scholarly journals Active tectonics of the onshore Hengchun Fault using UAS DSM combined with ALOS PS-InSAR time series (Southern Taiwan)

2018 ◽  
Vol 18 (3) ◽  
pp. 829-845 ◽  
Author(s):  
Benoit Deffontaines ◽  
Kuo-Jen Chang ◽  
Johann Champenois ◽  
Kuan-Chuan Lin ◽  
Chyi-Tyi Lee ◽  
...  

Abstract. Characterizing active faults and quantifying their activity are major concerns in Taiwan, especially following the major Chichi earthquake on 21 September 1999. Among the targets that still remain poorly understood in terms of active tectonics are the Hengchun and Kenting faults (Southern Taiwan). From a geodynamic point of view, the faults affect the outcropping top of the Manila accretionary prism of the Manila subduction zone that runs from Luzon (northern Philippines) to Taiwan. In order to better locate and quantify the location and quantify the activity of the Hengchun Fault, we start from existing geological maps, which we update thanks to the use of two products derived from unmanned aircraft system acquisitions: (1) a very high precision (< 50 cm) and resolution (< 10 cm) digital surface model (DSM) and (2) a georeferenced aerial photograph mosaic of the studied area. Moreover, the superimposition of the resulting structural sketch map with new Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) results obtained from PALSAR ALOS images, validated by Global Positioning System (GPS) and leveling data, allows the characterization and quantification of the surface displacements during the monitoring period (2007–2011). We confirm herein the geometry, characterization and quantification of the active Hengchun Fault deformation, which acts as an active left-lateral transpressive fault. As the Hengchun ridge was the location of one of the last major earthquakes in Taiwan (26 December 2006, depth: 44 km, ML= 7.0), Hengchun Peninsula active tectonics must be better constrained in order if possible to prevent major destructions in the near future.

2017 ◽  
Author(s):  
Benoit Deffontaines ◽  
Kuo-Jen Chang ◽  
Johann Champenois ◽  
Kuan-Chuan Lin ◽  
Chyi-Tyi Lee ◽  
...  

Abstract. Geometry, characterization and quantification of active faults are major concern in Taiwan, especially following the major Chichi earthquake of September 21st, 1999. Among the targets that still remain poorly known in terms of active tectonics, are the Hengchun and Kenting faults (Southern Taiwan). From the geodynamic point of view, the latter affects the outcropping top of the Manila accretionary prism of the Manila subduction zone that runs from Luzon (N. Philippines) to Taiwan. In order to settle the location, characterization and quantification of the Hengchun fault, we needed to up-date the Chinese Petroleum Corporation (CPC, 1993) and Central Geological Survey (Sung, 1991) existing geological maps using GIS mapping and photo-interpretation of both UAS's acquisition : 1). the very high precision (


2021 ◽  
Vol 13 (19) ◽  
pp. 11097
Author(s):  
Gheorghe-Gavrilă Hognogi ◽  
Ana-Maria Pop ◽  
Alexandra-Camelia Marian-Potra ◽  
Tania Someșfălean

UAS (Unmanned Aircraft Systems) technologies, also known as UAV (Unmanned Aerial Vehicle), drones, or Remotely Piloted Aircraft System (RPAS) and GIS (Geographic Information System) are recognised for the value of the results that can be achieved by their combined use. However, their use and the results achieved are rarely framed within the context of Digital Era Governance (DEG), an undertaking that would significantly reduce the capabilities of knowledge transfer from the academic and/or private environment to the public domain. The purpose of this study was to highlight, by a bibliometric analysis, the areas of proposed use of this team of tools and the extent to which these can enter the sphere of interest of public administrations, especially local ones. From a methodological point of view, based on the 439 articles filtered from the Web of Science database where UAS/UAV and GIS technologies were used, several bibliometric analyses have emerged. VOSviewer and R (Bibliometrix tool) were used to conduct the bibliometric analyses. Most scientific publications that used UAV technology as a working tool have predominant applicability in photogrammetry, while GIS applications are found in publications dedicated to image processing, landslides, and cultural and archaeological heritage. We point out that from the point of view of international cooperation, at the level of institutions or countries, certain international organisations from the USA, China, and the central and northern European states have a high interest in this topic, and a low cooperation between academia and public administration is exhibited. The conclusion is represented by the apparent lack of framing of the results of UAS–GIS technologies usage into wider and more topical contexts, such as digital era governance, and also a reduced applicability of the research results.


2018 ◽  
Vol 158 (1) ◽  
pp. 30-38 ◽  
Author(s):  
Kiichiro Kawamura ◽  
Yujiro Ogawa

AbstractThe eastern Nankai accretionary prism toe was surveyed to evaluate the nature and deformation of its frontal thrust. According to the determined porosities and yield strengths, turbidites were successively buried down to depths of 250–300 m before accretion, and were then exposed at the prism toe by uplift along the Tenryu frontal thrust during 3.4–1.98 Ma. Consolidation tests provided reasonable estimates of burial depth and, when combined with exposed sediment dates, yield prism toe uplift rates of 0.74–2.27 m ka–1. The displacement along the frontal thrust is estimated to be 500–900 m and the slip rates are 1.47–4.55 m ka–1, corresponding to the highest class of active faults on land in Japan. During the surveys of the Tenryu frontal thrust zone, we discovered a new active fault scarp that was several tens of centimetres high, interpreted to be a protothrust located c. 100 m south of the frontal thrust. This scarp is associated with chemosynthetic biocommunities. The thrust might potentially be the result of displacement during the East Nankai (To-Nankai) earthquake (Mw 8.1) in 1944. These lines of evidence indicate that the Tenryu frontal thrust is still active and that displacement along the thrust might induce a tsunami during future Tokai or To-Nankai earthquakes.


Author(s):  
B. A. Katsnelson ◽  
M. P. Sutunkova ◽  
N. A. Tsepilov ◽  
V. G. Panov ◽  
A. N. Varaksin ◽  
...  

Sodium fluoride solution was injected i.p. to three groups of rats at a dose equivalent to 0.1 LD50 three times a week up to 18 injections. Two out of these groups and two out of three groups were sham-injected with normal saline and were exposed to the whole body impact of a 25 mT static magnetic field (SMF) for 2 or 4 hr a day, 5 times a week. Following the exposure, various functional and biochemical indices were evaluated along with histological examination and morphometric measurements of the femur in the differently exposed and control rats. The mathematical analysis of the combined effects of the SMF and fluoride based on the a response surface model demonstrated that, in full correspondence with what we had previously found for the combined toxicity of different chemicals, the combined adverse action of a chemical plus a physical agent was characterized by a tipological diversity depending not only on particular effects these types were assessed for but on the dose and effect levels as well. From this point of view, the indices for which at least one statistically significant effect was observed could be classified as identifying (I) mainly single-factor action; (II) additive unidirectional action; (III) synergism (superadditive unidirectional action); (IV) antagonism, including both subadditive unidirectional action and all variants of contradirectional action.


Author(s):  
Suraj G. Gupta ◽  
Mangesh Ghonge ◽  
Pradip M. Jawandhiya

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