scholarly journals Three-dimensional deformation time series of glacier motion from multiple-aperture DInSAR observation

2019 ◽  
Vol 93 (12) ◽  
pp. 2651-2660 ◽  
Author(s):  
Sergey Samsonov

AbstractThe previously presented Multidimensional Small Baseline Subset (MSBAS-2D) technique computes two-dimensional (2D), east and vertical, ground deformation time series from two or more ascending and descending Differential Interferometric Synthetic Aperture Radar (DInSAR) data sets by assuming that the contribution of the north deformation component is negligible. DInSAR data sets can be acquired with different temporal and spatial resolutions, viewing geometries and wavelengths. The MSBAS-2D technique has previously been used for mapping deformation due to mining, urban development, carbon sequestration, permafrost aggradation and pingo growth, and volcanic activities. In the case of glacier ice flow, the north deformation component is often too large to be negligible. Historically, the surface-parallel flow (SPF) constraint was used to compute the static three-dimensional (3D) velocity field at various glaciers. A novel MSBAS-3D technique has been developed for computing 3D deformation time series where the SPF constraint is utilized. This technique is used for mapping 3D deformation at the Barnes Ice Cap, Baffin Island, Nunavut, Canada, during January–March 2015, and the MSBAS-2D and MSBAS-3D solutions are compared. The MSBAS-3D technique can be used for studying glacier ice flow at other glaciers and other surface deformation processes with large north deformation component, such as landslides. The software implementation of MSBAS-3D technique can be downloaded from http://insar.ca/.

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Xiaowen Wang ◽  
Yosuke Aoki ◽  
Jie Chen

AbstractAsama volcano is one of the most active volcanoes in Japan. Spatially dense surface deformation at Asama volcano has rarely been documented because of its high topography and snow cover around the summit. This study presents the first interferometric synthetic aperture radar (InSAR) observation of ground deformation at Asama volcano with 120 Sentinel-1 SAR images from both ascending and descending tracks and 20 descending ALOS-2 images acquired between 2014 and 2018. We exploited both persistent and distributed scatterers to overcome decorrelation of SAR signals and applied a three-dimensional unwrapping method to retrieve the displacement time series efficiently. Our observations reveal an asymmetric deformation around the volcano with two main deformation regions on the northeast and southeast flanks, respectively. The northeast flank (NEF) exhibits line-of-sight (LOS) extensions in all the three SAR datasets with maximum velocities of − 14, − 10, and − 12 mm/year for the descending ALOS-2, ascending, and descending Sentinel-1 measurements, respectively. The southeast flank (SEF) shows LOS extensions in the ascending observations and LOS shortening in the descending observations with velocities between − 12 and 9 mm/year. Decomposition of the LOS displacements reveals nearly pure subsidence at the NEF, while the SEF exhibits a substantial eastward component as well as subsidence. Comparisons of the vertical subsidence at two continuous GNSS stations near the summit crater with our InSAR observations indicate small discrepancies smaller than 4 mm/year. We interpreted that the subsidence at the NEF of Asama is primarily due to the hydrothermal activity, while the deformation at SEF is plausibly due to flank instability. We highlight that efforts should be taken to monitor the slope instability at Asama volcano in the future.


2012 ◽  
Vol 226-228 ◽  
pp. 1504-1508
Author(s):  
Ai Bing Jin ◽  
Long Fu Li ◽  
Fu Gen Deng ◽  
Min Zhe Zhang

While the tunnel crossing the ancient Great Wall, we must take effective measures to control ground deformation, prevent ground deformation is too large, destroying the heritage. In order to study the effects of tunnel excavation types on strata deformation, a three-dimensional computational model is built to simulate surface settlement and horizontal displacement by three different excavation types which are both-side heading method, CRD method, and hole pile method. Following comparative analysis, in line with the realistic program is recommended. The results show that both-side heading method can better control the surface deformation, and has a high efficiency of construction, which was selected as the construction scheme of tunnel crossing the ancient great wall. The results of this study are expected to provide construction experience to the works of a similar background.


Ocean Science ◽  
2006 ◽  
Vol 2 (1) ◽  
pp. 11-18 ◽  
Author(s):  
A. Henry-Edwards ◽  
M. Tomczak

Abstract. A water mass analysis method based on a constrained minimization technique is developed to derive water property changes in water mass formation regions from oceanographic station data taken at significant distance from the formation regions. The method is tested with two synthetic data sets, designed to mirror conditions in the North Atlantic at the Bermuda BATS time series station. The method requires careful definition of constraints before it produces reliable results. It is shown that an analysis of the error fields under different constraint assumptions can identify which properties vary most over the period of the observations. The method reproduces the synthetic data sets extremely well if all properties other than those that are identified as undergoing significant variations are held constant during the minimization.


2011 ◽  
Vol 1 (1) ◽  
pp. 25-34 ◽  
Author(s):  
G. Wang ◽  
D. Philips ◽  
J. Joyce ◽  
F. Rivera

The Integration of TLS and Continuous GPS to Study Landslide Deformation: A Case Study in Puerto RicoTerrestrial Laser Scanning (TLS) and Global Positioning System (GPS) technologies provide comprehensive information on ground surface deformation in both spatial and temporal domains. These two data sets are critical inputs for geometric and kinematic modeling of landslides. This paper demonstrates an integrated approach in the application of TLS and continuous GPS (CGPS) data sets to the study of an active landslide on a steep mountain slope in the El Yunque National Forest in Puerto Rico. Major displacements of this landslide in 2004 and 2005 caused the closing of one of three remaining access roads to the national forest. A retaining wall was constructed in 2009 to restrain the landslide and allow the road reopen. However, renewed displacements of the landslide in the first half of 2010 resulted in deformation and the eventual rupture of the retaining wall. Continuous GPS monitoring and two TLS campaigns were performed on the lower portion of the landslide over a three-month period from May to August 2010. The TLS data sets identified the limits and total volume of themoving mass, while the GPS data quantified the magnitude and direction of the displacements. A continuous heavy rainfall in late July 2010 triggered a rapid 2-3 meter displacement of the landslide that finally ruptured the retaining wall. The displacement time series of the rapid displacement is modeled using a fling-step pulse from which precise velocity and acceleration time series of the displacement are derived. The data acquired in this study have demonstrated the effectiveness and power of the integrating TLS and continuous GPS techniques for landslide studies.


2021 ◽  
Author(s):  
Qingyun Zhang ◽  
Jingfa Zhang ◽  
Yongsheng Li ◽  
Bingqun Li ◽  
Quancai Xie ◽  
...  

Abstract. The Kumamoto earthquake is analyzed mainly with InSAR data combined with strong earthquake and GPS data, using a variety of joint InSAR technology methods and multisource data solution methods and comprehensively considering the normalization and weighting of multisource data. The three-dimensional (3D) deformation field is determined. The results show that the joint solution of multisource data can improve the accuracy of the 3D solution deformation results to a certain extent. From the 3D solution results, the maximum east-west deformation caused by the 2016 Kumamoto earthquake is approximately 2 m; the north-south direction mainly manifests expansion and stretching; the northwestern side subsides vertically, with a maximum subsidence of 2 m; and the southeastern side is uplifted. The horizontal deformation characteristics show that the earthquake is dominated by right-lateral strike-slip; the strike is NE-SW, the dip of the seismogenic fault is nearly vertical, and the Futagawa fault has a few normal fault properties. By analyzing the coseismic 3D deformation field, the seismogenic fault can be better understood, which provides a foundation for studying seismic mechanisms.


2020 ◽  
Vol 10 (7) ◽  
pp. 2294 ◽  
Author(s):  
Mimi Peng ◽  
Chaoying Zhao ◽  
Qin Zhang ◽  
Zhong Lu ◽  
Lin Bai ◽  
...  

Shandong peninsula, the largest peninsula of China, is prone to severe land subsidence hazards along the coastline. In this paper, we provide, for the first time, multi-scale and multi-dimensional time series deformation measurements of the entire Shandong peninsula with advanced time series Interferometric Synthetic Aperture Radar (InSAR) techniques. We derive the spatiotemporal evolutions of the land subsidence by integrating multi-track Sentinel-1A/B and RADARSAT-2 satellite images. InSAR measurements are cross validated by the independent deformation rate results generated from different SAR tracks, reaching a precision of less than 1.3 cm/a. Two-dimensional time series over the Yellow River Delta (YRD) from 2017 to 2019 are revealed by integrating time series InSAR measurements from both descending and ascending tracks. Land subsidence zones are mainly concentrated on the YRD. In total, twelve typical localized subsidence zones are identified in the cities of Dongying (up to 290 mm/a; brine and groundwater exploitation for industrial usage), Weifang (up to 170 mm/a; brine exploitation for industrial usage), Qingdao (up to 70 mm/a; aquaculture and land reclamation), Yantai (up to 50 mm/a; land reclamation) and Rizhao (up to 60 mm/a; land reclamation). The causal factors of localized ground deformation are discussed, encompassing groundwater and brine exploitation, aquaculture and land reclamation. Multi-scale surveys of spatiotemporal deformation evolution and mechanism analysis are critical to make decisions on underground fluid exploitation and land reclamation.


Author(s):  
G. C. Hays ◽  
A. J. Warner

The mean annual towing speed of the Continuous Plankton Recorder (CPR) varied systematically between 1946 and 1991. By mounting a pressure transducer on the CPR to record towing depth, it was shown, however, that changes in towing speed did not cause a significant change in towing depth, although the mean towing depth (6–7 m, SD=l-7 m, N=77) was shallower than the previously assumed towing depth of 10 m. Thus the observed changes in towing speed are unlikely to have caused discontinuities in the CPR time-series by affecting sampling depth.Long-term data sets play an important role in attempts to understand the causes of fluctua- tions in plankton abundance. The Continuous Plankton Recorder (CPR) survey provides multi- decadal information on plankton abundance in the North Sea and North Atlantic (McGowan, 1990), and is one of the longest standing marine plankton abundance time-series. However, while the CPR time-series has great potential, as with all other data sets spanning many years, questions may be asked regarding the consistency with which the data have been collected and hence the true continuity of the time-series.


2021 ◽  
Vol 13 (2) ◽  
pp. 179
Author(s):  
Yonghong Zhang ◽  
Hongan Wu ◽  
Mingju Li ◽  
Yonghui Kang ◽  
Zhong Lu

Interferometric synthetic aperture radar (InSAR) mapping of localized ground surface deformation has become an important tool to manage subsidence-related geohazards. However, monitoring land surface deformation using InSAR at high spatial resolution over a large region is still a formidable task. In this paper, we report a research on investigating ground subsidence and the causes over the entire 107, 200 km2 province of Jiangsu, China, using time-series InSAR. The Sentinel-1 Interferometric Wide-swath (IW) images of 6 frames are used to map ground subsidence over the whole province for the period 2016–2018. We present processing methodology in detail, with emphasis on the three-level co-registration scheme of S-1 data, retrieval of mean subsidence velocity (MSV) and subsidence time series, and mosaicking of multiple frames of results. The MSV and subsidence time series are generated for 9,276,214 selected coherent pixels (CPs) over the Jiangsu territory. Using 688 leveling measurements in evaluation, the derived MSV map of Jiangsu province shows an accuracy of 3.9 mm/year. Moreover, subsidence causes of the province are analyzed based on InSAR-derived subsidence characteristics, historical optical images, and field-work findings. Main factors accounting for the observed subsidence include: underground mining, groundwater withdrawal, soil consolidations of marine reclamation, and land-use transition from agricultural (paddy) to industrial land. This research demonstrates not only the capability of S-1 data in mapping ground deformation over wide areas in coastal and heavily vegetated region of China, but also the potential of inferring valuable knowledge from InSAR-derived results.


Geosciences ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 370 ◽  
Author(s):  
Panara ◽  
Toscani ◽  
Cooke ◽  
Seno ◽  
Perotti

Coseismic ground displacements detected through remote sensing surveys are often used to invert the coseismic slip distribution on geologically reliable fault planes. We analyze a well-known case study (2009 L’Aquila earthquake) to investigate how three-dimensional (3D) slip configuration affects coseismic ground surface deformation. Different coseismic slip surface configurations reconstructed using aftershocks distribution and coseismic cracks, were tested using 3D boundary element method numerical models. The models include two with slip patches that reach the surface and three models of blind normal-slip surfaces with different configurations of slip along shallowly-dipping secondary faults. We test the sensitivity of surface deformation to variations in stress drop and rock stiffness. We compare numerical models’ results with line of sight (LOS) surface deformation detected from differential SAR (Synthetic Aperture Radar) interferometry (DInSAR). The variations in fault configuration, rock stiffness and stress drop associated with the earthquake considerably impact the pattern of surface subsidence. In particular, the models with a coseismic slip patch that does not reach the surface have a better match to the line of sight coseismic surface deformation, as well as better match to the aftershock pattern, than models with rupture that reaches the surface. The coseismic slip along shallowly dipping secondary faults seems to provide a minor contribution toward surface deformation.


2019 ◽  
Author(s):  
Philipp Reutter ◽  
Patrick Neis ◽  
Susanne Rohs ◽  
Bastien Sauvage

Abstract. Cirrus clouds and their potential formation regions, so-called ice-supersaturated regions (ISSRs) occur frequently in the tropopause region. It is assumed that ISSRs and cirrus clouds can change the tropopause structure by diabatic processes, driven by latent heating due to phase transition and interaction with radiation. For many research questions a three-dimensional picture including a sufficient temporal resolution of the water vapour fields in the tropopause region is required. This requirement is fulfilled nowadays by reanalysis products such as the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim reanalysis. However, for a meaningful investigation of water vapour in the tropopause region a comparison of the reanalysis data with measurement is advisable, since it is difficult to measure water vapour and to assimilate meaningful measurements into reanalysis products. Here, we present an intercomparison of high-resolution in-situ measurements aboard passenger aircraft within the European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System; http://www.iagos.org) with ERA-Interim. Temperature and humidity data over the North Atlantic from 2000 to 2010 are compared relative to the dynamical tropopause. The comparison of the temperature shows a good agreement between measurement and ERA-Interim. While ERA-Interim can reproduce the main features of the water vapour measurements of IAGOS, the variability of the data is underestimated by the reanalysis data. The combination of temperature and water vapour leads to the relative humidity with respect to ice (RHi). Here ERA-Interim deviates from the measurements concerning values of larger than RHi=100 %, both in number and strength of supersaturation. The comparison of ISSR pathlengths shows distinct differences, which can be traced back to the spatial resolution of both data sets. IAGOS shows significantly more smaller ISSRs compared to ERA-Interim. A good agreement begins only at pathlengths in the order of the ERA-Interim spatial resolution and larger.


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