods used for large-scale security operations and important infrastructure systems, such as the high-speed railways, are discrete and nonlinear; thus they cannot issue emergency warnings in a timely manner. The emergence of optical fiber sensing technology can solve this problem. This technology has progressed rapidly in its application to the monitoring of railway security and it has attracted much attention within the industry. This study considers the newly built passenger railway line between Shijiazhuang and Jinan as an example. The web-based, all-in-one fiber Bragg grating static level is described as well as a set of online monitoring systems, which is automated, real-time, remote, visual, and adaptable to the standards of the Beijing-Shanghai high-speed railway. According to our theoretical analysis, the planned automated monitoring of settlement deformation for the Beijing-Shanghai high-speed railway and the real-time analysis and calculation of monitoring data can ensure the operational security of this section of China’s high-speed railway system.

  14. An Air-Ground Wireless Sensor Network for Crop Monitoring

    Directory of Open Access Journals (Sweden)

    Claudio Rossi

    2011-06-01

    Full Text Available This paper presents a collaborative system made up of a Wireless Sensor Network (WSN and an aerial robot, which is applied to real-time frost monitoring in vineyards. The core feature of our system is a dynamic mobile node carried by an aerial robot, which ensures communication between sparse clusters located at fragmented parcels and a base station. This system overcomes some limitations of the wireless networks in areas with such characteristics. The use of a dedicated communication channel enables data routing to/from unlimited distances.

  15. Global optimal design of ground water monitoring network using embedded kriging.

    Science.gov (United States)

    Dhar, Anirban; Datta, Bithin

    2009-01-01

    We present a methodology for global optimal design of ground water quality monitoring networks using a linear mixed-integer formulation. The proposed methodology incorporates ordinary kriging (OK) within the decision model formulation for spatial estimation of contaminant concentration values. Different monitoring network design models incorporating concentration estimation error, variance estimation error, mass estimation error, error in locating plume centroid, and spatial coverage of the designed network are developed. A big-M technique is used for reformulating the monitoring network design model to a linear decision model while incorporating different objectives and OK equations. Global optimality of the solutions obtained for the monitoring network design can be ensured due to the linear mixed-integer programming formulations proposed. Performances of the proposed models are evaluated for both field and hypothetical illustrative systems. Evaluation results indicate that the proposed methodology performs satisfactorily. These performance evaluation results demonstrate the potential applicability of the proposed methodology for optimal ground water contaminant monitoring network design.

  16. GROUND DEFORMATION EXTRACTION USING VISIBLE IMAGES AND LIDAR DATA IN MINING AREA

    Directory of Open Access Journals (Sweden)

    W. Hu

    2016-06-01

    23.1 m and covering about 2.3 km2 till 2015. The results in this paper are preliminary currently; we are making efforts to improve more precision results with invariant ground control data for validation.

  17. Application of GPS Technology in Deformation Monitoring and Development Trend%GPS技术在变形监测中的应用及发展趋势

    Institute of Scientific and Technical Information of China (English)

    李黎

    2012-01-01

    In order to control or prevent ground settlement and geological hazards, develop rationally and utilize the underground space resources to provide the planning and decision basis, the modern communication technology and "3S" etc. spatial technologies are widely applied in the ground settlement,geological hazards regional monitoring and deformation monitoring of large buildings etc. in every city. It gives full play to GPS in high-speed position,observation without weather limited, automatic data collection and transmission, no sight demand between stations and high-precision three-dimensional coordinates of monitoring points and so on. Combined with accuracy leveling, the key areas is mainly monitored, and the deformation monitoring system integrated with GPS and other technology is built, the monitoring network for the city ground subsidence is preliminary set up, the online real-time analysis system based on "3S" deformation monitoring and the information feedback and automatic alarm system based on Web are studied, the ground settlement monitoring is quantitatively analyzed and the monitoring information is showed by 3D visualization, so the early warning system for city ground settlement and geological disaster is set up.%为控制或防治地面沉降和地质灾害,合理开发和利用地下空间资源提供规划和决策依据,各城市在地面沉降、地质灾害区域监测、大型构建筑物变形监测等工作中广泛应用现代通信技术、“3S”等空间技术,充分发挥GPS定位速度快、全天候观测、数据自动采集与传输、测站之间无通视要求、可同时测定监测点高精度的三维坐标的特点.结合精密水准测量对重点区域进行重点监测,建立GPS与其他变形监测技术集成应用的变形监测系统,初步建立城市地面沉降监测网络,研究基于“3S”的变形监控在线实时分析系统和基于Web的监测信息反馈及自动报警系统,实现地面

  18. Hanford Site ground-water monitoring for April through June 1987

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.C.; Mitchell, P.J.; Dennison, D.I.

    1988-01-01

    Pacific Northwest Laboratory (PNL) is conducting ground-water monitoring at the Hanford Site. Results for monitoring by PNL and Westinghouse Hanford Company (WHC) during April-June 1987 show that certain regulated hazardous materials and radionuclides exist in Hanford Site ground waters. The presence of regulated constituents in the ground water derives both from site operations and from natural sources. The major contamination problems defined by recent monitoring activities are carbon tetrachloride in the 200 West Area; cyanide in and north of the 200 East Area; hexavalent chromium contamination in the 100B, 100D, 100K, and 100H areas; chlorinated hydrocarbons in the vicinity of the Central Landfill; uranium at the 216-U-1 and 216-U-2 cribs in the 200 West Area; tritium across the site; and nitrate across the site. The distribution of hazardous materials related to site operations is more limited than the distribution of tritium and nitrate. 8 refs., 22 figs., 5 tabs.

  19. Acoustic monitoring on a humpback whale (Megaptera novaeangliae) feeding ground shows continual singing into late Spring.

    OpenAIRE

    Clark, Christopher W.; Clapham, Phillip J.

    2004-01-01

    Singing by males is a major feature of the mating system of humpback whales, Megaptera novaeangliae (Borowski). Although a few songs have been opportunistically recorded on the whales' high-latitude feeding grounds, singing in these regions was thought to be only sporadic. We report results from the first continuous acoustic monitoring of a humpback whale feeding ground (off Cape Cod, MA, USA) in spring. Using autonomous sea-floor recording systems, we found singing on a daily basis over the ...

  20. Spinal Cord Monitoring Data in Pediatric Spinal Deformity Patients With Spinal Cord Pathology.

    Science.gov (United States)

    Aleem, Alexander W; Thuet, Earl D; Padberg, Anne M; Wallendorf, Michael; Luhmann, Scott J

    2015-01-01

    Retrospective. The purpose of this study is to review the efficacy of monitoring data and outcomes in pediatric patients with spinal cord pathology. The incidence of spinal cord pathology in pediatric patients with scoliosis has been reported between 3% and 20%. Previous studies demonstrated that intraoperative spinal cord monitoring (IOM) during scoliosis surgery can be reliable despite underlying pathology. A single-center retrospective review of 119 spinal surgery procedures in 82 patients with spinal cord pathology was performed. Diagnoses included Arnold-Chiari malformation, syringomyelia, myelomeningocele, spinal cord tumor, tethered cord, and diastematomyelia. Baseline neurologic function and history of prior neurosurgical intervention were identified. Outcome measures included ability to obtain reliable monitoring data during surgery and presence of postoperative neurologic deficits. Results were compared for 82 patients with adolescent idiopathic scoliosis (AIS). Usable IOM data were obtained in 82% of cases (97/119). Twenty-two cases (18%) had no lower extremity data. Patients with Arnold-Chiari malformation or syringomyelia pathologies, in isolation or together, had a significantly higher rate of reliable data compared to other pathologies (p < .0001). Among study group cases with usable data, there were 1 false negative (1%) and 4 true positive (4%) outcomes. There were no permanent neurologic deficits. The spinal cord pathology group demonstrated 80% sensitivity and 92% specificity. Spinal cord monitoring is a valuable tool in pediatric patients with spinal cord pathology undergoing spinal deformity surgeries. When obtained, data allow to detect changes in spinal cord function. Patients with a diagnosis of Arnold-Chiari or syringomyelia have monitoring data similar to those patients with AIS. Patients with other spinal cord pathologies have less reliable data, and surgeons should have a lower threshold for performing wake-up tests to assess spinal cord

  1. A Low-Cost Optical Remote Sensing Application for Glacier Deformation Monitoring in an Alpine Environment

    Directory of Open Access Journals (Sweden)

    Daniele Giordan

    2016-10-01

    Full Text Available In this work, we present the results of a low-cost optical monitoring station designed for monitoring the kinematics of glaciers in an Alpine environment. We developed a complete hardware/software data acquisition and processing chain that automatically acquires, stores and co-registers images. The system was installed in September 2013 to monitor the evolution of the Planpincieux glacier, within the open-air laboratory of the Grandes Jorasses, Mont Blanc massif (NW Italy, and collected data with an hourly frequency. The acquisition equipment consists of a high-resolution DSLR camera operating in the visible band. The data are processed with a Pixel Offset algorithm based on normalized cross-correlation, to estimate the deformation of the observed glacier. We propose a method for the pixel-to-metric conversion and present the results of the projection on the mean slope of the glacier. The method performances are compared with measurements obtained by GB-SAR, and exhibit good agreement. The system provides good support for the analysis of the glacier evolution and allows the creation of daily displacement maps.

  2. Monitoring of Gangotri glacier using remote sensing and ground observations

    Indian Academy of Sciences (India)

    H S Negi; N K Thakur; A Ganju; Snehmani

    2012-08-01

    In this study, Gangotri glacier was monitored using Indian Remote Sensing (IRS) LISS-III sensor data in combination with field collected snow-meteorological data for a period of seven years (2001–2008). An overall decreasing trend in the areal extent of seasonal snow cover area (SCA) was observed. An upward shifting trend of wet snow line was observed in the beginning of melt period, i.e., in May and dominant wet snow conditions were observed between May and October. Snow meteorological parameters collected in the Gangotri sub-basin suggest reduction in fresh snowfall amount during winter, increase in rainfall amount during summer, decrease in snowfall days, increase in rainfall days and rising trend of average temperature. The prevailing wet snow condition on glacier has caused scouring of slopes which led the excessive soil/debris deposition on the glacier surface. This was observed as one of the major factor for activating fast melting and affecting the glacier health significantly. Apart from climatic conditions, terrain factors were observed for changing the glacio-morphology. The significant changes on the glacier surface were observed in the regions of abrupt slope change. The above factors affecting the Gangotri glacier health were also validated using high resolution satellite imageries and field visit. A deglaciation of 6% in overall area of Gangotri glacier was observed between the years 1962 and 2006.

  3. Oceanographic signatures and pressure monitoring of seafloor vertical deformation in near-coastal, shallow-water areas: a case study from Santorini Caldera.

    Science.gov (United States)

    Vilaseca, Géraud; Deplus, Christine; Escartin, Javier; Ballu, Valérie; Nomikou, Paraskevi; Mével, Catherine; Andreani, Muriel

    2016-04-01

    Bottom pressure, tilt and seawater physical-properties were monitored for a year using two instruments within the immerged Santorini caldera (Greece). Piggy-backed on the CALDERA2012 cruise, this geodetic experiment was designed to monitor evolution of the 2011-2012 Santorini unrest. Conducted during a quiescent period, it allowed us to study oceanographic and atmospheric signal in our data series. We observe periodic oceanographic signals associated with tides, and seiches that are likely linked to both the caldera and Cretan basin geometries. In winter, the caldera witnesses sudden cooling events that tilt an instrument towards the Southeast, indicating cold-water influx likely originating from the north-western passage between Thirasia and Oia. We do not obtain evidence of long-term vertical seafloor deformation from the pressure signal, although it may be masked by instrumental drift. However, tilt data suggests a local seafloor tilt event ~1 year after the end of the unrest period which could be consistent with inflation under or near Nea Kameni. In addition, we illustrate that tilt sensor can roughly record seismic induced ground motion which in our case led to a shift in sensors attitude for one seismic event. Seafloor geodetic data recorded at the bottom of the Santorini caldera illustrates that the oceanographic signature is an important part of the signal, which needs to be considered for monitoring volcanic or geological seafloor deformation in shallow-water and/or nearshore areas.

  4. Volcano seismicity and ground deformation unveil the gravity-driven magma discharge dynamics of a volcanic eruption.

    Science.gov (United States)

    Ripepe, Maurizio; Donne, Dario Delle; Genco, Riccardo; Maggio, Giuseppe; Pistolesi, Marco; Marchetti, Emanuele; Lacanna, Giorgio; Ulivieri, Giacomo; Poggi, Pasquale

    2015-05-18

    Effusive eruptions are explained as the mechanism by which volcanoes restore the equilibrium perturbed by magma rising in a chamber deep in the crust. Seismic, ground deformation and topographic measurements are compared with effusion rate during the 2007 Stromboli eruption, drawing an eruptive scenario that shifts our attention from the interior of the crust to the surface. The eruption is modelled as a gravity-driven drainage of magma stored in the volcanic edifice with a minor contribution of magma supplied at a steady rate from a deep reservoir. Here we show that the discharge rate can be predicted by the contraction of the volcano edifice and that the very-long-period seismicity migrates downwards, tracking the residual volume of magma in the shallow reservoir. Gravity-driven magma discharge dynamics explain the initially high discharge rates observed during eruptive crises and greatly influence our ability to predict the evolution of effusive eruptions.

  5. GPS and InSAR observations of ground deformation in the northern Malawi (Nyasa) rift from the SEGMeNT project

    Science.gov (United States)

    Durkin, W. J., IV; Pritchard, M. E.; Elliott, J.; Zheng, W.; Saria, E.; Ntambila, D.; Chindandali, P. R. N.; Nooner, S. L.; Henderson, S. T.

    2016-12-01

    We describe new ground deformation observations from the SEGMeNT (Study of Extension and maGmatism in Malawi aNd Tanzania) spanning the northern sector of the Malawi (Nyasa) rift, which is one of the few places in the world suitable for a comprehensive study of early rifting processes. We installed 12 continuous GPS sensors spanning 700 km across the rift including Tanzania, Malawi, and Zambia to measure the width and gradient within the actively deforming zone. Most of these stations have 3 or more years of data now, although a few have shorter time series because of station vandalism. Spanning a smaller area, but with higher spatial resolution, we have created a time series of ground deformation using 150 interferograms from the Japanese ALOS-1 satellite spanning June 2007 to December 2010. We also present interferograms from other satellites including ERS, Envisat, and Sentinel spanning shorter time intervals. The observations include the 2009-2010 Karonga earthquake sequence and associated postseismic deformation as seen by multiple independent satellite lines-of-sight, that we model using a fault geometry determined using relocated aftershocks recorded by a local seismic array. We have not found any ground deformation at the Rungwe volcanic province from InSAR within our detection threshold ( 2 cm/yr), but we have observed localized seasonal ground movements exceeding 8 cm that are associated with subsidence in the dry season and uplift at the beginning of the wet season.

  6. Kondo effects in a triangular triple quantum dot II: ground-state properties for deformed configurations

    Science.gov (United States)

    Oguri, Akira; Amaha, Shinichi; Nisikawa, Yunori; Hewson, A. C.; Tarucha, Seigo; Numata, Takahide

    2010-03-01

    We study transport through a triangular triple quantum dot (TTQD) connected to two noninteracting leads, using the numerical renormalization group. The system has been theoretically revealed to show a variety of Kondo effects depending on the electron filling of the triangle [1]. For instance, the SU(4) Kondo effect takes place at three-electron filling, and a two-stage Kondo screening of a high-spin S=1 Nagaoka state takes place at four-electron filling. Because of the enhanced freedom in the configurations, however, the large parameter space of the TTQD still has not been fully explored, especially for large deformations. We report the effects of the inhomogeneity in the inter-dot couplings and the level positions in a wide region of the filling. [1] T. Numata, Y. Nisikawa, A. Oguri, and A. C. Hewson: PRB 80, 155330 (2009).

  7. Rotating nuclei: from ground state to the extremes of spin and deformation

    CERN Document Server

    Afanasjev, A V

    2015-01-01

    The rotating nuclei represent one of most interesting subjects for theoretical and experimental studies. They open a new dimension of nuclear landscape, namely, spin direction. Contrary to the majority of nuclear systems, their properties sensitively depend on time-odd mean fields and currents in density functional theories. Moreover, they show a considerable interplay of collective and single-particle degrees of freedom. In this chapter, I discuss the basic features of the description of rotating nuclei in one-dimensional cranking approximation of covariant density functional theory. The successes of this approach to the description of rotating nuclei at low spin in pairing regime and at high spin in unpaired regime in wide range of deformations (from normal to hyperdeformation) are illustrated. I also discuss the recent progress and open questions in our understanding of the role of proton-neutron pairing in rotating nuclei at $N\\approx Z$, the physics of band termination and other phenomena in rotating nuc...

  8. In situ monitoring of the deformation mechanisms in titanium with different oxygen contents

    Energy Technology Data Exchange (ETDEWEB)

    Barkia, B. [Laboratoire de Mécanique des Solides, UMR 7649, CNRS, École Polytechnique, Palaiseau (France); Institut de Chimie et des Matériaux Paris-Est (ICMPE), UMR 7182, CNRS/UPEC, Thiais (France); Doquet, V. [Laboratoire de Mécanique des Solides, UMR 7649, CNRS, École Polytechnique, Palaiseau (France); Couzinié, J.P., E-mail: couzinie@icmpe.cnrs.fr [Institut de Chimie et des Matériaux Paris-Est (ICMPE), UMR 7182, CNRS/UPEC, Thiais (France); Guillot, I. [Institut de Chimie et des Matériaux Paris-Est (ICMPE), UMR 7182, CNRS/UPEC, Thiais (France); Héripré, E. [Laboratoire de Mécanique des Solides, UMR 7649, CNRS, École Polytechnique, Palaiseau (France)

    2015-06-11

    The deformation mechanisms of two titanium batches with different oxygen contents were monitored during tensile tests performed along the rolling and transverse directions under an optical or scanning electron microscope, after EBSD mappings of grain orientations. Whereas the contribution of mechanical twinning was very limited, grain boundary sliding, sometimes leading to intergranular decohesion, as well as kink bands formation were observed. Based on the identification of the primary slip traces in a significant number of grains, the critical resolved shear stresses (CRSSs) for prismatic, basal and π{sub 1}〈a〉 were estimated. Transmission electron microscopy was used to identify unambiguously dislocations of π{sub 1}〈c+a〉 systems and to estimate the corresponding CRSS. The difference in oxygen content between T40 and T60 was found to modify the magnitude of the CRSSs, but to leave their relative values nearly unchanged. The evolutions in the work hardening rate were correlated with the active deformation mechanisms.

  9. A new technique for monitoring inhomogeneous deformation during flyer plate impact

    Science.gov (United States)

    Walker, James D.; Grosch, Donald J.; Chocron, Sidney; Dannemann, Kathryn A.; Bigger, Rory P.; Moore, Thomas Z.; Kirchdoerfer, Trenton T.

    2017-01-01

    A new and unique experimental configuration was developed and demonstrated to measure the inhomogeneous deformation of heterogeneous materials during flyer plate impact tests. Flyer plate experiments were performed on a granite material with a small scale structure; strain rates ranged from 105 to 107 s-1. A cross section of an impacted target was monitored and photographed during, and immediately following, passage of the shock wave through the material. Up to fourteen images were taken during passage of the shock wave. This was accomplished using an ultra-high speed Imacon camera with very short exposure times; for example, in one experiment the exposure time was 5 nanoseconds with a framing rate of 5 million frames per second. Continuous wave lasers were used as the illumination source. Edge and notch filters were used to lessen the intensity of the impact flash in the image. The photographic data was analyzed using a digital image correlation (DIC) system. These experiments examined inhomogeneous deformation on a cut plane within an inhomogeneous geological (granite) target.

  10. Late Quaternary tectonics and active ground deformation in the Catania urban area (eastern Sicily): New constraints from a geological investigation

    Science.gov (United States)

    Catalano, Stefano; Pavano, Francesco; Romagnoli, Gino; Tortorici, Giuseppe

    2017-08-01

    New surface and subsurface geological data on the Catania urban area, in eastern Sicily, are here illustrated by a detailed geological map of the city and by four significant cross-sections. Our study aims at defining the prolongation of the principal regional Late Quaternary tectonic features, beneath the city. The resulting geometry of the investigated structures completes the tectonic pictures of two different stages of deformation. The earlier structural association, ranging in age from 600 to 125 ka, consists of a transpressive dextral belt that include E-W oblique thrust ramp, located to the south and the north of the city respectively, connected by a wide NE-SW oriented anticline crossing the urban area. The younger structural association developed since the Late Pleistocene and includes a set of ENE-trending folds that originated at the hangingwall of a main thrust ramp running just beneath the old town (Catania Thrust Ramp). These contractional features have been active during the last 60 ka and their geometry is consistent with the active ground deformation observed by the available geodetic data (GPS vectors and DInSAR analyses). The entire set of the recent structures are bordered to the north by a dextral transfer zone, reactivating part of the previous E-W alignment, that now represents the tectonic boundary with the Mt. Etna Volcano transtensional domain. Our data suggest that the Catania Thrust Ramp could play a main role in the active deformation pattern of the region, thus representing a potential seismotectonic feature to be carefully investigated for the re-evaluation of the seismic hazard of the area.

  11. Monitoring and Deformation Analysis of Groynes Using Tls at the River Elbe

    Science.gov (United States)

    Tschirschwitz, F.; Mechelke, K.; Jansch, H.; Kersten, T. P.

    2016-06-01

    To enter the Port of Hamburg, one of Europe's busiest ports all vessels need to navigate around 145 km along the Elbe river, a tide influenced navigation channel. To protect the Elbe shoreline from erosion and to channel the waterway groynes (rigid hydraulic structures) have been built along the river. In the past years since ca. 2001 there has been a large increase in damage of groynes structural integrity at parts of the German waterways. The reason for this was determined in the ever growing size of container vessels passing by and inducing long periodical primary waves which have such a force that they erode the groynes rock structure. To analyse and improve the groynes structural resistance for vessel-induced long periodical wave loads an in-situ study is carried out at Juelssand, located at the Elbe river estuary. Over a period of two years the change of the geometrical structure of two different groyne shapes is monitored automatically by utilising two terrestrial laser scanners mounted in protective housings, located each on a 12 m high platform. The self-contained monitoring systems perform scanning of the two groynes one to two times a day at low tide, as the structures are fully submerged at high tide. The long-periodical wave loads are also determined using pressure sensors in each groyne. To correlate the captured data with vessel events and analyse the effects, vessel related parameters are recorded utilizing the Automatic Identification System (AIS). This paper describes the automated processes for the data acquisition and focusses on the deformation that is calculated using current, extended and new algorithms of the Point Cloud Library. It shows the process chain from the acquisition of raw scan files from an elevated station to the filtering of point cloud, the registration, the calculation of pointwise changes and the aggregation to a grid for later correlation with ship parameters. When working outdoor in all kinds of weather conditions, the

  12. MONITORING AND DEFORMATION ANALYSIS OF GROYNES USING TLS AT THE RIVER ELBE

    Directory of Open Access Journals (Sweden)

    F. Tschirschwitz

    2016-06-01

    Full Text Available To enter the Port of Hamburg, one of Europe’s busiest ports all vessels need to navigate around 145 km along the Elbe river, a tide influenced navigation channel. To protect the Elbe shoreline from erosion and to channel the waterway groynes (rigid hydraulic structures have been built along the river. In the past years since ca. 2001 there has been a large increase in damage of groynes structural integrity at parts of the German waterways. The reason for this was determined in the ever growing size of container vessels passing by and inducing long periodical primary waves which have such a force that they erode the groynes rock structure. To analyse and improve the groynes structural resistance for vessel-induced long periodical wave loads an in-situ study is carried out at Juelssand, located at the Elbe river estuary. Over a period of two years the change of the geometrical structure of two different groyne shapes is monitored automatically by utilising two terrestrial laser scanners mounted in protective housings, located each on a 12 m high platform. The self-contained monitoring systems perform scanning of the two groynes one to two times a day at low tide, as the structures are fully submerged at high tide. The long-periodical wave loads are also determined using pressure sensors in each groyne. To correlate the captured data with vessel events and analyse the effects, vessel related parameters are recorded utilizing the Automatic Identification System (AIS. This paper describes the automated processes for the data acquisition and focusses on the deformation that is calculated using current, extended and new algorithms of the Point Cloud Library. It shows the process chain from the acquisition of raw scan files from an elevated station to the filtering of point cloud, the registration, the calculation of pointwise changes and the aggregation to a grid for later correlation with ship parameters. When working outdoor in all kinds of weather

  13. Accuracy analysis of continuous deformation monitoring using BeiDou Navigation Satellite System at middle and high latitudes in China

    Science.gov (United States)

    Jiang, Weiping; Xi, Ruijie; Chen, Hua; Xiao, Yugang

    2017-02-01

    As BeiDou Navigation Satellite System (BDS) has been operational in the whole Asia-Pacific region, it means a new GNSS system with a different satellite orbit structure will become available for deformation monitoring in the future. Conversely, GNSS deformation monitoring data are always processed with a regular interval to form displacement time series for deformation analysis, where the interval can neither be too long from the time perspective nor too short from the precision of determined displacements angle. In this paper, two experimental platforms were designed, with one being at mid-latitude and another at higher latitude in China. BDS data processing software was also developed for investigating the accuracy of continuous deformation monitoring using current in-orbit BDS satellites. Data over 20 days at both platforms were obtained and were processed every 2, 4 and 6 h to generate 3 displacement time series for comparison. The results show that with the current in-orbit BDS satellites, in the mid-latitude area it is easy to achieve accuracy of 1 mm in horizontal component and 2-3 mm in vertical component; the accuracy could be further improved to approximately 1 mm in both horizontal and vertical directions when combined BDS/GPS measurements are employed. At higher latitude, however, the results are not as good as expected due to poor satellite geometry, even the 6 h solutions could only achieve accuracy of 4-6 and 6-10 mm in horizontal and vertical components, respectively, which implies that it may not be applicable to very high-precision deformation monitoring at high latitude using the current BDS. With the integration of BDS and GPS observations, however, in 4-h session, the accuracy can achieve 2 mm in horizontal component and 4 mm in vertical component, which would be an optimal choice for high-accuracy structural deformation monitoring at high latitude.

  14. Measurement of the spin and magnetic moment of $^{31}$Mg Evidence for a strongly deformed intruder ground state

    CERN Document Server

    Nevens, G; Yordanov, D; Blaum, K; Himpe, P; Lievens, P; Mallion, S; Neugart, R; Vermeulen, N; Utsuno, Y; Otsuka, T

    2005-01-01

    Unambiguous values of the spin and magnetic moment of $^{31}$Mg are obtained by combining the results of a hyperfine-structure measurement and a $\\beta$-NMR measurement, both performed with an optically polarized ion beam. With a measured nuclear $\\textit{g}$-factor and spin $\\scriptstyle\\textrm{I}$= 1/2, the magnetic moment $\\mu(^{31}\\!$Mg)=-0.88355(15)$\\mu\\scriptstyle_\\textrm{N}$ is deduced. A revised level scheme of $^{31}$Mg( Z=12, N=19 ) with ground state spin/parity $\\scriptstyle\\textrm{I}$$^{\\pi}$= 1/2$^{+}$ is presented, revealing the coexistence of 1p-1h and 2p-2h intruder states below 500keV. Advanced shell-model calculations and the Nilsson model suggest that the $\\scriptstyle\\textrm{I}$$^{\\pi}$= 1/2$^{+}$ ground state is a strongly prolate deformed intruder state. This result plays a key role for the understanding of nuclear structure changes due to the disappearance of the N=20 shell gap in neutron-rich nuclei.

  15. Ground Deformation during Papandayan Volcano 2002 Eruption as Detected by GPS Surveys

    Directory of Open Access Journals (Sweden)

    Hasanuddin Z. Abidin

    2003-05-01

    Full Text Available Papandayan is an A-type active volcano located in the southern part of Garut Regency, about 70 km southeast of Bandung, Indonesia. Its earliest recorded eruption, and most violent and devastating outburst occurred in 1772 and the latest eruptions occurred in the period of 11 November to 8 December 2002, and consisted of freatic, freatomagmatic and magmatic types of eruption.During the latest eruption period, GPS surveys were conducted at several points inside and around the crater in a radial mode using the reference point located at Papandayan observatory around 10 km from the crater. At the points closest to the erupting craters, GPS displacements up to a few dm were detected, whereas at the points outside the crater, the displacements were in the cm level. The magnitude of displacements observed at each point also show a temporal variation according to the eruption characteristics. The results show that deformation during eruption tends to be local, e.g. just around the crater. Pressure source is difficult to be properly modeled from GPS results, due to limited GPS data available and differences in topography, geological structure and/or rheology related to each GPS station.

  16. Biodiversity in School Grounds: Auditing, Monitoring and Managing an Action Plan

    Science.gov (United States)

    Mansell, Michelle

    2010-01-01

    The idea of using site biodiversity action plans to introduce biodiversity management initiatives into school grounds is outlined. Selected parts of a case study, involving the use of such an action plan to record, monitor and plan for biodiversity on a university campus, are described and ideas for applying a similar plan to a school setting are…

  17. Biodiversity in School Grounds: Auditing, Monitoring and Managing an Action Plan

    Science.gov (United States)

    Mansell, Michelle

    2010-01-01

    The idea of using site biodiversity action plans to introduce biodiversity management initiatives into school grounds is outlined. Selected parts of a case study, involving the use of such an action plan to record, monitor and plan for biodiversity on a university campus, are described and ideas for applying a similar plan to a school setting are…

  18. Hanford Site ground-water monitoring for January through June 1988

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.C.; Bryce, R.W.; Sherwood, D.R.

    1989-05-01

    The Pacific Northwest Laboratory monitors ground-water quality at the Hanford Site for the US Department of Energy to assess the impact of Site operations on the environment. Work undertaken between January and June 1988 included monitoring ground-water elevations across the Site, and monitoring hazardous chemicals and radionuclides in ground water. Water levels continued to rise in areas receiving increased recharge (e.g., beneath B Pond) and decline in areas where the release of water to disposal facilities has been terminated (e.g., U Pond). The major areas of ground-water contamination defined by monitoring activities are (1) carbon tetrachloride in the 200-West Area; (2) cyanide in and north of the 200-East and 200-West Areas; (3) hexavalent chromium contamination in the 100-B, 100-D, 100-F, 100-H, 100-K, and 200-West Areas; (4) chlorinated hydrocarbons in the vicinity of the Solid Waste Landfill and 300 Area; (5) uranium in the 100-F, 100-H, 200-West, and 300 Areas; and (6) tritium and nitrate across the Site. In addition, several new analytical initiatives were undertaken during this period. These include cyanide speciation in the BY Cribs plume, inductively coupled argon plasma/mass spectrometry (ICP/MS) measurements on a broad selection of samples from the 100, 200, 300, and 600 Areas, and high sensitivity gas chromatography measurements performed at the Solid Waste Landfill-Nonradioactive Dangerous Waste Landfill. 23 figs., 25 tabs.

  19. Ground-based remote sensing scheme for monitoring aerosol–cloud interactions (discussion)

    NARCIS (Netherlands)

    Sarna, K.; Russchenberg, H.W.J.

    2015-01-01

    A method for continuous observation of aerosol–cloud interactions with ground-based remote sensing instruments is presented. The main goal of this method is to enable the monitoring of cloud microphysical changes due to the changing aerosol concentration. We use high resolution measurements from lid

  20. Ground-based remote sensing scheme for monitoring aerosol-cloud interactions

    NARCIS (Netherlands)

    Sarna, K.; Russchenberg, H.W.J.

    2016-01-01

    A new method for continuous observation of aerosol–cloud interactions with ground-based remote sensing instruments is presented. The main goal of this method is to enable the monitoring of the change of the cloud droplet size due to the change in the aerosol concentration. We use high-resolution mea

  1. Revised ground-water monitoring compliance plan for the 300 area process trenches

    Energy Technology Data Exchange (ETDEWEB)

    Schalla, R.; Aaberg, R.L.; Bates, D.J.; Carlile, J.V.M.; Freshley, M.D.; Liikala, T.L.; Mitchell, P.J.; Olsen, K.B.; Rieger, J.T.

    1988-09-01

    This document contains ground-water monitoring plans for process-water disposal trenches located on the Hanford Site. These trenches, designated the 300 Area Process Trenches, have been used since 1973 for disposal of water that contains small quantities of both chemicals and radionuclides. The ground-water monitoring plans contained herein represent revision and expansion of an effort initiated in June 1985. At that time, a facility-specific monitoring program was implemented at the 300 Area Process Trenches as part of a regulatory compliance effort for hazardous chemicals being conducted on the Hanford Site. This monitoring program was based on the ground-water monitoring requirements for interim-status facilities, which are those facilities that do not yet have final permits, but are authorized to continue interim operations while engaged in the permitting process. The applicable monitoring requirements are described in the Resource Conservation and Recovery Act (RCRA), 40 CFR 265.90 of the federal regulations, and in WAC 173-303-400 of Washington State's regulations (Washington State Department of Ecology 1986). The program implemented for the process trenches was designed to be an alternate program, which is required instead of the standard detection program when a facility is known or suspected to have contaminated the ground water in the uppermost aquifer. The plans for the program, contained in a document prepared by the US Department of Energy (USDOE) in 1985, called for monthly sampling of 14 of the 37 existing monitoring wells at the 300 Area plus the installation and sampling of 2 new wells. 27 refs., 25 figs., 15 tabs.

  2. Robowell: An automated process for monitoring ground water quality using established sampling protocols

    Science.gov (United States)

    Granato, G.E.; Smith, K.P.

    1999-01-01

    Robowell is an automated process for monitoring selected ground water quality properties and constituents by pumping a well or multilevel sampler. Robowell was developed and tested to provide a cost-effective monitoring system that meets protocols expected for manual sampling. The process uses commercially available electronics, instrumentation, and hardware, so it can be configured to monitor ground water quality using the equipment, purge protocol, and monitoring well design most appropriate for the monitoring site and the contaminants of interest. A Robowell prototype was installed on a sewage treatment plant infiltration bed that overlies a well-studied unconfined sand and gravel aquifer at the Massachusetts Military Reservation, Cape Cod, Massachusetts, during a time when two distinct plumes of constituents were released. The prototype was operated from May 10 to November 13, 1996, and quality-assurance/quality-control measurements demonstrated that the data obtained by the automated method was equivalent to data obtained by manual sampling methods using the same sampling protocols. Water level, specific conductance, pH, water temperature, dissolved oxygen, and dissolved ammonium were monitored by the prototype as the wells were purged according to U.S Geological Survey (USGS) ground water sampling protocols. Remote access to the data record, via phone modem communications, indicated the arrival of each plume over a few days and the subsequent geochemical reactions over the following weeks. Real-time availability of the monitoring record provided the information needed to initiate manual sampling efforts in response to changes in measured ground water quality, which proved the method and characterized the screened portion of the plume in detail through time. The methods and the case study described are presented to document the process for future use.

  3. Ground Control Point - Wireless System Network for UAV-based environmental monitoring applications

    Science.gov (United States)

    Mejia-Aguilar, Abraham

    2016-04-01

    In recent years, Unmanned Aerial Vehicles (UAV) have seen widespread civil applications including usage for survey and monitoring services in areas such as agriculture, construction and civil engineering, private surveillance and reconnaissance services and cultural heritage management. Most aerial monitoring services require the integration of information acquired during the flight (such as imagery) with ground-based information (such as GPS information or others) for improved ground truth validation. For example, to obtain an accurate 3D and Digital Elevation Model based on aerial imagery, it is necessary to include ground-based information of coordinate points, which are normally acquired with surveying methods based on Global Position Systems (GPS). However, GPS surveys are very time consuming and especially for longer time series of monitoring data repeated GPS surveys are necessary. In order to improve speed of data collection and integration, this work presents an autonomous system based on Waspmote technologies build on single nodes interlinked in a Wireless Sensor Network (WSN) star-topology for ground based information collection and later integration with surveying data obtained by UAV. Nodes are designed to be visible from the air, to resist extreme weather conditions with low-power consumption. Besides, nodes are equipped with GPS as well as Inertial Measurement Unit (IMU), accelerometer, temperature and soil moisture sensors and thus provide significant advantages in a broad range of applications for environmental monitoring. For our purpose, the WSN transmits the environmental data with 3G/GPRS to a database on a regular time basis. This project provides a detailed case study and implementation of a Ground Control Point System Network for UAV-based vegetation monitoring of dry mountain grassland in the Matsch valley, Italy.

  4. 大庆地区地面变形对哈齐客专的影响研究%Study on Influence of Ground Deformation in Daqing Region on Harbin-Qiqihaer Passenger Dedicated Line

    Institute of Scientific and Technical Information of China (English)

    甄庆廷

    2013-01-01

    研究目的:哈尔滨至齐齐哈尔客运专线穿过的大庆油田由于高强度注水采油和工业、生活超量开采地下水,致使在油田采区及地下水下降漏斗区产生了不同程度的地面隆起和沉降变形,不均匀地面变形会对高速行驶的列车安全产生一定程度的影响,因此,查明和研究地面变形发生的范围、速率、变形量及对客运专线的影响程度,为设计采取必要的措施提供依据是非常必要的.研究结论:(1)为准确了解大庆地区地面变形规律,应建立地面变形动态监测系统,监测第四系沉降变形和白垩系隆起变形特征.(2)多采用化学驱油方式,控制注水压力,尽量保持压力场的平衡,并对靠近线路的采油井和注水井进行适当迁改.(3)在动态监测的基础上,建立地下水开采、采油注水、地面变形的耦合模型,预测地面变形发生、发展趋势,为铁路工程提供准确的预报预警.通过分析得出随着采油工艺的改进、地下水减采和动态监测系统的建立,大庆地区地面变形会得到有效控制和缓解,不会对哈齐客运专线工程造成较大影响.%Research purposes: The Harbin - Qiqihaer Passenger Dedicated Line passes through the Daqing oilfield in where the ground rises or settles in the oil extraction area and the underground water dropping area because of the high -pressure waterflooding for oil extraction and the over exploitation of groundwater for production and living. The uneven ground deformation maybe influences the safety of high -speed railway. Thus, it is necessary to find out and study the range, speed and deformation volume of the ground deformation and their influence on the passenger dedicated line for providing the reference to the railway design. Research conclusions: (1) For accurately knowing the regulation of the ground deformation of the Daqing area, the dynamic monitoring system for the ground deformation should be established to monitor

  5. Ground-coupled airwaves at Pavlof Volcano, Alaska, and their potential for eruption monitoring

    Science.gov (United States)

    Smith, Cassandra M.; McNutt, Stephen R.; Thompson, Glenn

    2016-07-01

    An abnormally high number of explosion quakes were noted during the monitoring effort for the 2007 eruption of Pavlof Volcano on the Alaska Peninsula. In this study, we manually cataloged the explosion quakes from their characteristic ground-coupled airwaves. This study investigates how the ground-coupled airwaves might be used in a monitoring or analysis effort by estimating energy release and gas mass release. Over 3 × 104 quakes were recorded. The energy release from the explosions is approximated to be 3 × 1011 J, and the total gas mass (assuming 100 % water) released was 450 t. The tracking of explosion quakes has the potential to estimate relative eruption intensity as a function of time and is thus a useful component of a seismic monitoring program.

  6. Systems Health Monitoring — From Ground to Air — The Aerospace Challenges

    Science.gov (United States)

    Austin, Mary

    2007-03-01

    The aerospace industry and the government are significantly investing in jet engine systems health monitoring. Government organizations such as the Air Force, Navy, Army, National Labs and NASA are investing in the development of state aware sensing for health monitoring of jet engines such as the Joint Strike Fighter, F119 and F100's. This paper will discuss on-going work in systems health monitoring for jet engines. Topics will include a general discussion of the approaches to engine structural health monitoring and the prognosis of engine component life. Real-world implementation challenges on the ground and in the air will be reviewed. The talk will conclude with a prediction of where engine health monitoring will be in twenty years.

  7. Ground Truth Observations of the Interior of a Rockglacier as Validation for Geophysical Monitoring Data Sets

    Science.gov (United States)

    Hilbich, C.; Roer, I.; Hauck, C.

    2007-12-01

    Monitoring the permafrost evolution in mountain regions is currently one of the important tasks in cryospheric studies as little data on past and present changes of the ground thermal regime and its material properties are available. In addition to recently established borehole temperature monitoring networks, techniques to determine and monitor the ground ice content have to be developed. A reliable quantification of ground ice is especially important for modelling the thermal evolution of frozen ground and for assessing the hazard potential due to thawing permafrost induced slope instability. Near surface geophysical methods are increasingly applied to detect and monitor ground ice occurrences in permafrost areas. Commonly, characteristic values of electrical resistivity and seismic velocity are used as indicators for the presence of frozen material. However, validation of the correct interpretation of the geophysical parameters can only be obtained through boreholes, and only regarding vertical temperature profiles. Ground truth of the internal structure and the ice content is usually not available. In this contribution we will present a unique data set from a recently excavated rockglacier near Zermatt/Valais in the Swiss Alps, where an approximately 5 m deep trench was cut across the rockglacier body for the construction of a ski track. Longitudinal electrical resistivity tomography (ERT) and refraction seismic tomography profiles were conducted prior to the excavation, yielding data sets for cross validation of commonly applied geophysical interpretation approaches in the context of ground ice detection. A recently developed 4-phase model was applied to calculate ice-, air- and unfrozen water contents from the geophysical data sets, which were compared to the ground truth data from the excavated trench. The obtained data sets will be discussed in the context of currently established geophysical monitoring networks in permafrost areas. In addition to the

  8. Existing Resources, Standards, and Procedures for Precise Monitoring and Analysis of Structural Deformations. Volume 2. Appendices

    Science.gov (United States)

    1992-09-01

    APPENDIX 5. Geometrical Analysis of Deformation Surveys APPENDIX 6. Integrated Analysis of Deformation Surveys at Mactaquac APPENDIX 7. Combination of...1989a). "Integrated analysis of deformation surveys at Mactaquac ." International Water Power and Dam Construction, August, pp. 17-22. Czaja, J. (1971...New Brunswick P.O.Box 4400 Fredericton, N.B., E3B 5A3, Canada APPENDIX 6. INTEGRATED ANALYSIS OF DEFORMATION SURVEYS AT MACTAQUAC A-. k . - .. USA and

  9. Long-term and seasonal ground deformation in the Santa Clara Valley, California, revealed by multi decadal InSAR time series

    Science.gov (United States)

    Chaussard, E.; Burgmann, R.; Shirzaei, M.; Baker, B.

    2013-12-01

    The Santa Clara Valley, California, is a shallow basin located between the San Andreas and Hayward-Calaveras fault zones. The Valley is known to experience land subsidence and uplift related to groundwater extraction and recharge. We use Small Baseline (SB) Interferometric Synthetic Aperture Radar (InSAR) time series to precisely map time-dependent ground deformation at the scale of the basin, relying on data sets from 4 satellites (ERS1, ERS2, Envisat, and ALOS1) to cover a twenty-year time period (1992-2012). The ground deformation map produced provides constraints on the lateral distribution of water-bearing units in the valley, information that is critical to effectively manage groundwater resources, and on the areas more likely to experience subsidence related ground deformation or flooding. Multi-year and seasonal time-series reveal different ground deformation patterns. Long-term uplift at few millimeters per year dominates east of the Silver Creek fault (SCF) and likely relates to the poroelastic response of the confined aquifer to recovery of groundwater levels since the 1960s. In contrast seasonal uplift and subsidence in winter and summer, respectively, dominate west of the SCF, near San Jose. We compare the InSAR derived deformation to precipitation and well data to explain this seasonal variability. The differential subsidence across the SCF indicates that the fault partitions the shallow confined aquifer and was likely active since the deposition of these Holocene sediments. Relying on the multiple viewing geometries from the different spacecraft we isolate a narrow band of horizontal deformation in the immediate vicinity of the SCF. This zone of high extensional strain is due to the localized differential subsidence and is likely to experience fissuring.

  10. Contrasts between deformation accommodated by induced seismic and aseismic processes revealed by combined monitoring of seismicity and surface deformations: Brady Geothermal Field, Nevada, USA

    Science.gov (United States)

    Davatzes, N. C.; Ali, S. T.; Mellors, R. J.; Foxall, W.; Wang, H. F.; Feigl, K. L.; Drakos, P. S.; Zemach, E.

    2013-12-01

    associated with subsidence. During the latter half of 2013, Enhanced Geothermal Systems demonstration well 15-12ST1, located immediately SSW of the current production area along the direction of the structural trend and SHmax, will be stimulated to expand the reservoir, providing the opportunity to evaluate injection dominated behavior. Along with a geomechanical model of the stress state from borehole observations and well testing, modeling of the deformation and pumping history provides a key means to characterize the stress state and pre-stimulation reservoir properties. Continued monitoring of surface deformation and seismicity accompanying production and injection following stimulation will test if the stimulation significantly pre-existing patterns.

  11. A system for automated monitoring of embankment deformation along the Qinghai-Tibet Railway in permafrost regions

    Institute of Scientific and Technical Information of China (English)

    YongPeng Yang; YaoHui Qu; HanCheng Cai; Jia Cheng; CaiMei Tang

    2015-01-01

    At present, the monitoring of embankment deformation in permafrost regions along the Qinghai-Tibet Railway is mainly done manually. However, the harsh climate on the plateau affects the results greatly by lowering the observation frequency, so the manual monitoring can barely meet the observational demand. This research develops a system of automated monitoring of embankment deformation, and aims to address the problems caused by the plateau climate and the perma-frost conditions in the region. The equipment consists of a monitoring module, a data collection module, a transmission module, and a data processing module. The field experiments during this program indicate that (1) the combined auto-mated monitoring device overcame the problems associated with the complicated and tough plateau environment by means of wireless transmission and automatic analysis of the embankment settlement data;(2) the calibration of the combined settlement gauge at −20 °C was highly accurate, with an error rate always <0.5%; (3) the gauge calibration at high-temperature conditions was also highly accurate, with an error rate<0.5%even though the surface of the instrument reached more than 50 °C;and (4) compared with the data manually taken, the data automatically acquired during field monitoring experiments demonstrated that the combined settlement gauge and the automated monitoring system could meet the requirements of the monitoring mission in permafrost regions along the Qinghai-Tibet Railway.

  12. UAV-based landslide deformation monitoring - first results from Corvara landslide

    Science.gov (United States)

    Thiebes, Benni; Tomelleri, Enrico; Mejia-Aguilar, Abraham; Schlögel, Romy; Darvishi, Mehdi; Remondino, Fabio; Toschi, Isabella; Rutzinger, Martin; Zieher, Thomas

    2016-04-01

    In recent years, unmanned aerial vehicles (UAVs) have been more frequently utilised to study geomorphological and natural hazard processes, including gravitational mass movements such as landslides. UAVs can be equipped with different sensors, e.g. photo cameras and laser scanners, and the data that can be achieved can substantially improve the monitoring and understanding of the involved natural processes. One of the main advantages of UAVs is their flexibility that allows for carrying out assessments of large areas in short periods of time and at much lower costs than other platforms, e.g. airplanes or helicopters. Thereby, UAVs represent an interesting technique to complement more traditional monitoring methods. Here we present some first results of the EUREGIO-funded LEMONADE project that is concerned with the combination and integration of novel and traditional landslide monitoring techniques. We carried out a series of UAV flights over a particularly active part of the Corvara landslide and acquired aerial imagery for quantitative assessments of the retrogressive enlargement of the landslide over recent years. Additional field surveys including terrestrial laser scanning, and UAV-based photogrammetry and laser scanning are scheduled for summer 2016. The Corvara landslide is a large complex earthflow in the Italian Dolomites that has been investigated by a wide range of methodologies over the past years. The landslide is characterised by movement patterns of greatly varying magnitude, ranging from annual rates of a few cm to more than 20 m. The current and past monitoring activities concentrated on GPS measurements as well as multi-temporal differential radar interferometry utilising artificial corner reflectors. Thereby, primarily punctual displacement data were achieved and spatial information on topographic and geomorphic changes were consequently sparse. For our photogrammetry study, we utilised a SoLeon octocopter equipped with a Ricoh GR 16.2 Megapixels

  13. Sill emplacement and corresponding ground deformation processes at the Alu-Dalafilla volcanic centre in the Danakil Depression, Ethiopia

    Science.gov (United States)

    Magee, Craig; Bastow, Ian; Hetherington, Rachel; van Wyk de Vries, Ben; Jackson, Christopher

    2016-04-01

    evaporitic host rock sequence. Important consequences of the shift to sill-dominated magmatism in the Danakil Depression include: (i) roof uplift induced by sill intrusion may not directly relate to the emplaced magma volume if intrusion promotes ductile deformation of the host evaporitic sequence (Schofield et al. 2014), implying that InSAR studies of ground deformation, crucial to volcanic hazard assessment, may under-estimate intruded magma volumes; and (ii) sill volumes are not incorporated into total melt volume estimates, which are used to constrain lithospheric processes active during continental break-up.

  14. First results of geodetic deformation monitoring after commencement of CO2 injection at the Aquistore underground CO2 storage site

    Science.gov (United States)

    Craymer, M.; White, D.; Piraszewski, M.; Zhao, Y.; Henton, J.; Silliker, J.; Samsonov, S.

    2015-12-01

    Aquistore is a demonstration project for the underground storage of CO2 at a depth of ~3350 m near Estevan, Saskatchewan, Canada. An objective of the project is to design, adapt, and test non-seismic monitoring methods that have not been systematically utilized to date for monitoring CO2 storage projects, and to integrate the data from these various monitoring tools to obtain quantitative estimates of the change in subsurface fluid distributions, pressure changes and associated surface deformation. Monitoring methods being applied include satellite-, surface- and wellbore-based monitoring systems and comprise natural- and controlled-source electromagnetic methods, gravity monitoring, continuous GPS, synthetic aperture radar interferometry (InSAR), tiltmeter array analysis, and chemical tracer studies. Here we focus on the GPS, InSAR and gravity monitoring. Five monitoring sites were installed in 2012 and another six in 2013, each including GPS and InSAR corner reflector monuments (some collocated on the same monument). The continuous GPS data from these stations have been processed on a daily basis in both baseline processing mode using the Bernese GPS Software and precise point positioning mode using CSRS-PPP. Gravity measurements at each site have also been performed in fall 2013, spring 2014 and fall 2015, and at two sites in fall 2014. InSAR measurements of deformation have been obtained for a 5 m footprint at each site as well as at the corner reflector point sources. Here we present the first results of this geodetic deformation monitoring after commencement of CO2 injection on April 14, 2015. The time series of these sites are examined, compared and analyzed with respect to monument stability, seasonal signals, longer term trends, and any changes in motion and mass since CO2 injection.

  15. Ground gas monitoring: implications for hydraulic fracturing and CO2 storage.

    Science.gov (United States)

    Teasdale, Christopher J; Hall, Jean A; Martin, John P; Manning, David A C

    2014-12-02

    Understanding the exchange of carbon dioxide (CO2) and methane (CH4) between the geosphere and atmosphere is essential for the management of anthropogenic emissions. Human activities such as carbon capture and storage and hydraulic fracturing ("fracking") affect the natural system and pose risks to future global warming and to human health and safety if not engineered to a high standard. In this paper an innovative approach of expressing ground gas compositions is presented, using data derived from regulatory monitoring of boreholes in the unsaturated zone at infrequent intervals (typically 3 months) with data from a high frequency monitoring instrument deployed over periods of weeks. Similar highly variable trends are observed for time scales ranging from decades to hourly for boreholes located close to sanitary landfill sites. Additionally, high frequency monitoring data confirm the effect of meteorological controls on ground gas emissions; the maximum observed CH4 and CO2 concentrations in a borehole monitored over two weeks were 40.1% v/v and 8.5% v/v respectively, but for 70% of the monitoring period only air was present. There is a clear weakness in current point monitoring strategies that may miss emission events and this needs to be considered along with obtaining baseline data prior to starting any engineering activity.

  16. Measuring and monitoring to understand and reduce the fall-of-ground risk

    CSIR Research Space (South Africa)

    Vogt, D

    2013-10-01

    Full Text Available -1 ICSMRI 2013: 35th International Conference of Safety in Mines Research Institutes, Central Hall, Westminster, London, UK, 15-17 October 2013 Measuring and monitoring to understand and reduce the fall-of-ground risk Declan Vogt, CSIR Centre...-of-ground still constitute the single largest cause of fatalities. The data show that small falls of between 4 m2 and 10 m2, affecting single people, are the major cause of fatalities. The critical parameters that characterize the risk of rockfalls are: rock...

  17. Advances in space-borne SAR interferometry and its application to ground deformation monitoring

    Institute of Scientific and Technical Information of China (English)

    LIU Zhen-guo; BIAN Zheng-fu

    2011-01-01

    The development of Differential Synthetic Aperture Radar Interferometry (D-InSAR), in terms of its evolution from classic to advanced forms, such as Least-Squares approach, Permanent Scatterer Interferometry, Small Baseline Subset, and Coherent Pixel Technique, is reviewed, describing concisely the main principles of each method and highlighting the difference and relationship between them. Applications of InSAR technology in China were then introduced, together with the obstacles to overcome and feasible strategies, such as integrating MERIS/MODIS data to compensate for the atmospheric effect and GPS, and multi-platform SAR data to make InSAR technique practical and operational under various conditions. The latest developments were then analyzed along with high-quality SAR data, available thanks to the newly launched high-tech satellites, TerraSAR-X, and Cosmo Sky-med, and conclusions were drawn about the main limitations of the technique.

  18. Monitoring of landfill leachate dispersion using reflectance spectroscopy and ground-penetrating radar.

    Science.gov (United States)

    Splajt, T; Ferrier, G; Frostick, L E

    2003-09-15

    The utility of ground-penetrating radar and reflectance spectroscopy in the monitoring of landfill sites has been investigated. Strong correlations between red edge inflection position and chlorophyll and heavy metal concentrations have been demonstrated from grassland species affected by leachate contamination of the soil adjacent to the landfill test site. This study demonstrated that reflectance spectroscopy can identify vegetation affected by leachate-contaminated soil at a range of spatial resolutions. To identify the vegetation affected by leachate contamination, the spectroradiometer must have contiguous bands at sufficient spectral resolution over the critical wave range that measures chlorophyll absorption and the red edge (between 650 and 750 nm). The utility of ground-penetrating radar data to identify leachate escaping from breakout points in the contaminant wall has also been demonstrated. An integrated approach using these techniques, combined with field and borehole sampling and contaminant migration modeling, offers a possible cost-effective monitoring approach for landfill sites.

  19. Simultaneous seismic and geotechnical monitoring for the characterization of superficial deformations of the mudslide in Super-Sauze, French Alps

    Science.gov (United States)

    Walter, Marco; Joswig, Manfred; Arnhardt, Christian; Malet, Jean-Philippe

    2010-05-01

    To characterize superficial deformations of the mudslide in Super-Sauze, southern French Alps, seismic and geotechnical monitoring techniques have been applied simultaneously during a field campaign in July 2009. Based on the method nanoseismic monitoring (Joswig, 2008), we installed three seismic mini-arrays with an aperture of 25-30m, each one consisting of one three-component central-station and three outer vertical-component stations. We identified two different deformation processes caused by the movement of the mudslide: fracture processes within the slope material and superficial fissure development (Walter & Joswig, 2009). The spatiotemporal occurrence of deformation processes identified by nanoseismic monitoring has been verified with geotechnical monitoring systems. GPS devices as well as a small wireless ad-hoc, multi hop sensor network (WSN) have been installed in the slope area. The network consist of 7 connection points, called nodes, that transfer data from different sensors via radio signal directly or over other nodes (Multi Hop) in real-time to a data collection point (gateway). To determine the varying deformation processes, like toppling, spreading, falling and sliding, 6 nodes were equipped with micro-sensors (each with 3-axis acceleration sensor, 2-axis tilt sensor and barometric pressure sensor). In order to monitor the deformation of a recent fissure, one node was equipped with a position-sensor (draw wire displacement transducer). Laboratory tests for the different sensors showed that tilt movements can be detected with an accuracy of +/- 0,06° and a resolution of >0,1°, accelerations with +/- 0,008g and >0,02g and displacements with +/- 0,1mm and >0,1mm. The analysis of data recorded by barometric pressure sensors is quite difficult due to the high natural pressure fluctuations in mountain areas, anyway, the detection of fluctuations of >0,5m was possible. Except the displacement transducers, the geotechnical sensors didn't detect any

  20. High rate and high spatial resolution surface deformation monitoring of the Argentiere glacier from complementary remote sensing and geodetic data

    Science.gov (United States)

    Benoit, Lionel; Pham, Ha-Thai; Trouvé, Emmanuel; Vernier, Flavien; Moreau, Luc; Martin, Olivier; Thom, Christian; Briole, Pierre

    2014-05-01

    The Argentière glacier in the French Alps (Mont-Blanc massif) is a 10 km long glacier covering 19 km². Its flow on a large scale has been studied for over a hundred years by glaciologists, but the time and space fluctuations of its flow are still poorly documented. We selected a small area of the glacier, about 1 km upstream of the Lognan serac fall to measure the glacier flow with in-situ GPS measurements combined with time series of ground based pictures and time series of synthetic aperture radar images from the TerreSAR-X satellite. The experiment took place during two months between September and November 2013 with a network of thirteen single-frequency GPS receivers (eleven set up on the glacier and two on the nearby bedrock) deployed in the field with a sampling rate of 30s. Our data processing allows us to estimate epoch by epoch coordinates of each GPS site with a centimetric precision. The main interest of this approach is twofold : the monitoring of the temporal evolution of the flow and the providing of ground control points for the local and satellite remote sensing imagery. The average velocities of the stations is around 15 cm/day with peaks reaching 25cm/day lasting a few hours to one day after rainfalls or cooling periods. We explain these accelerations as the consequence of an increased basal water pressure. The strain tensor analysis shows a good consistency between the main strain axis and the orientation of the cracks on both sides of the glacier. However, available only at eleven points, the GPS data can not in any case give a picture of the overall deformation of the glacier. In order to map the glacier flow as a whole, including crevasse areas or serac falls, two automatic digital cameras were installed during the experiment on the bedrock on the shore of the glacier with acquisitions every three hours during day time. The processing of the stereo pairs produces maps in which the pixels coordinates (and their changes) are estimated with a

  1. Similar Single-Difference Model and Its Algorithm for Solving GPS Monitoring Deformation Directly at Single Epoch

    Institute of Scientific and Technical Information of China (English)

    YU Xuexiang; XU Shaoquan; GAO Wei; LU Weicai

    2003-01-01

    A new similar single-difference mathematical model (SS-DM) and its corresponding algorithmare advanced to solve the deformationof monitoring point directly in singleepoch. The method for building theSSDM is introduced in detail, and themain error sources affecting the accu-racy of deformation measurement areanalyzed briefly, and the basic algo-rithm and steps of solving the deform-ation are discussed.In order to validate the correctnessand the accuracy of the similar single-difference model, the test with fivedual frequency receivers is carried outon a slideway which moved in plane inFeb. 2001. In the test,five sessions areobserved. The numerical results oftest data show that the advanced mod-el is correct.

  2. Kalman Filters in Geotechnical Monitoring of Ground Subsidence Using Data from MEMS Sensors.

    Science.gov (United States)

    Li, Cheng; Azzam, Rafig; Fernández-Steeger, Tomás M

    2016-07-19

    The fast development of wireless sensor networks and MEMS make it possible to set up today real-time wireless geotechnical monitoring. To handle interferences and noises from the output data, Kalman filter can be selected as a method to achieve a more realistic estimate of the observations. In this paper, a one-day wireless measurement using accelerometers and inclinometers was deployed on top of a tunnel section under construction in order to monitor ground subsidence. The normal vectors of the sensors were firstly obtained with the help of rotation matrices, and then be projected to the plane of longitudinal section, by which the dip angles over time would be obtained via a trigonometric function. Finally, a centralized Kalman filter was applied to estimate the tilt angles of the sensor nodes based on the data from the embedded accelerometer and the inclinometer. Comparing the results from two sensor nodes deployed away and on the track respectively, the passing of the tunnel boring machine can be identified from unusual performances. Using this method, the ground settlement due to excavation can be measured and a real-time monitoring of ground subsidence can be realized.

  3. Interim site characterization report and ground-water monitoring program for the Hanford site solid waste landfill

    Energy Technology Data Exchange (ETDEWEB)

    Fruland, R.M.; Hagan, R.A.; Cline, C.S.; Bates, D.J.; Evans, J.C.; Aaberg, R.L.

    1989-07-01

    Federal and state regulations governing the operation of landfills require utilization of ground-water monitoring systems to determine whether or not landfill operations impact ground water at the point of compliance (ground water beneath the perimeter of the facility). A detection-level ground-water monitoring system was designed, installed, and initiated at the Hanford Site Solid Waste Landfill (SWL). Chlorinated hydrocarbons were detected at the beginning of the ground-water monitoring program and continue to be detected more than 1 year later. The most probable source of the chlorinated hydrocarbons is washwater discharged to the SWL between 1985 and 1987. This is an interim report and includes data from the characterization work that was performed during well installation in 1987, such as field observations, sediment studies, and geophysical logging results, and data from analyses of ground-water samples collected in 1987 and 1988, such as field parameter measurements and chemical analyses. 38 refs., 27 figs., 8 tabs.

  4. Mechanism of rock deformation and failure and monitoring analysis in water-rich soft rock roadway of western China

    Institute of Scientific and Technical Information of China (English)

    MENG Qing-bin; HAN Li-jun; QIAO Wei-guo; LIN Deng-ge; YANG Ling

    2012-01-01

    Aiming to get the strata behavior and stability rules of surrounding rock of the main return airway of Yushujing Coal Mine,convergence deformation of two sides and force of U-shaped steel yieldable support and bolt were monitored,and deformation of surrounding rock and mechanical characteristics of support structure were timely obtained to guide the information construction and optimize supporting parameters in water-rich soft rock roadway.The field monitoring results indicate the following.(1) Convergence displacement of rock surface increases with time continuity and shows surrounding rock's intense rheological behavior.The original support scheme cannot control the large deformation and strongly rheological behavior;(2) Without backfilling,the U-shaped steel support begins to bear load after erecting for 4-7 days and increases rapidly in the first 30 days.The U-shaped steel support at the right shoulder and top of roadway bears a larger force and the left side and shoulder bears a smaller force; (3) The stress of bolt increasing over time and at the right shoulder of roadway has larger growth and value.The mechanism of rock deformation and the failure and strata behavior in water-rich soft rock roadway are revealed based on the results of the measured relaxation zone of surrounding rock,measured stresses,and the rock mechanics tests.

  5. Design and operation of a comprehensive and permanent rock slope deformation monitoring system at the Great Aletsch Glacier (Switzerland)

    Science.gov (United States)

    Glueer, Franziska; Loew, Simon; Seifert, Reto; Frukacz, Mariusz; Wieser, Andreas

    2015-04-01

    Most geodetic monitoring systems of rock slope instabilities include a series of stable reference points. However, detailed studies of Alpine rock slopes with long term Global Navigation Satellite Systems (GNSS), high-resolution tilt meters and Total Stations (TPS) have shown unequivocally, that truly stable points are very rare. The underlying causes of such natural movements are long- and short-periodic reversible deformations of stable slopes caused by annual and daily changes of pore pressure and temperature in fractured rock masses. These movements impact TPS measurements and cause inconsistencies in the reference frame which, if not accounted for, will introduce systematic errors in the calculated deformation pattern and time series. This complex situation can be found in many mountain slopes. However, detailed measurements and analyses of the superposition of reversible slope deformations and gravitational mass movements of active instabilities are not existing. At the terminus of the Great Aletsch Glacier a comprehensive permanent deformation and displacement monitoring system has been installed, which allows to investigate large scale reversible deformations as well as active rock slope instabilities (Moosfluh and Driest) in response to rapid glacier retreat. The system includes 2 high-precision TPS stations with automated reflector recognition, 58 reflectors, 4 GNSS stations, climate sensors, and 2 high-resolution tilt meters and provides a fully automated survey with high accuracies over distances up to 2 km. The self-sustaining monitoring systems at Aletsch are installed at two high-alpine locations, remotely operated and automatically collect data on a set time schedule mainly at night. Deformation artefacts from thermal and wind disturbances of total stations' pillars and climatic refraction are studied with separate monitoring programs. We describe various aspects of the design, construction, testing and practical operation of this unique monitoring

  6. Monitoring greenhouse gas emissions in Australian landscapes: Comparing ground based mobile surveying data to GOSAT observations

    Science.gov (United States)

    Bashir, S.; Iverach, C.; Kelly, B. F. J.

    2016-12-01

    Climate change is threatening the health and stability of the natural world and human society. Such concerns were emphasized at COP21 conference in Paris 2015 which highlighted the global need to improve our knowledge of sources of greenhouse gas and to develop methods to mitigate the effects of their emissions. Ongoing spatial and temporal measurements of greenhouse gases at both point and regional scales is important for clarification of climate change mechanisms and accounting. The Greenhouse gas Observing SATellite (GOSAT) is designed to monitor the global distribution of carbon dioxide (CO2) and methane (CH4) from orbit. As existing ground monitoring stations are limited and still unevenly distributed, satellite observations provide important frequent, spatially extensive, but low resolution observations. Recent developments in portable laser based greenhouse gas measurement systems have enabled the rapid measurement of greenhouse gases in ppb at the ground surface. This study was conducted to map major sources of CO2 and CH4 in the eastern states of Australia at the landscape scale and to compare the results to GOSAT observations. During April 2016 we conducted a regional CH4 and CO2 mobile survey, using an LGR greenhouse gas analyzer. Measurements were made along a 4000 KM circuit through major cities, country towns, dry sclerophyll forests, coastal wetlands, coal mining regions, coal seam gas developments, dryland farming and irrigated agricultural landscapes. The ground-based survey data were then compared with the data (L2) from GOSAT. Ground-based mobile surveys showed that there are clear statistical differences in the ground level atmospheric concentration of CH4 and CO2 associated with all major changes in land use. These changes extend for kilometers, and cover one or more GOSAT pixels. In the coal mining districts the ground-level atmospheric concentration of CH4 exceeded 2 ppm for over 40 km, yet this was not discernable in the retrieved data (L2

  7. Development of a Ground-Based Atmospheric Monitoring Network for the Global Mercury Observation System (GMOS

    Directory of Open Access Journals (Sweden)

    Sprovieri F.

    2013-04-01

    Full Text Available Consistent, high-quality measurements of atmospheric mercury (Hg are necessary in order to better understand Hg emissions, transport, and deposition on a global scale. Although the number of atmospheric Hg monitoring stations has increased in recent years, the available measurement database is limited and there are many regions of the world where measurements have not been extensively performed. Long-term atmospheric Hg monitoring and additional ground-based monitoring sites are needed in order to generate datasets that will offer new insight and information about the global scale trends of atmospheric Hg emissions and deposition. In the framework of the Global Mercury Observation System (GMOS project, a coordinated global observational network for atmospheric Hg is being established. The overall research strategy of GMOS is to develop a state-of-the-art observation system able to provide information on the concentration of Hg species in ambient air and precipitation on the global scale. This network is being developed by integrating previously established ground-based atmospheric Hg monitoring stations with newly established GMOS sites that are located both at high altitude and sea level locations, as well as in climatically diverse regions. Through the collection of consistent, high-quality atmospheric Hg measurement data, we seek to create a comprehensive assessment of atmospheric Hg concentrations and their dependence on meteorology, long-range atmospheric transport and atmospheric emissions.

  8. On the Design of Radar Corner Reflectors for Deformation Monitoring in Multi-Frequency InSAR

    OpenAIRE

    Garthwaite, Matthew C.

    2017-01-01

    Trihedral corner reflectors are being increasingly used as point targets in deformation monitoring studies using interferometric synthetic aperture radar (InSAR) techniques. The frequency and size dependence of the corner reflector Radar Cross Section (RCS) means that no single design can perform equally in all the possible imaging modes and radar frequencies available on the currently orbiting Synthetic Aperture Radar (SAR) satellites. Therefore, either a corner reflector design tailored to ...

  9. Long-term crustal deformation monitored by gravity and space geodetic techniques at Medicina

    Science.gov (United States)

    Richter, B.; Zerbini, S.; Lago, L.; Romagnoli, C.; Simon, D.

    2003-04-01

    In the framework of an international collaboration, during 1996, at Medicina, Italy, a continuous GPS (CGPS) and a superconducting gravimeter (SG) were installed by the University of Bologna and the Bundesamt fuer Kartographie und Geodaesie, Frankfurt, respectively. The main purpose of the research was the establishment and the demonstration of an observational procedure leading to a reliable estimate of height variations and to interpret gravity variations/changes in conjunction with mass variations/changes within and above the Earth's crust. To fulfill the stated objectives, additional information is needed. In particular, continuous registrations of meteoclimatic parameters such as sacrificial water table level, electrical conductivity and temperature, deep well levels, rainfall, air pressure and temperature and balloon radio sonde data. A comparison, performed over a period of more than six years of data, between the CGPS and SG series has shed light on the existence of relevant seasonal fluctuations in both data sets, quite similar in amplitude and phase. They were interpreted and modeled as the sum of various environmental loadings for the height and gravity series and the Newtonian attraction components for gravity alone. The removal of the observed oscillations is most important in order to estimate properly the long-term trends, which characterize the CGPS and SG series. Moreover, the combination of SG and repeated absolute gravity measurements shows the capability of both techniques to determine the long-term trend in gravity. Just the combined view allows a significant trend analysis. In addition, the CGPS measurements are compared with other geodetic space techniques available at the Medicina station. In total, a strategy has been developed demonstrating how the present day available techniques should be combined to monitor crustal deformations and achieve relevant information for possible causes.

  10. Recent gravity monitoring of ETS transient deformation in the northern Cascadia Subduction Zone

    Science.gov (United States)

    Henton, J. A.; Dragert, H.; Lambert, A.; Nykolaishen, L.; Liard, J.; Courtier, N.

    2012-12-01

    High-precision gravity observations are sensitive to vertical motion of the observation site as well as mass redistribution and can be used to investigate the physical processes involved in Episodic Tremor and Slip (ETS). For the 2011 ETS event in the northern portion of the Cascadia Subduction Zone, absolute gravity (AG) observations and continuous gravity monitoring with an earth tide (ET) gravimeter were carried out at the Pacific Geoscience Centre (PGC) in order to augment the GPS and borehole strainmeter (BSM) data used in constraining models of slip on the subduction plate interface. Unfortunately, the surface displacements and strains for the August 2011 slow slip event were significantly less for southern Vancouver Island than those recorded for previous events making this particular ETS episode less than ideal for the search for attendant gravity signals. Nonetheless, preliminary AG results for the 2011 ETS event show a subtle (≤ 1μGal) negative transient gravity signal but its origin is not clear. This residual gravity change, after accounting for the gravity offset predicted from the observed height change, may reflect a migration of fluids and/or a change in mean density. No significant vertical change is observed in the GPS data. Based on previous events, this is expected since PGC lies close to the hinge-line for vertical deformation for regional ETS. We attempt to improve the resolution of the GPS results by including results from NRCan's PPP software in our analyses. Data from the 3 co-located BSM's operated by the Plate Boundary Observatory show discrepancies that indicate interfering signals of likely non-tectonic origin. Preliminary data from the ET gravimeter appear to be dominated by non-linear instrumental drift that is often observed at the outset of continuous operation at a new location. To improve the resolution of the gravity signal, future monitoring of ETS events will be supplemented at PGC by continuous gravity measurements with a

  11. Wi-GIM system: a new wireless sensor network (WSN) for accurate ground instability monitoring

    Science.gov (United States)

    Mucchi, Lorenzo; Trippi, Federico; Schina, Rosa; Fornaciai, Alessandro; Gigli, Giovanni; Nannipieri, Luca; Favalli, Massimiliano; Marturia Alavedra, Jordi; Intrieri, Emanuele; Agostini, Andrea; Carnevale, Ennio; Bertolini, Giovanni; Pizziolo, Marco; Casagli, Nicola

    2016-04-01

    Landslides are among the most serious and common geologic hazards around the world. Their impact on human life is expected to increase in the next future as a consequence of human-induced climate change as well as the population growth in proximity of unstable slopes. Therefore, developing better performing technologies for monitoring landslides and providing local authorities with new instruments able to help them in the decision making process, is becoming more and more important. The recent progresses in Information and Communication Technologies (ICT) allow us to extend the use of wireless technologies in landslide monitoring. In particular, the developments in electronics components have permitted to lower the price of the sensors and, at the same time, to actuate more efficient wireless communications. In this work we present a new wireless sensor network (WSN) system, designed and developed for landslide monitoring in the framework of EU Wireless Sensor Network for Ground Instability Monitoring - Wi-GIM project (LIFE12 ENV/IT/001033). We show the preliminary performance of the Wi-GIM system after the first period of monitoring on the active Roncovetro Landslide and on a large subsiding area in the neighbourhood of Sallent village. The Roncovetro landslide is located in the province of Reggio Emilia (Italy) and moved an inferred volume of about 3 million cubic meters. Sallent village is located at the centre of the Catalan evaporitic basin in Spain. The Wi-GIM WSN monitoring system consists of three levels: 1) Master/Gateway level coordinates the WSN and performs data aggregation and local storage; 2) Master/Server level takes care of acquiring and storing data on a remote server; 3) Nodes level that is based on a mesh of peripheral nodes, each consisting in a sensor board equipped with sensors and wireless module. The nodes are located in the landslide ground perimeter and are able to create an ad-hoc WSN. The location of each sensor on the ground is

  12. Acoustic monitoring on a humpback whale (Megaptera novaeangliae) feeding ground shows continual singing into late Spring.

    Science.gov (United States)

    Clark, Christopher W; Clapham, Phillip J

    2004-05-22

    Singing by males is a major feature of the mating system of humpback whales, Megaptera novaeangliae (Borowski). Although a few songs have been opportunistically recorded on the whales' high-latitude feeding grounds, singing in these regions was thought to be only sporadic. We report results from the first continuous acoustic monitoring of a humpback whale feeding ground (off Cape Cod, MA, USA) in spring. Using autonomous sea-floor recording systems, we found singing on a daily basis over the entire 25 day monitoring period, from 14 May to 7 June 2000. For much of the period, song was recorded 24 h per day. These results, combined with evidence for aseasonal conceptions in whaling catch data, suggest that the humpback whale breeding season should no longer be considered as confined to lower-latitude regions in winter. Rather, we suggest breeding extends geographically and temporally onto feeding grounds into at least spring and early summer. Singing at these times represents either low-cost opportunistic advertising by (perhaps relatively few) males to court females that failed to conceive during the winter, and/or possibly an intrasexual display.

  13. Transformation of Ground Vibration Signal for Debris-Flow Monitoring and Detection in Alarm Systems

    Directory of Open Access Journals (Sweden)

    José Moya

    2012-04-01

    Full Text Available Debris flows are fast mass movements formed by a mix of water and solid materials, which occur in steep torrents, and are a source of high risks for human settlements. Geophones are widely used to detect the ground vibration induced by passing debris flows. However, the recording of geophone signals usually requires storing a huge amount of data, which leads to problems in storage capacity and power consumption. This paper presents a method to transform and simplify the signals measured by geophones. The key input parameter is the ground velocity threshold, which removes the seismic noise that is not related to debris flows. A signal conditioner was developed to implement the transformation and the ground velocity threshold was set by electrical resistors. The signal conditioner was installed at various European monitoring sites to test the method. Results show that data amount and power consumption can be greatly reduced without losing much information on the main features of the debris flows. However, the outcome stresses the importance of choosing a ground vibration threshold, which must be accurately calibrated. The transformation is also suitable to detect other rapid mass movements and to distinguish among different processes, which points to a possible implementation in alarm systems.

  14. Transformation of ground vibration signal for debris-flow monitoring and detection in alarm systems.

    Science.gov (United States)

    Abancó, Clàudia; Hürlimann, Marcel; Fritschi, Bruno; Graf, Christoph; Moya, José

    2012-01-01

    Debris flows are fast mass movements formed by a mix of water and solid materials, which occur in steep torrents, and are a source of high risks for human settlements. Geophones are widely used to detect the ground vibration induced by passing debris flows. However, the recording of geophone signals usually requires storing a huge amount of data, which leads to problems in storage capacity and power consumption. This paper presents a method to transform and simplify the signals measured by geophones. The key input parameter is the ground velocity threshold, which removes the seismic noise that is not related to debris flows. A signal conditioner was developed to implement the transformation and the ground velocity threshold was set by electrical resistors. The signal conditioner was installed at various European monitoring sites to test the method. Results show that data amount and power consumption can be greatly reduced without losing much information on the main features of the debris flows. However, the outcome stresses the importance of choosing a ground vibration threshold, which must be accurately calibrated. The transformation is also suitable to detect other rapid mass movements and to distinguish among different processes, which points to a possible implementation in alarm systems.

  15. The value of long-term monitoring in the development of ground-water-flow models

    Science.gov (United States)

    Feinstein, Daniel T.; Hart, David J.; Krohelski, James T.

    2004-01-01

    As environmental issues have come to the forefront of public concern, so has the awareness of the importance of ground water in the overall water cycle and as a source of the Nation’s drinking water. Heightened interest has spawned a host of scientific enterprises (Taylor and Alley, 2001). Some activities are directed toward collection of water-level data and related information to monitor the physical and chemical state of the resource. Other activities are directed at interpretive studies undertaken, for example, to optimize the location of new water-supply wells or to protect rivers and lakes fed by ground water. An important type of interpretive study is the computer ground-water-flow model that inte- grates field data in a mathematical framework. Long-term, systematic collection of hydro- logic data is crucial to the construction and testing of ground-water models so that they can reproduce the evolution of flow systems and forecast future conditions. 

  16. 4D very high-resolution topography monitoring of surface deformation using UAV-SfM framework.

    Science.gov (United States)

    Clapuyt, François; Vanacker, Veerle; Schlunegger, Fritz; Van Oost, Kristof

    2016-04-01

    During the last years, exploratory research has shown that UAV-based image acquisition is suitable for environmental remote sensing and monitoring. Image acquisition with cameras mounted on an UAV can be performed at very-high spatial resolution and high temporal frequency in the most dynamic environments. Combined with Structure-from-Motion algorithm, the UAV-SfM framework is capable of providing digital surface models (DSM) which are highly accurate when compared to other very-high resolution topographic datasets and highly reproducible for repeated measurements over the same study area. In this study, we aim at assessing (1) differential movement of the Earth's surface and (2) the sediment budget of a complex earthflow located in the Central Swiss Alps based on three topographic datasets acquired over a period of 2 years. For three time steps, we acquired aerial photographs with a standard reflex camera mounted on a low-cost and lightweight UAV. Image datasets were then processed with the Structure-from-Motion algorithm in order to reconstruct a 3D dense point cloud representing the topography. Georeferencing of outputs has been achieved based on the ground control point (GCP) extraction method, previously surveyed on the field with a RTK GPS. Finally, digital elevation model of differences (DOD) has been computed to assess the topographic changes between the three acquisition dates while surface displacements have been quantified by using image correlation techniques. Our results show that the digital elevation model of topographic differences is able to capture surface deformation at cm-scale resolution. The mean annual displacement of the earthflow is about 3.6 m while the forefront of the landslide has advanced by ca. 30 meters over a period of 18 months. The 4D analysis permits to identify the direction and velocity of Earth movement. Stable topographic ridges condition the direction of the flow with highest downslope movement on steep slopes, and diffuse

  17. Evaluation of chemical sensors for in situ ground-water monitoring at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, E.M.; Hostetler, D.D.

    1989-03-01

    This report documents a preliminary review and evaluation of instrument systems and sensors that may be used to detect ground-water contaminants in situ at the Hanford Site. Three topics are covered in this report: (1) identification of a group of priority contaminants at Hanford that could be monitored in situ, (2) a review of current instrument systems and sensors for environmental monitoring, and (3) an evaluation of instrument systems that could be used to monitor Hanford contaminants. Thirteen priority contaminants were identified in Hanford ground water, including carbon tetrachloride and six related chlorinated hydrocarbons, cyanide, methyl ethyl ketone, chromium (VI), fluoride, nitrate, and uranium. Based on transduction principles, chemical sensors were divided into four classes, ten specific types of instrument systems were considered: fluorescence spectroscopy, surface-enhanced Raman spectroscopy (SERS), spark excitation-fiber optic spectrochemical emission sensor (FOSES), chemical optrodes, stripping voltammetry, catalytic surface-modified ion electrode immunoassay sensors, resistance/capacitance, quartz piezobalance and surface acoustic wave devices. Because the flow of heat is difficult to control, there are currently no environmental chemical sensors based on thermal transduction. The ability of these ten instrument systems to detect the thirteen priority contaminants at the Hanford Site at the required sensitivity was evaluated. In addition, all ten instrument systems were qualitatively evaluated for general selectivity, response time, reliability, and field operability. 45 refs., 23 figs., 7 tabs.

  18. Monitoring ground subsidence in urban environments: M-30 tunnels under Madrid City (Spain

    Directory of Open Access Journals (Sweden)

    Rubén Martínez Marín

    2015-08-01

    Full Text Available Big cities improvement usually requires the construction of large underground infrastructures, in order to ensure proper communication and optimize urban use. Monitoring ground subsidences is therefore one of the main challenges in changing urban environments. The "Madrid Río" project (2003-2008 is an effort to reclaim the riverfront land and improve the busy M-30 beltway that involved the construction of 7.93 km of tunnels underneath the southern center of Madrid City. This paper presents a remote-sensing approach to monitor ground subsidences induced by tunneling excavation.  The Persistent Scatterers Interferometry technique (PSI was used to estimate subsidence and displacement time series from Synthetic Aperture Radar images, acquired between August 2003 and April 2008 from ENVISAT.  Remote sensed results were compared to traditional extensometric measures, fitting adequately for selected sectors. Spatial analysis of displacements allowed evaluating impacts of tunneling on surrounding buildings and facilities, highlighting critical areas. The availability of a spatial distribution of displacements in a time series allowed analyzing longitudinal, cross-sectional and temporal dynamics. The main limitations during this work were the heterogeneous spatial distribution of Persistent Scatterers, the absence of measurement points in work areas, the threshold for velocity detection and low temporal resolution of ENVISAT images. Nevertheless, these limitations of DInSAR for monitoring infrastructures are overcome by actual satellites, being a complementary technique with an exceptional added value and temporal analysis capability.

  19. Satellite synthetic aperture radar for monitoring of surface deformation in shallow underground mining environments

    CSIR Research Space (South Africa)

    Engelbrecht, J

    2016-08-01

    Full Text Available Surface deformations associated with shallow underground mining activities have significant implications for both the natural- and built environment. Environmental problems include the exacerbation of acid mine drainage and the alteration...

  20. Exploring the relationship between monitored ground-based and satellite aerosol measurements over the City of Johannesburg

    CSIR Research Space (South Africa)

    Garland, Rebecca M

    2012-09-01

    Full Text Available This project studied the relationship between aerosol optical depth (AOD) from the Multi-angle Imaging SpectroRadiometer (MISR) instrument on the Terra satellite, and ground-based monitored particulate matter (PM) mass concentrations measured...

  1. Multidimensional High Spatiotemporal Resolution InSAR Time Series Assist Interdisciplinary Space- And Ground-Based Monitoring To Reveal Pre-Eruptive Signals At Nyamulagira Volcano (North Kivu, D.R.C.)

    Science.gov (United States)

    d'Oreye, N.; Smets, B.; Kervyn, F.; Kervyn, M.; Albino, F.; Arellano, S. R.; Arjona, A. A.; Carn, S. A.; Fernandez, J.; Galle, B.; Gonzalez, P. J.; Head, E.; Pallero, J.; Prieto, J. F.; Samsonov, S. V.; Tedesco, D.; Tiampo, K. F.; Wauthier, C.

    2013-12-01

    Interdisciplinary space- and ground-based monitoring systems allowed the quantitative and detailed study of the Nyamulagira 2010 eruption (Congo). Field observations revealed the event as 4 eruptive phases delimited by major changes in effusive activity. Signals from ground deformation, seismicity, SO2 emission and thermal flux correlate with these eruptive phases. Moreover, MSBAS InSAR time series combining data acquired under different geometries and with different satellites (Samsonov and d'Oreye, 2012) allowed the detection of pre-, co- and inter-eruptive deformation in the Nyamulagira volcanic field. Using 8 years of ENVISAT, RADARSAT2 and ALOS data, the MSBAS method reveals the first unambiguous pre-eruptive ground deformations in the Virunga Volcanic Province. Precursory ground deformations are detected up to 3 weeks prior the onset of the 2010 eruption by images acquired by 3 different sensors in different geometries. These deformations took place in the main crater and along the SE flank of the volcano, where eruptive fractures will ultimately opened. Deformations coincide with small, though clear, increase of the short period seismicity and SO2 emissions.These seismic and SO2 variations alone were too small, however, to raise attention. The pre-eruptive ground deformation signals revealed by InSAR are of about the same amplitude and spatial extent as atmospheric noise and therefore cannot be identified on individual differential interferograms. Conventional time-series methods based on single acquisition geometry do not have a sufficient time resolution to discriminate such a precursory signal from an atmospheric artifact. The 3-week precursors detected at Nyamulagira contrast with the only precursory signal previously recognized so far in the Virunga, namely the increase of tremors and long period seismicity no more than few hours or days before the eruption onset. In January 2010, such short-term seismic precursors were detected less than two hours

  2. Geodetic and Non-Geodetic Methods for Deformation Monitoring of Rock-Fill Dams, a Case Study at Ataturk DAM

    Science.gov (United States)

    Kalkan, Y.; Bilgi, S.

    2012-12-01

    Necessity to water is increasing day by day with respect to the World population, rising of living standards and destruction of nature. Water resources have to be controlled and supplied for agricultural uses, drinking and industrial purposes by the countries having limited water resources. This situation is also considerable for Turkey which has a location in the middle zone of World and having limited water sources. Dams are among the most important engineering structures which are used for these purposes. However, the functioning life of dams is as important as the investment and construction. Nevertheless, in order to provide safety of human life living around, well planned monitoring is essential for dams. Deformation measurements have an important status among various engineering surveying. Considering the time and labor consumed by long-term measurements, processing and analysis of measured data, importance of the horizontal and vertical small structural motions at regular intervals could be comprehended. Ataturk Dam in Turkey is the 6th largest dam of world considering the filling volume of embankment. Deformation of Ataturk Dam is being monitoring yearly since 2006 by Istanbul Technical University Department of Geomatics Engineering. We apply both GPS and conventional techniques. In this study, we present the result of radial deformations on Ataturk Dam between 2006 and 2010. The results show significant horizontal movements among the 72% of object points. Maximum movement is found as 14.12 cm (with a radial component of 14.08 cm) in 4.5 years.

  3. A styrene-butadiene rubber (SBR)/carbon nanotube-based smart force sensor for automotive tire deformation monitoring

    Science.gov (United States)

    Cho, Min-Young; Kim, Ji-Sik; Lee, Ho-Geun; Choi, Seung-Bok; Kim, Gi-Woo

    2016-04-01

    This paper provides a preliminary study on the piezoresistive effect of a styrene-butadiene Rubber (SBR), one of the main ingredients of automotive tire, dispersed with carbon nanotubes (CNTs) to explore its feasibility as a force sensor embedded in automotive tires. Typically, the application of CNTs has been successfully applied to the mechanical sensing technology such as a stress/strain and impact sensor. In this study, the potential of using the SBR/CNT as a force sensor for monitoring automotive tire deformation is evaluated for the first time. Experimental results show that the electrical resistance of the SBR/CNT composite changes in response to the sinusoidal loading, as well as static compressive load. These piezoresistive responses of the SBR/CNT composite will be used for sensing the tire deformation caused by the vehicle loading or cracks of tires.

  4. Long-term ionospheric anomaly monitoring for ground based augmentation systems

    Science.gov (United States)

    Jung, Sungwook; Lee, Jiyun

    2012-08-01

    Extreme ionospheric anomalies can pose a potential integrity threat to ground-based augmentation of the Global Positioning System (GPS), and thus the development of ionospheric anomaly threat models for each region of operation is essential for system design and operation. This paper presents a methodology for automated long-term ionospheric anomaly monitoring, which will be used to build an ionospheric anomaly threat model, evaluate its validity over the life cycle of the system, continuously monitor ionospheric anomalies, and update the threat model if necessary. This procedure automatically processes GPS data collected from external networks and estimates ionospheric gradients at regular intervals. If ionospheric gradients large enough to be potentially hazardous to users are identified, manual data examination is triggered. This paper also develops a simplified truth processing method to create precise ionospheric delay estimates in near real-time, which is the key to automating the ionospheric monitoring procedure. The performance of the method is examined using data from the 20 November 2003 and 9 November 2004 ionospheric storms. These results demonstrate the effectiveness of simplified truth processing within long-term ionosphere monitoring. From the case studies, the automated procedure successfully identified extreme ionospheric anomalies, including the two worst ionospheric gradients observed and validated previously based on manual analysis. The automation of data processing enables us to analyze ionospheric data continuously going forward and to more accurately categorize ionospheric behavior under both nominal and anomalous conditions.

  5. Ground deformation associated with the precursory unrest and early phases of the January 2006 eruption of Augustine volcano, Alaska

    Science.gov (United States)

    Cervelli, P.F.; Fournier, T.; Freymueller, Jeffrey T.; Power, J.A.

    2006-01-01

    On January 11, 2006 Augustine Volcano erupted after nearly 20 years of quiescence. Global Positioning System (GPS) instrumentation at Augustine, consisting of six continuously recording, telemetered receivers, measured clear precursory deformation consistent with a source of inflation or pressurization beneath the volcano's summit at a depth of around sea level. Deformation began in early summer 2005, and was preceded by a subtle, but distinct, increase in seismicity, which began in May 2005. After remaining more or less constant, deformation rates accelerated on at least three stations beginning in late November 2005. After this date, GPS data suggest the upward propagation of a small dike into the edifice, which, based on the style of deformation and high levels of gas emission, appears to have ascended to shallow levels by mid-December 2005, about four weeks before the eruption began.

  6. Proceedings of the 27th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marvin A. [Editor; Benson, Jody [Editor; Patterson, Eileen F. [Editor

    2005-09-20

    These proceedings contain papers prepared for the 27th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 20-22 September, 2005 in Rancho Mirage, California. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  7. Monitoring of Carbon Dioxide and Methane Plumes from Combined Ground-Airborne Sensors

    Science.gov (United States)

    Jacob, Jamey; Mitchell, Taylor; Honeycutt, Wes; Materer, Nicholas; Ley, Tyler; Clark, Peter

    2016-11-01

    A hybrid ground-airborne sensing network for real-time plume monitoring of CO2 and CH4 for carbon sequestration is investigated. Conventional soil gas monitoring has difficulty in distinguishing gas flux signals from leakage with those associated with meteorologically driven changes. A low-cost, lightweight sensor system has been developed and implemented onboard a small unmanned aircraft and is combined with a large-scale ground network that measures gas concentration. These are combined with other atmospheric diagnostics, including thermodynamic data and velocity from ultrasonic anemometers and multi-hole probes. To characterize the system behavior and verify its effectiveness, field tests have been conducted with simulated discharges of CO2 and CH4 from compressed gas tanks to mimic leaks and generate gaseous plumes, as well as field tests over the Farnsworth CO2-EOR site in the Anadarko Basin. Since the sensor response time is a function of vehicle airspeed, dynamic calibration models are required to determine accurate location of gas concentration in space and time. Comparisons are made between the two tests and results compared with historical models combining both flight and atmospheric dynamics. Supported by Department of Energy Award DE-FE0012173.

  8. Proceedings of the 28th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wetovsky, Marvin A. [Editor; Benson, Jody [Editor; Patterson, Eileen F. [Editor

    2006-09-19

    These proceedings contain papers prepared for the 28th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 19-21 September, 2006 in Orlando, Florida. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  9. Description of the ground state of axially deformed nuclei within the Relativistic Hartree-Fock-Bogoliubov model

    Energy Technology Data Exchange (ETDEWEB)

    Ebran, J-P [CEA/DAM/DIF, F-91297 Arpajon (France); Khan, E; Arteaga, D Pena [Institut de Physique Nucleaire, University Paris-Sud, IN2P3-CNRS, F-91406 Orsay Cedex (France); Vretenar, D, E-mail: jean-paul.ebran@cea.fr [Physics Department, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia)

    2011-09-16

    The Relativistic Hartree-Fock-Bogoliubov model for axially deformed nuclei (RHFBz) is presented. The model involves a phenomenological Lagrangian with density-dependent meson-nucleon couplings in the particle-hole channel and the central part of the Gogny force in the particle-particle channel. The RHFBz equations are solved by expansion in the basis of a deformed harmonic oscillator. Illustrative RHFBz calculations are performed for Neon isotopes.

  10. 3D Monitoring under the Keciova Mosque (Casbah-Algier, Algeria) with Ground Penetrating Radar Method

    Science.gov (United States)

    Kadioglu, Selma; Kagan Kadioglu, Yusuf; Deniz, Kiymet; Akin Akyol, Ali

    2014-05-01

    Keciova (Ketchaoua) Mosque, in Casbah-Algiers, the capital of Algeria, is a UNESCO World Heritage Site. Keciova Mosque was originally built in 1612 by the Ottoman Empire. A RAMAC CU II GPR system and a 250 MHz shielded antenna have been employed inside of the Mosque including the Cathedral and inside of the burial chambers under the Cathedral Site on parallel profiles spaced approximately 0.30 m apart to measure data. After applying standard two-dimensional (2D) and three dimensional (3D) imaging techniques, transparent 3D imaging techniques have been used to photograph the foundational infrastructures, buried remains and safety problems of the Mosque. The results showed that we obtained 3D GPR visualization until 12.0 m in depth. Firstly we imaged the base floor including corridors. Then we monitored buried remains under the first ground level between 5.0-7.0 m in depths. Finally we indicated 3D GPR photographs a spectacular protected buried old mosque structures under the second ground level between 9.0-12.0 m in depths. This project has been supported by Republic of Turkey Prime Ministry Turkish Cooperation and Coordination Agency (TIKA). This study is a contribution to the EU funded COST action TU1208, "Civil Engineering Applications of Ground penetrating Radar".

  11. Real-time monitoring of seismicity and deformation during the Bárdarbunga rifting event and associated caldera subsidence

    Science.gov (United States)

    Jónsdóttir, Kristín; Ófeigsson, Benedikt; Vogfjörd, Kristín; Roberts, Matthew; Barsotti, Sara; Gudmundsson, Gunnar; Hensch, Martin; Bergsson, Bergur; Kjartansson, vilhjálmur; Erlendsson, Pálmi; Friðriksdóttir, Hildur; Hreinsdóttir, Sigrún; Guðmundsson, Magnús; Sigmundsson, Freysteinn; Árnadóttir, Thóra; Heimisson, Elías; Hjorleifsdóttir, Vala; Soring, Jón; Björnsson, Bogi; Oddsson, Björn

    2015-04-01

    We present a monitoring overview of a rifting event and associated caldera subsidence in a glaciated environment during the Bárðarbunga volcanic crisis. Following a slight increase in seismicity and a weak deformation signal, noticed a few months before the unrest by the SIL monitoring team, an intense seismic swarm began in the subglacial Bárðarbunga caldera on August 16 2014. During the following two weeks, a dyke intruded into the crust beneath the Vatnajökull ice cap, propagating 48 km from the caldera to the east-north-east and north of the glacier where an effusive eruption started in Holuhraun. The eruption is still ongoing at the time of writing and has become the largest eruption in over 200 years in Iceland. The dyke propagation was episodic with a variable rate and on several occasions low frequency seismic tremor was observed. Four ice cauldrons, manifestations of small subglacial eruptions, were detected. Soon after the swarm began the 7x11 km wide caldera started to subside and is still subsiding (although at slower rates) and has in total subsided over 60 meters. Unrest in subglacial volcanoes always calls for interdisciplinary efforts and teamwork plays a key role for efficient monitoring. Iceland has experienced six subglacial volcanic crises since modern digital monitoring started in the early 90s. With every crisis the monitoring capabilities, data interpretations, communication and information dissemination procedures have improved. The Civil Protection calls for a board of experts and scientists (Civil Protection Science Board, CPSB) to share their knowledge and provide up-to-date information on the current status of the volcano, the relevant hazards and most likely scenarios. The evolution of the rifting was monitored in real-time by the joint interpretation of seismic and cGPS data. The dyke propagation could be tracked and new, updated models of the dyke volume were presented at the CPSB meetings, often daily. In addition, deformation

  12. Application of open-source photogrammetric software MicMac for monitoring surface deformation in laboratory models

    Science.gov (United States)

    Galland, Olivier; Bertelsen, Hâvard S.; Guldstrand, Frank; Girod, Luc; Johannessen, Rikke F.; Bjugger, Fanny; Burchardt, Steffi; Mair, Karen

    2016-04-01

    Quantifying deformation is essential in modern laboratory models of geological systems. This paper presents a new laboratory monitoring method through the implementation of the open-source software MicMac, which efficiently implements photogrammetry in Structure-from-Motion algorithms. Critical evaluation is provided using results from two example laboratory geodesy scenarios: magma emplacement and strike-slip faulting. MicMac automatically processes images from synchronized cameras to compute time series of digital elevation models (DEMs) and orthorectified images of model surfaces. MicMac also implements digital image correlation to produce high-resolution displacements maps. The resolution of DEMs and displacement maps corresponds to the pixel size of the processed images. Using 24 MP cameras, the precision of DEMs and displacements is ~0.05 mm on a 40 × 40 cm surface. Processing displacement maps with Matlab® scripts allows automatic fracture mapping on the monitored surfaces. MicMac also offers the possibility to integrate 3-D models of excavated structures with the corresponding surface deformation data. The high resolution and high precision of MicMac results and the ability to generate virtual 3-D models of complex structures make it a very promising tool for quantitative monitoring in laboratory models of geological systems.

  13. Characterization and Monitoring of Natural Attenuation of Chlorinated Solvents in Ground Water: A Systems Approach

    Science.gov (United States)

    Cutshall, N. H.; Gilmore, T.; Looney, B. B.; Vangelas, K. M.; Adams, K. M.; Sink, C. H.

    2006-05-01

    Like many US industries and businesses, the Department of Energy (DOE) is responsible for remediation and restoration of soils and ground water contaminated with chlorinated ethenes. Monitored Natural Attenuation (MNA) is an attractive remediation approach and is probably the universal end-stage technology for removing such contamination. Since 2003 we have carried out a multifaceted program at the Savannah River Site designed to advance the state of the art for MNA of chlorinated ethenes in soils and groundwater. Three lines of effort were originally planned: 1) Improving the fundamental science for MNA, 2) Promoting better characterization and monitoring (CM) techniques, and 3) Advancing the regulatory aspects of MNA management. A fourth line, developing enhanced attenuation methods based on sustainable natural processes, was added in order to deal with sites where the initial natural attenuation capacity cannot offset contaminant loading rates. These four lines have been pursued in an integrated and mutually supportive fashion. Many DOE site-cleanup program managers view CM as major expenses, especially for natural attenuation where measuring attenuation is complex and the most critical attenuation mechanisms cannot be determined directly. We have reviewed new and developing approaches to CM for potential application in support of natural attenuation of chlorinated hydrocarbons in ground water at DOE sites (Gilmore, Tyler, et al., 2006 WSRC-TR- 2005-00199). Although our project is focused on chlorinated ethenes, many of the concepts and strategies are also applicable to a wider range of contaminants including radionuclides and metals. The greatest savings in CM are likely to come from new management approaches. New approaches can be based, for example, on conceptual models of attenuation capacity, the ability of a formation to reduce risks caused by contaminants. Using the mass balance concept as a guide, the integrated mass flux of contaminant is compared to

  14. Monitoring of Sea Floor Dynamics by the Application of Geodetic Deformation Analysis

    Science.gov (United States)

    Dorst, L.

    2003-04-01

    detection capability of smaller scale dynamics can be applied by scientists that wish to investigate the sea floor on a more detailed level than sand waves. The analysis possibilities can be illustrated by several examples, using data collected on the Netherlands continental shelf, in areas with and without a sand wave pattern. E.g., an example containing deliberately wrongly chosen critical values gives insight in the advantages and dangers of this method for sea floor dynamics monitoring. References: Caspary, W.F., 'Concepts of Network and Deformation Analysis'. Monograph 11, Kensington, Australia: University of New South Wales, School of Surveying, 1987. Chilès, Jean-Paul, and Pierre Delfiner, 'Geostatistics, modelling spatial uncertainty'. New York: John Wiley &Sons, 1999. Hulscher, Suzanne J. M. H., and G. Matthijs van den Brink, 'Comparison between predicted and observed sand waves and sand banks in the North Sea'. In: Journal of Geophysical Research, vol. 106, no. C5, pp.9327-9338, May 2001. International Hydrographic Organization, 'IHO Standards for Hydrographic Surveys, Special Publication no.44, 4th Edition'. Monaco: International Hydrographic Bureau, April 1998.

  15. Efficacy of StaMPS technique for monitoring surface deformation in L'Aquila, Italy

    Science.gov (United States)

    Tiwari, A.; Dwivedi, R.; Narayan, A. B.; Dikshit, O.; Singh, A. K.

    2014-11-01

    This research work investigates the efficacy of the Stanford Method for Persistent Scatterer Interferometry (StaMPS) in measuring the surface deformation over the L'Aquila region, Italy just before an event of earthquake of magnitude Mw 6.3 by using seven descending Envisat C-Band ASAR images. The results show that the StaMPS technique successfully extracted sufficient number of Persistent Scatterers (PS) to derive a one dimensional (1D) time series displacement map which shows the deformation rates up to 59 mm/year in the satellite Line of Sight (LOS) direction and 50.8 mm/year in the direction opposite to the satellite LOS. Further, several deformation gradients are also observed from this map which indicate the occurrence of multiple crustal movement mechanism. Another dataset of 14 ASAR images is processed covering a time period before and after the earthquake in the study area to validate the results obtained by the previous dataset. We observed that the generated displacement map follows the deformation characteristics of the earlier displacement map in terms of magnitude and surface movement. We conclude that the generated displacement maps validate the presence of a normal fault mechanism with a tectonic process stretching in a NW-SE direction as predicted by earlier research studies.

  16. Deformation monitoring on ancient terracotta warriors by microscopic TV-holography

    Science.gov (United States)

    Gülker, Gerd; Hinsch, Klaus D.; Kraft, Arne

    2001-11-01

    In order to investigate deterioration processes on the famous 2000-yr-old Chinese Terracotta warriors, deformation measurements were performed with TV-holography. The aim of the investigations is to estimate the suitability of several conservation agents and procedures, which are developed to preserve the extremely endangered paint layers of the figures. Due to the occurrence of small-scale deformation areas the field of view had to be reduced. A microscopic system was constructed and typical object deformations due to shrinkage and swelling are presented. To investigate the individual layers of the multilayered objects a short-coherent superluminescence diode instead of a laser diode is used in a further modification. By changing the path length of one of the interfering beams it is possible to select a region limited in depth where deformations are measured even if it is located below the surface. Results on an artificial test object and on original terracotta fragments demonstrate the capabilities of this new short-coherence TV-holography system.

  17. Optical Communication System for Remote Monitoring and Adaptive Control of Distributed Ground Sensors Exhibiting Collective Intelligence

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, S.M.; Stantz, K.M.; Trahan, M.W.; Wagner, J.S.

    1998-11-01

    Comprehensive management of the battle-space has created new requirements in information management, communication, and interoperability as they effect surveillance and situational awareness. The objective of this proposal is to expand intelligent controls theory to produce a uniquely powerful implementation of distributed ground-based measurement incorporating both local collective behavior, and interoperative global optimization for sensor fusion and mission oversight. By using a layered hierarchal control architecture to orchestrate adaptive reconfiguration of autonomous robotic agents, we can improve overall robustness and functionality in dynamic tactical environments without information bottlenecks. In this concept, each sensor is equipped with a miniaturized optical reflectance modulator which is interactively monitored as a remote transponder using a covert laser communication protocol from a remote mothership or operative. Robot data-sharing at the ground level can be leveraged with global evaluation criteria, including terrain overlays and remote imaging data. Information sharing and distributed intelli- gence opens up a new class of remote-sensing applications in which small single-function autono- mous observers at the local level can collectively optimize and measure large scale ground-level signals. AS the need for coverage and the number of agents grows to improve spatial resolution, cooperative behavior orchestrated by a global situational awareness umbrella will be an essential ingredient to offset increasing bandwidth requirements within the net. A system of the type described in this proposal will be capable of sensitively detecting, tracking, and mapping spatial distributions of measurement signatures which are non-stationary or obscured by clutter and inter- fering obstacles by virtue of adaptive reconfiguration. This methodology could be used, for example, to field an adaptive ground-penetrating radar for detection of underground structures in

  18. Monitoring of Conservation Tillage and Tillage Intensity by Ground and Satellite Imagery

    Directory of Open Access Journals (Sweden)

    M.A Rostami

    2014-09-01

    Full Text Available Local information about tillage intensity and ground residue coverage is useful for policies in agricultural extension, tillage implement design and upgrading management methods. The current methods for assessing crop residue coverage and tillage intensity such as residue weighing methods, line-transect and photo comparison methods are tedious and time-consuming. The present study was devoted to investigate accurate methods for monitoring residue management and tillage practices. The satellite imagery technique was used as a rapid and spatially explicit method for delineating crop residue coverage and as an estimator of conservation tillage adoption and intensity. The potential of multispectral high-spatial resolution WorldView-2 local data was evaluated using the total of eleven satellite spectral indices and Linear Spectral Unmixing Analysis (LSUA. The total of ninety locations was selected for this study and for each location the residue coverage was measured by the image processing method and recorded as ground control. The output of indices and LSUA method were individually correlated to the control and the relevant R2 was calculated. Results indicated that crop residue cover was related to IPVI, RVI1, RVI2 and GNDVI spectral indices and satisfactory correlations were established (0.74 - 0.81. The crop residue coverage estimated from the LSUA approach was found to be correlated with the ground residue data (0.75. Two effective indices named as Infrared Percentage Vegetation Index (IPVI and Ratio Vegetation Index (RVI with maximum R2 were considered for classification of tillage intensity. Results indicated that the classification accuracy with IPVI and RVI indices in different conditions varied from 78-100 percent and therefore in good agreement with ground measurement, observations and field records.

  19. Land subsidence, Ground Fissures and Buried Faults: InSAR Monitoring of Ciudad Guzmán (Jalisco, Mexico

    Directory of Open Access Journals (Sweden)

    Carlo Alberto Brunori

    2015-07-01

    Full Text Available We study land subsidence processes and the associated ground fissuring, affecting an active graben filled by thick unconsolidated deposits by means of InSAR techniques and fieldwork. On 21 September 2012, Ciudad Guzmán (Jalisco, Mexico was struck by ground fissures of about 1.5 km of length, causing the deformation of the roads and the propagation of fissures in adjacent buildings. The field survey showed that fissures alignment is coincident with the escarpments produced on 19 September 1985, when a strong earthquake with magnitude 8.1 struck central Mexico. In order to detect and map the spatio-temporal features of the processes that led to the 2012 ground fissures, we applied InSAR multi-temporal techniques to process ENVISAT-ASAR and RADARSAT-2 satellite SAR images acquired between 2003 and 2012. We detect up to 20 mm/year of subsidence of the northwestern part of Ciudad Guzmán. These incremental movements are consistent with the ground fissures observed in 2012. Based on interferometric results, field data and 2D numerical model, we suggest that ground deformations and fissuring are due to the presence of areal subsidence correlated with variable sediment thickness and differential compaction, partly driven by the exploitation of the aquifers and controlled by the distribution and position of buried faults.

  20. Assessment of ground-based monitoring techniques applied to landslide investigations

    Science.gov (United States)

    Uhlemann, S.; Smith, A.; Chambers, J.; Dixon, N.; Dijkstra, T.; Haslam, E.; Meldrum, P.; Merritt, A.; Gunn, D.; Mackay, J.

    2016-01-01

    A landslide complex in the Whitby Mudstone Formation at Hollin Hill, North Yorkshire, UK is periodically re-activated in response to rainfall-induced pore-water pressure fluctuations. This paper compares long-term measurements (i.e., 2009-2014) obtained from a combination of monitoring techniques that have been employed together for the first time on an active landslide. The results highlight the relative performance of the different techniques, and can provide guidance for researchers and practitioners for selecting and installing appropriate monitoring techniques to assess unstable slopes. Particular attention is given to the spatial and temporal resolutions offered by the different approaches that include: Real Time Kinematic-GPS (RTK-GPS) monitoring of a ground surface marker array, conventional inclinometers, Shape Acceleration Arrays (SAA), tilt meters, active waveguides with Acoustic Emission (AE) monitoring, and piezometers. High spatial resolution information has allowed locating areas of stability and instability across a large slope. This has enabled identification of areas where further monitoring efforts should be focused. High temporal resolution information allowed the capture of 'S'-shaped slope displacement-time behaviour (i.e. phases of slope acceleration, deceleration and stability) in response to elevations in pore-water pressures. This study shows that a well-balanced suite of monitoring techniques that provides high temporal and spatial resolutions on both measurement and slope scale is necessary to fully understand failure and movement mechanisms of slopes. In the case of the Hollin Hill landslide it enabled detailed interpretation of the geomorphological processes governing landslide activity. It highlights the benefit of regularly surveying a network of GPS markers to determine areas for installation of movement monitoring techniques that offer higher resolution both temporally and spatially. The small sensitivity of tilt meter measurements

  1. Estimation of Phase Delay due to Precipitable Water for Dinsarbased Land Deformation Monitoring

    Science.gov (United States)

    Susaki, J.; Maeda, N.; Akatsuka, S.

    2017-09-01

    In this paper, we present a method for using the estimated precipitable water (PW) to mitigate atmospheric phase delay in order to improve the accuracy of land-deformation assessment with differential interferometric synthetic aperture radar (DInSAR). The phase difference obtained from multi-temporal synthetic aperture radar images contains errors of several types, and the atmospheric phase delay can be an obstacle to estimating surface subsidence. In this study, we calculate PW from external meteorological data. Firstly, we interpolate the data with regard to their spatial and temporal resolutions. Then, assuming a range direction between a target pixel and the sensor, we derive the cumulative amount of differential PW at the height of the slant range vector at pixels along that direction. The atmospheric phase delay of each interferogram is acquired by taking a residual after a preliminary determination of the linear deformation velocity and digital elevation model (DEM) error, and by applying high-pass temporal and low-pass spatial filters. Next, we estimate a regression model that connects the cumulative amount of PW and the atmospheric phase delay. Finally, we subtract the contribution of the atmospheric phase delay from the phase difference of the interferogram, and determine the linear deformation velocity and DEM error. The experimental results show a consistent relationship between the cumulative amount of differential PW and the atmospheric phase delay. An improvement in land-deformation accuracy is observed at a point at which the deformation is relatively large. Although further investigation is necessary, we conclude at this stage that the proposed approach has the potential to improve the accuracy of the DInSAR technique.

  2. ESTIMATION OF PHASE DELAY DUE TO PRECIPITABLE WATER FOR DINSARBASED LAND DEFORMATION MONITORING

    Directory of Open Access Journals (Sweden)

    J. Susaki

    2017-09-01

    Full Text Available In this paper, we present a method for using the estimated precipitable water (PW to mitigate atmospheric phase delay in order to improve the accuracy of land-deformation assessment with differential interferometric synthetic aperture radar (DInSAR. The phase difference obtained from multi-temporal synthetic aperture radar images contains errors of several types, and the atmospheric phase delay can be an obstacle to estimating surface subsidence. In this study, we calculate PW from external meteorological data. Firstly, we interpolate the data with regard to their spatial and temporal resolutions. Then, assuming a range direction between a target pixel and the sensor, we derive the cumulative amount of differential PW at the height of the slant range vector at pixels along that direction. The atmospheric phase delay of each interferogram is acquired by taking a residual after a preliminary determination of the linear deformation velocity and digital elevation model (DEM error, and by applying high-pass temporal and low-pass spatial filters. Next, we estimate a regression model that connects the cumulative amount of PW and the atmospheric phase delay. Finally, we subtract the contribution of the atmospheric phase delay from the phase difference of the interferogram, and determine the linear deformation velocity and DEM error. The experimental results show a consistent relationship between the cumulative amount of differential PW and the atmospheric phase delay. An improvement in land-deformation accuracy is observed at a point at which the deformation is relatively large. Although further investigation is necessary, we conclude at this stage that the proposed approach has the potential to improve the accuracy of the DInSAR technique.

  3. Method of Monitoring Urban Area Deformation Based on Differential TomoSAR

    Directory of Open Access Journals (Sweden)

    WANG Aichun

    2016-12-01

    Full Text Available While the use of differential TomoSAR based on compressive sensing (CS makes it possible to solve the layover problem and reconstruct the deformation information of an observed urban area scene acquired by moderate-high resolution SAR satellite, the performance of the reconstruction decreases for a sparse and structural observed scene due to ignoring the structural characteristics of the observed scene. To deal with this issue, the method for differential SAR tomography based on Khatri-Rao subspace and block compressive sensing (KRS-BCS is proposed. The proposed method changes the reconstruction of the sparse and structural observed scene into a BCS problem under Khatri-Rao subspace, using the structure information of the observed scene and Khatri-Rao product property of the reconstructed observation matrix for differential TomoSAR, such that the KRS-BCS problem is efficiently solved with a block sparse l1/l2 norm optimization signal model, and the performance of resolution capability and reconstruction estimation is compared and analyzed qualitatively and quantitatively by the theoretical analysis and the simulation experiments, all of the results show the propose KRS-BCS method practicably overcomes the problems of CS method, as well as, quite maintains the high resolution characteristics, effectively reduces the probability of false scattering target and greatly improves the reconstruction accurate of scattering point. Finally, the application is taking the urban area of the Mobara(in Chiba, Japan as the test area and using 34 ENVISAT-ASAR images, the accuracy is verifying with the reference deformations derived from first level point data and GPS tracking data, the results show the trend is consistent and the overall deviation is small between reconstruction deformations of the propose KRS-BCS method and the reference deformations, and the accuracy is high in the estimation of the urban area deformation.

  4. Monitoring of surface deformation in open pit mine using DInSAR time-series: a case study in the N5W iron mine (Carajás, Brazil) using TerraSAR-X data

    Science.gov (United States)

    Mura, José C.; Paradella, Waldir R.; Gama, Fabio F.; Santos, Athos R.; Galo, Mauricio; Camargo, Paulo O.; Silva, Arnaldo Q.; Silva, Guilherme G.

    2014-10-01

    We present an investigation of surface deformation using Differential SAR Interferometry (DInSAR) time-series carried out in an active open pit iron mine, the N5W, located in the Carajás Mineral Province (Brazilian Amazon region), using 33 TerraSAR-X (TSX-1) scenes. This mine has presented a historical of instability and surface monitoring measurements over sectors of the mine (pit walls) have been done based on ground based radar. Two complementary approaches were used: the standard DInSAR configuration, as an early warning of the slope instability conditions, and the DInSAR timeseries analysis. In order to decrease the topographic phase error a high resolution DEM was generated based on a stereo GeoEye-1 pair. Despite the fact that a DinSAR contains atmospheric and topographic phase artifacts and noise, it was possible to detect deformation in some interferometric pairs, covering pit benches, road ramps and waste piles. The timeseries analysis was performed using the 31 interferometric pairs, which were selected based on the highest mean coherence of a stack of 107 interferograms, presenting less phase unwrapping errors. The time-series deformation was retrieved by the Least-Squares (LS) solution using an extension of the Singular Value Decomposition (SVD), with a set of additional weighted constrain on the acceleration deformation. The atmospheric phase artifacts were filtered in the space-time domain and the DEM height errors were estimated based on the normal baseline diversity. The DInSAR time-series investigation showed good results for monitoring surface displacement in the N5W mine located in a tropical rainforest environment, providing very useful information about the ground movement for alarm, planning and risk assessment.

  5. Development of a Ground Water Data Portal for Interoperable Data Exchange within the U.S. National Ground Water Monitoring Network and Beyond

    Science.gov (United States)

    Booth, N. L.; Brodaric, B.; Lucido, J. M.; Kuo, I.; Boisvert, E.; Cunningham, W. L.

    2011-12-01

    The need for a national groundwater monitoring network within the United States is profound and has been recognized by organizations outside government as a major data gap for managing ground-water resources. Our country's communities, industries, agriculture, energy production and critical ecosystems rely on water being available in adequate quantity and suitable quality. To meet this need the Subcommittee on Ground Water, established by the Federal Advisory Committee on Water Information, created a National Ground Water Monitoring Network (NGWMN) envisioned as a voluntary, integrated system of data collection, management and reporting that will provide the data needed to address present and future ground-water management questions raised by Congress, Federal, State and Tribal agencies and the public. The NGWMN Data Portal is the means by which policy makers, academics and the public will be able to access ground water data through one seamless web-based application from disparate data sources. Data systems in the United States exist at many organizational and geographic levels and differing vocabulary and data structures have prevented data sharing and reuse. The data portal will facilitate the retrieval of and access to groundwater data on an as-needed basis from multiple, dispersed data repositories allowing the data to continue to be housed and managed by the data provider while being accessible for the purposes of the national monitoring network. This work leverages Open Geospatial Consortium (OGC) data exchange standards and information models. To advance these standards for supporting the exchange of ground water information, an OGC Interoperability Experiment was organized among international participants from government, academia and the private sector. The experiment focused on ground water data exchange across the U.S. / Canadian border. WaterML2.0, an evolving international standard for water observations, encodes ground water levels and is exchanged

  6. Joint measurement of height and deformation by radar Interferometry: the example of the Eiffel Tower

    OpenAIRE

    Weissgerber, Flora; Nicolas, Jean-Marie

    2016-01-01

    International audience; The measurement of altitude and ground movements are well-known problems in InSAR. With the refinement of the resolution, the same techniques can be considered for monitoring individual buildings. Since the measure of the height and the deformations are interlinked in the interferometric phase, a measure of the height is necessary to obtain the deformations. In this article, we monitor the deformations of the Eiffel Tower using 50 images acquired by TerraSAR-X, with a ...

  7. Arctic ecosystem functional zones: identification and quantification using an above and below ground monitoring strategy

    Science.gov (United States)

    Hubbard, Susan S.; Ajo-Franklin, Jonathan B.; Dafflon, Baptiste; Dou, Shan; Kneafsey, Tim J.; Peterson, John E.; Tas, Neslihan; Torn, Margaret S.; Phuong Tran, Anh; Ulrich, Craig; Wainwright, Haruko; Wu, Yuxin; Wullschleger, Stan

    2015-04-01

    Although accurate prediction of ecosystem feedbacks to climate requires characterization of the properties that influence terrestrial carbon cycling, performing such characterization is challenging due to the disparity of scales involved. This is particularly true in vulnerable Arctic ecosystems, where microbial activities leading to the production of greenhouse gasses are a function of small-scale hydrological, geochemical, and thermal conditions influenced by geomorphology and seasonal dynamics. As part of the DOE Next-Generation Ecosystem Experiment (NGEE-Arctic), we are advancing two approaches to improve the characterization of complex Arctic ecosystems, with an initial application to an ice-wedge polygon dominated tundra site near Barrow, AK, USA. The first advance focuses on developing a new strategy to jointly monitor above- and below- ground properties critical for carbon cycling in the tundra. The strategy includes co-characterization of properties within the three critical ecosystem compartments: land surface (vegetation, water inundation, snow thickness, and geomorphology); active layer (peat thickness, soil moisture, soil texture, hydraulic conductivity, soil temperature, and geochemistry); and permafrost (mineral soil and ice content, nature, and distribution). Using a nested sampling strategy, a wide range of measurements have been collected at the study site over the past three years, including: above-ground imagery (LiDAR, visible, near infrared, NDVI) from various platforms, surface geophysical datasets (electrical, electromagnetic, ground penetrating radar, seismic), and point measurements (such as CO2 and methane fluxes, soil properties, microbial community composition). A subset of the coincident datasets is autonomously collected daily. Laboratory experiments and new inversion approaches are used to improve interpretation of the field geophysical datasets in terms of ecosystem properties. The new strategy has significantly advanced our ability

  8. Performance Assessment Monitoring Plan for the Hanford Site Low Level Waste Burial Grounds

    Energy Technology Data Exchange (ETDEWEB)

    SONNICHSEN, J.C.

    2000-11-15

    As directed by the U.S. Department of Energy (DOE), Richland Operations Office (DOE-RL), Fluor Hanford, Inc. will implement the requirements of DOE Order 435.1, Radioactive Waste Management, as the requirements relate to the continued operation of the low-level waste disposal facilities on the Hanford Site. DOE Order 435.1 requires a disposal authorization statement authorizing operation (or continued operation) of a low-level waste disposal facility. The objective of this Order is to ensure that all DOE radioactive waste is managed in a manner that protects the environment and personnel and public health and safety. The manual (DOE Order 435.1 Manual) implementing the Order states that a disposal authorization statement shall be issued based on a review of the facility's performance assessment and composite analysis or appropriate Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) of 1980 documentation. The disposal authorization shall specify the limits and conditions on construction, design, operations, and closure of the low-level waste facility. Failure to obtain a disposal authorization statement shall result in shutdown of an operational disposal facility. In fulfillment of the requirements of DOE Order 435.1, a disposal authorization statement was issued on October 25, 1999, authorizing the Hanford Site to transfer, receive, possess, and dispose of low-level radioactive waste at the 200 East Area and the 200 West Area Low-Level Burial Grounds. The disposal authorization statement constitutes approval of the performance assessment and composite analysis, authorizes operation of the facility, and includes conditions that the disposal facility must meet. One of the conditions is that monitoring plans for the 200 East Area and 200 West Area Low-Level Burial Grounds be written and approved by the DOE-RL. The monitoring plan is to be updated and implemented within 1 year following issuance of the disposal authorization statement to

  9. Modeling of Morelia Fault Earthquake (Mw=5.4) source fault parameters using the coseismic ground deformation and groundwater level changes data

    Science.gov (United States)

    Sarychikhina, O.; Glowacka, E.; Mellors, R. J.; Vázquez, R.

    2009-12-01

    On 24 May 2006 at 04:20 (UTC) a moderate-size (Mw=5.4) earthquake struck the Mexicali Valley, Baja California, México, roughly 30 km to the southeast of the city of Mexicali, in the vicinity of the Cerro Prieto Geothermal Field (CPGF). The earthquake occurred on the Morelia fault, one of the east-dipping normal faults in the Mexicali Valley. Locally, this earthquake was strongly felt and caused minor damage. The event created 5 km of surface rupture and down-dip displacements of up to 25-30 cm were measured at some places along this surface rupture. Associated deformation was measured by vertical crackmeter, leveling profile, and Differential Synthetic Aperture Radar Interferometry (D-InSAR). A coseismic step-like groundwater level change was detected at 7 wells. The Mw=5.4 Morelia Fault earthquake had significant scientific interest, first, because of surprisingly strong effects for an earthquake of such size; second, the variability of coseismic effects data from different ground-based and space-based techniques which allows to the better constrain of the source fault parameters. Source parameters for the earthquake were estimated using forward modeling of both surface deformation data and static volume strain change (inferred from coseismic changes in groundwater level). All ground deformation data was corrected by anthropogenic component caused by the geothermal fluid exploitation in the CPGF. Modeling was based on finite rectangular fault embedded in an elastic media. The preferred fault model has a strike, rake, and dip of (48°, -89°, 45°) and has a length of 5.2 km, width of 6.7 km, and 34 cm of uniform slip. The geodetic moment, based on the modeled fault parameters, is 1.18E+17 Nm. The model matches the observed surface deformation, expected groundwater level changes, and teleseismic moment reasonably well and explains in part why the earthquake was so strongly felt in the area.

  10. Ground deformation cycles participating with sub-Plinian, Vulcanian eruptions, and a magma effusive stage at Kirishima volcanoes

    Science.gov (United States)

    Takeo, M.; Maehara, Y.; Ohminato, T.; Ichihara, M.; Oikawa, J.

    2012-12-01

    Volcanoes display several kinds of explosive eruptions, such as Plinian, sub-Plinian, Vulcanian, and Strombolian eruptions. The ground deformation data participating in explosive eruptions yield a fruitful knowledge about the dynamics of explosive eruptions. In this paper, we present tilt motions, near a summit crater during the 2011 eruption of Shinmoe-dake, Kirishima volcanoes, participated with the different kinds of volcanic activities, and make clear the characteristics of tilt motions and time sequences. The beginning period of volcanic activity at Shimoe-dake volcano in 2001 is divided into three different stages: the sub-Plinian stage (26-27 January 2011), the magma effusive stage (28-31 January 2011), and the Vulcanian stage (1-7 February 2011). During these three distinct stages, different kinds of tilt motions were observed participating with these activities. The sub-Plinian and the Vulcanian eruptions were preceded by inflations directed to the summit. A time sequence of the tilt ratio between NS component at KISH and that at SMN represents a gradual increment approaching the first sub-Plinian eruption on 26 January 2011: from 0.3 at 14:30 to 0.4 at 14:40. Employing a cylindrical pressure source in a conduit and taking into account the topography of Shinmoe-dake volcano in a calculation of tilts [Maeda et al., 2011], it became clear that the gradual increment of tilt ratio from 0.3 to 0.4 corresponds to the deepening of the source depth from 810 m to 710 m above sea level. The inflation-deflation cycles with the typical period of one hour were also recorded during the magma effusive stage; these cycles synchronized with volcanic tremors or long-period events in the last term of this stage. Almost all Vulcanian eruptions are preceded by step-like inflations. The tilt motions represented various time sequences after the inflations halted: no distinct tilt change until the Vulcanian eruption, gradual deflation preceding the Vulcanian eruption, and

  11. Continuous monitoring of a mountain snowpack in the Austrian Alps by above-ground neutron sensing

    Science.gov (United States)

    Schattan, Paul; Baroni, Gabriele; Oswald, Sascha E.; Schöber, Johannes; Fey, Christine; Francke, Till; Huttenlau, Matthias; Achleitner, Stefan

    2017-04-01

    In alpine catchments the knowledge of the spatially and temporally heterogeneous dynamics of snow accumulation and depletion is crucial for modelling and managing water resources. While snow covered area can be retrieved operationally from remote sensing data, continuous measurements of other snow state variables like snow depth (SD) or snow water equivalent (SWE) remain challenging. Existing methods of retrieving both variables in alpine terrain face severe issues like a lack of spatial representativeness, labour-intensity or discontinuity in time. Recently, promising new measurement techniques combining a larger support with low maintenance cost like above-ground gamma-ray scintillators, GPS interferometric reflectometry or above-ground cosmic-ray neutron sensors (CRNS) have been suggested. While CRNS has proven its potential for monitoring soil moisture in a wide range of environments and applications, the empirical knowledge of using CRNS for snowpack monitoring is still very limited and restricted to shallow snowpacks with rather uniform evolution. The characteristics of an above-ground cosmic-ray neutron sensor (CRNS) were therefore evaluated for monitoring a mountain snowpack in the Austrian Alps (Kaunertal, Tyrol) during three winter seasons. The measurement campaign included a number of measurements during the period from 03/2014 to 06/2016: (i) neutron count measurements by CRNS, (ii) continuous point-scale SD and SWE measurements from an automatic weather station and (iii) 17 Terrestrial Laser Scanning (TLS) with simultaneous SD and SWE surveys. The highest accumulation in terms of SWE was found in 04/2014 with 600 mm. Neutron counts were compared to all available snow data. While previous studies suggested a signal saturation at around 100 mm of SWE, no complete signal saturation was found. A strong non-linear relation was found for both SD and SWE with best fits for spatially distributed TLS based snow data. Initially slightly different shapes were

  12. 40 CFR 265 interim status indicator-evaluation ground-water monitoring plan for the 216-B-63 trench

    Energy Technology Data Exchange (ETDEWEB)

    Bjornstad, B.N.; Dudziak, S.

    1989-03-01

    This document outlines a ground-water monitoring plan for the 216-B-63 trench located in the northeast corner of the 200-East Area on the Hanford Site in southeastern Washington State. It has been determined that hazardous materials (corrosives) were disposed of to the trench during past operations. Installation of an interim-status ground-water monitoring system is required to determine whether hazardous chemicals are leaching to the ground water from beneath the trench. This document summarizes the existing data that are available from near the 216-B-63 trench and presents a plan to determine the extent of ground-water contamination, if any, derived from the trench. The plan calls for the installation of four new monitoring wells located near the west end of the trench. These wells will be used to monitor ground-water levels and water quality immediately adjacent to the trench. Two existing RCRA monitoring wells, which are located near the trench and hydraulically upgradient of it, will be used as background wells. 46 refs., 15 figs., 12 tabs.

  13. An application of Global Positioning System data from the Plate Boundary Observatory for deformation monitoring purposes (Invited)

    Science.gov (United States)

    Murray-Moraleda, J. R.; Liu, Z.; Segall, P.

    2009-12-01

    The Plate Boundary Observatory (PBO) represents a major step forward in Global Positioning System (GPS) coverage for the western United States by increasing the spatial density of stations, generating daily position estimates, and providing the infrastructure for high-rate and real-time positioning. In addition to producing vital input for a wide range of crustal deformation studies, PBO significantly expands opportunities for monitoring and event response. This presentation will focus on one such effort. Data from large continuous GPS networks like PBO should be monitored for temporal changes, be they tectonic, volcanic, hydrologic, anthropogenic, or instrumental in origin. Since it is not feasible to review time series by eye on a daily basis, automated approaches are required. Here we apply a Kalman filtering based method, termed the Network Inversion Filter (Segall and Matthews, 1997; McGuire and Segall, 2003), to monitor daily GPS data for deformation-related transient signals. This approach relies on the spatial coherence of signals due to transient sources such as fault slip in order to separate them from spatially-localized time-dependent noise. The dense GPS coverage provided by PBO has augmented pre-existing continuous GPS networks making it now feasible to test this method in California. Results from synthetic tests using the >400 station southern California continuous GPS network configuration demonstrate this approach can extract fault slip signals from data contaminated by plausible noise processes. We will present results using real data from the San Francisco Bay Area and discuss the role and limitations of this methodology in hazard monitoring.

  14. Terrestrial Laser Scanner for Monitoring the Deformations and the Damages of Buildings

    Science.gov (United States)

    Vacca, G.; Mistretta, F.; Stochino, F.; Dessi, A.

    2016-06-01

    scanner provides the ability to detect the geometric 3D model of a building without any physical contact with the structure. Knowledge of the 3D model will give the opportunity to study the deformation and quantify the damages. Three case studies are presented relating to damaged and/or unsafe buildings: Sivillier Castle (Villasor - Sardinia- Italy), the Bell Tower of Mores (Sardinia-Italy) and industrial building (Cagliari - Italy). The first two cases concern buildings of historical and architectural importance that present a state of compromised conservation; the last, an industrial building compromised by fire. In all cases, a laser scanner survey was carried out that not only provided valuable information but also highlighted structural metric deformation and degradation.

  15. Near real-time monitoring of volcanic surface deformation from GPS measurements at Long Valley Caldera, California

    Science.gov (United States)

    Ji, Kang Hyeun; Herring, Thomas A.; Llenos, Andrea L.

    2013-01-01

    Long Valley Caldera in eastern California is an active volcanic area and has shown continued unrest in the last three decades. We have monitored surface deformation from Global Positioning System (GPS) data by using a projection method that we call Targeted Projection Operator (TPO). TPO projects residual time series with secular rates and periodic terms removed onto a predefined spatial pattern. We used the 2009–2010 slow deflation as a target spatial pattern. The resulting TPO time series shows a detailed deformation history including the 2007–2009 inflation, the 2009–2010 deflation, and a recent inflation that started in late-2011 and is continuing at the present time (November 2012). The recent inflation event is about four times faster than the previous 2007–2009 event. A Mogi source of the recent event is located beneath the resurgent dome at about 6.6 km depth at a rate of 0.009 km3/yr volume change. TPO is simple and fast and can provide a near real-time continuous monitoring tool without directly looking at all the data from many GPS sites in this potentially eruptive volcanic system.

  16. Near real-time monitoring of volcanic surface deformation from GPS measurements at Long Valley Caldera, California

    Science.gov (United States)

    Ji, Kang Hyeun; Herring, Thomas A.; Llenos, Andrea L.

    2013-03-01

    Long Valley Caldera in eastern California is an active volcanic area and has shown continued unrest in the last three decades. We have monitored surface deformation from Global Positioning System (GPS) data by using a projection method that we call Targeted Projection Operator (TPO). TPO projects residual time series with secular rates and periodic terms removed onto a predefined spatial pattern. We used the 2009-2010 slow deflation as a target spatial pattern. The resulting TPO time series shows a detailed deformation history including the 2007-2009 inflation, the 2009-2010 deflation, and a recent inflation that started in late-2011 and is continuing at the present time (November 2012). The recent inflation event is about four times faster than the previous 2007-2009 event. A Mogi source of the recent event is located beneath the resurgent dome at about 6.6 km depth at a rate of 0.009 km3/yr volume change. TPO is simple and fast and can provide a near real-time continuous monitoring tool without directly looking at all the data from many GPS sites in this potentially eruptive volcanic system.

  17. Octupole deformation in the ground states of even-even nuclei: a global analysis within the covariant density functional theory

    CERN Document Server

    Agbemava, S E; Ring, P

    2016-01-01

    A systematic investigation of octupole deformed nuclei is presented for even-even systems with $Z\\leq 106$ located between the two-proton and two-neutron drip lines. For this study we use five most up-to-date covariant energy density functionals of different types, with a non-linear meson coupling, with density dependent meson couplings, and with density-dependent zero-range interactions. Pairing correlations are treated within relativistic Hartree-Bogoliubov (RHB) theory based on an effective separable particle-particle interaction of finite range. This allows us to assess theoretical uncertainties within the present covariant models for the prediction of physical observables relevant for octupole deformed nuclei. In addition, a detailed comparison with the predictions of non-relativistic models is performed. A new region of octupole deformation, centered around $Z\\sim 98, N\\sim 196$ is predicted for the first time. In terms of its size in the $(Z,N)$ plane and the impact of octupole deformation on binding e...

  18. A simple, low-cost method to monitor duration of ground water pumping.

    Science.gov (United States)

    Massuel, S; Perrin, J; Wajid, M; Mascre, C; Dewandel, B

    2009-01-01

    Monitoring ground water withdrawals for agriculture is a difficult task, while agricultural development leads frequently to overexploitation of the aquifers. To fix the problem, sustainable management is required based on the knowledge of water uses. This paper introduces a simple and inexpensive direct method to determine the duration of pumping of a well by measuring the temperature of its water outlet pipe. A pumping phase is characterized by a steady temperature value close to ground water temperature. The method involves recording the temperature of the outlet pipe and identifying the different stages of pumping. It is based on the use of the low-cost and small-size Thermochron iButton temperature logger and can be applied to any well, provided that a water outlet pipe is accessible. The temperature time series are analyzed to determine the duration of pumping through manual and automatic posttreatments. The method was tested and applied in South India for irrigation wells using electricity-powered pumps. The duration of pumping obtained by the iButton method is fully consistent with the duration of power supply (1.5% difference).

  19. Ground and river water quality monitoring using a smartphone-based pH sensor

    Directory of Open Access Journals (Sweden)

    Sibasish Dutta

    2015-05-01

    Full Text Available We report here the working of a compact and handheld smartphone-based pH sensor for monitoring of ground and river water quality. Using simple laboratory optical components and the camera of the smartphone, we develop a compact spectrophotometer which is operational in the wavelength range of 400-700 nm and having spectral resolution of 0.305 nm/pixel for our equipment. The sensor measures variations in optical absorption band of pH sensitive dye sample in different pH solutions. The transmission image spectra through a transmission grating gets captured by the smartphone, and subsequently converted into intensity vs. wavelengths. Using the designed sensor, we measure water quality of ground water and river water from different locations in Assam and the results are found to be reliable when compared with the standard spectrophotometer tool. The overall cost involved for development of the sensor is relatively low. We envision that the designed sensing technique could emerge as an inexpensive, compact and portable pH sensor that would be useful for in-field applications.

  20. Ground and river water quality monitoring using a smartphone-based pH sensor

    Science.gov (United States)

    Dutta, Sibasish; Sarma, Dhrubajyoti; Nath, Pabitra

    2015-05-01

    We report here the working of a compact and handheld smartphone-based pH sensor for monitoring of ground and river water quality. Using simple laboratory optical components and the camera of the smartphone, we develop a compact spectrophotometer which is operational in the wavelength range of 400-700 nm and having spectral resolution of 0.305 nm/pixel for our equipment. The sensor measures variations in optical absorption band of pH sensitive dye sample in different pH solutions. The transmission image spectra through a transmission grating gets captured by the smartphone, and subsequently converted into intensity vs. wavelengths. Using the designed sensor, we measure water quality of ground water and river water from different locations in Assam and the results are found to be reliable when compared with the standard spectrophotometer tool. The overall cost involved for development of the sensor is relatively low. We envision that the designed sensing technique could emerge as an inexpensive, compact and portable pH sensor that would be useful for in-field applications.

  1. Real time monitoring for nowcasting and forecasting ionospheric space weatherin Europe with ground digisondes

    Directory of Open Access Journals (Sweden)

    A. Belehaki

    2005-06-01

    Full Text Available The Earth's ionosphere largely determines space weather effects on radio wave communications, navigation and surveillance systems. Lately there has been an increasing demand for ionospheric nowcast and accurate forecast services by various groups of users, including European industry. The paper reviews research activities in Europe based on the exploitation of real-time ground digisondes for the provision of nowcasting and forecasting ionospheric space weather information and useful products and services to support operational applications. During the last few years, important progress in databasing, modelling and forecasting ionospheric disturbances based on real-time data from ground digisondes was achieved in the frames of COST Action 271 «Effects of the Upper Atmosphere on Terrestrial and Earth-Space Communications». Further developments are expected to be deployed with the new COST Action 724 on «Developing the basis for monitoring, modelling and predicting space weather», as well as through the Space Weather Pilot Project of the European Space Agency and through projects funded by the European Commission programmes.

  2. Coupling of ground biosensor networks for water monitoring with satellite observations in assessing Leptospirosis

    Science.gov (United States)

    Skouloudis, A. N.; Rickerby, D. G.

    2012-12-01

    mapping is reliant on the identification of location where such networks could be of use. Systematic monitoring from satellite images are utilized for increasing the potential areas of application, for assessing the geographical representativeness on the measurements of the sensors and proposing the methodology on assessing the environmental conditions that are associated with outbreaks of leptospirosis. Unfortunately, several combined deployments of earth observations with ground sensors are required before for the understanding of the connections between hydrology and the human health. Ultimately this will lead to the establishment of early warning system that might investigate the effectiveness of key control measures, including vaccine (when they will become available) and affront the water decontamination, and animal control issues.

  3. Using TerraSAR-X and hyperspectral airborne data to monitor surface deformation and physical properties of the Barrow permafrost landscape, Alask

    Science.gov (United States)

    Haghshenas-Haghighi, M.; Motagh, M.; Heim, B.; Sachs, T.; Kohnert, K.; Streletskiy, D. A.

    2014-12-01

    In this study, we assess seasonal subsidence/heaving due to thawing/freezing of the permafrost in Barrow (71.3 N, 156.5 W) at the northernmost point of Alaska. The topographic relief in this area is low. Thick Permafrost underlies the entire area, with large ice volumes in its upper layer. With a large collection of field measurements during the past decades at the Barrow Environmental Observatory (BEO), it is an ideal site for permafrost investigation. There are long term systematic geocryological investigations within the Global Terrestrial Network (GTN-P) of the Circumpolar Active Layer Monitoring (CALM) programme. We use 28 TerraSAR-X images, acquired between December 2012 and December 2013 and analyze them using the Small BAseline Subset (SBAS) technique to extract time-series of ground surface deformation. We also analyze hyperspectral images acquired by the airborne AISA sensor over Barrow area, within the AIRMETH2013 programme, to assess physical characteristics such as vegetation biomass and density, surface moisture, and water bodies. Finally, we combine the information derived from both InSAR and hyperspectral analysis, with field measurements to investigate the link between physical characteristics of the permafrost and surface displacement.

  4. Existing Resources, Standards, and Procedures for Precise Monitoring and Analysis of Structural Deformations. Volume 1

    Science.gov (United States)

    1992-09-01

    commonplace, particularly in the monitoring of dams and hydro-electric power generating stations. Italy’s ENEL (Ente Nazionale per 1’ Energia Elettrica...State Commissions to enforce supervision and monitoring of dams by the new owners. Currently, dams owned by state organizations such as Agua y Energia ...Large Dams, Rio de Janeiro, Brazil May. Millmore, J.P. and J.A. Charles (1988). "A -survey of UK embankment dams." Proceedings of Reservoir Renovation 88

  5. Thrust faulting and 3D ground deformation of the 3 July 2015 Mw 6.4 Pishan, China earthquake from Sentinel-1A radar interferometry

    Science.gov (United States)

    Sun, Jianbao; Shen, Zheng-Kang; Li, Tao; Chen, Jie

    2016-06-01

    Boosted by the launch of Sentinel-1A radar satellite from the European Space Agency (ESA), we now have the opportunity of fast, full and multiple coverage of the land based deformation field of earthquakes. Here we use the data to investigate a strong earthquake struck Pishan, western China on July 3, 2015. The earthquake fault is blind and no ground break features are found on-site, thus Synthetic Aperture Radar (SAR) data give full play to its technical advantage for the recovery of coseismic deformation field. By using the Sentinel-1A radar data in the Interferometric Wide Swath mode, we obtain 3 tracks of InSAR data over the struck region, and resolve the 3D ground deformation generated by the earthquake. Then the Line-of-Sight (LOS) InSAR data are inverted for the slip-distribution of the seismogenic fault. The final model shows that the earthquake is completely blind with pure-thrust motion. The maximum slip is 0.48 m at a depth of 7 km, consistent with the depth estimate from seismic reflection data. In particular, the inverted model is also compatible with a south-dipping fault ramp among a group of fault interfaces detected by the seismic reflection profile over the region. The seismic moment obtained equals to a Mw 6.4 earthquake. The Pishan earthquake ruptured the frontal part of the thrust ramps under the Slik anticline, and unloaded the coulomb stress of them. However, it may have loaded stress to the back-thrust above the thrust ramps by 1-4 bar, and promoted it for future failure. Moreover, the stress loading on the west side of the earthquake fault is much larger than that on the east side, indicating a higher risk for failure to the west of the Zepu fault.

  6. Analysis of the ground level enhancements on 14 July 2000 and on 13 December 2006 using neutron monitor data

    CERN Document Server

    Mishev, Alexander

    2016-01-01

    On the basis of neutron monitor data we estimate the energy spectrum, anisotropy axis direction and pitch-angle distribution of solar energetic particles during two major ground level enhancements (GLE 59 on 14 July 2000 and GLE 70 on 13 December 2006). For the analysis we use a newly computed neutron monitor yield function. The method consists of several consecutive steps: definition of the asymptotic viewing cones of neutron monitor stations considered for the data analysis by computations of cosmic ray particles propagation in a model magnetosphere with the MAGNETOCOSMICS code; computation of the neutron monitor model responses and derivation of the solar energetic particle characteristics on the basis of inverse problem solution. The pitch-angle distribution and rigidity spectrum of high-energy protons are obtained as function of time in the course of ground level enhancements. A comparison with previously reported results is performed and reasonable agreement is achieved. A discussion of the obtained res...

  7. Monitoring of pipeline deformations using optical fiber sensors based on Bragg lattices; Monitoracao de deformacoes em dutos utilizando sensores a fibra optica com base em redes de Bragg

    Energy Technology Data Exchange (ETDEWEB)

    Moszkowica, Viktor Nigri [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil)]. E-mail: vnigri@bol.com.br

    2002-06-01

    In the petroleum sector there is a growing need for the use of pipelines as well as for their monitoring. A way to avoid leaks that can cause great damage to the environment is by the monitoring of deformations. In case failures can not be avoided through operational procedures, the monitoring of deformations can identify the initial moment and location of the leak, allowing for quick action on the part of the cleaning and depollution teams. Also important is the monitoring of slopes and soil movements. The same thing applies to production and transfer submarine pipelines subject to complex dynamic loadings that combine internal and external pressure, torsion, axial stress and, the most common of all, flexion loading. For this type of application, optical fiber sensors present a number of interesting features. Multiplexing, remote operation and long distance distribution of sensors are characteristics that attract their use in deformation monitoring systems. Presented herein are the research results of works that had the objective of developing deformation monitoring techniques in pipelines using optical fiber sensors based on Bragg grating. The technical feasibility of this technology is demonstrated through laboratorial tests. Also discussed herein are methods for field implementation of sensors, optical signal multiplexing techniques and potential advantages of applying this technology. (author)

  8. A complex geo-scientific strategy for landslide hazard mitigation ─ from airborne mapping to ground monitoring

    Directory of Open Access Journals (Sweden)

    W. Jaritz

    2008-01-01

    Full Text Available After a large landslide event in Sibratsgfäll/Austria several exploration methods were evaluated on their applicability to investigate and monitor landslide areas. The resulting optimised strategy consists of the combined application of airborne electromagnetics, ground geoelectrical measurements and geoelectrical monitoring combined with hydrological and geological mapping and geotechnical modelling. Interdisciplinary communication and discussion was the primary key to assess this complicated hazard situation.

  9. Integrating radar and laser-based remote sensing techniques for monitoring structural deformation of archaeological monuments

    OpenAIRE

    Tapete D.; Casagli N.; Luzi G.; Fanti R.; Gigli G.; Leva D.

    2013-01-01

    Ground-Based Synthetic Aperture Radar Interferometry (GBInSAR) and Terrestrial Laser Scanning (TLS) were purposely integrated to obtain 3D interferometric radar point clouds to facilitate the spatial interpretation of displacements affecting archaeological monuments. The paper describes the procedure to implement this integrated approach in the real-world situations of surveillance of archaeological and built heritage. Targeted tests were carried out on the case study of the Domus Tiberiana s...

  10. Ground Subsidence over Beijing-Tianjin-Hebei Region during Three Periods of 1992 to 2014 Monitored by Interferometric SAR

    Directory of Open Access Journals (Sweden)

    ZHANG Yonghong

    2016-09-01

    Full Text Available The Beijing-Tianjin-Hebei region suffers the most serious ground subsidence in China, which has caused huge economic losses every year. Therefore, ground subsidence was listed as an important mission in the project of geographic conditions monitoring over Beijing-Tianjin-Hebei launched by the National Administration of Surveying, Mapping and Geoinformation in 2013. In this paper, we propose a methodology of ground subsidence monitoring over wide area, which is entitled "multiple master-image coherent target small-baseline interferometric SAR (MCTSB-InSAR". MCTSB-InSAR is an improved time series InSAR technique with some unique features. SAR datasets used for ground subsidence monitoring over the Beijing-Tianjin-Hebei region include ERS-1/2 SAR images acquired between 1992 to 2000, ENVISAT ASAR images acquired between 2003 to 2010 and RADARSAT-2 images acquired between 2012 to 2014. This research represents a first ever effort on mapping ground subsidence over Beijing-Tianjin-Hebei region and over such as a long time span in China. In comparison with more than 120 leveling measurements collected in Beijing and Tianjin, the derived subsidence velocity has the accuracy of 8.7mm/year (1992—2000, 4.7mm/year (2003—2010, and 5.4mm/year (2012—2014 respectively. The spatial-temporal characteristics of the development of ground subsidence in Beijing and Tianjin are analyzed. In general, ground subsidence in Beijing kept continuously expanding in the period of 1992 to 2014. While, ground subsidence in Tianjin had already been serious in 1990s, had dramatically expanded during 2000s, and started to alleviate in recent years. The monitoring result is of high significance for prevention and mitigation of ground subsidence disaster, for making development plan, for efficient and effective utilization of water resource, and for adjustment of economic framework of this region. The result also indicates the effectiveness and reliability of the MCTSB

  11. Results from New Strainmeters and Forward and Inverse Models for Monitoring Deformation During CO2 Injection

    Science.gov (United States)

    DeWolf, S.; Murdoch, L. C.; Smith, J. E.; Germanovich, L. N.; Moysey, S. M.; Hanna, A.

    2016-12-01

    Injecting fluids into a well deforms the enveloping rocks in a complex pattern that increases in magnitude and expands outward with time. While this evolving strain field creates space needed to store these fluids, it can also signal problems. Fault slip occurs when stresses caused by injection reach a critical value, and maintaining stresses below a critical stress state is important for limiting the risk of faulting and subsequent leakage. The common approach is to measure displacement or strain to then calculate stress change. The geodetic research community has developed borehole strainmeters capable of measuring the horizontal strain tensor with high resolution (>1 nanostrain), but these require permanent installation and are too expensive to be abandoned after short term studies.Three new instruments have been deployed at our field station near Clemson University. Two of these use non-contact eddy current transducers configured to measure four components of strain and two tilts to 1 part-per-billion. While one system is designed for permanent installation, the other is removable for short term deployments. The third system is a very low cost volumetric strainmeter consisting of an optical fiber embedded in a metal casing that is interrogated using laser interferometry. This system is designed to be a permanently installed borehole casing segment that leaves the inner diameter open for other instrumentation. Poroelastic models and representative material properties and fluxes of a sandstone reservoir are used to characterize deformation during fluid injection at our CO2 analog site near Osage, OK. An axisymmetric model of a homogeneous reservoir suggests optimal locations of strain and tilt signals are on the order of microstrain and microradian over a 10 day injection period. The deformation signal at shallow depths (< 50 m) and radial distances between 150 - 300 m is three orders of magnitude greater than instrument resolution. A distributed stochastic

  12. Volcano dome dynamics at Mount St. Helens: Deformation and intermittent subsidence monitored by seismicity and camera imagery pixel offsets

    Science.gov (United States)

    Salzer, Jacqueline T.; Thelen, Weston A.; James, Mike R.; Walter, Thomas R.; Moran, Seth; Denlinger, Roger

    2016-11-01

    The surface deformation field measured at volcanic domes provides insights into the effects of magmatic processes, gravity- and gas-driven processes, and the development and distribution of internal dome structures. Here we study short-term dome deformation associated with earthquakes at Mount St. Helens, recorded by a permanent optical camera and seismic monitoring network. We use Digital Image Correlation (DIC) to compute the displacement field between successive images and compare the results to the occurrence and characteristics of seismic events during a 6 week period of dome growth in 2006. The results reveal that dome growth at Mount St. Helens was repeatedly interrupted by short-term meter-scale downward displacements at the dome surface, which were associated in time with low-frequency, large-magnitude seismic events followed by a tremor-like signal. The tremor was only recorded by the seismic stations closest to the dome. We find a correlation between the magnitudes of the camera-derived displacements and the spectral amplitudes of the associated tremor. We use the DIC results from two cameras and a high-resolution topographic model to derive full 3-D displacement maps, which reveals internal dome structures and the effect of the seismic activity on daily surface velocities. We postulate that the tremor is recording the gravity-driven response of the upper dome due to mechanical collapse or depressurization and fault-controlled slumping. Our results highlight the different scales and structural expressions during growth and disintegration of lava domes and the relationships between seismic and deformation signals.

  13. Structural control and health monitoring of building structures with unknown ground excitations: Experimental investigation

    Science.gov (United States)

    He, Jia; Xu, You-Lin; Zhan, Sheng; Huang, Qin

    2017-03-01

    When health monitoring system and vibration control system both are required for a building structure, it will be beneficial and cost-effective to integrate these two systems together for creating a smart building structure. Recently, on the basis of extended Kalman filter (EKF), a time-domain integrated approach was proposed for the identification of structural parameters of the controlled buildings with unknown ground excitations. The identified physical parameters and structural state vectors were then utilized to determine the control force for vibration suppression. In this paper, the possibility of establishing such a smart building structure with the function of simultaneous damage detection and vibration suppression was explored experimentally. A five-story shear building structure equipped with three magneto-rheological (MR) dampers was built. Four additional columns were added to the building model, and several damage scenarios were then simulated by symmetrically cutting off these columns in certain stories. Two sets of earthquakes, i.e. Kobe earthquake and Northridge earthquake, were considered as seismic input and assumed to be unknown during the tests. The structural parameters and the unknown ground excitations were identified during the tests by using the proposed identification method with the measured control forces. Based on the identified structural parameters and system states, a switching control law was employed to adjust the current applied to the MR dampers for the purpose of vibration attenuation. The experimental results show that the presented approach is capable of satisfactorily identifying structural damages and unknown excitations on one hand and significantly mitigating the structural vibration on the other hand.

  14. Monitoring rock glacier dynamics and ground temperatures in the semiarid Andes (Chile, 30°S)

    Science.gov (United States)

    Brenning, Alexander; Azócar, Guillermo F.; Bodin, Xavier

    2013-04-01

    Rock glaciers and mountain permafrost are widespread in the high semiarid Andes of Chile, where they concentrate greater amounts of ice than glaciers. Rock glaciers are of particular interest because in some cases the permafrost they contain might be in a degrading in response to climatic warming. This could result in increased dynamics and even to destabilization, which has been observed on some rock glaciers in the studied area. Displacement rates and active-layer temperatures of two rock glaciers as well as ground surface temperatures of the periglacial environment in the upper Elqui valley have been monitored since summer 2009/10 with funding from the Chilean Dirección General de Aguas. Differential GPS measurements of 115 points on the surface of two rock glaciers since April 2010 showed horizontal displacements of up to 1.3 m/a on the Llano de las Liebres rock glacier and up to 1.2 m/a on the Tapado rock glacier. General velocity patterns are consistent with the morphological evidence of activity (e.g., front slopes, looseness of debris) and for the Tapado complex, a clearly distinct activity from the debris-covered glacier was observed. Temperature measurements in four boreholes indicate active-layer depths of about 2.5 m at the highest locations on the Tapado rock glacier (~4400 m a.s.l.) and about 8 m near the front of the Llano rock glacier (3786 m a.s.l.). Spatial patterns of mean ground surface temperature (MGST) were analyzed with regards to influences of elevation, potential incoming solar radiation, location on ice-debris landforms (rock and debris-covered glaciers), and snow cover duration using linear mixed-effects models. While accounting for the other variables, sites with long-lasting snow patches had ~0.4°C lower MGST, and ice-debris landforms had ~0.4-0.6°C lower MGST than general debris surfaces, highlighting important local modifications to the general topographic variation of ground thermal conditions.

  15. Using distributed temperature sensing to monitor field scale dynamics of ground surface temperature and related substrate heat flux

    NARCIS (Netherlands)

    Bense, V.F.; Read, T.; Verhoef, A.

    2016-01-01

    We present one of the first studies of the use of distributed temperature sensing (DTS) along fibre-optic cables to purposely monitor spatial and temporal variations in ground surface temperature (GST) and soil temperature, and provide an estimate of the heat flux at the base of the canopy layer

  16. Fusion of Landsat TM and ground spectrometry data in monitoring of non-operating mine

    Science.gov (United States)

    Borisova, Denitsa; Nikolov, Hristo N.

    2009-09-01

    Surface mining activities in Europe are estimated to cover an area of 5-10 000 km2. In this paper we suggest that the availability of Landsat Thematic Mapper (TM) for Earth observation allows the collection of environmental and minerelated data for use in the planning and undertaking of mine restoration work on cost-effective basis. The advantage is that these data are acquired digitally and can be easily processed and utilized in various information formats. Important step in the data processing is the verification of airborne data. For this purpose ground spectrometry measurements of samples taken from test sites have been performed. In the last decade several mining areas and corresponding dumps are subject to reclamation process in Bulgaria. We focused our research on one of the most important in the copper production for 20 year period for our country - Asarel-Medet deposit. This mining complex consists of an open mine, the dumps and a processing plant. After ceasing the exploitation of Medet deposit in 1994 a rehabilitation program for soil cover and hydrographic network was established and launched. A continuous task is the monitoring of these activities from the beginning for at least 15 years period, which is to end this year. To process the data, which characterize the progress of the land cover restoration, several techniques, both standard, such as basic and advanced statistics, image enhancement and data fusion, and novel methods for supervised classification were used. The results obtained show that used data and the implemented approach are useful in environmental monitoring and are economically attractive for the company responsible for the ecological state of the region.

  17. Estimating youth locomotion ground reaction forces using an accelerometer-based activity monitor.

    Directory of Open Access Journals (Sweden)

    Jennifer M Neugebauer

    Full Text Available To address a variety of questions pertaining to the interactions between physical activity, musculoskeletal loading and musculoskeletal health/injury/adaptation, simple methods are needed to quantify, outside a laboratory setting, the forces acting on the human body during daily activities. The purpose of this study was to develop a statistically based model to estimate peak vertical ground reaction force (pVGRF during youth gait. 20 girls (10.9 ± 0.9 years and 15 boys (12.5 ± 0.6 years wore a Biotrainer AM over their right hip. Six walking and six running trials were completed after a standard warm-up. Average AM intensity (g and pVGRF (N during stance were determined. Repeated measures mixed effects regression models to estimate pVGRF from Biotrainer activity monitor acceleration in youth (girls 10-12, boys 12-14 years while walking and running were developed. Log transformed pVGRF had a statistically significant relationship with activity monitor acceleration, centered mass, sex (girl, type of locomotion (run, and locomotion type-acceleration interaction controlling for subject as a random effect. A generalized regression model without subject specific random effects was also developed. The average absolute differences between the actual and predicted pVGRF were 5.2% (1.6% standard deviation and 9% (4.2% standard deviation using the mixed and generalized models, respectively. The results of this study support the use of estimating pVGRF from hip acceleration using a mixed model regression equation.

  18. Forsmark site investigation. A deformation analysis of the Forsmark GPS monitoring network from 2005 to 2009

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, Lars; Ljungberg, Annika (Caliterra AB (Sweden))

    2010-10-15

    The objective of the study is to identify possible movements in the bedrock within and outside the candidate area at Forsmark. Seven physically stable stations were built in the Forsmark area in the autumn of 2005. Stations were established within a ten-kilometer radius. The stations were placed in three different areas separated by regional deformation zones: NE of the Singoe zone, within the candidate area, and SW of the Forsmark zone. Data have been collected in eighteen campaigns, each with a duration of about five days, from November 2005 to December 2009. Stations consist of a stainless steel rod fixed in the bedrock on which the GPS antenna mounts. Each station has dedicated GPS equipment only used at the specific site. Sets consist of a GPS receiver collecting raw GPS data and a choke ring antenna linked to the receiver using a coaxial cable. The receivers and antennas are dual frequency high precision geodetic grade. During each campaign the GPS receiver saves a reading every second for the duration of the five days campaign. The antennas remain mounted on the stations during the entire project, whereas all other equipment is in place at the station only during the campaigns. The measurements were related to the SWEPOS network stations Lovoe, Uppsala and Maartsbo that are defined as stations with stable fundaments by the National Land Survey of Sweden (Lantmaeteriet). This report deals with altogether 18 campaigns. The first 13 campaigns were performed during the period November 2005 to August 2008. However, the number of campaigns has been extended by adding a fourth year to the project. Optimization of the data processing depends on the properties of the entire data set comprising a period of four years. We divided the data into periods of 24 hours with each period processed as a separate session in the Bernese post processing software, after which we analyzed the residuals to conclude that data are of the expected quality. The entire data set from four

  19. Analysis of Mining Terrain Deformation Characteristics with Deformation Information System

    Science.gov (United States)

    Blachowski, Jan; Milczarek, Wojciech; Grzempowski, Piotr

    2014-05-01

    Mapping and prediction of mining related deformations of the earth surface is an important measure for minimising threat to surface infrastructure, human population, the environment and safety of the mining operation itself arising from underground extraction of useful minerals. The number of methods and techniques used for monitoring and analysis of mining terrain deformations is wide and increasing with the development of geographical information technologies. These include for example: terrestrial geodetic measurements, global positioning systems, remote sensing, spatial interpolation, finite element method modelling, GIS based modelling, geological modelling, empirical modelling using the Knothe theory, artificial neural networks, fuzzy logic calculations and other. The aim of this paper is to introduce the concept of an integrated Deformation Information System (DIS) developed in geographic information systems environment for analysis and modelling of various spatial data related to mining activity and demonstrate its applications for mapping and visualising, as well as identifying possible mining terrain deformation areas with various spatial modelling methods. The DIS concept is based on connected modules that include: the spatial database - the core of the system, the spatial data collection module formed by: terrestrial, satellite and remote sensing measurements of the ground changes, the spatial data mining module for data discovery and extraction, the geological modelling module, the spatial data modeling module with data processing algorithms for spatio-temporal analysis and mapping of mining deformations and their characteristics (e.g. deformation parameters: tilt, curvature and horizontal strain), the multivariate spatial data classification module and the visualization module allowing two-dimensional interactive and static mapping and three-dimensional visualizations of mining ground characteristics. The Systems's functionality has been presented on

  20. Real-time monitoring for fast deformations using GNSS low-cost receivers

    Directory of Open Access Journals (Sweden)

    T. Bellone

    2016-03-01

    Full Text Available Landslides are one of the major geo-hazards which have constantly affected Italy especially over the last few years. In fact 82% of the Italian territory is affected by this phenomenon which destroys the environment and often causes deaths: therefore it is necessary to monitor these effects in order to detect and prevent these risks. Nowadays, most of this type of monitoring is carried out by using traditional topographic instruments (e.g. total stations or satellite techniques such as global navigation satellite system (GNSS receivers. The level of accuracy obtainable with these instruments is sub-centimetrical in post-processing and centimetrical in real-time; however, the costs are very high (many thousands of euros. The rapid diffusion of GNSS networks has led to an increase of using mass-market receivers for real-time positioning. In this paper, the performances of GNSS mass-market receiver are reported with the aim of verifying if this type of sensor can be used for real-time landslide monitoring: for this purpose a special slide was used for simulating a landslide, since it enabled us to give manual displacements thanks to a micrometre screw. These experiments were also carried out by considering a specific statistical test (a modified Chow test which enabled us to understand if there were any displacements from a statistical point of view in real time. The tests, the algorithm and results are reported in this paper.

  1. Haze event monitoring and investigation in Penang Island, Malaysia using a ground-based backscatter Lidar

    Science.gov (United States)

    Hee, W. S.; Tan, F.; Lim, H. S.; Matjafri, M. Z.

    2014-06-01

    During 24th July 2013 to 1st August 2013, a haze event struck Penang Island, causing the visibility to decrease and increase in Air Pollution Index (API). A ground-based backscatter Lidar, operate at 355 nm which was setup at the roof top of the School of Physics, Universiti Sains Malaysia. It was used to monitor and investigate the haze event. For this work, we studied the daytime variation of the aerosol intensity, distribution, planetary boundary layer (PBL) height and the aerosol optical depth (AOD) values during these days. We found that the aerosol are very intense during the first two days of the haze event and slowly decline as time passed. Finally the haze event died off on 1st August 2013. As for daily aerosol distribution, aerosols are generally more intense during the afternoon. Its intensity is slightly lower in the morning and evening. Similar trends were observed for AOD values as they increase from morning to afternoon and slowly decrease in the evening. Most aerosols are found contained below the PBL which generally found at around 1000 - 2000 m in height.

  2. Development of a ground level enhancement alarm system based upon neutron monitors

    Science.gov (United States)

    Kuwabara, T.; Bieber, J. W.; Clem, J.; Evenson, P.; Pyle, R.

    2006-10-01

    We have developed a system that watches for count rate increases recorded in real time by eight neutron monitors, which triggers an alarm if a ground level enhancement (GLE) is detected. In this work, we determine optimal strategies for detecting the GLE event at a very early stage, while still keeping the false alarm rate at a very low level. We study past events to optimize appropriate intensity threshold values and a baseline to determine the intensity increase. The highest-level alarm, which we term an "alert," is generated when a 4% increase is recorded at three stations in 3 min averaged data. At this level, the false alarm rate obtained by backtesting over the past 4.4 years is zero. Ten GLEs occurred in this period, and our system produced GLE alarms for nine events. Alarm times for these nine events are compared with satellite proton data. The GLE alert precedes the earliest alert from GOES (100 MeV or 10 MeV protons) by ˜10-30 min. Real-time GLE data may be viewed at http://neutronm.bartol.udel.edu/spaceweather. An automated e-mail alert system is under development.

  3. Design of a Nanosatellite Ground Monitoring and Control Software – a Case Study

    Directory of Open Access Journals (Sweden)

    Freddy Alexander Díaz González

    2016-04-01

    Full Text Available The growing countries that have carried out the development of CubeSat missions for academic purposes do not offer aerospace engineering programs at their universities. This causes difficulties for traditional engineers upon the formal use of different standards and frameworks for aerospace development, such as the European Cooperation for Space Standardization and Space Mission Analysis and Design . One way in which traditional software engineers can easily understand the structure of an aerospace framework, in order to apply it on the development of CubeSat mission software parts, is comparing its most important elements in relation to the elements suggested by a more familiar method. In this paper, we present a hybrid framework between the ECSS-E-ST-40C standard and the Rational Unified Process, which can be used by traditional software engineers as a guide model for the development of software elements in academic nanosatellite missions. The model integrates the processes and documentation suggested by the ECSS-E-ST-40C with the disciplines, workflows and artifacts suggested in Rational Unified Process. This simplifies the structure of ECSS-E-ST-40C and allows traditional software engineers to easily understand its work elements. The paper describes as study case the implementation of the hybrid model in the analysis and design of ground monitoring and control software for the Libertad-2 satellite mission, which is currently being developed by the Universidad Sergio Arboleda in Colombia.

  4. Ground-based remote sensing scheme for monitoring aerosol–cloud interactions

    Directory of Open Access Journals (Sweden)

    K. Sarna

    2015-11-01

    Full Text Available A method for continuous observation of aerosol–cloud interactions with ground-based remote sensing instruments is presented. The main goal of this method is to enable the monitoring of cloud microphysical changes due to the changing aerosol concentration. We use high resolution measurements from lidar, radar and radiometer which allow to collect and compare data continuously. This method is based on a standardised data format from Cloudnet and can be implemented at any observatory where the Cloudnet data set is available. Two example study cases were chosen from the Atmospheric Radiation Measurement (ARM Program deployment at Graciosa Island, Azores, Portugal in 2009 to present the method. We show the Pearson Product–Moment Correlation Coefficient, r, and the Coefficient of Determination, r2 for data divided into bins of LWP, each of 10 g m−2. We explain why the commonly used way of quantity aerosol cloud interactions by use of an ACI index (ACIr,τ = dln re,τ/dlnα is not the best way of quantifying aerosol–cloud interactions.

  5. Monitoring and analysis of thermal deformation waves with a high-speed phase measurement system.

    Science.gov (United States)

    Taylor, Lucas; Talghader, Joseph

    2015-10-20

    Thermal effects in optical substrates are vitally important in determining laser damage resistance in long-pulse and continuous-wave laser systems. Thermal deformation waves in a soda-lime-silica glass substrate have been measured using high-speed interferometry during a series of laser pulses incident on the surface. Two-dimensional images of the thermal waves were captured at a rate of up to six frames per thermal event using a quantitative phase measurement method. The system comprised a Mach-Zehnder interferometer, along with a high-speed camera capable of up to 20,000 frames-per-second. The sample was placed in the interferometer and irradiated with 100 ns, 2 kHz Q-switched pulses from a high-power Nd:YAG laser operating at 1064 nm. Phase measurements were converted to temperature using known values of thermal expansion and temperature-dependent refractive index for glass. The thermal decay at the center of the thermal wave was fit to a function derived from first principles with excellent agreement. Additionally, the spread of the thermal distribution over time was fit to the same function. Both the temporal decay fit and the spatial fit produced a thermal diffusivity of 5×10-7  m2/s.

  6. An Early Warning System from debris flows based on ground vibration monitoring data

    Science.gov (United States)

    Arattano, Massimo; Coviello, Velio

    2015-04-01

    Among the different countermeasures that can be adopted for the mitigation of landslide hazard, Early Warning Systems (EWSs) are receiving an increasing attention. EWSs are the set of capacities needed to generate and disseminate timely and meaningful warning information to enable individuals and communities threatened by a hazard to appropriately act, in sufficient time, to reduce the possibility of harm or loss (UNEP, 2012). An EWS from debris flows can be classified into two main categories: advance and event EWSs. Advance EWSs predict the occurrence of a debris flow by monitoring hydro-meteorological conditions that may lead to its initiation. Despite their widespread adoption, these latter systems are prone to false alarms because they are heavily affected by bias between regional rainfall threshold and local conditions. Event EWSs, on the contrary, detect the occurrence of a debris flow when the process is already in progress. They usually rely on the use of algorithms for processing in real time the monitoring data. Their effectiveness depends on the reliability of those algorithms, which require long development and testing phases. A specific testing field for event EWSs has been equipped in the Gadria instrumented basin, located in the Eastern Italian Alps. A specifically designed monitoring unit capable to record data from different type of sensors and to implement aboard warning algorithms has been installed along a straight reach of the torrent. A flashing light, installed on the bank of the torrent, has been wired to this unit. The flashing light is framed by a fixed video camera that also shoots the passage of debris flows in the torrent. This provides a visual verification of the efficacy of the algorithm under test, particularly useful to show to practitioners and administrators a clear demonstration of the warning outcome. In this work, we present the performance of a warning algorithm that has been experimented in the Gadria testing field in 2013

  7. A new methodology for monitoring wood fluxes in rivers using a ground camera: Potential and limits

    Science.gov (United States)

    Benacchio, Véronique; Piégay, Hervé; Buffin-Bélanger, Thomas; Vaudor, Lise

    2017-02-01

    Ground imagery, which produces large amounts of valuable data at high frequencies, is increasingly used by fluvial geomorphologists to survey and understand processes. While such technology provides immense quantities of information, it can be challenging to analyze and requires automatization and associated development of new methodologies. This paper presents a new approach to automate the processing of image analysis to monitor wood delivery from the upstream Rhône River (France). The Génissiat dam is used as an observation window; all pieces of wood coming from the catchment are trapped here, hence a wood raft accumulates over time. In 2011, we installed an Axis 211W camera to acquire oblique images of the reservoir every 10 min with the goal of automatically detecting a wood raft area, in order to transform it to wood weight (t) and flux (t/d). The methodology we developed is based on random forest classification to detect the wood raft surface over time, which provided a good classification rate of 97.2%. Based on 14 mechanical wood extractions that included weight of wood removed each time, conducted during the survey period, we established a relationship between wood weight and wood raft surface area observed just before the extraction (R2 = 0.93). We found that using such techniques to continuously monitor wood flux is difficult because the raft undergoes very significant changes through time in terms of density, with a very high interday and intraday variability. Misclassifications caused by changes in weather conditions can be mitigated as well as errors from variation in pixel resolution (owing to camera position or window size), but a set of effects on raft density and mobility must still be explored (e.g., dam operation effects, wind on the reservoir surface). At this stage, only peak flow contribution to wood delivery can be well calculated, but determining an accurate, continuous series of wood flux is not possible. Several recommendations are

  8. Geodetic networks in Al-Hoceima, Fez-Meknes and Ouarzazate regions (Morocco) to monitor local deformations

    Science.gov (United States)

    Gil, A. J.; Ruiz, A. M.; Lacy, M. C.; Galindo-Zaldívar, J.; Anahnah, F.; Ruano, P.; Álvarez-Lobato, P. Ayarza, F.; Arboleya, A. Teixel, M. L.; Azzouz, O.; Ahmamou, A. Chalouan, M.; Kchikach, A.

    2009-04-01

    In the framework of some interdisciplinary research projects, several geodetic studies have been initiated aiming to quantify ground deformation in some areas of Morocco: the Al-Hoceima region (Rif cordillera), the Fez-Meknes region and the Ouarzazate region (Atlas Mountains). The Al-Hoceima region, located in the central part of the Rif Cordilleras, has undergone an intense seismic activity, in which the most significant events occurred in 1994 and 2004 (M= 6.3). Although seismicity data support the presence of transcurrent faults, and available radar interferometry researches evidence surface deformations, geological data suggest that main seismogentic fault zone has not a surface expression. Anyway, a set of N-S oriented normal faults (Rouadi, Al-Hoceima, Trougout) determines the present-day geomorphology and seems to continue to be active in surface. In this area, a new non-permanent GPS network consisting of 6 sites has been installed and surveyed in June 2007 and September 2008. The repeated measurements of this network may allow to exactly determine the surface expression of deep tectonic deformations in this region, and to quantify the creep and the coseismic motions in the area, that will contribute to better understand the seismic hazard. The Prerif Ridges located in the Fez-Meknes region, constitute the active mountain front of the Rif cordillera that accommodates most of the recent convergence between Eurasia and African plates. South of the ridges, the Saïss foreland basin overlies the foreland rocks corresponding to the Middle Atlas. There are evidences of Quaternary uplift of the Prerif Ridges and deformation of recent sediments as consequence of the southwards propagation of reverse faults along the mountain front. In addition, the foreland basin undergoes a roughly N-S extensional regime. The region undergoes a moderate seismic activity, with catastrophic events like that occurred in 1755 which damaged Fez and Meknes. On September 2007, a non

  9. A piece of cake: the ground-state energies in γ i -deformed = 4 SYM theory at leading wrapping order

    Science.gov (United States)

    Fokken, Jan; Sieg, Christoph; Wilhelm, Matthias

    2014-09-01

    In the non-supersymmetric γi-deformed = 4 SYM theory, the scaling dimensions of the operators tr[ Z L ] composed of L scalar fields Z receive finite-size wrapping and prewrapping corrections in the 't Hooft limit. In this paper, we calculate these scaling dimensions to leading wrapping order directly from Feynman diagrams. For L ≥ 3, the result is proportional to the maximally transcendental `cake' integral. It matches with an earlier result obtained from the integrability-based Lüscher corrections, TBA and Y-system equations. At L = 2, where the integrability-based equations yield infinity, we find a finite rational result. This result is renormalization-scheme dependent due to the non-vanishing β-function of an induced quartic scalar double-trace coupling, on which we have reported earlier. This explicitly shows that conformal invariance is broken — even in the 't Hooft limit. [Figure not available: see fulltext.

  10. A piece of cake: the ground-state energies in gamma_i-deformed N=4 SYM theory

    CERN Document Server

    Fokken, Jan; Wilhelm, Matthias

    2014-01-01

    In the non-supersymmetric gamma_i-deformed N=4 SYM theory, the scaling dimensions of the operators tr[Z^L] composed of L scalar fields Z receive finite-size wrapping and prewrapping corrections in the 't Hooft limit. In this paper, we calculate these scaling dimensions to leading wrapping order directly from Feynman diagrams. For L>=3, the result is proportional to the maximally transcendental `cake' integral. It matches with an earlier result obtained from the integrability-based Luescher corrections, TBA and Y-system equations. At L=2, where the integrability-based equations yield infinity, we find a finite rational result. This result is renormalization-scheme dependent due to the non-vanishing beta-function of an induced quartic scalar double-trace coupling, on which we have reported earlier. This explicitly shows that conformal invariance is broken - even in the 't Hooft limit.

  11. Ground subsidence and associated ground fracturing in urban areas: InSAR monitoring of active tectonic structures (Ciudad Guzman, Colima Graben - Mexico)

    Science.gov (United States)

    Bignami, C.; Brunori, C.; Zucca, F.; Groppelli, G.; Norini, G.; Hernandez, N. D.; Stramondo, S.

    2013-12-01

    This study focuses on the observation of a creeping phenomenon that produces subsidence of the Zapotlan basin and ground fracturing in correspondence of the Ciudad Guzmàn (Jalisco - Mexico). The September 21, 2012, the Ciudad Guzmàn has been struck by a phenomenon of ground fracturing of about 1.5 km of length. This event caused the deformation of the roads and the damage of 30 houses, of which eight have been declared uninhabitable. The alignment of fractures is coincident with the escarpments produced in September 19, 1985, in the Ciudad Guzman urban area, when a strong earthquake, magnitude 8.1, struck the Mexican area, causing the deaths of at least 10,000 people and serious damage in Mexico City. In Ciudad Guzmán, about 60% of the buildings were destroyed, with about 50 loss of life. The city is located in the Zapotlan basin (northern Colima graben), a wide tectonic depression where the depth of the infilling sediments is about 1 km. This subsidence cannot be measured outside the urbanized area, but it can be considered as a deformation mechanism of the central part of the basin. In order to detect and mapping the spatio-temporal features of the processes that led to this event, we applied InSAR multi-temporal techniques to analyze a dataset of ENVISAT satellite SAR images, acquired in a time span between 2003-2010. InSAR techniques detect a subsidence of the north-western part of Ciudad Guzmàn of about 15 mm/yr in the time interval 2003-2010. The displacement occurred in September 21, 2012, was detected using two RadarSAT2 acquisitions (2012-03-22 and 2013-03-17). The explanation of surface movements based on interferometric results, ground data and geological field observations, allowed confirming surface effect due to the overexploitation of the aquifers and highlights a subsidence due to anthropogenic causes coupled to buried tectonic structures.

  12. Image-based dynamic deformation monitoring of civil engineering structures from long ranges

    Science.gov (United States)

    Ehrhart, Matthias; Lienhart, Werner

    2015-02-01

    In this paper, we report on the vibration and displacement monitoring of civil engineering structures using a state of the art image assisted total station (IATS) and passive target markings. By utilizing the telescope camera of the total station, it is possible to capture video streams in real time with 10fps and an angular resolution of approximately 2″/px. Due to the high angular resolution resulting from the 30x optical magnification of the telescope, large distances to the object to be monitored are possible. The laser distance measurement unit integrated in the total station allows to precisely set the camera's focus position and to relate the angular quantities gained from image processing to units of length. To accurately measure the vibrations and displacements of civil engineering structures, we use circular target markings rigidly attached to the object. The computation of the targets' centers is performed by a least squares adjustment of an ellipse according to the Gauß-Helmert model from which the parameters of the ellipse and their standard deviations are derived. In laboratory experiments, we show that movements can be detected with an accuracy of better than 0.2mm for single frames and distances up to 30m. For static applications, where many video frames can be averaged, accuracies of better than 0.05mm are possible. In a field test on a life-size footbridge, we compare the vibrations measured by the IATS to reference values derived from accelerometer measurements.

  13. Restoration and monitoring of a vessel grounding on a shallow reef in the Florida Keys

    Directory of Open Access Journals (Sweden)

    Joe Schittone

    2010-10-01

    Full Text Available This paper summarizes the results of a monitoring event designed to track the recovery of a repaired coral reef injured by the M/V Alec Owen Maitland vessel grounding incident of October 25, 1989. This grounding occurred within the Florida Keys National Marine Sanctuary. Pursuant to the National Marine Sanctuaries Act, NOAA recovers money for injury to Sanctuary resources, and uses it to restore those resources. A monitoring program tracks patterns of recovery, in order to determine the success of restoration measures. To evaluate success, reference habitats adjacent to the restoration site are concurrently monitored to compare the condition of restored areas with natural areas. Restoration of this site was completed in September 1995 by means of cement and limestone rock, and the monitoring results from summer 2007 are presented. Monitoring consisted of omparison of the biological conditions in the restored area with the reference area. Monitored corals are divided into the Orders: Gorgonians, Milleporans, and Scleractinians. Densities at the restored and reference areas are compared, and are shown to be greater in the restored. Size-class frequency distributions for the most abundant Scleractinians are examined, and reveal that the restoration is converging on the reference area. Also, for the Scleractinians, number and percentage of colonies by species, as well as several common biodiversity indices are provided; measures for the restored area approximate the reference area. A quantitative comparison of colony substrate settlement preference in the restored area is provided for all Orders, and for Scleractinians is further broken down for the two most frequent Genera. Rev. Biol. Trop. 58 (Suppl. 3: 151-161. Epub 2010 October 01.Este artículo sintetiza los resultados del seguimiento diseñado para medir la recuperación de un arrecife restaurado que fue impactado por el encallamiento del M/V Alec Owen Maitland el 25 de octubre de 1989. Este

  14. Monitoring surface geothermal features using time series of aerial and ground-based photographs

    Science.gov (United States)

    Bromley, C.; van Manen, S. M.; Graham, D.

    2010-12-01

    Geothermal systems are of high conservation and scientific value and monitoring of these is an important management tool to assess natural variations and changes resulting from development and utilization. This study examines time series of aerial and ground-based photographs of geothermal areas within the Taupo Volcanic Zone, New Zealand. A time series of aerial photographs from 1946-2007 of the Broadlands Road Scenic Reserve (Taupo, New Zealand) highlights large changes to this small area as the result of the start of geothermal fluid production for the nearby Wairakei power plant in 1958 and other causes. Prior to the opening of the plant the area was not geothermally active, but expansion of steam zones due to pressure drawdown has resulted in significant thermal changes in the subsurface. These subsurface thermal changes are evident in the aerial photographs as the appearance of hydrothermal eruption craters and areas of thermal bare ground, which are too hot for vegetation to grown on. In addition, in the late 1960’s thermotolerant vegetation started to establish itself in the adjacent area. Changes in the surface area covered by each of these, reflect changes in the geothermal system as well as changes in management (e.g. exclusion of livestock), and a time series of these changes has been produced using ArcMap™. Monthly photographs of surface geothermal expressions in the Rotorua area show changes in colour and size of chloride springs with time. Colour and size changes are difficult to quantify due to varying exposure settings, weather conditions, and vantage points. However, these qualitative descriptions can be combined with quantitative time series such as temperature measurements, to provide better insight into surface changes that have occurred at this geothermal field. This study highlights the value of both qualitative and quantitative data that can be obtained from time series of photographs, including photographs that were obtained before the

  15. Unattended instruments for ground-based hyperspectral measurements: development and application for plant photosynthesis monitoring

    Science.gov (United States)

    Cogliati, S.; Rossini, M.; Meroni, M.; Barducci, A.; Julitta, T.; Colombo, R.

    2011-12-01

    and long-term hyperspectral data in different measurement conditions. As a demonstration of the potential of these instruments for monitoring plant photosynthesis, the collected time series (NDVI, PRI and F@760) were successfully used as inputs of Light Use Efficiency (LUE). However, HSI and MRI would be also useful to routinely collect at ground observations of other environmental compartments, for example for calibration/validation of RS data and products.

  16. Monitoring in situ deformation induced by a fluid injection in a fault zone in shale using seismic velocity changes

    Science.gov (United States)

    Rivet, D.; De Barros, L.; Guglielmi, Y.; Castilla, R.

    2015-12-01

    We monitor seismic velocity changes during an experiment at decametric scale aimed at artificially reactivate a fault zone by a high-pressure hydraulic injection in a shale formation of the underground site of Tournemire, South of France. A dense and a multidisciplinary instrumentation, with measures of pressure, fluid flow, strain, seismicity, seismic properties and resistivity allow for the monitoring of this experiment. We couple hydromechanical and seismic observations of the fault and its adjacent areas to better understand the deformation process preceding ruptures, and the role played by fluids. 9 accelerometers recorded repeated hammers shots on the tunnel walls. For each hammer shot we measured small travel time delays on direct P and S waves. We then located the seismic velocity perturbations using a tomography method. At low injection pressure, i.e. Pchange in S waves velocity. When the pressure overcomes 15 Bars, velocity perturbations dramatically increase with both P and S waves affected. A decrease of velocity is observed close to the injection point and is surrounded by regions of increasing velocity. Our observations are consistent with hydromechanical measures. Below 15 Bars, we interpret the P-wave velocity increase to be related to the compression of the fault zone around the injection chamber. Above 15 Bars, we measure a shear and dilatant fault movement, and a rapid increase in the injected fluid flow. At this step, our measures are coherent with a poroelastic opening of the fault with velocities decrease at the injection source and velocities increase related to stress transfer in the far field. Velocity changes prove to be efficient to monitor stress/strain variation in an activated fault, even if these observations might produce complex signals due to the highly contrasted hydromechanical responses in a heterogeneous media such as a fault zone.

  17. Atmospheric effects on infrared measurements at ground level: Application to monitoring of transport infrastructures

    Science.gov (United States)

    Boucher, Vincent; Dumoulin, Jean

    2014-05-01

    Being able to perform easily non-invasive diagnostics for surveillance and monitoring of critical transport infrastructures is a major preoccupation of many technical offices. Among all the existing electromagnetic methods [1], long term thermal monitoring by uncooled infrared camera [2] is a promising technique due to its dissemination potential according to its low cost on the market. Nevertheless, Knowledge of environmental parameters during measurement in outdoor applications is required to carry out accurate measurement corrections induced by atmospheric effects at ground level. Particularly considering atmospheric effects and measurements in foggy conditions close as possible to those that can be encountered around transport infrastructures, both in visible and infrared spectra. In the present study, atmospheric effects are first addressed by using data base available in literature and modelling. Atmospheric attenuation by particles depends greatly of aerosols density, but when relative humidity increases, water vapor condenses onto the particulates suspended in the atmosphere. This condensed water increases the size of the aerosols and changes their composition and their effective refractive index. The resulting effect of the aerosols on the absorption and scattering of radiation will correspondingly be modified. In a first approach, we used aerosols size distributions derived from Shettle and Fenn [3] for urban area which could match some of experimental conditions encountered during trials on transport infrastructures opened to traffic. In order to calculate the influence of relative humidity on refractive index, the Hänel's model [4] could be used. The change in the particulate size is first related to relative humidity through dry particle radius, particle density and water activity. Once the wet aerosol particle size is found, the effective complex refractive index is the volume weighted average of the refractive indexes of the dry aerosol substance

  18. Resource conservation and recovery act ground-water monitoring projects for Hanford facilities: Progress report, January 1--March 31, 1989

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.M.; Bates, D.J.; Lundgren, R.E.

    1989-06-01

    This document describes the progress of 13 Hanford Site ground-water monitoring projects for the period January 1 to March 31, 1989. The work described in this document is conducted by the Pacific Northwest Laboratory under the management of Westinghouse Hanford Company for the US Department of Energy. Concentrations of ground-water constituents are compared to federal drinking water standards throughout this document for reference purposes. All drinking water supplied from the sampled aquifer meets regulatory standards for drinking water quality. 32 refs., 30 figs., 103 tabs.

  19. SURFACE WATER AND GROUND WATER QUALITY MONITORING FOR RESTORATION OF URBAN LAKES IN GREATER HYDERABAD, INDIA

    Science.gov (United States)

    Mohanty, A. K.

    2009-12-01

    SURFACE WATER AND GROUND WATER QUALITY MONITORING FOR RESTORATION OF URBAN LAKES IN GREATER HYDERABAD, INDIA A.K. Mohanty, K. Mahesh Kumar, B. A. Prakash and V.V.S. Gurunadha Rao Ecology and Environment Group National Geophysical Research Institute, (CSIR) Hyderabad - 500 606, India E-mail:atulyakumarmohanty@yahoo.com Abstract: Hyderabad Metropolitan Development Authority has taken up restoration of urban lakes around Hyderabad city under Green Hyderabad Environment Program. Restoration of Mir Alam Tank, Durgamcheruvu, Patel cheruvu, Pedda Cheruvu and Nallacheruvu lakes have been taken up under the second phase. There are of six lakes viz., RKPuramcheruvu, Nadimicheruvu (Safilguda), Bandacheruvu Patelcheruvu, Peddacheruvu, Nallacheruvu, in North East Musi Basin covering 38 sq km. Bimonthly monitoring of lake water quality for BOD, COD, Total Nitrogen, Total phosphorous has been carried out for two hydrological cycles during October 2002- October 2004 in all the five lakes at inlet channels and outlets. The sediments in the lake have been also assessed for nutrient status. The nutrient parameters have been used to assess eutrophic condition through computation of Trophic Status Index, which has indicated that all the above lakes under study are under hyper-eutrophic condition. The hydrogeological, geophysical, water quality and groundwater data base collected in two watersheds covering 4 lakes has been used to construct groundwater flow and mass transport models. The interaction of lake-water with groundwater has been computed for assessing the lake water budget combining with inflow and outflow measurements on streams entering and leaving the lakes. Individual lake water budget has been used for design of appropriate capacity of Sewage Treatment Plants (STPs) on the inlet channels of the lakes for maintaining Full Tank Level (FTL) in each lake. STPs are designed for tertiary treatment i.e. removal of nutrient load viz., Phosphates and Nitrates. Phosphates are

  20. Environmental radiation monitoring plan for depleted uranium and beryllium areas, Yuma Proving Ground

    Energy Technology Data Exchange (ETDEWEB)

    Ebinger, M.H.; Hansen, W.R.

    1994-05-11

    This Environmental Radiation Monitoring Plan (ERM) discusses sampling soils, vegetation, and biota for depleted uranium (DU) and beryllium (Be) at Yuma Proving Ground (YPG). The existing ERM plan was used and modified to more adequately assess the potential of DU and Be migration through the YPG ecosystem. The potential pathways for DU and Be migration are discussed and include soil to vegetation, soil to animals, vegetation to animals, animals to animals, and animals to man. Sample collection will show DU deposition and will be used to estimate DU migration. The number of samples from each area varies and depends on if the firing range of interest is currently used for DU testing (GP 17A) or if the range is not used currently for DU testing (GP 20). Twenty to thirty-five individual mammals or lizards will be sampled from each transect. Air samples and samples of dust in the air fall will be collected in three locations in the active ranges. Thirty to forty-five sediment samples will be collected from different locations in the arroys near the impact areas. DU and Be sampling in the Hard Impact and Soft Impact areas changed only slightly from the existing ERM. The modifications are changes in sample locations, addition of two sediment transport locations, addition of vegetation samples, mammal samples, and air sampling from three to five positions on the impact areas. Analysis of samples for DU or total U by inductively-coupled mass spectroscopy (ICP/MS), cc spectroscopy, neutron activation analysis (NAA), and kinetic phosphorimetric analysis (KPA) are discussed, and analysis for Be by ICP/MS are recommended. Acquiring total U (no isotope data) from a large number of samples and analysis of those samples with relatively high total U concentrations results in fewer isotopic identifications but more information on U distribution. From previous studies, total U concentrations greater than about 3 times natural background are usually DU by isotopic confirmation.

  1. 地基SAR干涉测量原理及其形变监测应用研究%Ground-based SAR Interferometry Principles and Its Applications to Displacement Monitoring

    Institute of Scientific and Technical Information of China (English)

    王鹏; 周校

    2012-01-01

    详细介绍了地基SAR的基本理论,结合建筑物二维和一维的实测数据,分析了其在距离向和方位向的分辨率以及形变的监测精度,说明了地基SAR在形变监测中的有效性,并对地基SAR今后的应用与发展作了初步展望。%We describe the basic theoretical principles for ground-based SAR, including stepped- frequency continuous wave, synthetic aperture radar and interferometric measurement. The anal-ysis of the measured monitoring data of a building structure in two-dimension and one-dimension shows the validity of ground-based SAR in ground deformation monitoring. We also make some preliminary look in applications and developments of ground-based SAR in future.

  2. Earthquake Triggering Inferred from Rupture Histories, DInSAR Ground Deformation and Stress-Transfer Modelling: The Case of Central Italy During August 2016-January 2017

    Science.gov (United States)

    Papadopoulos, G. A.; Ganas, A.; Agalos, A.; Papageorgiou, A.; Triantafyllou, I.; Kontoes, Ch.; Papoutsis, I.; Diakogianni, G.

    2017-07-01

    On August 24, October 26 and 30, 2016, Central Apennines (Italy) were hit by three shallow, normal faulting very strong earthquakes rupturing in an NW-SE striking zone. Event 3 (Norcia) occurred between event 1 (Amatrice) at the SE and event 2 (Visso) at the NW of the entire rupture zone. The rupture histories of the three events, as revealed by teleseismic P-wave inversion, showed that all were characterized by bilateral rupture process with stronger rupture directivity towards NW for events 1 and 3 and towards SSE for event 2. Maximum seismic slip of 1.2, 0.8, and 1.4 m in the hypocenter and magnitude of M w 6.2, 6.1, and 6.5 were calculated for the three events, respectively. DInSaR measurements based on Sentinel-1 and 2 satellite images showed ground deformation directivity from events 1 and 2 towards event 3, which is consistent with the rupture process directivity. For events 1, 2, and 3, the maximum ground subsidence was found equal to 0.2, 0.15, and 0.35 m. Based on rupture directivity and ground deformation pattern, we put forward the hypothesis that the area of the second event was stress loaded by the first one and that both the first and second earthquake events caused stress loading in the area, where the third event ruptured. Coulomb stress-transfer modelling yields strong evidence in favor of our hypothesis. The stress in the fault plane of event 2 was increased by 0.19 bars due to loading from event 1. Event 3 fault plane was loaded by an amount of 2 bars, due to the combined stress transfer from the two previous events, despite its proximity to the negative/positive lobe boundary. The three events produced combined stress loading of more than +0.5 bar along the Apennines to the NW and SE of the entire rupture zone. In the SE stress lobe, a series of strong earthquakes of M w 5.3, 5.6, and 5.7 occurred on January 18, 2017, but likely, seismic potential remains in the area. We consider that in the NW and more extensive stress lobe, the seismic

  3. Thermo-mechanical evolution of the magmatic plumbing system of Soufrière Hills volcano, Montserrat, and resultant ground deformation

    Science.gov (United States)

    Gottsmann, Joachim; Odbert, Henry

    2014-05-01

    We exploit cyclic ground deformation timeseries from Soufrière Hills volcano expressed by ground uplift during reservoir priming and subsidence during extrusion. This study focuses on the period of eruptive repose between July 2003 and August 2005 marked by ground uplift prior to renewed dome growth thereafter. Using finite - element analysis we simulate the stress and pressure evolution in the magmatic plumbing system using a time-dependent, non-linear pressure-time history and inelastic thermo-mechanical properties of the upper crust. We compare two models of the plumbing system assembly: 1) two stacked spheroidal reservoirs and 2) a single prolate reservoir. In addition, two different crustal rheology models are tested for each of the plumbing models, with one order of magnitude difference in near-surface (beeswax - to fit both near and far-field deformation data. Although one might invoke such low rigidities in the immediate (heated) vicinity of an active magmatic plumbing system, they are unreasonable to assume over a large subsurface volume. Our results show that the thermal perturbation of the geotherm by the presence of a hot plumbing system is significant and fundamentally alters the portioning of subsurface stresses and strains. We further find that the thermal perturbation caused by best-fitting dual source and single source models are very similar, yielding practically identical relaxation times of encasing rocks if generalised Maxwell visco-elastic properties are invoked for the crust. The reservoir excess pressures upon simulated periodic recharge over the 15 months of uplift reach 4 MPa for a single large pressurised volume of 100 km3 extending from 6 to 17 km depth before reservoir failure and the onset of depressurisation. The pressure increase in the stacked reservoir assembly is predicted at 6 MPa almost exclusively incurred by pressurisation of a deep reservoir at 12 km depth. On the basis of the simulations and their fit to observations, we

  4. Long-distance laser propulsion and deformation- monitoring of cells in optofluidic photonic crystal fiber.

    Science.gov (United States)

    Unterkofler, Sarah; Garbos, Martin K; Euser, Tijmen G; St J Russell, Philip

    2013-09-01

    We introduce a unique method for laser-propelling individual cells over distances of 10s of cm through stationary liquid in a microfluidic channel. This is achieved by using liquid-filled hollow-core photonic crystal fiber (HC-PCF). HC-PCF provides low-loss light guidance in a well-defined single mode, resulting in highly uniform optical trapping and propulsive forces in the core which at the same time acts as a microfluidic channel. Cells are trapped laterally at the center of the core, typically several microns away from the glass interface, which eliminates adherence effects and external perturbations. During propagation, the velocity of the cells is conveniently monitored using a non-imaging Doppler velocimetry technique. Dynamic changes in velocity at constant optical powers up to 350 mW indicate stress-induced changes in the shape of the cells, which is confirmed by bright-field microscopy. Our results suggest that HC-PCF will be useful as a new tool for the study of single-cell biomechanics.

  5. Analysis of the ground level enhancement on 17 May 2012 using data from the global neutron monitor network

    Science.gov (United States)

    Mishev, A. L.; Kocharov, L. G.; Usoskin, I. G.

    2014-02-01

    We have analyzed the data of the world neutron monitor network for the first ground level enhancement of solar cycle 24, the ground level enhancement (GLE) on 17 May 2012. A newly computed neutron monitor yield function and an inverse method are applied to estimate the energy spectrum, anisotropy axis direction, and pitch angle distribution of the high-energy solar particles in interplanetary space. The method includes the determination of the asymptotic viewing cones of neutron monitor stations through computations of trajectories of cosmic rays in a model magnetosphere. The cosmic ray particle trajectories are determined with the GEANT-based MAGNETOCOSMICS code using Tsyganenko 1989 and International Geomagnetic Reference Field models. Subsequent calculation of the neutron monitor responses with the model function is carried out, that represents an initial guess of the inverse problem. Derivation of the solar energetic particle characteristics is fulfilled by fitting the data of the global neutron monitor network using the Levenberg-Marquardt method over the nine-dimensional parameter space. The pitch angle distribution and rigidity spectrum of high-energy protons are obtained as function of time in the course of the GLE. The angular distribution appears quite complicated. It comprises a focused beam along the interplanetary magnetic field line from the Sun and a loss-cone feature around the opposite direction, possibly indicative of the particle transport in interplanetary magnetic field structures associated with previous coronal mass ejections.

  6. Landslide deformation monitoring using point-like target offset tracking with multi-mode high-resolution TerraSAR-X data

    Science.gov (United States)

    Shi, Xuguo; Zhang, Lu; Balz, Timo; Liao, Mingsheng

    2015-07-01

    Many landslides in the Three Georges area have shown active deformations associated with water level fluctuations since the full operation of the Three Georges Dam. Such active deformations of landslide bodies need to be closely monitored for disaster prevention and warning. One way to do this is to employ SAR pixel offset tracking, a powerful technique that can be used for measuring two-dimensional large displacements. As an improvement of the original pixel offset tracking technique, the point-like target (PT) offset tracking method focuses on stable point-like targets and thus can obtain more reliable measurements. In this paper, the PT offset tracking method is employed to investigate historical evolution of the Shuping landslide, using time series TerraSAR-X data acquired in both Stripmap (SM) and High-resolution Spotlight (HS) modes. Artificial corner reflectors (CR) installed at/near the landslide are identified as PTs and used to analyze the spatial-temporal pattern of landslide deformations. Results showed that the maximum accumulative deformation of the Shuping landslide reached more than 1.5 m over a time span of two years. A correlation analysis between the deformation trends and the fluctuation of reservoir water level indicated that most deformations of the landslide happened during the water level declining period.

  7. Methodological and experimental study of the relationship between displacement rate of landslide and GNSS strategy for deformation monitoring

    Science.gov (United States)

    Giordan, Daniele; Piras, Marco; Allasia, Paolo; Dabove, Paolo

    2016-04-01

    The use of GNSS for landslide monitoring is not a novelty. In the field of large slope instabilities, where the phenomena are usually wide and the use of complex monitoring networks is needed, often a continuous monitoring is required. In this case, the installed GNSS solution is composed by a dual frequency receiver, with a solar power and with a radio connection to a ground station, where the measurement sessions of the rovers are collected and processed. The management of the collected data is the most critical aspect because the approach, which is commonly used, assumes a fixed position of the GNSS antenna during the acquisition time window. When the landslide is active, the position shift of the point can be considered insignificant for the low displacement rate, but together with the increase of the velocity, the GNSS time series processing becomes a crucial aspect to obtain reliable and enough accurate measurements. Starting from real case studies as the Italian large slope instabilities of Montaguto (Avellino, Italy) and Mont de La Saxe (Courmayeur, Italy), we focused on the presence of different kinematic domains with dissimilar displacement behaviors and velocities. In particular, the range of velocities registered during the main active periods ranges from several millimeters/day up to several meters/day, so the strategy for the GNSS processing data must be very different. Methodology for data acquisition (continuous or windowed) and its duration, type of receivers and antenna used (single or dual frequency, GPS or GNSS, mass market or geodetic), data processing strategies (i.e. single epoch, kinematic), and eventually GNSS network services are fundamental factors, which may favor one or another solution, according to time, economy and infrastructure readiness in the field. In the greater part of these studies, the choices were made based on the experience of responsible in the similar conditions. Starting from the behavior of real cases previously cited

  8. Monitoring of ground movement in open pit iron mines of Carajás Province (Amazon region) based on A-DInSAR techniques using TerraSAR-X data

    Science.gov (United States)

    Silva, Guilherme Gregório; Mura, José Claudio; Paradella, Waldir Renato; Gama, Fabio Furlan; Temporim, Filipe Altoé

    2017-04-01

    Persistent scatterer interferometry (PSI) analysis of a large area is always a challenging task regarding the removal of the atmospheric phase component. This work presents an investigation of ground movement measurements based on a combination of differential SAR interferometry time-series (DTS) and PSI techniques, applied on a large area of extent with open pit iron mines located in Carajás (Brazilian Amazon Region), aiming at detecting linear and nonlinear ground movement. These mines have presented a history of instability, and surface monitoring measurements over sectors of the mines (pit walls) have been carried out based on ground-based radar and total station (prisms). Using a priori information regarding the topographic phase error and a phase displacement model derived from DTS, temporal phase unwrapping in the PSI processing and the removal of the atmospheric phases can be performed more efficiently. A set of 33 TerraSAR-X (TSX-1) images, acquired during the period from March 2012 to April 2013, was used to perform this investigation. The DTS analysis was carried out on a stack of multilook unwrapped interferograms using an extension of SVD to obtain the least-square solution. The height errors and deformation rates provided by the DTS approach were subtracted from the stack of interferograms to perform the PSI analysis. This procedure improved the capability of the PSI analysis for detecting high rates of deformation, as well as increased the numbers of point density of the final results. The proposed methodology showed good results for monitoring surface displacement in a large mining area, which is located in a rain forest environment, providing very useful information about the ground movement for planning and risk control.

  9. Evaluation of the applicability of optical fiber strain sensors for monitoring rock deformation caused by ocean tide -a case study at the Aburatsubo site, Japan-

    Science.gov (United States)

    Matsui, H.; Kashiwai, Y.; Sano, O.; Tokunaga, T.; He, Z.; Mogi, K.; Wang, H. F.

    2009-12-01

    Monitoring rock deformation with high resolution is one of the essential factors for crustal deformation studies. Extensometers with several tens of meters long and inclinometer with similar length have been used as conventional monitoring methods. Because these large scale sensors require vast space for monitoring, it is difficult to distribute many monitoring points with high density. It is also difficult to conduct spatially high resolution monitoring. These limits on present monitoring methods make it difficult to evaluate the effects of heterogeneity of the rock masses and of the existence of fractures on the measured behavior of rock masses. In other words, scale dependency of rock deformation has not yet been studied through in-situ data. Thus, the small sensors with high resolution are required. We are planning to develop an ultra-high resolution sensor based on the optical fiber sensing technology in the three-year period. The optical fiber sensor has advantages against conventional electric sensors; long term stability, flexibility of incorporating many types of sensors on a single data acquisition cable, and a future promise for the methods to become even better, cheaper, and faster. The Fiber Bragg Grating (FBG) sensing technology is chosen as a potential method out of many kinds of optical fiber sensing methods, and a pair of commercially available FBG sensors were deployed in the Aburatsubo Earthquake Observation Center, the Earthquake Research Institute, University of Tokyo, for verifying their resolution and stability. According to the strain measurements by conventional extensometers at the Aburatsubo site, deformation on the order of 10-7 strain caused by ocean tides is observed. Purpose of the first stage of this developing work is to evaluate the commercially available FBG sensor and to study the feasibility for developing the precise small sensor for rock mechanics study. The FBG sensor successfully monitored the deformations caused by ocean

  10. GPS在变形监测技术现状及发展趋势%Present Situation of GPS technology in deformation monitoring and development trend

    Institute of Scientific and Technical Information of China (English)

    张家明; 吴新宇; 彭述刚

    2015-01-01

    GPS技术以速度快、全天候、高精度、自动化等诸多优点,被广泛运用到高层建筑、地质灾害、矿山矿井等变形监测中,由于垂直位移监测精度低、噪声干扰等问题,促使了与其他技术相互集成。文章阐述了基于GPS周期性与连续性2种变形监测模式及其数据处理方式,探讨了单一GPS变形监测技术存在的5方面主要问题,分析了目前基于3S集成技术、在线实时分析系统、结合小波分析等主流GPS变形监测技术现状,提出了基于3S技术、Web动态监测、四维可视化监测、移动终端监测的GPS变形监测未来发展趋势。%Global Positioning System(GPS ) technology has been widely applied to deformation monitoring of high-rise buildings, geological disasters and mines with advantages of fast, all-weather, high precision and automation. Problem of low vertical displacement monitoring accuracy and noise has been promoted mutual integration with other technologies.This paper describes two kinds of deformation monitoring model and its data processing based on GPS cyclical and continuity,discusses the main issues in five areas GPS deformation monitoring technology exists, analyzes the deformation monitoring technology based on the current status of 3S integration technology, online real-time analysis system, combining wavelet analysis, proposes development trend of GPS deformation monitoring based on 3S technology, Web dynamic monitoring, 4D visualization monitoring and mobile terminal monitoring.

  11. Landslide Investigation by Repeat Airborne LiDAR and Ground Monitoring in the Western Suburb of Sapporo, Japan

    Science.gov (United States)

    Kasai, M.; Marutani, T.; Yoshida, H.

    2014-12-01

    This study presents landslide investigation using the combination of airborne LiDAR and ground monitoring data. The study site is located on the Teine Landslide (width: 2 km, Length: 6.5 km) in the western suburb of Sapporo city in Hokkaido Island, Japan, which collapsed more than 50,000 years ago. Since then streams have been developing and incising the landslide mass consisted of rock debris and volcanic deposits, presently causing a series of small deep-seated landslides along the banks. Because Sapporo is the economic center of Hokkaido and the suburb is expanding at the toe of the Teine slide, it is important to understand the behaviors of these active slopes to protect residents and infrastructures from unexpected disasters possibly triggered by an intense storm or earthquake. The LiDAR data for the area was first obtained by a manned helicopter in August 2010, and another survey by an unmanned helicopter is planned in autumn 2014 to estimate their activities from changes in the ground surfaces during the period from 2010 to 2014. Ground water level and landslide mass movements have also been monitored on site by using the coring holes for sampling since 2013. The combination of the data sets can make up the deficits of these methods, e.g., errors created through data processing for LiDAR survey and spatially limited information for ground monitoring, enabling to provide a solid three dimensional view of the slope movements. The notion obtained can be utilized to predict their future behaviors as well as to discover active but hiding landslides nearby. This study also showed that repeat monitoring of sites is a way of utilizing UAVs, particularly in terms of cost and convenience.

  12. Spatio-temporal monitoring of cotton cultivation using ground-based and airborne multispectral sensors in GIS environment.

    Science.gov (United States)

    Papadopoulos, Antonis; Kalivas, Dionissios; Theocharopoulos, Sid

    2017-07-01

    Multispectral sensor capability of capturing reflectance data at several spectral channels, together with the inherent reflectance responses of various soils and especially plant surfaces, has gained major interest in crop production. In present study, two multispectral sensing systems, a ground-based and an aerial-based, were applied for the multispatial and temporal monitoring of two cotton fields in central Greece. The ground-based system was Crop Circle ACS-430, while the aerial consisted of a consumer-level quadcopter (Phantom 2) and a modified Hero3+ Black digital camera. The purpose of the research was to monitor crop growth with the two systems and investigate possible interrelations between the derived well-known normalized difference vegetation index (NDVI). Five data collection campaigns were conducted during the cultivation period and concerned scanning soil and plants with the ground-based sensor and taking aerial photographs of the fields with the unmanned aerial system. According to the results, both systems successfully monitored cotton growth stages in terms of space and time. The mean values of NDVI changes through time as retrieved by the ground-based system were satisfactorily modelled by a second-order polynomial equation (R (2) 0.96 in Field 1 and 0.99 in Field 2). Further, they were highly correlated (r 0.90 in Field 1 and 0.74 in Field 2) with the according values calculated via the aerial-based system. The unmanned aerial system (UAS) can potentially substitute crop scouting as it concerns a time-effective, non-destructive and reliable way of soil and plant monitoring.

  13. Impact of grounding and filtering on power insulation monitoring in insulated terrestrial power networks

    NARCIS (Netherlands)

    van Vugt, Pieter Karel Anton; Bijman, Rob; Timens, R.B.; Leferink, Frank Bernardus Johannes

    2013-01-01

    Insulated terrestrial power networks are used for reliable systems such as large production plants, hospital operating rooms and naval ships. The system is isolated from ground and a first fault, such as a short circuit between a phase and ground, will not result in disconnection of the power via

  14. Comparison and Intercalibration of Vegetation Indices from Different Sensors for Monitoring Above-Ground Plant Nitrogen Uptake in Winter Wheat

    Directory of Open Access Journals (Sweden)

    Yan Zhu

    2013-03-01

    Full Text Available Various sensors have been used to obtain the canopy spectral reflectance for monitoring above-ground plant nitrogen (N uptake in winter wheat. Comparison and intercalibration of spectral reflectance and vegetation indices derived from different sensors are important for multi-sensor data fusion and utilization. In this study, the spectral reflectance and its derived vegetation indices from three ground-based sensors (ASD Field Spec Pro spectrometer, CropScan MSR 16 and GreenSeeker RT 100 in six winter wheat field experiments were compared. Then, the best sensor (ASD and its normalized difference vegetation index (NDVI (807, 736 for estimating above-ground plant N uptake were determined (R2 of 0.885 and RMSE of 1.440 g·N·m−2 for model calibration. In order to better utilize the spectral reflectance from the three sensors, intercalibration models for vegetation indices based on different sensors were developed. The results indicated that the vegetation indices from different sensors could be intercalibrated, which should promote application of data fusion and make monitoring of above-ground plant N uptake more precise and accurate.

  15. Cost-effective monitoring of ground motion by joint use of a single-frequency GPS and a MEMS accelerometer

    Science.gov (United States)

    Tu, Rui; Wang, Rongjiang; Ge, Maorong; Walter, Thomas R.; Ramatschi, Markus; Milkereit, Claus; Bindi, Dino; Dahm, Torsten

    2014-05-01

    Real-time detection and precise estimation of strong ground motion are crucial for rapid assessment and early warning of geohazards such as earthquakes, landslides, and volcanic activity. This challenging task can be accomplished by combining GPS and accelerometer measurements because of their complementary capabilities to resolve broadband ground motion signals. However, for implementing an operational monitoring network of such joint measurement systems, cost-effective techniques need to be developed and rigorously tested. We propose a new approach for joint processing of single-frequency GPS and MEMS (micro-electro-mechanical systems) accelerometer data in real time. To demonstrate the performance of our method, we describe results from outdoor experiments under controlled conditions. For validation, we analysed dual-frequency GPS data and images recorded by a video camera. The results of the different sensors agree very well, suggesting that real-time broadband information of ground motion can be provided by using single-frequency GPS and MEMS accelerometers. Reference: Tu, R., R. Wang, M. Ge, T. R. Walter, M. Ramatschi, C. Milkereit, D. Bindi, and T. Dahm (2013), Cost-effective monitoring of ground motion related to earthquakes, landslides, or volcanic activity by joint use of a single-frequency GPS and a MEMS accelerometer, Geophysical Research Letters, 40, 3825-3829, doi:10.1002/grl.50653.

  16. Initial Findings from an Improved GNSS Solution for Long Term Monitoring of New Zealand's Secular and Earthquake Induced Deformation

    Science.gov (United States)

    Hansen, D. N.; Crook, C.

    2016-12-01

    New Zealand's unique position straddling the Australian and Pacific plate boundary ensures that it experiences both secular tectonic plate motion, and non-secular motions associated with earthquakes. The purpose of the 39 PositioNZ network CORS sites, jointly operated by Land Information New Zealand and GeoNet, are to maintain the national datum as these sporadic and ongoing events occur. Positions and velocities from these sites are integrated into the deformation model which translates between the present ITRF coordinates from GNSS into New Zealand's national datum NZGD2000. The Long Term Monitoring of land movements in New Zealand is carried out through a homogeneous reprocessing of the historical data for 39 CORS sites and 194 IGB08 global reference sites using a double difference strategy. This global solution is computed using Bernese GNSS software and CODE's reprocessed EGSIEM products and Final orbits and earth rotation parameters. A priori troposphere values are interpolated from gridded VMF1G files based on the ECMWF values, and these are mapped using the Vienna Mapping function. The network is aligned to the IGB08 reference frame through the 194 core reference stations using minimal constraints. The results of this reprocessing solution will be presented and discussed. The time series effects of various types of earthquakes will be shown as well as various methods of modelling these time series for datum maintenance. Additionally, the impacts of the new homogeneous processing strategy on the noise, position, and computed velocities will be outlined.

  17. Monitoring the surface deformation of Hurd rockglacier using D-GPS measurements and D-INSAR: first results (Livingston Island, Antarctica)

    Science.gov (United States)

    Vieira, Gonçalo; Catalão, João; Prates, Gonçalo; Correia, António

    2014-05-01

    Rockglaciers have been described by various authors in the South Shetlands archipelago (Antarctic Peninsula region), with the main contribution being that of Serrano and Lopez-Martínez (2000), who have described 9 rockglaciers and 11 protalus lobes. However, little is known about the deformation rates of rockglaciers in the region nor about possible changes associated with climate warming. Since the Western Antarctic Peninsula region is one of the areas on Earth which has been warming at a faster rate, monitoring rockglacier deformation should provide insight into the influence of climate change on geomorphodynamics. Hurd rockglacier is located in the south part of Hurd Peninsula, in a glacial cirque with a ridge varying from 227 to 301 m asl that connects directly to False Bay through a series of raised-beach terraces. The bedrock is composed of sandstones, shales and greywackes with a flysch facies, of the Myers Bluff formation. The valley shows steep rockwalls with extensive scree slopes and a small retreating valley glacier with a prominent frontal moraine, from where the rockglacier develops. The rockglacier body is ci 630 m long and 290 m wide and the surface shows frequent pressure ridges and furrows, especially in the lower sector. The rockglacier front is 15-20 m high and shows a slope of 45º (Serrano and López-Martínez 2000). In this poster we present the first data from surface deformation monitoring using stakes and D-GPS measurements conducted annually since 2011. Preliminary results show deformation values of 8 to 15 cm/year. Since 2011 we are also conducting DInSAR analysis using TerraSAR-X imagery and despite problems related mostly to snow cover, we have obtained image pairs allowing to identify deformation in the same order of magnitude of field observations. We expect to be able to present new results from the summer of 2013-14 campaign, which include a more intensive image acquisition plan. Results from a Vertical Electrical Sounding fro

  18. Unattended wireless proximity sensor networks for counterterrorism, force protection, littoral environments, PHM, and tamper monitoring ground applications

    Science.gov (United States)

    Forcier, Bob

    2003-09-01

    This paper describes a digital-ultrasonic ground network, which forms an unique "unattended mote sensor system" for monitoring the environment, personnel, facilities, vehicles, power generation systems or aircraft in Counter-Terrorism, Force Protection, Prognostic Health Monitoring (PHM) and other ground applications. Unattended wireless smart sensor/tags continuously monitor the environment and provide alerts upon changes or disruptions to the environment. These wireless smart sensor/tags are networked utilizing ultrasonic wireless motes, hybrid RF/Ultrasonic Network Nodes and Base Stations. The network is monitored continuously with a 24/7 remote and secure monitoring system. This system utilizes physical objects such as a vehicle"s structure or a building to provide the media for two way secure communication of key metrics and sensor data and eliminates the "blind spots" that are common in RF solutions because of structural elements of buildings, etc. The digital-ultrasonic sensors have networking capability and a 32-bit identifier, which provide a platform for a robust data acquisition (DAQ) for a large amount of sensors. In addition, the network applies a unique "signature" of the environment by comparing sensor-to-sensor data to pick up on minute changes, which would signal an invasion of unknown elements or signal a potential tampering in equipment or facilities. The system accommodates satellite and other secure network uplinks in either RF or UWB protocols. The wireless sensors can be dispersed by ground or air maneuvers. In addition, the sensors can be incorporated into the structure or surfaces of vehicles, buildings, or clothing of field personnel.

  19. Forest Watch: Using Student Data to Monitor Forest Response to Ground-Level Ozone

    Science.gov (United States)

    Spencer, S.; Rock, B. N.

    2006-12-01

    Forest Watch, a k-12 science outreach program begun at the University of New Hampshire (UNH) in 1991, has engaged pre-college students in providing UNH researchers with data on the annual response of white pine (Pinus strobus; a bio-indicator species for ozone exposure) to ground-level ozone across the New England region. Each year, student-collected growth and foliar symptomology data for 5 pine trees adjacent to their schools, along with first-year foliar samples, are submitted to UNH. Key foliar symptoms and student data are compared with summer monthly (JJA) maximum ozone concentrations collected by state and federal ozone monitoring stations across the region. To date, tree health indicators are inversely correlated (r2=0.83;p=0.10) with ozone concentrations: low ozone levels correlate with symptoms of good health (spectral indices diagnostic of high foliar chlorophyll levels and moisture content, normal incremental growth, low number of foliar symptoms), while summers characterized by high ozone concentrations correlate with symptoms of reduced health (low chlorophyll indices and moisture content, reduced incremental growth, increased number of foliar symptoms). In drought years (1999, 2001, 2002, 2003) few foliar symptoms of ozone damage are seen even though ozone levels were high, likely due to drought-induced stomatal closure. Based on student data since 1998, either low ozone summers, or drought summers have resulted in improved health in the sampled trees (n=30). Based on the success of Forest Watch in New England, we are exploring the extension of the program to Colorado as Front Range Forest Watch, operated from Colorado State University (CSU). The primary objective is to develop a student-scientist-local agency project that addresses real ecological issues in northern Colorado, including ozone pollution, and to provide pre-college students and teachers authentic science experiences. CSU runs a GK-12 program with Poudre School District in northern

  20. How Cities Breathe: Ground-Referenced, Airborne Hyperspectral Imaging Precursor Measurements To Space-Based Monitoring

    Science.gov (United States)

    Leifer, Ira; Tratt, David; Quattrochi, Dale; Bovensmann, Heinrich; Gerilowski, Konstantin; Buchwitz, Michael; Burrows, John

    2013-01-01

    the complex and often aerosol laden, humid, urban microclimates, atmospheric transport and profile monitoring, spatial resolution, temporal cycles (diurnal and seasonal which involve interactions with the surrounding environment diurnal and seasonal cycles) and representative measurement approaches given traffic realities. Promising approaches incorporate contemporaneous airborne remote sensing and in situ measurements, nocturnal surface surveys, with ground station measurement

  1. Monitoring particulate matters in urban areas in Malaysia using remote sensing and ground-based measurements

    Science.gov (United States)

    Kanniah, K. D.; Kamarul Zaman, Nurul Amalin Fatihah; Lim, H. Q.; Reba, Mohd Nadzri Md.

    2014-10-01

    Monitoring particulate matter less than 10 μm (PM10) near the ground routinely is critical for Malaysia for emergency management because Malaysia receives considerable amount of pollutants from both local and trans-boundary sources. Nevertheless, aerosol data covering major cities over a large spatial extent and on a continuous manner are limited. Thus, in the present study we aimed to estimate PM10 at 5 km spatial scale using AOD derived from MERIS sensor at 3 metropolitan cities in Malaysia. MERIS level 2 AOD data covering 5 years (2007-2011) were used to develop an empirical model to estimate PM10 at 11 locations covering Klang valley, Penang and Johor Bahru metropolitan cities. This study is different from previous studies conducted in Malaysia because in the current study we estimated PM10 by considering meteorological parameters that affect aerosol properties, including atmospheric stability, surface temperature and relative humidity derived from MODIS data and our product will be at ~5 km spatial scale. Results of this study show that the direct correlation between monthly averaged AOD and PM10 yielded a low and insignificant relationship (R2= 0.04 and RMSE = 7.06μg m-3). However, when AOD, relative humidity, land surface temperature and k index (atmospheric stability) were combined in a multiple linear regression analysis the correlation coefficient increased to 0.34 and the RMSE decreased to 8.91μg m-3. Among the variables k- index showed highest correlation with PM 10 (R2=0.35) compared to other variables. We further improved the relationship among PM10 and the independent variables using Artificial Neural Network. Results show that the correlation coefficient of the calibration dataset increased to 0.65 with low RMSE of 6.72μg m-3. The results may change when we consider more data points covering 10 years (2002- 2011) and enable the construction of a local model to estimate PM10 in urban areas in Malaysia.

  2. Inelastic deformation demands of regular steel frames subjected to pulse-like near-fault ground shakings

    Science.gov (United States)

    Siahpolo, Navid; Gerami, Mohsen; Vahdani, Reza

    2016-09-01

    Evaluating the capability of elastic Load Patterns (LPs) including seismic codes and modified LPs such as Method of Modal Combination (MMC) and Upper Bound Pushover Analysis (UBPA) in estimating inelastic demands of non deteriorating steel moment frames is the main objective of this study. The Static Nonlinear Procedure (NSP) is implemented and the results of NSP are compared with Nonlinear Time History Analysis (NTHA). The focus is on the effects of near-fault pulselike ground motions. The primary demands of interest are the maximum floor displacement, the maximum story drift angle over the height, the maximum global ductility, the maximum inter-story ductility and the capacity curves. Five types of LPs are selected and the inelastic demands are calculated under four levels of inter-story target ductility ( μ t) using OpenSees software. The results show that the increase in μ t coincides with the migration of the peak demands over the height from the top to the bottom stories. Therefore, all LPs estimate the story lateral displacement accurately at the lower stories. The results are almost independent of the number of stories. While, the inter-story drift angle (IDR) obtained from MMC method has the most appropriate accuracy among the other LPs. Although, the accuracy of this method decreases with increasing μ t so that with increasing number of stories, IDR is smaller or greater than the values resulted from NTHA depending on the position of captured results. In addition, increasing μ t decreases the accuracy of all LPs in determination of critical story position. In this case, the MMC method has the best coincidence with distribution of inter-story ductility over the height.

  3. Application of CPIII to deformation monitoring%CP Ⅲ技术在变形监测中的应用

    Institute of Scientific and Technical Information of China (English)

    岳仁宾; 张恒; 李超

    2015-01-01

    CPⅢ控制网是直接控制无碴轨道施工的最后一级平面、高程控制网,已经在高速铁路建设中大量采用,其数据采集和数据处理技术已日趋成熟。文中结合重庆市某桥墩变形监测项目,介绍将CPⅢ技术应用于变形监测工程的操作流程。监测结果表明,CPⅢ后方交会测量精度达毫米级,能够满足大部分变形监测工程的精度要求。%As the final level flat and vertical control network of Non‐ballast Track ,CPIII control network has been used in high‐speed railway construction ,of which the data acquisition and data processing technology have matured .It presents the CPIII operation flow deformation monitoring project ,combined with a pier deformation monitoring project in Chongqing .Monitoring results show that CPIII resection measurement has reached an accuracy of millimeter level ,w hich can meet the requirements of most deformation monitoring projects .

  4. Scheme Design of the Deformation Monitoring in the Foundation Pit Supporting Project%浅谈基坑支护工程变形监测方案

    Institute of Scientific and Technical Information of China (English)

    邹安安

    2012-01-01

    针对基坑支护围护结构顶部沉降与水平位移监测技术与变形方法进行研究。通过对基坑支护围护结构顶部沉降与水平位移监测数据进行分析,解算各监测点的累积沉降和总体位移变化量,从而及时掌握基坑的变形状况。根据监测点的变形限值标准,确定可能出现预警的变形点,并分析基坑不同部位发生沉降和偏移的原因。%Foundation pit support for the building envelope at the top of the settlement and horizontal displacement monitoring technology and methods of deformation. Through the excavation enclosure at the top of the settlement and horizontal displacement monitoring data analysis, calculate the cumula- tive settlement of all monitoring points and the overall displacement volume, and thus grasp the de- formation of foundation. According to the deformation limit of the standard monitoring to identify early warning of possible deformation point, and analysis of foundation settlement and migration occurred in different parts of the reason.

  5. Atmospheric mercury concentrations observed at ground-based monitoring sites globally distributed in the framework of the GMOS network

    Science.gov (United States)

    Sprovieri, Francesca; Pirrone, Nicola; Bencardino, Mariantonia; D'Amore, Francesco; Carbone, Francesco; Cinnirella, Sergio; Mannarino, Valentino; Landis, Matthew; Ebinghaus, Ralf; Weigelt, Andreas; Brunke, Ernst-Günther; Labuschagne, Casper; Martin, Lynwill; Munthe, John; Wängberg, Ingvar; Artaxo, Paulo; Morais, Fernando; Barbosa, Henrique de Melo Jorge; Brito, Joel; Cairns, Warren; Barbante, Carlo; Diéguez, María del Carmen; Garcia, Patricia Elizabeth; Dommergue, Aurélien; Angot, Helene; Magand, Olivier; Skov, Henrik; Horvat, Milena; Kotnik, Jože; Read, Katie Alana; Mendes Neves, Luis; Gawlik, Bernd Manfred; Sena, Fabrizio; Mashyanov, Nikolay; Obolkin, Vladimir; Wip, Dennis; Feng, Xin Bin; Zhang, Hui; Fu, Xuewu; Ramachandran, Ramesh; Cossa, Daniel; Knoery, Joël; Marusczak, Nicolas; Nerentorp, Michelle; Norstrom, Claus

    2016-09-01

    Long-term monitoring of data of ambient mercury (Hg) on a global scale to assess its emission, transport, atmospheric chemistry, and deposition processes is vital to understanding the impact of Hg pollution on the environment. The Global Mercury Observation System (GMOS) project was funded by the European Commission (gmos.eu" target="_blank">http://www.gmos.eu) and started in November 2010 with the overall goal to develop a coordinated global observing system to monitor Hg on a global scale, including a large network of ground-based monitoring stations, ad hoc periodic oceanographic cruises and measurement flights in the lower and upper troposphere as well as in the lower stratosphere. To date, more than 40 ground-based monitoring sites constitute the global network covering many regions where little to no observational data were available before GMOS. This work presents atmospheric Hg concentrations recorded worldwide in the framework of the GMOS project (2010-2015), analyzing Hg measurement results in terms of temporal trends, seasonality and comparability within the network. Major findings highlighted in this paper include a clear gradient of Hg concentrations between the Northern and Southern hemispheres, confirming that the gradient observed is mostly driven by local and regional sources, which can be anthropogenic, natural or a combination of both.

  6. 程潮铁矿井区变形监测分析及处置建议%Monitoring Analysis of Well Area Deformation and Disposal Propose in Chengchao Iron Mine

    Institute of Scientific and Technical Information of China (English)

    陈维维; 陈从新; 肖国锋

    2012-01-01

    程潮铁矿东主井和西风井区相继出现地表裂缝和井筒开裂现象,且地表裂缝范围在不断扩大,已经对东主井和西风井的结构安全构成威胁.为此,主要依据井筒开裂和地表裂缝的现场调查以及在变形监测的基础上,对井筒结构及地基变形开裂的岩体力学机理进行分析,探讨了东主井和西风井井区地表变形和井筒开裂的成因,得出地下水疏干和地下采矿是引起地表变形和地面塌陷现象的直接原因,而矿区工程地质构造和水文地质条件等对地表变形特征产生影响,并提出了相应的减缓井区地表变形的措施.%The surface cracks and wellbore cracking phenomenon have appeared successively in the area of the east and west air shaft well of Chengchao iron mine, and the surface cracks scope is also in the unceasing expansion. It has already threatened the safely of the east and west air wellbore structure. Based on the deformation monitor situation of the wellbore cracking and the surface fissures as well as the scene investigation, the mechanics mechanism of the wellbore structure and foundation deformation was studied. It analyses the causes which results in the surface deformation and the wellbore cracking in the east and west air shaft well area,and obtains the drainage of underground water and underground mining are the direct causes of the surface deformation and the ground subsidence phenomenon, moreover the engineering geology structure and the hydro - geological conditions in the mining area also have influence to the surface deformation characteristic, and some corresponding measures to slow down the surface deformation in the wellbore areas is proposed.

  7. Temporal monitoring of the soil freeze-thaw cycles over snow-cover land by using off-ground GPR

    KAUST Repository

    Jadoon, Khan

    2013-07-01

    We performed off-ground ground-penetrating radar (GPR) measurements over a bare agricultural field to monitor the freeze-thaw cycles over snow-cover. The GPR system consisted of a vector network analyzer combined with an off-ground monostatic horn antenna, thereby setting up an ultra-wideband stepped-frequency continuous-wave radar. Measurements were performed during nine days and the surface of the bare soil was exposed to snow fall, evaporation and precipitation as the GPR antenna was mounted 110 cm above the ground. Soil surface dielectric permittivity was retrieved using an inversion of time-domain GPR data focused on the surface reflection. The GPR forward model used combines a full-waveform solution of Maxwell\\'s equations for three-dimensional wave propagation in planar layered media together with global reflection and transmission functions to account for the antenna and its interactions with the medium. Temperature and permittivity sensors were installed at six depths to monitor the soil dynamics in the top 8 cm depth. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and permittivity data and in particular freeze and thaw events were clearly visible. A good agreement of the trend was observed between the temperature, permittivity and GPR time-lapse data with respect to five freeze-thaw cycles. The GPR-derived permittivity was in good agreement with sensor observations. The proposed method appears to be promising for the real-time mapping and monitoring of the frozen layer at the field scale. © 2013 IEEE.

  8. 程潮铁矿东区地表及井筒变形监测分析%Monitoring and Interpretation of Surface Movement and Shaft Deformation in the Eastern Area of Chengchao Iron Mine

    Institute of Scientific and Technical Information of China (English)

    柏威伟; 陈从新; 肖国峰; 黄平路

    2011-01-01

    On account of gradually aggravated situation on stability of ground surfaco and affiliated architecture in the eastern area of Chengchao iron mine, a monitoring network consisting of GPS, leveling instrument and digital fissure extensometer was established to monitor the three - dimensional deformation of the ground surface and the fissure propagation in the shafts in 2007. Based on the data of surface movement and fissure propagation obtained by in- situ monitoring about two years, detailed analysis and interpretation on the laws and trend of the surface movement and the shafts deformation were carried out. Combining with the field engineering geology conditions and the situation of mining,the several seemingly special phenomena such as fluctuation in the horizontal displacement value of ground surface, closing up of fissures and the regional differences of ground surface displacement in different zones, were analyzed and discussed. The results showed that the development of mined - out areas in spatial or temporal dimension determined the trend of surface movement and shafts deformation directly, the field engineering geological and hydrogeololgical conditions, including faults and joints, tectonic stress field, groundwater activities and so on dominated the regional deformation features indirectly. In the western ventilation shaft zone, the fluctuation of horizontal displacement value resulted from the specific site of the zone in relation to the eastern and western mined - out areas. The trend of fissures closing appeared after January,2009 is mainly attributed to the rotation of displacement vector.%针对程潮铁矿东区地表及构筑物开裂变形日趋严重的问题,采用GPS、水准仪和数字裂缝计开展了高精度的地表三维变形和井筒裂缝变形的监测工作.根据现场接近两年实测的东区地表位移和两主井井筒裂缝变形数据,分析了矿区地表及井筒变形规律和趋势.结合场地工程地质条件、

  9. Field Monitoring of Deformations and Internal Forces of Surrounding Rocks and Lining Structures in the Construction of the Gangkou Double-Arched Tunnel—A Case Study

    Directory of Open Access Journals (Sweden)

    Qixiang Yan

    2017-02-01

    Full Text Available Double-arched tunnel is a special and complex underground structure which needs to be monitored carefully during construction. Taking the Gangkou tunnel as the engineering background, this paper presents a case study of field monitoring of a representative double-arched tunnel. Typical cross sections were chosen in each class of surrounding rock masses in the tunnel area and different types of sensors were embedded in designed locations, and the deformations and forces of both surrounding rocks and lining structures were monitored systematically. The dynamic evolution as well as the spatial distribution characteristics of the monitoring data including the internal displacements of surrounding rocks and the contact pressures between surrounding rocks and primary linings, the axial forces in rock bolts and the internal forces in both steel arches and secondary linings were analyzed. The monitoring and analysis results show that the deformations and forces of both surrounding rocks and lining structures are directly related to the construction procedures, geological conditions and locations in the double-arched tunnel. According to the results, some reasonable suggestions were provided for the improvement of the tunnel construction. This study will provide useful reference and guidance for the design, construction and monitoring of similar engineering projects in future.

  10. A new debris flow monitoring barrier to measure debris flow impact/structure/ground interaction in the Gadria torrent

    Science.gov (United States)

    Nagl, Georg; Hübl, Johannes

    2017-04-01

    Debris flow monitoring is a keystone in debris flow research. Based on the lack of investigations of the interaction of rapid mass movement and structural mitigation measures, a new monitoring system has been installed in the well monitored Gadria torrent in South Tyrol. For design of active structural measures, like check dams, the engineering task is to come to an amicable solution of all necessary subjects. Starting with the estimation of parameters of the rapid mass movement itself to the design load and finally to the foundation of the structure. At all stages big uncertainties are given. The basis for accurate design is a comprehensive approach. For this reason, a new monitoring station was built in autumn 2016, to investigate the interaction of a debris flow with the structures and the ground. Two structures unify the new monitoring system. The first, a transversal check dam, flush to channel bed, contain two weighing devices each equipped with a pore pressure sensor. One device is also able to measure the shear force additional in two directions. The second barrier similar to a debris flow breaker but only with one singe wall centered on a foundation plate, is located downstream to the first one. 14 load cells are installed on the upward front of the structure to analyze the spatial force distribution of debris flow impact pressure. Nine earth pressure sensors under the foundation of the structure deliver the earth pressure distribution. The acceleration of the construction can be measured by a 3D accelerometer installed on the top. In case of a movement, two extensometers detect any displacement. Mounted strain gauges give insights of stresses in concrete and reinforcement. Each sensor has a sampling frequency of 2400 Hz. Furthermore it is planned to measure the flow velocity distribution over flow depth too. The new monitoring station should help to acquire data for understanding the debris flow/structure/ground interaction to facilitate the improvement

  11. Monitoring the removal of phosphate from ground water discharging through a pond-bottom permeable reactive barrier

    Science.gov (United States)

    McCobb, T.D.; LeBlanc, D.R.; Massey, A.J.

    2009-01-01

    Installation of a permeable reactive barrier to intercept a phosphate (PO4) plume where it discharges to a pond provided an opportunity to develop and test methods for monitoring the barrier's performance in the shallow pond-bottom sediments. The barrier is composed of zero-valent-iron mixed with the native sediments to a 0.6-m depth over a 1100-m2 area. Permanent suction, diffusion, and seepage samplers were installed to monitor PO 4 and other chemical species along vertical transects through the barrier and horizontal transects below and near the top of the barrier. Analysis of pore water sampled at about 3-cm vertical intervals by using multilevel diffusion and suction samplers indicated steep decreases in PO4 concentrations in ground water flowing upward through the barrier. Samples from vertically aligned pairs of horizontal multiport suction samplers also indicated substantial decreases in PO4 concentrations and lateral shifts in the plume's discharge area as a result of varying pond stage. Measurements from Lee-style seepage meters indicated substantially decreased PO4 concentrations in discharging ground water in the treated area; temporal trends in water flux were related to pond stage. The advantages and limitations of each sampling device are described. Preliminary analysis of the first 2 years of data indicates that the barrier reduced PO4 flux by as much as 95%. ?? 2009 National Ground Water Association.

  12. GPS-derived ground deformation (2005-2014) within the Gulf of Mexico region referred to a stable Gulf of Mexico reference frame

    Science.gov (United States)

    Yang, L.; Yu, J.; Wang, G.

    2016-12-01

    This study investigates current ground deformation derived from the GPS geodesy infrastructure in the Gulf of Mexico region. The positions and velocity vectors of 161 continuous GPS (CGPS) stations are presented with respect to a newly established local reference frame, the Stable Gulf of Mexico Reference Frame (SGOMRF). Thirteen long-term ( > 5 years) CGPS are used to realize the local reference frame. The root mean square (RMS) of the velocities of the 13 SGOMRF reference stations achieves 0.2 mm yr -1 in the horizontal and 0.3 mm yr -1 in the vertical directions. GPS observations presented in this study indicate significant land subsidence in the coastal area of southeastern Louisiana, the greater Houston metropolitan area, and two cities in Mexico (Aguascalientes and Mexico City). The most rapid subsidence is recorded at the Mexico City International airport, which is up to 26.6 cm yr -1 (2008-2014). Significant spatial variation of subsidence rates is observed in both Mexico City and the Houston area. The overall subsidence rate in the Houston area is decreasing. The subsidence rate in southeastern Louisiana is relatively smaller (4.0-6.0 mm yr -1 ) but tends to be steady over time. This poses a potential threat to the safety of coastal infrastructure in the long-term.

  13. GPS-derived ground deformation (2005-2014) within the Gulf of Mexico region referred to a stable Gulf of Mexico reference frame

    Science.gov (United States)

    Yu, Jiangbo; Wang, Guoquan

    2016-07-01

    This study investigates current ground deformation derived from the GPS geodesy infrastructure in the Gulf of Mexico region. The positions and velocity vectors of 161 continuous GPS (CGPS) stations are presented with respect to a newly established local reference frame, the Stable Gulf of Mexico Reference Frame (SGOMRF). Thirteen long-term (> 5 years) CGPS are used to realize the local reference frame. The root mean square (RMS) of the velocities of the 13 SGOMRF reference stations achieves 0.2 mm yr-1 in the horizontal and 0.3 mm yr-1 in the vertical directions. GPS observations presented in this study indicate significant land subsidence in the coastal area of southeastern Louisiana, the greater Houston metropolitan area, and two cities in Mexico (Aguascalientes and Mexico City). The most rapid subsidence is recorded at the Mexico City International airport, which is up to 26.6 cm yr-1 (2008-2014). Significant spatial variation of subsidence rates is observed in both Mexico City and the Houston area. The overall subsidence rate in the Houston area is decreasing. The subsidence rate in southeastern Louisiana is relatively smaller (4.0-6.0 mm yr-1) but tends to be steady over time. This poses a potential threat to the safety of coastal infrastructure in the long-term.

  14. Monitoring of the antioxidant BHT and its metabolite BHT-CHO in German river water and ground water.

    Science.gov (United States)

    Fries, Elke; Püttmann, Wilhelm

    2004-02-05

    The behavior of anthropogenic polar organic compounds in ground water during infiltration of river water to ground water was studied at the Oderbruch area on the eastern border of Germany. Additionally, waste water sewage treatment works (STWs) discharging their treated waste water into the Oder River and rain water precipitation from the Oderbruch area were investigated. The study was carried out from March 2000 to July 2001 to investigate seasonal variations of the target analytes. Samples were collected from four sites along the Oder River, from 24 ground water monitoring wells located close to the Oder, from one rain water collection station, from two roof runoffs, and from four STWs upstream of the Oderbruch. Results of the investigations of the antioxidant 3,5-di-tert-butyl-4-hydroxy-toluene (BHT) and its degradation product 3,5-di-tert-butyl-4-hydroxy-benzaldehyde (BHT-CHO) are presented. BHT and BHT-CHO were detected in all samples of the Oder River with mean concentrations of 178 and 102 ngl(-1), respectively. BHT and BHT-CHO were also detected in effluent waste water samples from municipal STWs at mean concentrations of 132 and 70 ngl(-1), respectively. Both compounds are discharged into river water directly via treated waste water. In the rain water sample, 308 ngl(-1) of BHT and 155 ngl(-1) of BHT-CHO were measured. Both compounds were detected in roof runoff with mean concentrations of 92 ngl(-1) for BHT and 138 ngl(-1) for BHT-CHO. The median values of BHT and BHT-CHO in ground water samples were 132 and 84 ngl(-1), respectively. The chemical composition of ground water from parts of the aquifer located less than 4.5 m distant from the river are greatly influenced by bank filtration. However, wet deposition followed by seepage of rain water into the aquifer is also a source of BHT and BHT-CHO in ground water.

  15. Coupling ground penetrating radar and fluid flow modeling for oilfield monitoring applications

    NARCIS (Netherlands)

    Miorali, M.; Zhou, F.; Slob, E.C.; Arts, R.J.

    2011-01-01

    The recent introduction of smart well technology allows for new geophysical monitoring opportunities. Smart wells, which allow zonal production control, combined with monitoring techniques capable of capturing the arrival of undesired fluids, have the potential to significantly increase the oil reco

  16. Coupling ground penetrating radar and fluid flow modeling for oilfield monitoring applications

    NARCIS (Netherlands)

    Miorali, M.; Zhou, F.; Slob, E.C.; Arts, R.

    2011-01-01

    The recent introduction of smart well technology allows for new geophysical monitoring opportunities. Smart wells, which allow zonal production control, combined with monitoring techniques capable of capturing the arrival of undesired fluids, have the potential to significantly increase the oil reco

  17. Monitoring Australian rangeland sites using landscape function indicators and ground- and remote-based techniques

    NARCIS (Netherlands)

    Ludwig, J.A.; Bastin, G.N.; Eager, R.W.; Karfs, R.; Ketner, P.; Pearce, G.

    2000-01-01

    If the goal for managing rangelands is to achieve a balance between production and conservation, then monitoring is essential to detect change and apply corrective action. In some rangeland areas of northern Australia, monitoring has detected a tilt in the production-conservation balance towards exc

  18. Behaviour recognition of ground vehicle using airborne monitoring of unmanned aerial vehicles

    Science.gov (United States)

    Oh, Hyondong; Kim, Seungkeun; Shin, Hyo-Sang; Tsourdos, Antonios; White, Brian A.

    2014-12-01

    This paper proposes a behaviour recognition methodology for ground vehicles moving within road traffic using unmanned aerial vehicles in order to identify suspicious or abnormal behaviour. With the target information acquired by unmanned aerial vehicles and estimated by filtering techniques, ground vehicle behaviour is first classified into representative driving modes, and then a string pattern matching theory is applied to detect suspicious behaviours in the driving mode history. Furthermore, a fuzzy decision-making process is developed to systematically exploit all available information obtained from a complex environment and confirm the characteristic of behaviour, while considering spatiotemporal environment factors as well as several aspects of behaviours. To verify the feasibility and benefits of the proposed approach, numerical simulations on moving ground vehicles are performed using realistic car trajectory data from an off-the-shelf traffic simulation software.

  19. Monitoring of Underground Coal Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Yang, X. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wagoner, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ramirez, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-08-31

    For efficient and responsible UCG operations, a UCG process must be monitored in the following three categories: 1) process parameters such as injection and product gas flow rates, temperature, pressure and syngas content and heating value; 2) geomechanical parameters, e.g., cavity and coal seam pressures, cavity development, subsidence and ground deformation; and 3) environmental parameters, e.g., groundwater chemistry and air quality. This report focuses on UCG monitoring with geophysical techniques that can contribute to monitoring of subsurface temperature, cavity development, burn front, subsidence and deformation.

  20. The Prospect of using Three-Dimensional Earth Models To Improve Nuclear Explosion Monitoring and Ground Motion Hazard Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Antoun, T; Harris, D; Lay, T; Myers, S C; Pasyanos, M E; Richards, P; Rodgers, A J; Walter, W R; Zucca, J J

    2008-02-11

    The last ten years have brought rapid growth in the development and use of three-dimensional (3D) seismic models of earth structure at crustal, regional and global scales. In order to explore the potential for 3D seismic models to contribute to important societal applications, Lawrence Livermore National Laboratory (LLNL) hosted a 'Workshop on Multi-Resolution 3D Earth Models to Predict Key Observables in Seismic Monitoring and Related Fields' on June 6 and 7, 2007 in Berkeley, California. The workshop brought together academic, government and industry leaders in the research programs developing 3D seismic models and methods for the nuclear explosion monitoring and seismic ground motion hazard communities. The workshop was designed to assess the current state of work in 3D seismology and to discuss a path forward for determining if and how 3D earth models and techniques can be used to achieve measurable increases in our capabilities for monitoring underground nuclear explosions and characterizing seismic ground motion hazards. This paper highlights some of the presentations, issues, and discussions at the workshop and proposes a path by which to begin quantifying the potential contribution of progressively refined 3D seismic models in critical applied arenas.

  1. Long-term crustal deformation monitored by gravity and space techniques at Medicina, Italy and Wettzell, Germany

    Science.gov (United States)

    Richter, B.; Zerbini, S.; Matonti, F.; Simon, D.

    2004-10-01

    Series of gravity recordings at the stations Medicina (Italy) and Wettzell (Germany) are investigated to separate seasonal gravity variations from long-term trends in gravity. The findings are compared to height variations monitored by continuous GPS observations. To study the origin of these variations in height and gravity the environmental parameters at the stations are included in the fact finding. In Medicina, a clear seasonal signal is visible in the gravity and height data series, caused by seasonal fluctuations in the atmosphere including mass redistribution, the ocean, groundwater but also by geo-mechanical effects such as soil consolidation and thermal expansion of the structure supporting the GPS antenna. In Wettzell, no seasonal effect could be clearly identified, and the long-term trend in gravity is mainly caused by ground water variations. The successful combination of height and gravity series with the derived ratio of gravity to height changes indicates that the long-term trends in height and gravity are most likely due to mass changes rather than to tectonic movements.

  2. Ground Water Monitoring Requirements for Hazardous Waste Treatment, Storage and Disposal Facilities

    Science.gov (United States)

    The groundwater monitoring requirements for hazardous waste treatment, storage and disposal facilities (TSDFs) are just one aspect of the Resource Conservation and Recovery Act (RCRA) hazardous waste management strategy for protecting human health and the

  3. GROUND WATER MONITORING AND SAMPLING: MULTI-LEVEL VERSUS TRADITIONAL METHODS – WHAT’S WHAT?

    Science.gov (United States)

    Recent studies have been conducted to evaluate different sampling techniques for determining VOC concentrations in groundwater. Samples were obtained using multi-level and traditional sampling techniques in three monitoring wells at the Raymark Superfund site in Stratford, CT. Ve...

  4. Combustion/Emission Species Monitoring Ground and Flight Aeronautical Research Using a Gas Microsensor Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this program is to develop a miniaturized and in-situ operated gas microsensor array for the real time monitoring of chemical composition of turbine...

  5. Gravity Monitoring of Ground-Water Storage Change in the Southwestern United States

    Science.gov (United States)

    Winester, D.; Pool, D. R.; Schmerge, D. L.; Hoffmann, J. P.; Keller, G. R.

    2004-12-01

    Repeat measurements of absolute gravity have been made since 1998 to estimate changes in ground-water mass as part of ground-water budget estimates in arid and semiarid regions of the Southwestern United States. The absolute acceleration of gravity is measured twice each year at 16 stations to an accuracy of about plus or minus 2 microGal, or about 5 cm of water. Observations are normally done for the purpose of providing gravity control for relative gravity surveys of networks of stations across wider areas. Other data incorporated into the ground-water budget estimates include precipitation, water levels, moisture content in the unsaturated zone, surface water runoff, and ellipsoid heights using the Global Positioning System (GPS). Gravity and water-level changes are correlated for stations measured in the Basin and Range Physiographic Province near Tucson, Phoenix, Casa Grande, and Sierra Vista, Arizona. Decreasing gravity and water levels in the Tucson area since the summer of 1998 are likely related to predominant drought conditions and decreases in ground-water storage following above average winter precipitation and recharge during the El Nino of 1998. Increases in gravity at stations in the upper and middle Verde Valley Watershed in central Arizona since the fall of 2000 do not correlate well with declining streamflows and water levels and may be caused by temporary increases in soil moisture following wet winters. There have been no significant observed gravity changes at two stations in the El Paso, Texas, area since the initial observations during the summer of 2003, even though ground-water pumping in the area has been heavy.

  6. Mapping refuse profile in Singapore old dumping ground through electrical resistivity, S-wave velocity and geotechnical monitoring.

    Science.gov (United States)

    Yin, Ke; Tong, Huan Huan; Noh, Omar; Wang, Jing-Yuan; Giannis, Apostolos

    2015-03-01

    The purpose of this study was to track the refuse profile in Lorong Halus Dumping Ground, the largest landfill in Singapore, by electrical resistivity and surface wave velocity after 25 years of closure. Data were analyzed using an orthogonal set of plots by spreading 24 lines in two perpendicular geophone-orientation directions. Both geophysical techniques determined that refuse boundary depth was 13 ± 2 m. The refuse boundary revealed a certain degree of variance, mainly ascribed to the different principle of measurements, as well as the high heterogeneity of the subsurface. Discrepancy was higher in spots with greater heterogeneity. 3D analysis was further conducted detecting refuse pockets, leachate mounding and gas channels. Geotechnical monitoring (borehole) confirmed geophysical outcomes tracing different layers such as soil capping, decomposed refuse materials and inorganic wastes. Combining the geophysical methods with borehole monitoring, a comprehensive layout of the dumping site was presented showing the hot spots of interests.

  7. CoRoT and asteroseismology. Preparatory work and simultaneous ground-based monitoring

    CERN Document Server

    Poretti, Ennio; Uytterhoeven, Katrien; Cutispoto, Giuseppe; Distefano, Elisa; Romano, Paolo

    2007-01-01

    The successful launch of the CoRoT (COnvection, ROtation and planetary Transits) satellite opens a new era in asteroseismology. The space photometry is complemented by high-resolution spectroscopy and multicolour photometry from ground, to disclose the pulsational content of the asteroseismic targets in the most complete way. Some preliminary results obtained with both types of data are presented. The paper is based on observations collected at S. Pedro Martir, Serra La Nave, La Silla, and Telescopio Nazionale Galileo Observatories.

  8. Monitoring ground subsidence due to underground mining using integrated space geodetic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Linlin Ge; Michael Hsing-Chung Chang; Chris Rizos [University of NSW, NSW (Australia)

    2004-04-01

    Differential radar interferometry (DInSAR) can deliver {approximately} 1cm height change resolution. The combination of regular radar beam scanning and movement of the satellites carrying the radar sensor enables imaging of the mining region in seconds, from which subtle ground movements can be detected. Quantitative validation comparing the DInSAR-derived subsidence profile against ground truth shows a best RMS error of 1.4cm. A methodology has been developed to use GPS (the Global Positioning System) observations to measure atmospheric disturbances so that the DInSAR results can be corrected. A Geographic Information System (GIS) has been used to post-process InSAR results throughout this project. GIS can be used to present the final results in various formats, for example, profiles for validating with ground truth, subsidence contour maps, and three-dimensional views. Professional looking thematic maps can be generated based on these analyses, lining up with the practice within the mining industry to deliver drawings/maps in a GIS format. Multi-temporal DInSAR results can be analysed using GIS, and the final results compiled into an animation, showing the subsidence region moving as time passes. A virtual reality image has been generated in the GIS, combining DEM, aerial photography, and DInSAR subsidence results. The UNSW InSAR-GPS-GIS Integration Software has been developed to support the seamless flow of data among the three technologies, DInSAR, GPS, and GIS. Several radar satellite missions, some especially designed for InSAR, are scheduled for launch in the near future. Therefore radar data of global coverage with weekly or even daily revisit will be made available at multiple radar bands. With atmospheric disturbances properly accounted for, DInSAR will be a cost-effective, reliable, and operational tool that complements traditional ground survey methods.

  9. Ground-water monitoring compliance projects for Hanford Site facilities: Volume 1, The report and Appendix A, Progress report for the period October 1 to December 31, 1986

    Energy Technology Data Exchange (ETDEWEB)

    1987-02-01

    This report documents recent progress on ground-water monitoring projects for four Hanford Site facilities: the 300 Area Process Trenches, the 183-H Solar Evaporation Basins, the 200 Area Low-Level Burial Grounds, and the Nonradioactive Dangerous Waste (NRDW) Landfill. The existing ground-water monitoring projects for the first two facilities named in the paragraph above are currently being expanded by adding new wells to the networks. During the reporting period, sampling of the existing wells continued on a monthly basis, and the analytical results for samples collected from September through November 1986 are included and discussed in this document. 8 refs., 41 figs., 7 tabs.

  10. On the Design of Radar Corner Reflectors for Deformation Monitoring in Multi-Frequency InSAR

    Directory of Open Access Journals (Sweden)

    Matthew C. Garthwaite

    2017-06-01

    Full Text Available Trihedral corner reflectors are being increasingly used as point targets in deformation monitoring studies using interferometric synthetic aperture radar (InSAR techniques. The frequency and size dependence of the corner reflector Radar Cross Section (RCS means that no single design can perform equally in all the possible imaging modes and radar frequencies available on the currently orbiting Synthetic Aperture Radar (SAR satellites. Therefore, either a corner reflector design tailored to a specific data type or a compromise design for multiple data types is required. In this paper, I outline the practical and theoretical considerations that need to be made when designing appropriate radar targets, with a focus on supporting multi-frequency SAR data. These considerations are tested by performing field experiments on targets of different size using SAR images from TerraSAR-X, COSMO-SkyMed and RADARSAT-2. Phase noise behaviour in SAR images can be estimated by measuring the Signal-to-Clutter ratio (SCR in individual SAR images. The measured SCR of a point target is dependent on its RCS performance and the influence of clutter near to the deployed target. The SCR is used as a metric to estimate the expected InSAR displacement error incurred by the design of each target and to validate these observations against theoretical expectations. I find that triangular trihedral corner reflectors as small as 1 m in dimension can achieve a displacement error magnitude of a tenth of a millimetre or less in medium-resolution X-band data. Much larger corner reflectors (2.5 m or greater are required to achieve the same displacement error magnitude in medium-resolution C-band data. Compromise designs should aim to satisfy the requirements of the lowest SAR frequency to be used, providing that these targets will not saturate the sensor of the highest frequency to be used. Finally, accurate boresight alignment of the corner reflector can be critical to the overall

  11. Model Selection Coupled with a Particle Tracking Proxy Using Surface Deformation Data for Monitoring CO2 Plume Migration

    Science.gov (United States)

    Min, B.; Nwachukwu, A.; Srinivasan, S.; Wheeler, M. F.

    2015-12-01

    This study formulates a framework of a model selection that refines geological models for monitoring CO2 plume migration. Special emphasis is placed on CO2 injection, and the particular techniques that are used for this study including model selection, particle tracking proxies, and partial coupling of flow and geomechanics. The proposed process starts with generating a large initial ensemble of reservoir models that reflect a prior uncertainty in reservoir description, including all plausible geologic scenarios. These models are presumed to be conditioned to available static data. In the absence of production or injection data, all prior reservoir models are regarded as equiprobable. Thus, the model selection algorithm is applied to select a few representative reservoir models that are more consistent with observed dynamic responses. A quick assessment of the models must then be performed to evaluate their dynamic characteristics and flow connectivity. This approach develops a particle tracking proxy and a finite element method solver for solving the flow equation and the stress problem, respectively. The shape of CO2 plume is estimated using a particle-tracking proxy that serves as a fast approximation of finite-difference simulation models. Sequentially, a finite element method solver is coupled with the proxy for analyzing geomechanical effects resulting from CO2 injection. A method is then implemented to group the models into clusters based on similarities in the estimated responses. The posterior model set is chosen as the cluster that produces the minimum deviation from the observed field data. The efficacy of non-dominated sorting based on Pareto-optimality is also tested in the current model selection framework. The proposed scheme is demonstrated on a carbon sequestration project in Algeria. Coupling surface deformation data with well injection data enhances the efficiency of tracking the CO2 plume. Therefore, this algorithm provides a probabilistic

  12. Monitoring of Land Deformation Due to Oil Production by InSAR Time Series Analysis Using PALSAR Data in Bolivarian Republic of Venezuela

    Science.gov (United States)

    Deguchi, Tomonori; Narita, Tatsuhiko

    2015-05-01

    The target area of this study is the Maracaibo sedimentary basin located in the western part of Bolivarian Republic of Venezuela. The full-scale exploration and development for oil resources in Venezuela which was the greatest oil-producing country in South America had begun at the Maracaibo sedimentary basin in the 1910s, and it was a center of the oil product in Venezuela until the 1980s. But, in most of oil fields in the Maracaibo sedimentary basin, there is concern over the drain on recoverable reserves due to deterioration, and the production amount of petroleum in Venezuela has been diminishing these days. Leveling and GPS surveying were carried out in the past, and they revealed that the large-scale subsidence phenomenon of which cumulative subsidence amount was approximately 5 meter had occurred. The authors applied the vertical displacement measurement by InSAR time series analysis using PALSAR data obtained in the Fine-beam and ScanSAR observation mode. As a result, it could be confirmed clear ground deformation in the surrounding of three oil fields (Tia Juana, Lagunillas and Bachaquero) and easily recognized that the areas of phase anomalies detected by this analysis had expanded and the number of interference fringes had increased over time. The annual velocity of vertical ground surface displacement measured by InSAR time series analysis was -51 mm per year, -103 mm per year and -58 mm per year in Tia Juana, Lagunillas and Bachaquero oil field respectively. The tendency that an earth surface shifted towards the center of phase anomalies was detected from the result of the horizontal ground change measurement. It was interpreted from Google Earth and Landsat images that oil-related facilities (mainly bowling stations) were built intensively over the areas where phase anomalies were detected. Therefore, it was inferred that there was a high association between the operation activity of the oil field and ground deformation. In addition, the deterioration

  13. Field Test of Qiantangjiang Embankment Deformation Monitoring Caused by Pipe-jacking Construction%顶管穿越钱塘江大堤变形监测现场试验研究

    Institute of Scientific and Technical Information of China (English)

    吴军君; 张开伟; 刘振伟

    2011-01-01

    Taking the Qiantangjiang embankment deformation monitoring caused by sewage pipe-jacking construction of Tongxiang in Zhejiang province for an example, according to the field monitoring and test results, the influence of pipe-jacking during and after construction on soil disturbance deformation around the dike is analyzed. The methods of O'Reilly and Loganathan are proposed to calculate slot width coefficient of land subsidence during pipe-jacking construction. Then it is substituted to Peck formula for fitting horizontal ground settlement curvet which has good fitting degree. Finally, it points out that the settlement calculation after construction must be selected zero point rationally and the hyperbolic fitting is more applicable. The results show that the proposed method is effective, which has guided meaning for safety e-valuation of embankment.%以浙江省桐乡污水顶管穿越钱塘江大堤变形监测项目为例,根据现场监测与试验结果,分析了顶管施工期间和工后对大堤周围土体扰动变形的影响,提出项管施工期间分别依据O' Reilly和Loganathan法推算地面沉降槽宽度系数代入Peck公式拟合地面横向沉降曲线,拟合度较好,指出工后沉降推算需合理选取零点,采用双曲线拟合法更适用.结果表明,该方法行之有效,对堤防安全评价有指导意义.

  14. Depleted uranium risk assessment for Jefferson Proving Ground using data from environmental monitoring and site characterization. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ebinger, M.H.; Hansen, W.R.

    1996-10-01

    This report documents the third risk assessment completed for the depleted uranium (DU) munitions testing range at Jefferson Proving Ground (JPG), Indiana, for the U.S. Army Test and Evaluation command. Jefferson Proving Ground was closed in 1995 under the Base Realignment and Closure Act and the testing mission was moved to Yuma Proving Ground. As part of the closure of JPG, assessments of potential adverse health effects to humans and the ecosystem were conducted. This report integrates recent information obtained from site characterization surveys at JPG with environmental monitoring data collected from 1983 through 1994 during DU testing. Three exposure scenarios were evaluated for potential adverse effects to human health: an occasional use scenario and two farming scenarios. Human exposure was minimal from occasional use, but significant risk were predicted from the farming scenarios when contaminated groundwater was used by site occupants. The human health risk assessments do not consider the significant risk posed by accidents with unexploded ordnance. Exposures of white-tailed deer to DU were also estimated in this study, and exposure rates result in no significant increase in either toxicological or radiological risks. The results of this study indicate that remediation of the DU impact area would not substantially reduce already low risks to humans and the ecosystem, and that managed access to JPG is a reasonable model for future land use options.

  15. Close-range photogrammetry in underground mining ground control

    Science.gov (United States)

    Benton, Donovan J.; Chambers, Amy J.; Raffaldi, Michael J.; Finley, Seth A.; Powers, Mark J.

    2016-09-01

    Monitoring underground mine deformation and support conditions has traditionally involved visual inspection and geotechnical instrumentation. Monitoring displacements with conventional instrumentation can be expensive and time-consuming, and the number of locations that can be effectively monitored is generally limited. Moreover, conventional methods typically produce vector rather than tensor descriptions of geometry changes. Tensor descriptions can provide greater insight into hazardous ground movements, particularly in recently excavated openings and in older workings that have been negatively impacted by high stress concentrations, time-dependent deformation, or corrosion of ground support elements. To address these issues, researchers with the National Institute for Occupational Safety and Health, Spokane Mining Research Division are developing and evaluating photogrammetric systems for ground control monitoring applications in underground mines. This research has demonstrated that photogrammetric systems can produce millimeter-level measurements that are comparable to conventional displacement-measuring instruments. This paper provides an overview of the beneficial use of close-range photogrammetry for the following three ground control applications in underground mines: monitoring the deformation of surface support, monitoring rock mass movement, and monitoring the corrosion of surface support. Preliminary field analyses, case studies, limitations, and best practices for these applications are also discussed.

  16. ENVIRONMENTAL MONITORING AT GROUND ZERO AND LOWER MANHATTAN FOLLOWING THE COLLAPSE OF THE WTC

    Science.gov (United States)

    The U.S. EPA National Exposure Research Laboratory (NERL), in conjunction with our Regional offices, established a network of air monitoring sites to characterize ambient air concentrations of gases and particles in lower Manhattan following the collapse of the World Trade Cent...

  17. Quality assurance project plan for ground water monitoring activities managed by Westinghouse Hanford Company. Revision 3

    Energy Technology Data Exchange (ETDEWEB)

    Stauffer, M.

    1995-11-01

    This quality assurance project plan (QAPP) applies specifically to the field activities and laboratory analysis performed for all RCRA groundwater projects conducted by Hanford Technical Services. This QAPP is generic in approach and shall be implemented in conjunction with the specific requirements of individual groundwater monitoring plans.

  18. Monitoring ground-surface heating during expansion of the Casa Diablo production well field at Mammoth Lakes, California

    Science.gov (United States)

    Bergfeld, D.; Vaughan, R. Greg; Evans, William C.; Olsen, Eric

    2015-01-01

    The Long Valley hydrothermal system supports geothermal power production from 3 binary plants (Casa Diablo) near the town of Mammoth Lakes, California. Development and growth of thermal ground at sites west of Casa Diablo have created concerns over planned expansion of a new well field and the associated increases in geothermal fluid production. To ensure that all areas of ground heating are identified prior to new geothermal development, we obtained high-resolution aerial thermal infrared imagery across the region. The imagery covers the existing and proposed well fields and part of the town of Mammoth Lakes. Imagery results from a predawn flight on Oct. 9, 2014 readily identified the Shady Rest thermal area (SRST), one of two large areas of ground heating west of Casa Diablo, as well as other known thermal areas smaller in size. Maximum surface temperatures at 3 thermal areas were 26–28 °C. Numerous small areas with ground temperatures >16 °C were also identified and slated for field investigations in summer 2015. Some thermal anomalies in the town of Mammoth Lakes clearly reflect human activity.Previously established projects to monitor impacts from geothermal power production include yearly surveys of soil temperatures and diffuse CO2 emissions at SRST, and less regular surveys to collect samples from fumaroles and gas vents across the region. Soil temperatures at 20 cm depth at SRST are well correlated with diffuse CO2 flux, and both parameters show little variation during the 2011–14 field surveys. Maximum temperatures were between 55–67 °C and associated CO2 discharge was around 12–18 tonnes per day. The carbon isotope composition of CO2 is fairly uniform across the area ranging between –3.7 to –4.4 ‰. The gas composition of the Shady Rest fumarole however has varied with time, and H2S concentrations in the gas have been increasing since 2009.

  19. Two decades of temperature-time monitoring experiment: air - ground surface - shallow subsurface interactions

    Science.gov (United States)

    Cermak, Vladimir; Dedecek, Petr; Safanda, Jan; Kresl, Milan

    2014-05-01

    Long-term observations (1994-2013) of air and shallow ground temperatures at borehole Prague-Sporilov (50º02'28.5"E, 14º28'40.2"N, 274 m a.s.l.) have been thoroughly analyzed to understand the relationship between these quantities and to describe the mechanism of heat transport at the land-atmosphere boundary layer. Data provided a surprisingly small mean ground-air temperature offset of only 0.31 K with no clear annual course and with the offset value changing irregularly even on a daily scale. Such value is substantially lower than similar values (1-2 K and more) found elsewhere, but may well characterize a mild temperate zone, when all so far available information referred rather to southern locations. Borehole data were correlated with similar observations in a polygon-site under four types of surface conditions (grass, soil, sand and asphalt) completed with registration of meteorological variables (wind direction & velocity, air & soil humidity, direct & reflected solar radiation, precipitation and snow cover). The "thermal orbits" technique proved to be an effective tool for the fast qualitative diagnostics of the thermal regime in the subsurface (conductive versus non-conductive).

  20. Measurements for monitoring ground motion resulting from mining operations in the Rhenish brown coal district; Messungen zur Ueberwachung von bergbaubedingten Bodenbewegungen im rheinischen Braunkohlenbergbau

    Energy Technology Data Exchange (ETDEWEB)

    Duddek, H.; Schaefer, W. [Rheinbraun AG, Koeln (Germany)

    1996-12-31

    Coal mining in the Rhenish brown coal district resulted in loose rock slopes with a total height of more than 350 m. Mining operations caused ground motion in open-cast mines, in the slopes and in the region ahead of the face. Internal dumping caused motions of the floors, the overburden tip and te slopes of the open-cast mines. The deformations were measured by different methods, and the evaluations are presented here. As examples, permanent monitoring of a slope using the GEOROBOT measuring system and continuous subsidence measurements in an overburdan dump by means of hydrostatic measuring systems are presented. GEOROBOT ensures quasi-continuous measurements of slope motion with an error of 5-7 mm. Hydrostatic measuring systems on the basis of pressure sensors were developed for measurements of single overburden dump strata and the overburden dump basis during dumping. (orig.) [Deutsch] In den rheinischen Braunkohlentagebauen entstehen Lockergesteinsboeschungen mit Gesamthoehen von mehr als 350 m. Die Gewinnungstaetigkeiten verursachen Entlastungsbewegungen im Tagebau, in den Boeschungen und im Tagebauvorfeld. Die Innenverkippung fuehrt erneut zu Bodenbewegungen im Liegenden, im Kippenkoerper und im Bereich der Tagebauraender. Die auftretenden Deformationen werden mit verschiedenen Messverfahren erfasst, ausgewertet und dargestellt. Beispielhaft werden die permanente Ueberwachung einer Boeschung mittels des automatischen Messsystems GEOROBOT und kontinuierliche Setzungsmessungen in einer Tagebaukippe mit hydrostatischen Messsystemen vorgestellt. Mit GEOROBOT werden quasi kontinuierlich Boeschungsbewegungsmessungen mit einer Genauigkeit von {+-}5 bis 7 mm durchgefuehrt. Auf der Basis von Drucksensoren wurden hydrostatische Messsysteme konzipiert, mit denen Setzungen einzelner Kippscheiben und der Kippenbasis waehrend des Kippenaufbaues ermittelt werden. (orig.)

  1. Ground Penetrating Radar in Dam Monitoring: The Test Case of Acerenza (Southern Italy

    Directory of Open Access Journals (Sweden)

    A. Loperte

    2011-01-01

    Full Text Available Nowadays, dam safety management is gaining great importance since it affects in a crucial way the monitoring and improvement of risky reservoirs, but this topic is very challenging since the dam safety requires long-term and time-continuous monitoring. In this framework, the exploitation of conventional geotechnical investigation methods often requires invasive actions in the inner of the structure to be investigated (destructiveness and only provides punctual information for small volumes. On the contrary, the application of noninvasive sensing techniques makes it possible to investigate higher volumes without affecting the structure. In this paper we describe the application of GPR for the monitoring and diagnostics of one of the largest dams in the Basilicata region (Southern Italy. The investigation aims at detecting and localizing underground sandstone banks that are potential ways of flow of water below the dam. The manageability and the noninvasiveness of GPR have resulted in particularly suitable for this kind of application because the versatility of this geophysical method allows to investigate large areas with a good spatial resolution giving the possibility to detect the presence of inhomogeneities in the subsoil below the dam.

  2. Monitoring the natural attenuation of petroleum in ground water at the former naval complex, Operable Unit A, Adak Island, Alaska, May and June 2003

    Science.gov (United States)

    Dinicola, R.S.; Simonds, F.W.; Defawe, Rose

    2005-01-01

    During May and June 2003, the U.S. Geological Survey installed monitoring wells and collected data to characterize the effectiveness of natural attenuation processes for remediating petroleum-contaminated ground water at Operable Unit A of the former Naval complex on Adak Island, Alaska. In addition, the evidence for petroleum biodegradation in ground water was evaluated at selected petroleum sites, plans for future natural attenuation monitoring were suggested for the selected petroleum sites, and the natural attenuation monitoring strategy for the Downtown area of Adak Island was reviewed and refinements were suggested. U.S. Geological Survey personnel measured water levels and collected ground-water samples from about 100 temporary boreholes and 50 monitoring wells. Most samples were analyzed on-site for concentrations of selected petroleum compounds and natural attenuation parameters such as dissolved oxygen, ferrous iron, and carbon dioxide. The U.S. Geological Survey evaluated the data on-site, selected new monitoring well locations, and installed, developed, and sampled 10 monitoring wells. The review and suggestions for the natural attenuation monitoring strategy focused on how to better achieve monitoring objectives specified in the Record of Decision for Adak Island petroleum sites. To achieve the monitoring objective of verifying that natural attenuation is occurring, the monitoring plans for each monitored natural attenuation site need to include sampling of at least one strategically placed well at the downgradient margin of the contaminant plume margin, preferably where contaminant concentrations are detectable but less than the cleanup level. Collection of natural attenuation parameter data and sampling background wells is no longer needed to achieve the monitoring objective of demonstrating the occurrence of natural attenuation. To achieve the objective of monitoring locations where chemical concentrations exceed specified cleanup levels, at least

  3. Oceanic loading monitored by ground-based tiltmeters at Cherbourg (France)

    Science.gov (United States)

    Florsch, Nicolas; Llubes, Muriel; Wöppelmann, Guy; Longuevergne, Laurent; Boy, Jean-Paul

    2009-12-01

    We installed two orthogonal Blum-Esnoult silica tiltmeters in an underground military facility close to the shore in Cherbourg (France). They have recorded the oceanic loading effects from March 2004 to July 2005. The signal to noise ratio is such that, within a period range from a few minutes to a few days, the main non-linear oceanic tides up to the M10 group can be observed. The modelling of the tidal tilt deformation has been carried out using oceanic models of the FES2004 family, with a stepwise refinement of the grid size based on the unstructured grid T-UGAm model leading to the NEA-2004 tidal solution. This improvement permits to reduce the discrepancy between the model and the data with respect to the use of FES2004 alone, and show that, although the misfit remains significant, one progresses toward an independent mean to validate the oceanic models and finally the whole modelling process. We also show that tiltmeters open new opportunities to explore loading of non-linear tides on a larger spectrum than gravimeters and GPS do.

  4. Identification and description of potential ground-water quality monitoring wells in Florida

    Science.gov (United States)

    Seaber, P.R.; Thagard, M.E.

    1986-01-01

    The results of a survey of existing wells in Florida that meet the following criteria are presented: (1) well location is known , (2) principal aquifer is known, (3) depth of well is known, (4) well casing depth is known, (5) well water had been analyzed between 1970 and 1982, and (6) well data are stored in the U.S. Geological Survey 's (USGS) computer files. Information for more than 20,000 wells in Florida were stored in the USGS Master Water Data Index of the National Water Data Exchange and in the National Water Data Storage and Retrieval System 's Groundwater Site Inventory computerized files in 1982. Wells in these computer files that had been sampled for groundwater quality before November 1982 in Florida number 13,739; 1,846 of these wells met the above criteria and are the potential (or candidate) groundwater quality monitoring wells included in this report. The distribution by principal aquifer of the 1,846 wells identified as potential groundwater quality monitoring wells is as follows: 1,022 tap the Floridan aquifer system, 114 tap the intermediate aquifers, 232 tap the surficial aquifers, 246 tap the Biscayne aquifer, and 232 tap the sand-and-gravel aquifer. These wells are located in 59 of Florida 's 67 counties. This report presents the station descriptions, which include location , site characteristics, period of record, and the type and frequency of chemical water quality data collected for each well. The 1,846 well locations are plotted on 14 USGS 1:250,000 scale, 1 degree by 2 degree, quadrangle maps. This relatively large number of potential (or candidate) monitoring wells, geographically and geohydrologically dispersed, provides a basis for a future groundwater quality monitoring network and computerized data base for Florida. There is a large variety of water quality determinations available from these wells, both areally and temporally. Future sampling of these wells would permit analyses of time and areal trends for selected water quality

  5. Rheticus Displacement: an Automatic Geo-Information Service Platform for Ground Instabilities Detection and Monitoring

    Science.gov (United States)

    Chiaradia, M. T.; Samarelli, S.; Agrimano, L.; Lorusso, A. P.; Nutricato, R.; Nitti, D. O.; Morea, A.; Tijani, K.

    2016-12-01

    Rheticus® is an innovative cloud-based data and services hub able to deliver Earth Observation added-value products through automatic complex processes and a minimum interaction with human operators. This target is achieved by means of programmable components working as different software layers in a modern enterprise system which relies on SOA (service-oriented-architecture) model. Due to its architecture, where every functionality is well defined and encapsulated in a standalone component, Rheticus is potentially highly scalable and distributable allowing different configurations depending on the user needs. Rheticus offers a portfolio of services, ranging from the detection and monitoring of geohazards and infrastructural instabilities, to marine water quality monitoring, wildfires detection or land cover monitoring. In this work, we outline the overall cloud-based platform and focus on the "Rheticus Displacement" service, aimed at providing accurate information to monitor movements occurring across landslide features or structural instabilities that could affect buildings or infrastructures. Using Sentinel-1 (S1) open data images and Multi-Temporal SAR Interferometry techniques (i.e., SPINUA), the service is complementary to traditional survey methods, providing a long-term solution to slope instability monitoring. Rheticus automatically browses and accesses (on a weekly basis) the products of the rolling archive of ESA S1 Scientific Data Hub; S1 data are then handled by a mature running processing chain, which is responsible of producing displacement maps immediately usable to measure with sub-centimetric precision movements of coherent points. Examples are provided, concerning the automatic displacement map generation process, as well as the integration of point and distributed scatterers, the integration of multi-sensors displacement maps (e.g., Sentinel-1 IW and COSMO-SkyMed HIMAGE), the combination of displacement rate maps acquired along both ascending

  6. Groundwater monitoring in the Savannah River Plant Low Level Waste Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.

    1983-12-31

    This document describes chemical mechanisms that may affect trace-level radionuclide migration through acidic sandy clay soils in a humid environment, and summarizes the extensive chemical and radiochemical analyses of the groundwater directly below the SRP Low-Level Waste (LLW) Burial Ground (643-G). Anomalies were identified in the chemistry of individual wells which appear to be related to small amounts of fission product activity that have reached the water table. The chemical properties which were statistically related to trace level transport of Cs-137 and Sr-90 were iron, potassium, sodium and calcium. Concentrations on the order of 100 ppM appear sufficient to affect nuclide migration. Several complexation mechanisms for plutonium migration were investigated.

  7. Estimating Saturated Hydraulic Conductivity from Surface Ground-Penetrating Radar Monitoring of Infiltration

    CERN Document Server

    Léger, Emmanuel; Coquet, Yves

    2013-01-01

    In this study we used Hydrus-1D to simulate water infiltration from a ring infiltrometer. We generated water content profiles at each time step of infiltration, based on a particular value of the saturated hydraulic conductivity while knowing the other van Genuchten parameters. Water content profiles were converted to dielectric permittivity profiles using the Complex Refractive Index Method relation. We then used the GprMax suite of programs to generate radargrams and to follow the wetting front using arrival time of electromagnetic waves recorded by a Ground-Penetrating Radar (GPR). Theoretically, the depth of the inflection point of the water content profile simulated at any infiltration time step is related to the peak of the reflected amplitude recorded in the corresponding trace in the radargram. We used this relationship to invert the saturated hydraulic conductivity for constant and falling head infiltrations. We present our method on synthetic examples and on two experiments carried out on sand. We f...

  8. Highly precise distributed Brillouin scattering sensor for structural health monitoring of optical ground wire cable

    Science.gov (United States)

    Zou, Lufan; Ravet, Fabien; Bao, Xiaoyi; Chen, Liang

    2004-07-01

    A distributed Brillouin scattering sensor with high special precision has been developed for the measurement of small damages/cracks of 1.5 cm. The out-layer damaged regions in an optical ground wire (OPGW) cable have been identified successfully by measuring the strain distributions every 5 cm using this technology. The stress increased to 127 kN which corresponds to more than 7500 micro-strain in the fibers. The locations of structural indentations comprising repaired and undamaged regions are found and distinguished using their corresponding strain data. The elongation of repaired region increases with time on 127 kN. These results are quantified in terms of the fiber orientation, stress, and behavior relative to undamaged sections.

  9. Monitoring Ground Subsidence in Hong Kong via Spaceborne Radar: Experiments and Validation

    Directory of Open Access Journals (Sweden)

    Yuxiao Qin

    2015-08-01

    Full Text Available The persistent scatterers interferometry (PSI technique is gradually becoming known for its capability of providing up to millimeter accuracy of measurement on ground displacement. Nevertheless, there is still quite a good amount of doubt regarding its correctness or accuracy. In this paper, we carried out an experiment corroborating the capability of the PSI technique with the help of a traditional survey method in the urban area of Hong Kong, China. Seventy three TerraSAR-X (TSX and TanDEM-X (TDX images spanning over four years are used for the data process. There are three aims of this study. The first is to generate a displacement map of urban Hong Kong and to check for spots with possible ground movements. This information will be provided to the local surveyors so that they can check these specific locations. The second is to validate if the accuracy of the PSI technique can indeed reach the millimeter level in this real application scenario. For validating the accuracy of PSI, four corner reflectors (CR were installed at a construction site on reclaimed land in Hong Kong. They were manually moved up or down by a few to tens of millimeters, and the value derived from the PSI analysis was compared to the true value. The experiment, carried out in unideal conditions, nevertheless proved undoubtedly that millimeter accuracy can be achieved by the PSI technique. The last is to evaluate the advantages and limitations of the PSI technique. Overall, the PSI technique can be extremely useful if used in collaboration with other techniques, so that the advantages can be highlighted and the drawbacks avoided.

  10. RCRA (Resource Conservation and Recovery Act of 1976) ground-water monitoring projects for Hanford facilities: Progress report, October 1--December 31, 1988: Volume 1, Text

    Energy Technology Data Exchange (ETDEWEB)

    Fruland, R.M.; Bates, D.J.; Lundgren, R.E.

    1989-04-01

    This report describes the progress of 13 Hanford ground-water monitoring projects for the period October 1 to December 31, 1988. There are 16 individual hazardous waste facilities covered by the 13 ground-water monitoring projects. The Grout Treatment Facility is included in this series of quarterly reports for the first time. The 13 projects discussed in this report were designed according to applicable interim-status ground-water monitoring requirements specified in the Resource Conservation and Recovery Act of 1976 (RCRA). During this quarter, field activities primarily consisted of sampling and analyses, and water-level monitoring. The 200 Areas Low-Level Burial Grounds section includes sediment analyses in addition to ground-water monitoring results. Twelve new wells were installed during the previous quarter: two at the 216-A-29 Ditch, six at the 216-A-10 Crib, and four at the 216-B-3 Pond. Preliminary characterization data for these new wells include drillers' logs and other drilling and site characterization data, and are provided in Volume 2 or on microfiche in the back of Volume 1. 26 refs., 28 figs., 74 tabs.

  11. Utilization of InSAR differential interferometry for surface deformation detection caused by mining

    Energy Technology Data Exchange (ETDEWEB)

    Yang, F. [Liaoning Technical Univ., Fuxin (China). School of Geomatics; Shao, Y. [Liaoning Technical Univ., Fuxin (China). Dept. of Foreign Language; Guichen, M. [Gifu Univ., Yanagido, Gifu (Japan). Dept. of Civil Engineering

    2010-07-01

    In China, the surface deformation of ground has been a significant geotechnical problem as a result of cracks in the ground surface, collapsing of house, and subsidence of roads. A powerful technology for detecting surface deformation in the ground is differential interferometry using synthetic aperture radar (INSAR). The technology enables the analysis from different phase of micro-wave between two observed data by synthetic aperture radar (SAR) of surface deformation of ground such as ground subsidence, land slide, and slope failure. In January 2006, the advanced land observing satellite was launched by the Japan Aerospace Exploration Agency. This paper presented an analytical investigation to detect ground subsidence or change caused by mining, overuse of ground water, and disaster. Specifically, the paper discussed the INSAR monitoring technology of the mine slope, including INSAR data sources and processing software; the principle of synthetic aperture radar interferometry; principles of differential SAR interferometry; and INSAR technology to slope monitoring of the Haizhou open pit mine. The paper also discussed the Haizhou strip mine side slope INSAR monitoring results and tests. It was concluded that the use of synthetic aperture radar interferometer technique was the optimal technique to provide three-dimensional spatial information and minimal change from ground surface by spatial remote sensing device. 18 refs., 5 figs.

  12. Space weather monitoring by ground-based means carried out in Polar Geophysical Center at Arctic and Antarctic Research Institute

    Science.gov (United States)

    Janzhura, Alexander

    A real-time information on geophysical processes in polar regions is very important for goals of Space Weather monitoring by the ground-based means. The modern communication systems and computer technology makes it possible to collect and process the data from remote sites without significant delays. A new acquisition equipment based on microprocessor modules and reliable in hush climatic conditions was deployed at the Roshydromet networks of geophysical observations in Arctic and is deployed at observatories in Antarctic. A contemporary system for on-line collecting and transmitting the geophysical data from the Arctic and Antarctic stations to AARI has been realized and the Polar Geophysical Center (PGC) arranged at AARI ensures the near-real time processing and analyzing the geophysical information from 11 stations in Arctic and 5 stations in Antarctic. The space weather monitoring by the ground based means is one of the main tasks standing before the Polar Geophysical Center. As studies by Troshichev and Janzhura, [2012] showed, the PC index characterizing the polar cap magnetic activity appeared to be an adequate indicator of the solar wind energy that entered into the magnetosphere and the energy that is accumulating in the magnetosphere. A great advantage of the PC index application over other methods based on satellite data is a permanent on-line availability of information about magnetic activity in both northern and southern polar caps. A special procedure agreed between Arctic and Antarctic Research Institute (AARI) and Space Institute of the Danish Technical University (DTUSpace) ensures calculation of the unified PC index in quasi-real time by magnetic data from the Thule and Vostok stations (see public site: http://pc-index.org). The method for estimation of AL and Dst indices (as indicators of state of the disturbed magnetosphere) based on data on foregoing PC indices has been elaborated and testified in the Polar Geophysical Center. It is

  13. Suitability of ground-based SfM-MVS for monitoring glacial and periglacial processes

    Science.gov (United States)

    Piermattei, Livia; Carturan, Luca; de Blasi, Fabrizio; Tarolli, Paolo; Dalla Fontana, Giancarlo; Vettore, Antonio; Pfeifer, Norbert

    2016-05-01

    Photo-based surface reconstruction is rapidly emerging as an alternative survey technique to lidar (light detection and ranging) in many fields of geoscience fostered by the recent development of computer vision algorithms such as structure from motion (SfM) and dense image matching such as multi-view stereo (MVS). The objectives of this work are to test the suitability of the ground-based SfM-MVS approach for calculating the geodetic mass balance of a 2.1 km2 glacier and for detecting the surface displacement of a neighbouring active rock glacier located in the eastern Italian Alps. The photos were acquired in 2013 and 2014 using a digital consumer-grade camera during single-day field surveys. Airborne laser scanning (ALS, otherwise known as airborne lidar) data were used as benchmarks to estimate the accuracy of the photogrammetric digital elevation models (DEMs) and the reliability of the method. The SfM-MVS approach enabled the reconstruction of high-quality DEMs, which provided estimates of glacial and periglacial processes similar to those achievable using ALS. In stable bedrock areas outside the glacier, the mean and the standard deviation of the elevation difference between the SfM-MVS DEM and the ALS DEM was -0.42 ± 1.72 and 0.03 ± 0.74 m in 2013 and 2014, respectively. The overall pattern of elevation loss and gain on the glacier were similar with both methods, ranging between -5.53 and + 3.48 m. In the rock glacier area, the elevation difference between the SfM-MVS DEM and the ALS DEM was 0.02 ± 0.17 m. The SfM-MVS was able to reproduce the patterns and the magnitudes of displacement of the rock glacier observed by the ALS, ranging between 0.00 and 0.48 m per year. The use of natural targets as ground control points, the occurrence of shadowed and low-contrast areas, and in particular the suboptimal camera network geometry imposed by the morphology of the study area were the main factors affecting the accuracy of photogrammetric DEMs negatively

  14. Results of ground-water, surface-water, and water-chemistry monitoring, Black Mesa area, northeastern Arizona, 1994

    Science.gov (United States)

    Littin, G.R.; Monroe, S.A.

    1995-01-01

    The Black Mesa monitoring program is designed to document long-term effects of ground-water pumping from the N aquifer by industrial and municipal users. The N aquifer is the major source of water in the 5,400-square-mile Black Mesa area, and the ground water occurs under confined and unconfined conditions. Monitoring activities include continuous and periodic measurements of (1) ground-water pumpage from the confined and unconfined areas of the aquifer, (2) ground-water levels in the confined and unconfined areas of the aquifer, (3) surface-water discharge, and (4) chemistry of the ground water and surface water. In 1994, ground-water withdrawals for industrial and municipal use totaled about 7,000 acre-feet, which is an 8-percent increase from the previous year. Pumpage from the confined part of the aquifer increased by about 9 percent to 5,400 acre-feet, and pumpage from the unconfined part of the aquifer increased by about 2 percent to 1,600 acre-feet. Water-level declines in the confined area during 1994 were recorded in 10 of 16 wells, and the median change was a decline of about 2.3 feet as opposed to a decline of 3.3 feet for the previous year. The median change in water levels in the unconfined area was a rise of 0.1 foot in 1994 as opposed to a decline of 0.5 foot in 1993. Measured low-flow discharge along Moenkopi Wash decreased from 3.0 cubic feet per second in 1993 to 2.9 cubic feet per second in 1994. Eleven low-flow measurements were made along Laguna Creek between Tsegi, Arizona, and Chinle Wash to determine the amount of discharge that would occur as seepage from the N aquifer under optimal base-flow conditions. Discharge was 5.6 cubic feet per second near Tsegi and 1.5 cubic feet per second above the confluence with Chinle Wash. Maximum discharge was 5.9 cubic feet per second about 4 miles upstream from Dennehotso. Discharge was measured at three springs. The changes in discharge at Burro and Whisky Springs were small and within the uncertainty of

  15. Ground calibration of the Chandrayaan-1 X-ray Solar Monitor (XSM)

    Energy Technology Data Exchange (ETDEWEB)

    Alha, L. [Observatory, P.O. Box 14, FI-00014 University of Helsinki (Finland)], E-mail: alha@mappi.helsinki.fi; Huovelin, J. [Observatory, P.O. Box 14, FI-00014 University of Helsinki (Finland); Nygard, K. [Division of X-ray Physics, Department of Physics, P.O. Box 64, FIN-00014 University of Helsinki (Finland); Andersson, H. [Oxford Instruments Analytical, P.O. Box 85, FIN-02631 Espoo (Finland); Esko, E. [Observatory, P.O. Box 14, FI-00014 University of Helsinki (Finland); Howe, C.J.; Kellett, B.J. [Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Narendranath, S. [Space Astronomy and Instrumentation Division, ISRO Satellite Centre, Bangalore 560017 (India); Maddison, B.J. [Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Crawford, I.A. [School of Earth Sciences, Birkbeck College, London (United Kingdom); Grande, M. [Institute of Mathematical and Physical Sciences, University of Wales, Aberystwyth, Ceredigion SY23 3BZ (United Kingdom); Shreekumar, P. [Space Astronomy and Instrumentation Division, ISRO Satellite Centre, Bangalore 560017 (India)

    2009-08-21

    The Chandrayaan-1 XSM ground calibrations are introduced. The aim of these calibrations was to characterize the performance of XSM, which enables a reliable spectral analysis with the solar X-ray data. The calibrations followed an improved procedure based on our experience from the SMART-1 XSM. The most important tasks in the calibrations were determination of the energy resolution as a function of the photon energy and mapping of the detector sensitivity over the FoV (Field of View) of the sensor. The FoV map was needed to determine the obscuration factor corresponding to various pointings with respect to the Sun. We made also a sensitivity comparison test between the Chandrayaan-1 XSM FM (Flight Model) and SMART-1 XSM FS (Flight Spare). The aim of this test was to link the new XSM performance to a performance of an already known and tested former instrument. We also performed a simple test to determine the pile up performance, and one specific test tailored for the operation of the new version of XSM. Also the first experiences on the in-flight operation are briefly described.

  16. Atmospheric Water Monitoring by Using Ground-Based GPS during Heavy Rains Produced by TPV and SWV

    Directory of Open Access Journals (Sweden)

    Guoping Li

    2013-01-01

    Full Text Available The time series of precipitable water (PW in 30 min intervals has been determined through experimentation and operational application of a ground-based global positioning system (GPS network in Chengdu Plain, which is used for precise and reliable meteorological research. This study is the first to apply PW to the southwest vortex (SWV and heavy rain events by using the data from an intensive SWV experiment conducted in summer 2010. The PW derived from the local ground-based GPS network was used in the monitoring and analysis of heavy rain caused by the SWV and the Tibetan Plateau vortex (TPV. Results indicate that an increase in GPS precipitable water (GPS-PW occurs prior to the development of the TPV and SWV; rainfall occurs mainly during high levels of GPS-PW. The evolution features of GPS-PW in rainfall process caused by different weather systems over the Tibetan Plateau (TP also differ. These results indicate the reference values for operational applications of GPS-PW data in short-term forecasting and nowcasting of high-impact weather in addition to further investigation of heavy rain caused by the TPV, SWV, and other severe weather systems over the TP.

  17. Seafloor monitoring west of Helgoland (German Bight, North Sea) using the acoustic ground discrimination system RoxAnn

    Science.gov (United States)

    Hass, H. Christian; Mielck, Finn; Fiorentino, Dario; Papenmeier, Svenja; Holler, Peter; Bartholomä, Alexander

    2017-04-01

    Marine habitats of shelf seas are in constant dynamic change and therefore need regular assessment particularly in areas of special interest. In this study, the single-beam acoustic ground discrimination system RoxAnn served to assess seafloor hardness and roughness, and combine these parameters into one variable expressed as RGB (red green blue) color code followed by k-means fuzzy cluster analysis (FCA). The data were collected at a monitoring site west of the island of Helgoland (German Bight, SE North Sea) in the course of four surveys between September 2011 and November 2014. The study area has complex characteristics varying from outcropping bedrock to sandy and muddy sectors with mostly gradual transitions. RoxAnn data enabled to discriminate all seafloor types that were suggested by ground-truth information (seafloor samples, video). The area appears to be quite stable overall; sediment import (including fluid mud) was detected only from the NW. Although hard substrates (boulders, bedrock) are clearly identified, the signal can be modified by inclination and biocover. Manually, six RoxAnn zones were identified; for the FCA, only three classes are suggested. The latter classification based on `hard' boundaries would suffice for stakeholder issues, but the former classification based on `soft' boundaries is preferred to meet state-of-the-art scientific objectives.

  18. Seafloor monitoring west of Helgoland (German Bight, North Sea) using the acoustic ground discrimination system RoxAnn

    Science.gov (United States)

    Hass, H. Christian; Mielck, Finn; Fiorentino, Dario; Papenmeier, Svenja; Holler, Peter; Bartholomä, Alexander

    2016-11-01

    Marine habitats of shelf seas are in constant dynamic change and therefore need regular assessment particularly in areas of special interest. In this study, the single-beam acoustic ground discrimination system RoxAnn served to assess seafloor hardness and roughness, and combine these parameters into one variable expressed as RGB (red green blue) color code followed by k-means fuzzy cluster analysis (FCA). The data were collected at a monitoring site west of the island of Helgoland (German Bight, SE North Sea) in the course of four surveys between September 2011 and November 2014. The study area has complex characteristics varying from outcropping bedrock to sandy and muddy sectors with mostly gradual transitions. RoxAnn data enabled to discriminate all seafloor types that were suggested by ground-truth information (seafloor samples, video). The area appears to be quite stable overall; sediment import (including fluid mud) was detected only from the NW. Although hard substrates (boulders, bedrock) are clearly identified, the signal can be modified by inclination and biocover. Manually, six RoxAnn zones were identified; for the FCA, only three classes are suggested. The latter classification based on `hard' boundaries would suffice for stakeholder issues, but the former classification based on `soft' boundaries is preferred to meet state-of-the-art scientific objectives.

  19. Development of a 22 GHz ground-based spectrometer for middle atmospheric water vapour monitoring

    Directory of Open Access Journals (Sweden)

    Pietro Paolo Bertagnolio

    2012-03-01

    Full Text Available The water Vapour Emission SPectrometer for Antarctica at 22 GHz (VESPA-22 has been designed for long-term middle atmospheric climate change monitoring and satellite data validation. It observes the water vapour spectral line at 22.235 GHz using the balanced beam-switching technique. The receiver antenna has been characterized, showing an HPBW of 3.5° and a sidelobe level 40 dB below the main lobe. The receiver front-end has a total gain of 105 dB and a LNA noise temperature of 125 K. A FFT spectrometer (bandwidth 1 GHz, resolution 63 kHz will be used as back-end, allowing the retrieval of H2O concentration profiles in the 20 to 80 km altitude range. The control I/O interface is based on reconfigurable hardware (USB-CPLD.

  20. 基于仿真计算的变形及应力监测%Simulation calculation of deformation and stress monitoring

    Institute of Scientific and Technical Information of China (English)

    蒋小青

    2015-01-01

    通过有限元程序Midas/Gen 6.9.1仿真计算施工方案及程序组织施工,并将仿真结果与现场实际变形及应力、裂缝监测进行对比,利用监测结果指导现场施工,确保了结构的顺利合龙。%Simulation calculation the construction scheme and the procedures of construction with the finite element software of Midas/Gen 6. 9. 1, and compared the simulation results with the actual deformation and stress,crack monitoring. Using the monitoring results guiding the construc-tion,to ensure that the structure of the successful closure.

  1. 矿区高精度GPS地表变形监测体系%High-precision surface deformation monitoring system with GPS in mining area

    Institute of Scientific and Technical Information of China (English)

    张敬霞; 刘超; 龙仁波; 王建鹏

    2013-01-01

    文章针对地表起伏较大或沟壑林立的矿区,引入GPS技术,建立了GPS矿区地表变形监测体系,结合具体的矿山生产案例,给出了该体系的基本技术流程及其数据结果,验证了采用GPS技术进行矿区高精度地表变形监测的可行性;建立了高精度三维变形监测基准网和区域似大地水准面模型,为矿区高精度正常高的快速获取以及多源变形数据的融合提供了有效的技术支持;以矿区地表变形规律的获取和高精度井塔实时动态监测为应用案例,说明了该监测体系的有效性.%In view of the variability of mine surfaces,global positioning system(GPS) technique is employed to establish the dynamic deformation monitoring system in mine area.Based on the productive practice in two coal mines,basic procedures of the system and detailed process of data processing are presented in order to verify the possibility of high-precision subsidence monitoring in mining area with GPS.High-precision 3D GPS control network and quasi-geoid model are constructed to offer the technical support for quickly acquiring the high-precision normal height and integrating the multi-source deformation data in mining area.Based on the deformation data measured by GPS,the surface movement and displacement law,surface movement parameters and shaft tower deformation can be obtained,showing the effectiveness of the monitoring system.

  2. Long-term dust climatology in the western United States reconstructed from routine aerosol ground monitoring

    Directory of Open Access Journals (Sweden)

    D. Q. Tong

    2012-06-01

    Full Text Available This study introduces an observation-based dust identification approach and applies it to reconstruct long-term dust climatology in the western United States. Long-term dust climatology is important for quantifying the effects of atmospheric aerosols on regional and global climate. Although many routine aerosol monitoring networks exist, it is often difficult to obtain dust records from these networks, because these monitors are either deployed far away from dust active regions (most likely collocated with dense population or contaminated by anthropogenic sources and other natural sources, such as wildfires and vegetation detritus. Here we propose an approach to identify local dust events relying solely on aerosol mass and composition from general-purpose aerosol measurements. Through analyzing the chemical and physical characteristics of aerosol observations during satellite-detected dust episodes, we select five indicators to be used to identify local dust records: (1 high PM10 concentrations; (2 low PM2.5/PM10 ratio; (3 higher concentrations and percentage of crustal elements; (4 lower percentage of anthropogenic pollutants; and (5 low enrichment factors of anthropogenic elements. After establishing these identification criteria, we conduct hierarchical cluster analysis for all validated aerosol measurement data over 68 IMPROVE sites in the western United States. A total of 182 local dust events were identified over 30 of the 68 locations from 2000 to 2007. These locations are either close to the four US Deserts, namely the Great Basin Desert, the Mojave Desert, the Sonoran Desert, and the Chihuahuan Desert, or in the high wind power region (Colorado. During the eight-year study period, the total number of dust events displays an interesting four-year activity cycle (one in 2000–2003 and the other in 2004–2007. The years of 2003, 2002 and 2007 are the three most active dust periods, with 46, 31 and 24

  3. An observation-based approach to identify local natural dust events from routine aerosol ground monitoring

    Directory of Open Access Journals (Sweden)

    D. Q. Tong

    2012-02-01

    Full Text Available Dust is a major component of atmospheric aerosols in many parts of the world. Although there exist many routine aerosol monitoring networks, it is often difficult to obtain dust records from these networks, because these monitors are either deployed far away from dust active regions (most likely collocated with dense population or contaminated by anthropogenic sources and other natural sources, such as wildfires and vegetation detritus. Here we propose a new approach to identify local dust events relying solely on aerosol mass and composition from general-purpose aerosol measurements. Through analyzing the chemical and physical characteristics of aerosol observations during satellite-detected dust episodes, we select five indicators to be used to identify local dust records: (1 high PM10 concentrations; (2 low PM2.5/PM10 ratio; (3 higher concentrations and percentage of crustal elements; (4 lower percentage of anthropogenic pollutants; and (5 low enrichment factors of anthropogenic elements. After establishing these identification criteria, we conduct hierarchical cluster analysis for all validated aerosol measurement data over 68 IMPROVE sites in the Western United States. A total of 182 local dust events were identified over 30 of the 68 locations from 2000 to 2007. These locations are either close to the four US Deserts, namely the Great Basin Desert, the Mojave Desert, the Sonoran Desert, and the Chihuahuan Desert, or in the high wind power region (Colorado. During the eight-year study period, the total number of dust events displays an interesting four-year activity cycle (one in 2000–2003 and the other in 2004–2007. The years of 2003, 2002 and 2007 are the three most active dust periods, with 46, 31 and 24 recorded dust events, respectively, while the years of 2000, 2004 and 2005 are the calmest periods, all with single digit dust records. Among these deserts, the Chihuahua Desert (59 cases and the

  4. Investigation of inhomogeneity and anisotropy in near ground layers of atmospheric air turbulence using image motion monitoring method

    Science.gov (United States)

    Mohammadi Razi, Ebrahim; Rasouli, Saifollah

    2017-01-01

    In this work the anisotropy and inhomogeneity of real atmospheric turbulence have been investigated using image motion monitoring and differential image motion monitoring methods. For this purpose the light beam of a point source is propagated through the atmospheric turbulence layers in horizontal path and then impinged to a telescope aperture. The telescope and point source were 350 m apart. In front of the telescope's aperture a mask consisting of four subapertures was installed. Image of the point source was formed on a sensitive CCD camera located at the focal plane of the telescope. By displacing CCD camera along the axis of telescope, four distinct images were recorded. Angle of arrival (AA) of each spot was calculated by image processing. Air turbulence causes AA to fluctuate. By comparing AA fluctuation variances of different spots in two directions isotropy and homogeneity of turbulence were studied. Results have shown that atmospheric turbulence in near ground layers is treated as an anisotropic and inhomogeneous medium. In addition, the inhomogeneity and anisotropy of turbulence decreases with the distance from earth surface.

  5. Use of combined Shewhart-CUSUM control charts for ground water monitoring applications

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, R.D.

    1999-10-01

    Statistical properties of combined Shewhart-CUSUM control charts are examined in terms of the site-wide false positive rate, false negative rate, and average run length (i.e., the average number of sampling events that it takes to detect a significant exceedance). The effects of multiple comparisons (i.e., multiple monitoring wells and constituents), verification resampling, background sample size, and background updating are incorporated into the analysis. The effects of (1) verification resampling plans including no resampling, pass one resample, pass one of two resamples, and pass two of two resamples; (2) background sample sizes (n = 8, 12, 16, 20, and 24); and (3) multiple comparisons (k = 1 to 500 future comparisons) were examined. In addition, various alternative control limit factors (h = SCL = 4.5, 5.0, 5.5, and 6.0) were considered, where the control limit is {bar x} + hs. Results of simulations revealed that it is possible to balance site-wide false positive and false negative rates at low levels using combined Shewhart-CUSUM control charts. The results revealed that it is important to select the appropriate multiplier, verification resampling plan, number of background samples, and number of intervening samples prior to updating background.

  6. Monitoring of atmospheric ozone and nitrogen dioxide over the south of Portugal by ground-based and satellite observations.

    Science.gov (United States)

    Bortoli, Daniele; Silva, Ana Maria; Costa, Maria João; Domingues, Ana Filipa; Giovanelli, Giorgio

    2009-07-20

    The SPATRAM (Spectrometer for Atmospheric TRAcers Monitoring) instrument has been developed as a result of the collaboration between CGE-UE, ISAC-CNR and Italian National Agency for New Technologies, Energy and the Environment (ENEA). SPATRAM is a multi-purpose UV-Vis-scanning spectrometer (250 - 950 nm) and it is installed at the Observatory of the CGE, in Evora, since April 2004. A brief description of the instrument is given, highlighting the technological innovations with respect to the previous version of similar equipment. The need for such measurements automatically taken on a routine basis in south-western European regions, specifically in Portugal, has encouraged the development and installation of the equipment and constitutes a major driving force for the present work. The main features and some improvements introduced in the DOAS (Differential Optical Absorption Spectroscopy) algorithms are discussed. The results obtained applying DOAS methodology to the SPATRAM spectrometer measurements of diffused spectral sky radiation are presented in terms of diurnal and seasonal variations of nitrogen dioxide (NO(2)) and ozone (O(3)). NO(2) confirms the typical seasonal cycle reaching the maximum of (6.5 +/- 0.3) x 10(+15) molecules cm(-2) for the sunset values (PM), during the summer season, and the minimum of (1.55 +/- 0.07) x 10(+15) molecules cm(-2) for the sunrise values (AM) in winter. O(3) presents the maximum total column of (433 +/- 5) Dobson Unit (DU) in the spring season and the minimum of (284 +/- 3) DU during the fall period. The huge daily variations of the O(3) total column during the spring season are analyzed and discussed. The ground-based results obtained for NO(2) and O(3) column contents are compared with data from satellite-borne equipment (GOME - Global Ozone Monitoring Experiment; SCIAMACHY - Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY; TOMS - Total Ozone Monitoring Spectrometer) and it is shown that the two data

  7. Design of the Mexico City UV monitoring network: UV-B measurements at ground level in the urban environment

    Science.gov (United States)

    Acosta, L. R.; Evans, W. F. J.

    2000-02-01

    Although there is concern for future stratospheric ozone depletion, several large urban populations are already being exposed to very high UV levels due to geographical factors. In Mexico City, ultraviolet radiation (UV) plays an important role in the generation of high levels of tropospheric ozone and other photochemical pollutants. The measurement of ultraviolet-B radiation in Mexico began in the spring 1993, as a pilot project for ultraviolet-B (UV-B) monitoring and as support for the first Hispanic public information program on the UV index through the Televisa (Mexican television network, which covers the Spanish speaking world). In 1996, based on our preliminary measurements, the Mexico City government commissioned the authors to design the Valley of Mexico UV-monitoring Network. The design of the network is presented. The preliminary measurements show that biologically active (UV-B) solar radiation can reach levels above 5 minimum erythemal dose (MED/hour) or 12 UV index units during spring and summer months. Annual UV measurements have shown seasonal variations of 40% between winter and summer months. Strong attenuation of UV-B radiation at ground level in the urban troposphere has been detected under polluted conditions. Measurements of the morphology of UV-B radiation have been taken at downtown and suburban monitoring stations, over diurnal, monthly and yearly periods. The network measurements show that the downtown UV-B levels are 20% lower than suburban levels on a seasonal basis, but differences can be greater than 40% on polluted days. The relationship between the Total Ozone Mapping Spectrometer (TOMS) total ozone column and tropospheric ozone concentrations in Mexico City is also discussed.

  8. The structurally-controlled rockslide of Barmasse (Valais, Switzerland): structural geology, ground-based monitoring and displacement vs. rainfall modeling.

    Science.gov (United States)

    Michoud, C.; Abellan, A.; Baillifard, F.-J.; Demierre, J.; Derron, M.-H.; Jaboyedoff, M.; Jakubowski, J.; May-Delasoie, F.

    2012-04-01

    In this communication, we show a case study on the Barmasse rockslide (Val de Bagnes, Valais, Switzerland), which is an active structurally-controlled instability that threaten roads and inhabitants. The entire slope is included within the Middle Penninic unit. According to regional tectonic stresses, the micaschists that compose the instability have been intensively deformed and metamorphised leading to an important foliation and fracturing. Structural settings have been extracted from 3D points-clouds of the crown area. These datasets were acquired with a terrestrial LiDAR (TLS) and processed with Coltop-3D software. The landslide can be defined as a complex instability, with a continuous movement on a basal surface. This deformation also generates a frequent rockfall activity in the upper part of the slope. The landslide was monitoring using different remote sensing techniques (TLS, GNSS and GB-InSAR): a) regarding TLS measurements, we monitored long term 3D displacements comparing two different TLS points clouds acquired in 2009 and 2011, showing more than 3 m displacements in two years in the upper part of the slope (crown area); b) differential GNSS measures were obtained at the toe of the slide, validating TLS measurements in those areas were vegetation hampered remote sensing measurement; c) finally the landslide was also monitored by a GB-InSAR in order to investigate short term displacements. The experiment was carried out during summer 2011, recording displacement rates exceeding 7 mm in 12 h in the main scarp, and confirmed the high amplitude of daily displacements. We are also continuously recording landslide displacements at a daily rate over the most active part of the slope using one crackmeter. The kinematics of the landslide is characterized by a continuous displacement (3rd creep state) which is clearly controlled by external forces (rainfall episodes): on the one side, landslide velocity sharply increases it value after rainfall episodes; on the

  9. Tunnel large deformation of surrounding rock research based on radar information and monitoring warning%基于雷达信息与监测预警的隧道围岩大变形研究

    Institute of Scientific and Technical Information of China (English)

    董辉; 陈家博; 杨珺博; 侯俊敏

    2012-01-01

    针对公路隧道溶洞和孔洞的存在给围岩的稳定性控制带来不同程度的困难且围岩大变形极易发生而造成工程事故,采用探地雷达超前探测和监控量测,归纳分析隧道围岩大变形的异常特征,并进一步通过贵州省晴兴高速公路登攀隧道出口围岩大变形预警的工程实例进行验算,获得黔西南区强风化多孔玄武岩及下伏灰岩溶洞雷达图像特征:有充填物时反射波振幅在洞腔范围内衰减强烈,强弱相间;无充填物时反射波基本无衰减,存在中断、起伏和错动现象。围岩大变形监测以拱顶下沉为主,21d最大累计沉降值达到89.40mm,变形速率最大波动范围为14.66~0.64mm/d。应用此结论可以在围岩出现大变形时及时预警并采取控制措施,更好地为后续工程服务。%Aiming at the existence of caves and holes in high.way tunnel will cause difficulty for surrounding rock' s stability in varying degrees and it is prone to result in large deformation of surrounding rock, cause accident, the paper summarizes and analyzes the abnormal characteristics of tunnel large deformation of surrounding rock by advanced detection of ground penetrating radar and monitoring. Meanwhile, with the project of Qingxing highway Dengpan tunnel exit surrounding rock' s large deformation and warning, we obtain radar images' characteristics to highly weathered porous basalt and underlying limestone caves in southwest of Guizhou province: reflection amplitude attenuates strongly and strength of the white in filling caves and there is almost no attenuation but with the phenomenon of disruption, ups and downs and dislocation in inanition. On the other side, when large deformation of surrounding rock is mainly vault sedimentation, its maximum cumulative settlement is 89.40mm during 21 days and deformation rate fluctuates from 14.66mm to 0.64mm per day. With the conclusion, it should be warned and take control measures timely

  10. The VENICE Project : A GPS Network to Monitor the Deformation of Western Provence and Eastern Languedoc (Southern France)

    Science.gov (United States)

    Masson, F.; Collard, P.; Chéry, J.; Ritz, J.-F.; Doerflinger, E.; Bellier, O.; Chardon, D.; Flouzat, M.

    2003-04-01

    The present-day tectonic activity of the Western Provence - Eastern Languedoc region is demonstrated by moderate seismicity (magnitudes of 5-6.5 and recurrence periods of several tens of thousands of years for the strongest events) and sparse geological and geomorphological observations of recent deformation. It probably results from the convergence between Africa and Europe which proceeds at a rate of ~0.6 cm/year around the Western Mediterranean region. It includes E-trending fold and thrust belts (Mont-Ventoux, Luberon, Costes, Trévaresse) and NNE-trending left-lateral strike-slip faults (Moyenne Durance, Nîmes and possibly Cévennes). Regional stress field determined from inversion of earthquake focal mechanisms suggests a drastic change in the stress regime from West to East. It is extensional with an E-trending s3 axis in the western zone, along the Rhône Valley, while it is compressional in the eastern part, with an about N- to NNE-trending s1. However the present-day kinematics of the deformation in the region are still largely unknown. GPS measurements provide unique data sets for assessing crustal deformation in regions of low strain rates. In 2001, we started the implementation of a network of 15 GPS stations measured each six months during a period of 2-3 weeks (VENICE - Ventoux/Nîmes/Cévennes - semipermanent network). We are complementing this network by stations implemented around the Trevaresse ridge, reactivated by the 1909 Lambesc (M=6) earthquake. The network is designed to surround most of the faults and to be able to record co-seismic displacement in case of low magnitude earthquakes (magnitude 5-5.5). We will present the objectives of the VENICE project, the GPS networks and the first results quantifying the quality of the data by a careful study of the repeatability.

  11. Diffeomorphic Statistical Deformation Models

    DEFF Research Database (Denmark)

    Hansen, Michael Sass; Hansen, Mads/Fogtman; Larsen, Rasmus

    2007-01-01

    In this paper we present a new method for constructing diffeomorphic statistical deformation models in arbitrary dimensional images with a nonlinear generative model and a linear parameter space. Our deformation model is a modified version of the diffeomorphic model introduced by Cootes et al. Th...... with ground truth in form of manual expert annotations, and compared to Cootes's model. We anticipate applications in unconstrained diffeomorphic synthesis of images, e.g. for tracking, segmentation, registration or classification purposes....

  12. Monitoring soil moisture patterns in alpine meadows using ground sensor networks and remote sensing techniques

    Science.gov (United States)

    Bertoldi, Giacomo; Brenner, Johannes; Notarnicola, Claudia; Greifeneder, Felix; Nicolini, Irene; Della Chiesa, Stefano; Niedrist, Georg; Tappeiner, Ulrike

    2015-04-01

    Soil moisture content (SMC) is a key factor for numerous processes, including runoff generation, groundwater recharge, evapotranspiration, soil respiration, and biological productivity. Understanding the controls on the spatial and temporal variability of SMC in mountain catchments is an essential step towards improving quantitative predictions of catchment hydrological processes and related ecosystem services. The interacting influences of precipitation, soil properties, vegetation, and topography on SMC and the influence of SMC patterns on runoff generation processes have been extensively investigated (Vereecken et al., 2014). However, in mountain areas, obtaining reliable SMC estimations is still challenging, because of the high variability in topography, soil and vegetation properties. In the last few years, there has been an increasing interest in the estimation of surface SMC at local scales. On the one hand, low cost wireless sensor networks provide high-resolution SMC time series. On the other hand, active remote sensing microwave techniques, such as Synthetic Aperture Radars (SARs), show promising results (Bertoldi et al. 2014). As these data provide continuous coverage of large spatial extents with high spatial resolution (10-20 m), they are particularly in demand for mountain areas. However, there are still limitations related to the fact that the SAR signal can penetrate only a few centimeters in the soil. Moreover, the signal is strongly influenced by vegetation, surface roughness and topography. In this contribution, we analyse the spatial and temporal dynamics of surface and root-zone SMC (2.5 - 5 - 25 cm depth) of alpine meadows and pastures in the Long Term Ecological Research (LTER) Area Mazia Valley (South Tyrol - Italy) with different techniques: (I) a network of 18 stations; (II) field campaigns with mobile ground sensors; (III) 20-m resolution RADARSAT2 SAR images; (IV) numerical simulations using the GEOtop hydrological model (Rigon et al

  13. The Prospect of using Three-Dimensional Earth Models To Improve Nuclear Explosion Monitoring and Ground Motion Hazard Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Zucca, J J; Walter, W R; Rodgers, A J; Richards, P; Pasyanos, M E; Myers, S C; Lay, T; Harris, D; Antoun, T

    2008-11-19

    The last ten years have brought rapid growth in the development and use of three-dimensional (3D) seismic models of Earth structure at crustal, regional and global scales. In order to explore the potential for 3D seismic models to contribute to important societal applications, Lawrence Livermore National Laboratory (LLNL) hosted a 'Workshop on Multi-Resolution 3D Earth Models to Predict Key Observables in Seismic Monitoring and Related Fields' on June 6 and 7, 2007 in Berkeley, California. The workshop brought together academic, government and industry leaders in the research programs developing 3D seismic models and methods for the nuclear explosion monitoring and seismic ground motion hazard communities. The workshop was designed to assess the current state of work in 3D seismology and to discuss a path forward for determining if and how 3D Earth models and techniques can be used to achieve measurable increases in our capabilities for monitoring underground nuclear explosions and characterizing seismic ground motion hazards. This paper highlights some of the presentations, issues, and discussions at the workshop and proposes two specific paths by which to begin quantifying the potential contribution of progressively refined 3D seismic models in critical applied arenas. Seismic monitoring agencies are tasked with detection, location, and characterization of seismic activity in near real time. In the case of nuclear explosion monitoring or seismic hazard, decisions to further investigate a suspect event or to launch disaster relief efforts may rely heavily on real-time analysis and results. Because these are weighty decisions, monitoring agencies are regularly called upon to meticulously document and justify every aspect of their monitoring system. In order to meet this level of scrutiny and maintain operational robustness requirements, only mature technologies are considered for operational monitoring systems, and operational technology necessarily lags

  14. 6. International FIG-symposium on deformation measurements. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Pelzer, H.; Heer, R. [eds.

    1996-12-31

    Due to the diversified fields of specialization of the authors, the papers span a very wide spectrum of theories, applications and case studies, concerning various problems of deformation studies in structural, geotechnical and mining engineering, in rock mechanics and earth crustal movements, covering such topics as: Design and analysis of deformations surveys; Integration of terrestrial, and space measurement techniques; New instrumental developements for automatic, continuous and telemetric data-acquisition with respect to geotechnical and geodetic applications; Monitoring and prediction of ground subsidence in mining areas, land slides and tectonic movements; Modeling and computation of deformations by Kalman-filtering techniques, finite element analysis and a special view to continuum mechanics; Application of expert systems and artificial intelligence; Description and analysis of dynamical deformation problems; special views in rock- and groundmechanics; Demonstration of mechanical engineering problems with respect to the supervision of industrial production and quality control. (orig.)

  15. Analysis of building deformation in landslide area using multisensor PSInSAR™ technique.

    Science.gov (United States)

    Ciampalini, Andrea; Bardi, Federica; Bianchini, Silvia; Frodella, William; Del Ventisette, Chiara; Moretti, Sandro; Casagli, Nicola

    2014-12-01

    Buildings are sensitive to movements caused by ground deformation. The mapping both of spatial and temporal distribution, and of the degree of building damages represents a useful tool in order to understand the landslide evolution, magnitude and stress distribution. The high spatial resolution of space-borne SAR interferometry can be used to monitor displacements related to building deformations. In particular, PSInSAR technique is used to map and monitor ground deformation with millimeter accuracy. The usefulness of the above mentioned methods was evaluated in San Fratello municipality (Sicily, Italy), which was historically affected by landslides: the most recent one occurred on 14th February 2010. PSInSAR data collected by ERS 1/2, ENVISAT, RADARSAT-1 were used to study the building deformation velocities before the 2010 landslide. The X-band sensors COSMO-SkyMed and TerraSAR-X were used in order to monitor the building deformation after this event. During 2013, after accurate field inspection on buildings and structures, damage assessment map of San Fratello were created and then compared to the building deformation velocity maps. The most interesting results were obtained by the comparison between the building deformation velocity map obtained through COSMO-SkyMed and the damage assessment map. This approach can be profitably used by local and Civil Protection Authorities to manage the post-event phase and evaluate the residual risks.

  16. Long-term ground-water monitoring program and performance-evaluation plan for the extraction system at the former Nike Missile Battery Site, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Senus, Michael P.; Tenbus, Frederick J.

    2000-01-01

    This report presents lithologic and ground-water-quality data collected during April and May 2000 in the remote areas of the tidal wetland of West Branch Canal Creek, Aberdeen Proving Ground, Maryland. Contamination of the Canal Creek aquifer with volatile organic compounds has been documented in previous investigations of the area. This study was conducted to investigate areas that were previously inaccessible because of deep mud and shallow water, and to support ongoing investigations of the fate and transport of volatile organic compounds in the Canal Creek aquifer. A unique vibracore drill rig mounted on a hovercraft was used for drilling and ground-water sampling. Continuous cores of the wetland sediment and of the Canal Creek aquifer were collected at five sites. Attempts to sample ground water were made by use of a continuous profiler at 12 sites, without well installation, at a total of 81 depths within the aquifer. Of those 81 attempts, only 34 sampling depths produced enough water to collect samples. Ground-water samples from two sites had the highest concentrations of volatile organic compounds?with total volatile organic compound concentrations in the upper part of the aquifer ranging from about 15,000 to 50,000 micrograms per liter. Ground-water samples from five sites had much lower total volatile organic compound concentrations (95 to 2,100 micrograms per liter), whereas two sites were essentially not contaminated, with total volatile organic compound concentrations less than or equal to 5 micrograms per liter.

  17. Question No. 5: What Role Can Satellites Take, as a Complement to Ground Based Measurement Systems, to Provide Sustained Observations to Monitor GHG Emissions?

    Science.gov (United States)

    Chahine, Moustafa; Olsen, Edward

    2011-01-01

    What role can satellites take, as a complement to ground based measurement systems, to provide sustained observations to monitor GHG emissions (e.g., CO2, CH4, O3, N2O, CFC s, NH3, and NF3) that contribute to global warming?

  18. Long-term sequential monitoring of controlled graves representing common burial scenarios with ground penetrating radar: Years 2 and 3

    Science.gov (United States)

    Schultz, John J.; Walter, Brittany S.; Healy, Carrie

    2016-09-01

    Geophysical techniques such as ground-penetrating radar (GPR) have been successfully used for forensic searches to locate clandestine graves and physical evidence. However, additional controlled research is needed to fully understand the applicability of this technology when searching for clandestine graves in various environments, soil types, and for longer periods of time post-burial. The purpose of this study was to determine the applicability of GPR for detecting controlled graves in a Spodosol representing multiple burial scenarios for Years 2 and 3 of a three-year monitoring period. Objectives included determining how different burial scenarios are factors in producing a distinctive anomalous response; determining how different GPR imagery options (2D reflection profiles and horizontal time slices) can provide increased visibility of the burials; and comparing GPR imagery between 500 MHz and 250 MHz dominant frequency antennae. The research site contained a grid with eight graves representing common forensic burial scenarios in a Spodosol, a common soil type of Florida, with six graves containing a pig carcass (Sus scrofa). Burial scenarios with grave items (a deep grave with a layer of rocks over the carcass and a carcass wrapped in a tarpaulin) produced a more distinctive response with clearer target reflections over the duration of the monitoring period compared to naked carcasses. Months with increased precipitation were also found to produce clearer target reflections than drier months, particularly during Year 3 when many grave scenarios that were not previously visible became visible after increased seasonal rainfall. Overall, the 250 MHz dominant frequency antenna imagery was more favorable than the 500 MHz. While detection of a simulated grave may be difficult to detect over time, long term detection of a grave in a Spodosol may be possible if the disturbed spodic horizon is detected. Furthermore, while grave visibility increased with the 2D

  19. THE STRESS-STRAIN STATE OF AN INFINITELY LONG ELASTIC ARRAYS OF DIFFERENT WIDTHS AND LIMITED THICKNESS ON THE HARD GROUND WHEN THEY HAVE FLAT DEFORMATION

    Directory of Open Access Journals (Sweden)

    I. K. Badalakha

    2009-12-01

    Full Text Available The article presents the results of solving several problems of a flat deformation of elastic infinitely long massifs of different width and limited thickness. Various cases of conditions at the massif/base contact. The relationships between stressed and strained states previously suggested by the author, which differ from the generalized Hooke’s law, are used in the solutions.

  20. Analysis and Treatment of Abnormal Displacement Monitoring Values in a Vacuum Laser Deformation Monitoring System%真空激光变形监测系统位移规律异常分析研究

    Institute of Scientific and Technical Information of China (English)

    赵杰; 徐翔

    2016-01-01

    介绍了深溪沟水电站坝顶真空激光变形监测系统位移规律的异常现象,就此进行系统的异常原因分析及测试,并对分析成果进行复核验证。通过对归一系数的改正,有效解决了坝顶真空激光垂直方向和水平方向位移变形规律均呈现“锯齿状”的异常规律,坝段间(或坝块间)相邻测点变形差异和坝顶不均匀上抬现象得到明显改善,可供后续工程参考和借鉴。%In the displacement monitoring values obtained from the vacuum laser deformation monitoring system in Shenxigou Hydropower Station , abnormal zigzag changes are observed .Reasons of this problem are analyzed .Treatment measures are then proposed and tested .With a correction of the normalization coefficient , the abnormal zigzag phenome-na in the vertical and horizontal displacement monitoring values of the dam crest are effectively removed .Also, the de-formation differences between monitoring points of adjacent dam sections ( or dam blocks ) and uneven uplift in the dam crest are also improved .It could be a useful reference for similar projects .

  1. Ground-water-level monitoring, basin boundaries, and potentiometric surfaces of the aquifer system at Edwards Air Force Base, California, 1992

    Science.gov (United States)

    Rewis, D.L.

    1995-01-01

    A ground-water-level monitoring program was implemented at Edwards Air Force Base, California, from January through December 1992 to monitor spatial and temporal changes in poten-tiometric surfaces that largely are affected by ground-water pumping. Potentiometric-surface maps are needed to determine the correlation between declining ground- water levels and the distribution of land subsidence. The monitoring program focused on areas of the base where pumping has occurred, especially near Rogers Lake, and involved three phases of data collection: (1) well canvassing and selection, (2) geodetic surveys, and (3) monthly ground-water-level measurements. Construction and historical water- level data were compiled for 118 wells and pi-ezometers on or near the base, and monthly ground-water-level measurements were made in 82 wells and piezometers on the base. The compiled water-level data were used in conjunction with previously collected geologic data to identify three types of no-flow boundaries in the aquifer system: structural boundaries, a principal-aquifer boundary, and ground-water divides. Heads were computed from ground-water-level measurements and land-surface altitudes and then were used to map seasonal potentiometric surfaces for the principal and deep aquifers underlying the base. Pumping has created a regional depression in the potentiometric surface of the deep aquifer in the South Track, South Base, and Branch Park well-field area. A 15-foot decline in the potentiometric surface from April to September 1992 and 20- to 30-foot drawdowns in the three production wells in the South Track well field caused locally unconfined conditions in the deep aquifer.

  2. Comparison of - and Mutual Informaton Based Calibration of Terrestrial Laser Scanner and Digital Camera for Deformation Monitoring

    Science.gov (United States)

    Omidalizarandi, M.; Neumann, I.

    2015-12-01

    In the current state-of-the-art, geodetic deformation analysis of natural and artificial objects (e.g. dams, bridges,...) is an ongoing research in both static and kinematic mode and has received considerable interest by researchers and geodetic engineers. In this work, due to increasing the accuracy of geodetic deformation analysis, a terrestrial laser scanner (TLS; here the Zoller+Fröhlich IMAGER 5006) and a high resolution digital camera (Nikon D750) are integrated to complementarily benefit from each other. In order to optimally combine the acquired data of the hybrid sensor system, a highly accurate estimation of the extrinsic calibration parameters between TLS and digital camera is a vital preliminary step. Thus, the calibration of the aforementioned hybrid sensor system can be separated into three single calibrations: calibration of the camera, calibration of the TLS and extrinsic calibration between TLS and digital camera. In this research, we focus on highly accurate estimating extrinsic parameters between fused sensors and target- and targetless (mutual information) based methods are applied. In target-based calibration, different types of observations (image coordinates, TLS measurements and laser tracker measurements for validation) are utilized and variance component estimation is applied to optimally assign adequate weights to the observations. Space resection bundle adjustment based on the collinearity equations is solved using Gauss-Markov and Gauss-Helmert model. Statistical tests are performed to discard outliers and large residuals in the adjustment procedure. At the end, the two aforementioned approaches are compared and advantages and disadvantages of them are investigated and numerical results are presented and discussed.

  3. COMPARISON OF TARGET- AND MUTUAL INFORMATON BASED CALIBRATION OF TERRESTRIAL LASER SCANNER AND DIGITAL CAMERA FOR DEFORMATION MONITORING

    Directory of Open Access Journals (Sweden)

    M. Omidalizarandi

    2015-12-01

    Full Text Available In the current state-of-the-art, geodetic deformation analysis of natural and artificial objects (e.g. dams, bridges,... is an ongoing research in both static and kinematic mode and has received considerable interest by researchers and geodetic engineers. In this work, due to increasing the accuracy of geodetic deformation analysis, a terrestrial laser scanner (TLS; here the Zoller+Fröhlich IMAGER 5006 and a high resolution digital camera (Nikon D750 are integrated to complementarily benefit from each other. In order to optimally combine the acquired data of the hybrid sensor system, a highly accurate estimation of the extrinsic calibration parameters between TLS and digital camera is a vital preliminary step. Thus, the calibration of the aforementioned hybrid sensor system can be separated into three single calibrations: calibration of the camera, calibration of the TLS and extrinsic calibration between TLS and digital camera. In this research, we focus on highly accurate estimating extrinsic parameters between fused sensors and target- and targetless (mutual information based methods are applied. In target-based calibration, different types of observations (image coordinates, TLS measurements and laser tracker measurements for validation are utilized and variance component estimation is applied to optimally assign adequate weights to the observations. Space resection bundle adjustment based on the collinearity equations is solved using Gauss-Markov and Gauss-Helmert model. Statistical tests are performed to discard outliers and large residuals in the adjustment procedure. At the end, the two aforementioned approaches are compared and advantages and disadvantages of them are investigated and numerical results are presented and discussed.

  4. 基于GPRS和PLC的飞机地面除冰监控系统%Aircraft ground deicing monitoring system based on GPRS and PLC

    Institute of Scientific and Technical Information of China (English)

    王立文; 陈垣均; 陈斌

    2016-01-01

    针对飞机地面除冰系统的远程管理和维护需求,提出基于 GPRS DTU (data transfer unit)通信模块和 PLC 控制单元的飞机地面除冰远程监控系统方案。通过以松下PLC为主控制单元的飞机地面除冰系统终端,将系统运行状况和故障信息经 GPRS网络实时传送到远程监控中心,经过对远程监控中心上位机软件的操纵,实现对飞机地面除冰系统的远程监测与控制,解决机场特殊环境下对飞机地面除冰信息传输和运行监控的难题。测试结果验证了该方案的可行性。%According to remote management and maintenance requirements of aircraft ground deicing system,the program of air-craft ground deicing remote monitoring system was proposed based on GPRS DTU and PLC control unit.Through aircraft ground deicing system terminal based on Panasonic PLC control unit,the system running status and fault information were real-time sent to the remote monitoring center via the GPRS network.The software of computer monitoring center was operated,re-mote measure and control of aircraft ground deicing system was realized.The problems of information transmitting and operation monitoring about aircraft ground deicing system were solved in the special environment at the airport.Testing results show that the monitoring system program is feasible.

  5. Preliminary results of sequential monitoring of simulated clandestine graves in Colombia, South America, using ground penetrating radar and botany.

    Science.gov (United States)

    Molina, Carlos Martin; Pringle, Jamie K; Saumett, Miguel; Hernández, Orlando

    2015-03-01

    In most Latin American countries there are significant numbers of missing people and forced disappearances, 68,000 alone currently in Colombia. Successful detection of shallow buried human remains by forensic search teams is difficult in varying terrain and climates. This research has created three simulated clandestine burial styles at two different depths commonly encountered in Latin America to gain knowledge of optimum forensic geophysics detection techniques. Repeated monitoring of the graves post-burial was undertaken by ground penetrating radar. Radar survey 2D profile results show reasonable detection of ½ clothed pig cadavers up to 19 weeks of burial, with decreasing confidence after this time. Simulated burials using skeletonized human remains were not able to be imaged after 19 weeks of burial, with beheaded and burnt human remains not being able to be detected throughout the survey period. Horizontal radar time slices showed good early results up to 19 weeks of burial as more area was covered and bi-directional surveys were collected, but these decreased in amplitude over time. Deeper burials were all harder to image than shallower ones. Analysis of excavated soil found soil moisture content almost double compared to those reported from temperate climate studies. Vegetation variations over the simulated graves were also noted which would provide promising indicators for grave detection.

  6. High-resolution remote sensing image-based extensive deformation-induced landslide displacement field monitoring method

    Institute of Scientific and Technical Information of China (English)

    Shanjun Liu; Han Wang; Jianwei Huang; Lixin Wu

    2015-01-01

    Landslide is one of the multitudinous serious geological hazards. The key to its control and reduction lies on dynamic monitoring and early warning. The article points out the insufficiency of traditional measuring means applied for large-scale landslide monitoring and proposes the method for extensive landslide displacement field monitoring using high-resolution remote images. Matching of cognominal points is realized by using the invariant features of SIFT algorithm in image translation, rotation, zooming, and affine transformation, and through recognition and comparison of characteristics of high-resolution images in different landsliding periods. Following that, landslide displacement vector field can be made known by measuring the distances and directions between cognominal points. As evidenced by field application of the method for landslide monitoring at West Open Mine in Fushun city of China, the method has the attraction of being able to make areal measurement through satellite observation and capable of obtaining at the same time the information of large-area intensive displacement field, for facilitating automatic delimitation of extent of landslide displacement vector field and sliding mass. This can serve as a basis for making analysis of laws governing occurrence of landslide and adoption of countermeasures.

  7. Ground deformation and source geometry of the 24 August 2016 Amatrice earthquake (Central Italy) investigated through analytical and numerical modeling of DInSAR measurements and structural-geological data

    Science.gov (United States)

    Lavecchia, G.; Castaldo, R.; Nardis, R.; De Novellis, V.; Ferrarini, F.; Pepe, S.; Brozzetti, F.; Solaro, G.; Cirillo, D.; Bonano, M.; Boncio, P.; Casu, F.; De Luca, C.; Lanari, R.; Manunta, M.; Manzo, M.; Pepe, A.; Zinno, I.; Tizzani, P.

    2016-12-01

    We investigate the ground deformation and source geometry of the 2016 Amatrice earthquake (Central Italy) by exploiting ALOS2 and Sentinel-1 coseismic differential interferometric synthetic aperture radar (DInSAR) measurements. They reveal two NNW-SSE striking surface deformation lobes, which could be the effect of two distinct faults or the rupture propagation of a single fault. We examine both cases through a single and a double dislocation planar source. Subsequently, we extend our analysis by applying a 3-D finite elements approach jointly exploiting DInSAR measurements and an independent, structurally constrained, 3-D fault model. This model is based on a double fault system including the two northern Gorzano and Redentore-Vettoretto faults (NGF and RVF) which merge into a single WSW dipping fault surface at the hypocentral depth (8 km). The retrieved best fit coseismic surface deformation pattern well supports the exploited structural model. The maximum displacements occur at 5-7 km depth, reaching 90 cm on the RVF footwall and 80 cm on the NGF hanging wall. The von Mises stress field confirms the retrieved seismogenic scenario.

  8. Deep soil compaction as a method of ground improvement and to stabilization of wastes and slopes with danger of liquefaction, determining the modulus of deformation and shear strength parameters of loose rock.

    Science.gov (United States)

    Lersow, M

    2001-01-01

    For the stabilization of dumps with the construction of hidden dams and for building ground improvement, for instance for traffic lines over dumps, nearly all applied compaction methods have the aim to reduce the pore volume in the loose rock. With these methods, a homogenization of the compacted loose rock will be obtained too. The compaction methods of weight compaction by falling weight, compaction by vibration and compaction by blasting have been introduced, and their applications and efficiencies have been shown. For the estimation of the effective depth of the compaction and for a safe planning of the bearing layer, respectively, the necessary material parameters have to be determined for each deep compaction method. Proposals for the determination of these parameters have been made within this paper. In connection with the stabilization of flow-slide-prone dump slopes, as well as for the improvement of dump areas for the use as building ground, it is necessary to assess the deformation behavior and the bearing capacity. To assess the resulting building ground improvement, deformation indexes (assessment of the flow-prone layer) and strength indexes (assessment of the bearing capacity) have to be determined with soil mechanical tests. Förster and Lersow, [Patentschrift DE 197 17 988. Verfahren, auf der Grundlage last- und/oder weggesteuerter Plattendruckversuche auf der Bohrlochsohle, zur Ermittlung des Spannungs-Verformungs-Verhaltens und/oder von Deformationsmoduln und/oder von Festigkeitseigenschaften in verschiedenen Tiefen insbesondere von Lockergesteinen und von Deponiekörpern in situ; Förster W, Lersow M. Plattendruckversuch auf der Bohrlochsohle, Ermittlung des Spannungs-Verformungs-Verhaltens von Lockergestein und Deponiematerial Braunkohle--Surface Mining, 1998;50(4): 369-77; Lersow M. Verfahren zur Ermittlung von Scherfestigkeitsparametern von Lockergestein und Deponiematerial aus Plattendruckversuchen auf der Bohrlochsohle. Braunkohle

  9. Real-time monitoring of genetically modified Chlamydomonas reinhardtii during the Foton M3 space mission and ground irradiation experiment

    Science.gov (United States)

    Lambreva, Maya; Rea, Giuseppina; Antonacci, Amina; Serafini, Agnese; Damasso, Mario; Margonelli, Andrea; Johanningmeier, Udo; Bertalan, Ivo; Pezzotti, Gianni; Giardi, Maria Teresa

    Long-term space exploration, colonization or habitation requires biological life support systems capable to cope with the deleterious space environment. The use of oxygenic photosynthetic microrganisms is an intriguing possibility mainly for food, O2 and nutraceutical compounds production. The critical points of utilizing plantsor algae-based life support systems are the microgravity and the ionizing radiation, which can influence the performance of these organisms. The aim of the present study was to assess the effects of space environment on the photosynthetic activity of various microrganisms and to select space stress-tolerant strains. Site-directed and random mutants of the unicellular green alga Chlamydomonas reinhardtii of Photosystem II D1 protein were used as a model system to test and select the amino acid substitutions capable to account for space stress tolerance. We focussed our studies also on the accumulation of the Photosystem II photoprotective carotenoids (the xantophylls violaxanthin, anteraxanthin and zeaxanthin), powerful antioxidants that epidemiological studies demonstrated to be human vision protectors. Metabolite profiling by quantitative HPLC methods revealed the organisms and the stress conditions capable to accumulate the highest pigment levels. In order to develop a project for a rationale metabolic engineering of algal secondary metabolites overproduction, we are performing expression analyses on the carotenoid biosynthetic pathway under physiological and mimicked space conditions. To identify the consequences of the space environment on the photosynthetic apparatus the changes in the Photosystem II efficiency were monitored in real time during the ESA-Russian Foton-M3 mission in September 2007. For the space flight a high-tech, multicell fluorescence biosensor, Photo-II, was designed and built by the Centre for Advanced Research in Space Optics in collaboration with Kayser-Italy, Biosensor and DAS. Photo-II is an automatic device

  10. Resource Conservation and Recovery Act ground-water monitoring projects for Hanford facilities: Progress report for the period July 1 to September 30, 1988: Volume 1, Text

    Energy Technology Data Exchange (ETDEWEB)

    Fruland, R.M.; Bates, D.J.; Lundgren, R.E.

    1989-02-01

    This report describes the progress of 12 Hanford ground-water monitoring projects for the period July 1 to September 30, 1988. During this quarter, field activities at the 300 Area process trenches, the Nonradioactive Dangerous Waste Landfill, the 183-H Solar Evaporation Basins, the 1324-N/NA Surface Impoundment and Percolation Ponds, the 1301-N and 1325-N Liquid Waste Disposal Facilities, and the 216-A-36B Crib consisted of ground-water sampling and analyses, and water-level monitoring. The 200 Area Low-Level Burial Grounds section includes well development data, sediment analysis, and water-level measurements. Ground-water sampling was begun at this site, and results will be included in next quarter's report. Twelve new wells were installed during the quarter, two at the 216-A-29 Ditch, size at the 216-A-10 Crib, and four at the 216-B-3 Pond. Preliminary characterization data for these new wells are included in this report. Driller's logs and other drilling and site characterization data will be provided in the next quarterly report. At the 2101-M Pond, construction was completed on four wells, and initial ground-water samples were taken. The drilling logs, geophysical logging data, and as-built diagrams are included in this report in Volume 2. 19 refs., 24 figs., 39 tabs.

  11. Shape Deformations in Atomic Nuclei

    CERN Document Server

    Hamamoto, Ikuko

    2011-01-01

    The ground states of some nuclei are described by densities and mean fields that are spherical, while others are deformed. The existence of non-spherical shape in nuclei represents a spontaneous symmetry breaking.

  12. Rapid, Repeat-sample Monitoring of Crustal Deformations and Environmental Phenomena with the Uninhabited Aerial Vehicle Synthetic Aperture Radar

    Science.gov (United States)

    Smith, Robert C.

    2006-01-01

    The Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) is a precision repeat-pass Interferometric Synthetic Aperture Radar (InSAR) mission being developed by the Jet Propulsion Laboratory and the Dryden Flight Research Center in support of NASA s Science Mission Directorate. UAVSAR's unique ability to fly a repeatable flight path, along with an electronically steerable array, allows interferometric data to be obtained with accuracies measured in millimeters. Deploying the radar on an airborne platform will also allow for radar images to be collected and compared with images from the same area taken hours or even years later - providing for long-term trending and near real-time notification of changes and deformations. UAVSAR s data processing algorithms will provide for near-real time data reduction providing disaster planning and response teams with highly accurate data to aid in the prediction of, and response to, natural phenomena. UAVSAR data can be applied to increasing our understanding of the processes behind solid earth, cryosphere, carbon cycle and other areas of interest in earth science. Technologies developed for UAVSAR may also be applicable to a future earth-orbiting InSAR mission and possibly for missions to the Moon or Mars. The UAVSAR is expected to fly on a Gulfstream III aircraft this winter, followed by a flight test program lasting until the second half of 2007. Following radar calibration and data reduction activities, the platform will be ready for science users in the summer of 2008.

  13. Resource Conservation and Recovery Act ground-water monitoring projects for Hanford facilities: Progress report for the period October 1 to December 31, 1989

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.M.; Bates, D.J.; Lundgren, R.E. (eds.)

    1990-03-01

    This is Volume 1 of a two-volume document that describes the progress of 15 Hanford Site ground-water monitoring projects for the period October 1 to December 31, 1989. This volume discusses the projects. The work described in this document is conducted by the Pacific Northwest Laboratory under the management of Westinghouse Hanford Company for the US Department of Energy. Concentrations of ground-water constituents are compared to federal drinking water standards throughout this document for reference purposes. All drinking water supplied from the samples aquifer meets regulatory standards for drinking water quality. 51 refs., 35 figs., 86 tabs.

  14. Elman神经网络在变形预报中的应用研究%Applied Research in the Deformation Monitoring Based on Elman Neural Network Method

    Institute of Scientific and Technical Information of China (English)

    白雪武; 梁东伟; 马友利

    2012-01-01

    As a rapid development of nonlinear science in dealing with some background unclear and extremely complex information, neural network will show its unique superiority. This article applies Elman neural network to deformation monitoring of landslide to set up the forecasting model and Matlab neural network toolbox of MATLAB program design is applied to concrete examples. Through the model of prediction accuracy, the Elman neural network model to landslide monitoring and forecasting of feasibility is verified.%神经网络作为一门快速发展起来的非线性科学,在处理一些背景不清楚而且极其复杂信息的时候,就会显示出其独特的优越性。本文通过Elman神经网络应用到滑坡变形监测中,建立预报模型,并以Matlab神经网络工具箱进行程序设计,最后运用到具体实例中,通过模型的预报精度,来验证Elman神经网络模型在滑坡监测预报中的可行性。

  15. Monitoring of Deformations Induced by Crystal Growth of Salts in Porous Systems Using Microscopic Speckle Pattern Interferometry

    Science.gov (United States)

    Gülker, G.; Jarad, A. El; Hinsch, K. D.; Juling, H.; Linnow, K.; Steiger, M.; Brüggerhoff, St.; Kirchner, D.

    Electronic speckle pattern interferometry (ESPI) has been used to monitor microdeformations and surface microstructure changes produced by crystallization or hydration pressure of magnesium sulfate in a porous material. Samples of fritted glass were chosen as a standard porous substrate because of its mean grain size, its porosity distribution, and its negligible humidity expansion. The glass samples, soaked with salt solution, were exposed to changes in relative humidity of the surrounding air. The full-field ESPI measurements were combined with cryogenic SEM visualizations. Results from these investigations were partly not expected theoretically and give new insight in the underlying salt phase transition processes.

  16. Automated Ground-based Time-lapse Camera Monitoring of West Greenland ice sheet outlet Glaciers: Challenges and Solutions

    Science.gov (United States)

    Ahn, Y.; Box, J. E.; Balog, J.; Lewinter, A.

    2008-12-01

    Monitoring Greenland outlet glaciers using remotely sensed data has drawn a great