scholarly journals Topographic Anaglyphs from Detailed Digital Elevation Models Covering Inland and Seafloor for the Tectonic Geomorphology Studies in and around Yoron Island, Ryukyu Arc, Japan

Geosciences ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 363 ◽  
Author(s):  
Hideaki Goto ◽  
Kohsaku Arai ◽  
Taichi Sato
Keyword(s):  
Late Quaternary ◽  
Active Faults ◽  
Aerial Photographs ◽  
Stress Axis ◽  
Tectonic Geomorphology ◽  
Surface Model ◽  
The North ◽  
Digital Elevation ◽  
Ryukyu Arc ◽  
Island Shelf

Anaglyphs produced using a digital elevation model (DEM) are effective to identify the characteristic tectono–geomorphic features. The objective of this study is to reinvestigate the tectonic geomorphology and to present novel tectonic maps of the late Quaternary in and around the Yoron island based on the interpretation of extensive topographical anaglyphs along the map areas that cover the inland and seafloor. Vintage aerial photographs are used to produce the 3-m mesh inland digital surface model (DSM); further, the 0.6-s to 2-s-mesh seafloor DEM is processed using the cloud point data generated through previous surveys. Thus, we identify anticlinal deformation on both the Pleistocene marine terrace and the seafloor to the north of the island. The deformation axis extends in a line and is parallel to the general trend of the island shelf. The Tsujimiya fault cuts the marine terraces, which extend to the Yoron basin’s seafloor. If we assume that the horizontal compressive stress axis is perpendicular to the island shelf, these properties can easily explain the distribution and style of the active faults and deformation. This study presents an effective methodology to understand the island arc tectonics, especially in case of small isolated islands.

Treatise on the tectonic geomorphology of active faults: The significance of using a universal digital elevation model

2018 ◽  
Vol 116 ◽  
pp. 241-252 ◽  
Author(s):  
Ioannis K. Koukouvelas ◽  
Vasiliki Zygouri ◽  
Konstantinos Nikolakopoulos ◽  
Sotirios Verroios
Keyword(s):  
Digital Elevation Model ◽  
Active Faults ◽  
Tectonic Geomorphology ◽  
Digital Elevation ◽  
Elevation Model

scholarly journals A photogrametric study on active faults in the Nepal Himalayas

1982 ◽  
Vol 2 ◽  
pp. 67-80
Author(s):  
Takashi Nakata
Keyword(s):  
Active Fault ◽  
Late Quaternary ◽  
Lateral Displacement ◽  
Active Faults ◽  
Aerial Photographs ◽  
Fault System ◽  
Lateral Movement ◽  
Active Faulting ◽  
Quaternary Period ◽  
Late Quaternary Period

Active faults in the Nepal Himalayas are identified by means of interpretation of vertical aerial photographs. They are mainly distributed along the major tectonic lines as older geological faults and are classified into four groups, the Main Central Active Fault system, the active faults in the Lower Himalayas, the Main Boundary Active Fault system and active faults along the Himalayan Front Fault. The mode of active faulting is closely related to the strikes of the faults. Along the NW-SE and NE-SW trending faults, lateral displacement with northward drop is prevailing, and right-lateral movement along the former and left-lateral movement along the latter is a rule in the sense of displacements. On the other hand, dip-slip faulting is observed mainly along the E-W trending faults belonging to the Main Boundary Active Fault system. However, apparent displacement along the faults is mostly of northward drop. It is considered that active faulting along the major tectonic lines except the Himalayan Front Fault does not favor the upheaval of the Himalayan ranges during the late Quaternary period.

scholarly journals LATE QUATERNARY AND HOLOCENE FAULTS OF THE NORTHERN GULF OF CORINTH RIFT, CENTRAL GREECE

2017 ◽  
Vol 50 (1) ◽  
pp. 164 ◽  
Author(s):  
S. Valkaniotis ◽  
S. Pavlides
Keyword(s):  
Late Quaternary ◽  
Active Faults ◽  
Geological Mapping ◽  
Tectonic Activity ◽  
Normal Faults ◽  
Central Greece ◽  
The North ◽  
Gulf Of Corinth ◽  
Area Of Study

New results for the recent tectonic activity in the northern part of the Gulf of Corinth rift are presented. Geological mapping and morphotectonic study re populate the area of study with numerous active and possible active faults. The area is dominated by individual and segmented normal faults along with major structures like Marathias and Delphi-Arachova faults. The results are in accordance with recent studies that reveal a more complex and wider structure of Corinth Rift to the north.

scholarly journals Integration von hochauflösenden Fernerkundungs- und Geländemodelldaten für die Landschaftsvisualisierung

1997 ◽  
Vol 52 (1) ◽  
pp. 21-26
Author(s):  
P. Pirchl ◽  
P. Hirtz ◽  
M. Suter ◽  
D. Nüesch
Keyword(s):  
Land Cover ◽  
Aerial Photographs ◽  
Surface Model ◽  
Northern Switzerland ◽  
Transition Zones ◽  
Gis Tools ◽  
Digital Elevation ◽  
Elevation Data ◽  
Digital Elevation Data ◽  
Elevation Model

Abstract. This paper presents experiments for realistic landscape visualization using high resolution digital aerial photographs and elevation modeis. The natural environment of a river in northern Switzerland is visualized. Photogrammetrically measured digital elevation data and ortho-rectified remote sensing imagery (Landsat Thematic Mapper/TM and aerial photographs) are combined to compute realistic 3D views of the landscape. To renderthe landscape more realistically, the digital elevation model (DEM) is transformed to a digital surface model (DSM), representing the surface and including objects like forests or bushes. For this transformation land cover information and GIS tools were used. Unnaturally looking vertical borders between different land cover classes were suppressed by interpolating transition zones. Additionally, 3D objects (trees) are used in the foreground to increase the realism of the views.

scholarly journals Surface rupture and characteristics of a fault associated with the 2011 and 2016 earthquakes in the southern Abukuma Mountains, northeastern Japan, triggered by the Tohoku-Oki earthquake

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Keitaro Komura ◽  
Kotaro Aiyama ◽  
Takahiro Nagata ◽  
Hiroshi P. Sato ◽  
Akihiro Yamada ◽  
...  
Keyword(s):  
Active Faults ◽  
Aerial Photographs ◽  
Japan Trench ◽  
Normal Faults ◽  
Interferometric Synthetic Aperture Radar ◽  
Northeastern Japan ◽  
Digital Elevation ◽  
Geomorphic Features ◽  
Surface Ruptures ◽  
Elevation Model

Abstract The 2011 Tohoku-Oki offshore subduction earthquake (Mw 9.0) triggered many normal-type earthquakes inland in northeastern Japan. Among these were two very similar normal-faulting earthquakes in 2011 (Mw 5.8) and 2016 (Mw 5.9), which created surface ruptures along the newly named Mochiyama fault within the southern Abukuma Mountains, northeastern Japan, where no active faults had been previously mapped by interpretation of aerial photographs. We conducted field surveys in this area immediately after both earthquakes, and we performed trench excavations and observations of fault fracture zones after the 2016 event. These activities were complemented by an interferometric synthetic aperture radar analysis that mapped the areas of deformation and locations of surface discontinuities for both events. The combined results document the coseismic behavior of the Mochiyama fault during both events. Subtle tectonic geomorphic features associated with the fault were evident in a lidar digital elevation model of the area, and layered structures of gouge were documented in the field. These lines of evidence indicate repeated activity at shallow crustal levels and the possibility of Quaternary activity. In addition, our trench excavations revealed at least one faulting event before 2011. Our comparison of paleoseismic records on this and two other normal faults in the Abukuma Mountains suggests that great earthquakes in the Japan Trench supercycle of 500–700 years do not consistently trigger ruptures on these faults, and the case of 2011, in which the Tohoku-Oki megathrust earthquake triggered all three faults, is a rare occurrence.

scholarly journals Stratigraphy and structure of the Peshawar basin, Pakistan

1998 ◽  
Vol 18 ◽  
Author(s):  
Ahmad Hussain ◽  
Joseph A. Dipietro ◽  
Kevin R. Pogue
Keyword(s):  
Late Quaternary ◽  
Field Studies ◽  
Flood Plain ◽  
Complete Sequence ◽  
Alluvial Fan ◽  
Aerial Photographs ◽  
Reverse Fault ◽  
The North ◽  
Southern Margin ◽  
Peshawar Basin

The Peshawar intermontane basin is a broad, oval shaped and low-lying depression at the southern margin of the Himalaya. It lies to the north of the Attock-Cherat Range and contains rocks transitional between the sedimentary fold-thrust belt to the south and a metamorphic terranc to the north. The basin came into existence as the Kalachitta Range was faulted south on the Main Boundary Thrust (MBT pushing the Siwalik foreland basin still farther south. The basin sediments predominantly comprise of the lacustrine, deltaic and fluvial deposits, which arc overlain by loess, flood plain and alluvial fans of younger age. As a result of the present study, especially the findings of conodonts, the bedrock sequence of the Peshawar basin established previously, has been modified and revised. An almost complete sequence of rocks ranging from the Precambrian to Triassic age has been established for the first time in the Peshawar basin. The study of the Landsat data, aerial photographs and subsequent field studies indicate presence of zone of late Quaternary deformation that extends across the southern margin of the Peshawar basin. Lacustrine, fluvial and alluvial fan deposits, which are dated at 2.8 to 0.6 Ma are tilted, folded and faulted along the four left-stepping pressure ridges that extend for nearly 60 km. Alluvial-fan and fluvial sediments are also folded and faulted in the Ghazi area where the base of the Indus River appears to be displaced by a reverse fault with its northwest side up. Additional minor lineaments and faults occur parallel and oblique to the major fault structures.

scholarly journals Traditional versus modern settlement on torrential alluvial fans considering the danger of debris flows: a case study of the Upper Sava Valley (NW Slovenia)

2019 ◽  
Vol 11 (1) ◽  
pp. 627-637
Author(s):  
Mateja Breg Valjavec ◽  
Blaž Komac
Keyword(s):  
Debris Flows ◽  
Drainage System ◽  
Aerial Photographs ◽  
Alluvial Fans ◽  
Natural Processes ◽  
The North ◽  
Digital Elevation ◽  
Julian Alps ◽  
Elevation Model ◽  
The 19Th Century

Abstract We analysed spatial development of traditional and modern settlements on active alluvial fans in the Upper Sava Valley (NW Slovenia), by using old cadastral data from the beginning of the 19th century, time series of aerial photographs from the middle of the 20th century and recent building cadastre. The valley is surrounded by the mountainous Julian Alps in the south and the Karavanke Mountains in the north where there is a lack of space for settlements due to steep slopes that are increasing the danger of slope processes, torrential processes and floods. By using a very high-resolution 1m LiDAR digital elevation model, we defined the morphometry of alluvial fans and the characteristics of the drainage system of contributing tributaries. We classified the areas according to the threat posed by the modelled torrents and debris flows. We analysed the resilience of settlement in different periods from this perspective and evaluated the integration of natural processes effects in modern spatial planning projects. We found that geomorphic processes threaten a relatively large proportion of some new and old settlements on alluvial fans and that safe planning of areas of settlement has been successful neither in the past nor in recent decades.

scholarly journals Improving Urban Seismic Risk Estimates for Bishkek, Kyrgyzstan, Incorporating Recent Geological Knowledge of Hazards

2021 ◽  
Author(s):  
Ruth Amey ◽  
John Elliott ◽  
C. Scott Watson ◽  
Richard Walker ◽  
Marco Pagani ◽  
...  
Keyword(s):  
Residential Buildings ◽  
Active Faults ◽  
Active Faulting ◽  
Ground Shaking ◽  
Earthquake Scenarios ◽  
The North ◽  
Digital Elevation ◽  
Earthquake Model ◽  
Hazard And Risk ◽  
The City

Many cities are built on or near active faults, which pose seismic hazard and risk to the urban population. This risk is exacerbated by city expansion, which may obscure signs of active faulting. Here we estimate the risk to Bishkek city, Kyrgyzstan, due to realistic earthquake scenarios based on historic earthquakes in the region and improved knowledge of the active faulting. We use previous literature and fault mapping, combined with new high-resolution digital elevation models to identify and characterise faults that pose a risk to Bishkek. We then estimate the hazard (ground shaking), damage to residential buildings and losses (economical cost and fatalities) using the Global Earthquake Model OpenQuake engine. We model historical events and hypothetical events on a variety of faults that could plausibly host significant earthquakes. This includes proximal, recognised, faults as well as a fault under folding in the north of the city that we identify using satellite DEMs. We find that potential earthquakes on faults nearest to Bishkek - Issyk Ata, Shamsi Tunduk, Chonkurchak and the northern fault - would cause the most damage to the city. An Mw 7.5 earthquake on the Issyk Ata fault could potentially cause 7,900 ± 2600 completely damaged buildings, a further 16,400 ± 2000 damaged buildings and 2400 ± 1500 fatalities. It is vital to properly identify, characterise and model active faults near cities as modelling the northern fault as a Mw 6.5 instead of Mw 6.0 would result in 37% more completely damaged buildings and 48% more fatalities.

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