Location of Active Faults using Geomorphic Indices in Eroded Landscapes, South Taranaki, New Zealand

Mapping Intimacies ◽

10.26686/wgtn.17004862 ◽

2021 ◽

Author(s):

◽

William Francis Ries

Keyword(s):

Equilibrium State ◽

Drainage Basin ◽

Active Faults ◽

Surface Expression ◽

Tree Cover ◽

Tectonic Activity ◽

International Studies ◽

Stream Channel ◽

Geomorphic Indices ◽

Digital Elevation

<p>South Taranaki region has a number of active faults that show surface expression in the younger and harder materials near the coast and central volcanoes of the North Island, but these traces finish abruptly inland when they cross into older, heavily eroded, mudstone and sandstone. Current methods to locate surface evidence of active faults (i.e. geomorphic interpretation of stereographic aerial photography) are not fully successful in this region. Erosion occurs here at a greater rate than surface rupture of faults which causes the removal of surface expression, and/or dense tree cover obscures surface expression. International studies of tectonic activity in eroded landscapes have identified geomorphic indices as useful reconnaissance tools to locate active faults. This research applies geomorphic indices to the Taranaki region for the first time. Four indices are tested; stream length-gradient index, stream channel sinuosity, hypsometry and drainage basin asymmetry. Results are obtained by applying the indices to four freely available national Digital Elevation Models (DEMs) of differing resolutions. This allowed comparison between DEMs, providing the ability to test DEM quality and at what scale geomorphic indices could be applied to these freely available data. Results show that the geomorphic indices used can identify changes to the equilibrium state at a catchment and stream channel scales. However, the myriad of physical processes occurring at a range of temporal scales within this area make identification of a tectonic signature a challenging task. Conclusive examples of tectonic processes are evident and analysis suggests that these examples are likely to be due to recent or large fault ruptures. There are many areas where a tectonic influence to the equilibrium state of a stream or catchment can be inferred. These areas could then be targeted for detailed geophysical or ground based geological studies. Furthermore, the comparison of results from the four DEMs highlights a range of issues with DEM collection methods and resolution. This study concludes that geomorphic indices can provide an effective method to locate evidence of recent and large faulting events. However, this type of analysis is hindered by the resolution of available digital elevation data.</p>

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Location of Active Faults using Geomorphic Indices in Eroded Landscapes, South Taranaki, New Zealand

10.26686/wgtn.17004862.v1 ◽

2021 ◽

Author(s):

◽

William Francis Ries

Keyword(s):

Equilibrium State ◽

Drainage Basin ◽

Active Faults ◽

Surface Expression ◽

Tree Cover ◽

Tectonic Activity ◽

International Studies ◽

Stream Channel ◽

Geomorphic Indices ◽

Digital Elevation

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Μορφοτεκτονική μελέτη της ευρύτερης περιοχής Θεσ/νίκης για τη χαρτογράφηση νεοτεκτονικών ρηγμάτων.

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.18420 ◽

2005 ◽

Vol 38 ◽

pp. 30 ◽

Cited By ~ 3

Author(s):

Α. ΖΕΡΒΟΠΟΥΛΟΥ ◽

Σ. ΠΑΥΛΙΔΗΣ

Keyword(s):

Drainage Basin ◽

Digital Elevation Models ◽

Active Faults ◽

Gradient Index ◽

Stream Length ◽

Drainage Patterns ◽

Digital Elevation ◽

Mountain Front ◽

Morphotectonic Indices

At this paper studied the neotectonic active faults of the broader area of Thessaloniki with morphotectonic criteria. We have studied three main faults of Anthemounta, Asvestophori and Pylaia - Panorama with the contribution of cartography, digital elevation models, drainage patterns, and the morphotectonic indices like drainage basin asymmetry, mountain front sinuosity, knick points and stream length-gradient index. Those faults show elements of activity.

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Evaluation of Active Tectonics in Northwest of Saveh

10.21203/rs.3.rs-303169/v1 ◽

2021 ◽

Author(s):

Bahar Rezaeinahal ◽

Mohsen PourKermani ◽

Mehdy Zare ◽

Maryam Dehbozorgi ◽

Reza Nozaem

Keyword(s):

Drainage Basin ◽

Active Tectonics ◽

Tectonic Activity ◽

Drainage Basins ◽

The North ◽

Level Of Activity ◽

Digital Elevation ◽

Arc Gis ◽

Elevation Model ◽

Gis Software

Abstract The northwest zone of Saveh city is located in the fault zone of the Indes, Koosh e Nosrat, Avaj and Aipak. Indes faults, Cox Nosrat, Avaj and Aipak are considered as the major faults of central Iran, which are also active in the Quaternary and the last movements of these faults are attributed to the present covenant, therefore, the estimation of morphometri in order to identify the effect of active tectonics on the tectonic evolution of drainage basins seems necessary. Therefore, in this study, six important morphotectonic indexes were analyzed; longitudinal gradient of the river, asymmetry of drainage basin, hypometric integral, Drainage basin shape,the ratio of the width of the floor to the height of the valley and forehead of the mountain is discussed.to create the basins on the studied area, Arc Hydro software (Arc GIS software) has been used based on data from a digital elevation model, Then, 6 morphotectonic indexes have been compiled and classified on each of the basins.Finally, according to which the region has been classified into 4 categories of high, medium and low tectonic activity the, Active Tectonic Index (IAT) has been calculated.According to the IAT index, 5% of the study area shows very high tectonic activity, 25% of the studied area has high tectonic activity, the average tectonic activity has 65% and about 5% of the tectonic activity are low. In this study, the highest level of tectonic activity is in the north-eastern part of the region. In most of the sectors, the level of activity is high and moderate, which is related to the activity of Koshk E Nosrat, Aipak, Avaj faults.

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Morphotectonic analysis of Heraklion Basin (Crete, Greece).

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.10950 ◽

2016 ◽

Vol 47 (1) ◽

pp. 285

Author(s):

E. Kokinou ◽

H. D. Skilodimou ◽

G. D. Bathrellos

Keyword(s):

Slope Angle ◽

Drainage System ◽

Fault System ◽

Tectonic Activity ◽

Geomorphic Indices ◽

Digital Elevation ◽

Mountain Front ◽

Elevation Model ◽

Tectonic Features ◽

The Impact

In the present study, geomorphological, geological data and morphotectonic analysis were combined in order to investigate the relation between the tectonic activity and the geomorphology in the Heraklion basin (Crete). GIS techniques were used for mapping the various topographic, geological and tectonic features of the study area. The digital elevation model (DEΜ) of the study area was created. The slope angle and aspect maps were derived from DEM and combined with fault system orientation. The influence of tectonism on the development of drainage system was examined by the comparison of fault and stream directions. Moreover, geomorphic indices are useful tools in evaluating tectonic activity, relating the sensitivity to rock resistance, climatic change and tectonic processes with the production of a certain landscape. The applied geomorphic indices, in the present study, are the mountain front sinuosity index (Smf) and the valley floor width to valley height ratio (Vf). The fault zones of the study area are generally oriented N-S, NE-SW, NW-SE and E-W. According to the morphological analysis, steep slopes and sudden changes corresponding to the azimuth of the slope direction, are mainly related to N-S, NNE-SSW and NNW-SSE oriented faulting. The main channel directions of the drainage system are mainly controlled by faults striking N-S. The E-W, NE-SW and NW-SE general trending fault systems affect the low order streams. The Smf and Vf values are low, implying that the tectonic activity influences the morphology of the study area. The above methodology was proved successful to examine the impact of the tectonic activity in the study area.

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Assessment of tectonic activity based on the geomorphic indices in the middle reaches of the upstream of Jinsha River, China

Geological Journal ◽

10.1002/gj.4148 ◽

2021 ◽

Author(s):

Yiqi Ji ◽

Shengrui Su ◽

Zhiheng Liu ◽

Qiangbing Huang

Keyword(s):

Tectonic Activity ◽

Jinsha River ◽

Geomorphic Indices

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Delineating active faults across the Narmada-Son Lineament (NSL), India using the technique of Fracture Induced Electromagnetic Radiation (FEMR)

10.5194/egusphere-egu21-2370 ◽

2021 ◽

Author(s):

Shreeja Das ◽

Jyotirmoy Mallik

Keyword(s):

Electromagnetic Radiation ◽

Process Zone ◽

Active Faults ◽

Central India ◽

Earthquake Forecasting ◽

Tectonic Activity ◽

Eurasian Plate ◽

Near Surface ◽

Crustal Stresses ◽

Tectonically Active

<p>The Fracture Induced Electromagnetic Radiation (FEMR) technique has gradually progressed in the past decade as a useful geophysical tool to determine the direction and magnitude of recent crustal stresses, visualize the modification and realignment of stresses inside tunnels thus proving to be an important precursor for geohazards, earthquake forecasting, as well as delineate landslide-prone slip planes in unstable regions. Its working principle is based on the generation of geogenic electromagnetic radiation emanating from the brittle rock bodies that are fractured being subjected to an incremental increase of the differential stress in the near-surface of the Earth&#8217;s crust. The &#8220;Process zone&#8221; at the fractured crack tip contains numerous microcracks which subsequently creates dipoles due to the polarization of charges on such microcrack tips which rapidly oscillates emitting FEMR waves of frequencies between KHz to MHz range. The coalescence of the microcracks eventually leads to a macro failure dampening the amplitude of the FEMR pulses. The attenuation of FEMR pulses is comparatively lesser than seismic waves making it a more efficient precursor to potential tectonic activities indicating an upcoming earthquake a few hours/days before the actual event. In the current study, we have attempted to exploit this technique to identify the locations of the potential active faults across the tectonically active Narmada-Son Lineament (NSL), Central India. Although the first tectonic stage involved rifting and formation of the NSL during the Precambrian time, the rifting continued at least till the time of Gondwana deposition. Later, tectonic inversion took place as a result of the collision between the Indian and the Eurasian plate resulting in reverse reactivation of the faults. Episodic reverse movement along NSL caused recurrent earthquakes and linear disposition of the sediments that were deposited at the foothills of the Satpura Horst. Although the origin of East-West trending NSL dates back to the Precambrian time, it is very much tectonically active as manifested by recent earthquakes. The study has been conducted by taking linear FEMR readings across 3 traverses along the NSL which on analysis provides an idea about the potential active faults, their locations, and frequency of occurrence. The accumulation of strain in the brittle rocks that can eventually lead to a macro failure is demarcated as an anomalous increase in the amplitude of the FEMR pulses indicative of an upcoming tectonic episode in the region. To further corroborate the analysis, we have attempted to determine the neo-tectonic activity in the region by calculating the morphometric parameters across the Khandwa-Itarsi-Jabalpur region, Central India. Finally, we attempt to comment on the tectonic evolution of Central India in the recent past. We also encourage researchers to adapt the novel technique of FEMR which is swift, affordable, and feasible compared to conventional techniques deployed to survey the active tectonics of a region.</p>

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Drainage Basin of Lake Kivu in the Western Rift of East Africa and Hazards Potential

Rwanda Journal of Engineering Science Technology and Environment ◽

10.4314/rjeste.v3i1.1s ◽

2020 ◽

Vol 3 (1) ◽

Author(s):

C. Kakonkwe ◽

D. E. Rwabuhungu ◽

M. Biryabarema

Keyword(s):

Water Supply ◽

Drainage Basin ◽

Landslide Hazard ◽

Mass Wasting ◽

Landslide Hazards ◽

Digital Elevation ◽

Lake Kivu ◽

Elevation Data ◽

Digital Elevation Data ◽

Land Sliding

A series of ArcGIS-generated maps were applied in analysing the potential for flooding and landslide hazards within the Lake Kivu drainage basin. This study was carried out using digital elevation data of the basin. The Kivu drainage basin encompasses an area of 7,382 km2. Sediment and water supply to Lake Kivu originate mostly from its eastern hinterland. The distribution of land sliding potentiality in the drainage basin shows that the northern and the southern portions of the basin are the ones with relatively low risk of land sliding, whereas the rift shoulders are most prone to land sliding. Mass wasting on slopes has the potential to grade downstream into debris and mudflows, promoting in turn further erosion and flooding. Keywords: drainage, Kivu, Africa, flooding, landslide, hazard

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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 ◽

10.3390/geosciences8100363 ◽

2018 ◽

Vol 8 (10) ◽

pp. 363 ◽

Cited By ~ 3

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.

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Recent active faults in Belgian Ardenne revealed in Rochefort Karstic network (Namur Province, Belgium)

Netherlands Journal of Geosciences – Geologie en Mijnbouw ◽

10.1017/s0016774600023891 ◽

2001 ◽

Vol 80 (3-4) ◽

pp. 297-304 ◽

Cited By ~ 6

Author(s):

S. Vandycke ◽

Y. Quinif

Keyword(s):

Stress Field ◽

Active Faults ◽

Ground Surface ◽

Local Stress ◽

Tectonic Activity ◽

Normal Faults ◽

Regional Stress ◽

Bedding Planes ◽

Local Modification ◽

A Minor

AbstractThis paper presents observations of recent faulting activity in the karstic network of the Rochefort Cave (Namur Province, Belgium, Europe). The principal recent tectonic features are bedding planes reactivated as normal faults, neo-formatted normal faults in calcite flowstone, fresh scaling, extensional features, fallen blocks and displacement of karstic tube. The seismo-tectonic aspect is expanded by the presence of fallen blocks where normally the cavity must be very stable and in equilibrium. Three main N 070° fault planes and a minor one affect, at a decimetre scale, the karst features and morphology. The faults are still active because recent fresh scaling and fallen blocks are observable. The breaking of Holocene soda straw stalactites and displacements of artificial features observed since the beginning of the tourist activity, in the last century, also suggest very recent reactivation of these faults. This recent faulting can be correlated to present-day tectonic activity, already evidenced by earthquakes in the neighbouring area. Therefore, karstic caves are favourable sites for the observation and the quantification of recent tectonic activity because they constitute a 3-D framework, protected from erosion. Fault planes with this recent faulting present slickensides. Thus a quantitative analysis in term of stress inversion, with the help of striated faults, has permitted to reconstruct the stress tensor responsible for the brittle deformation. The principal NW-SE extension (σ3 horizontal) is nearly perpendicular to that of the present regional stress as illustrated by the analysis of the last strong regional earthquake (Roermond, The Netherlands) in 1992. During the Meso-Cenozoic, the main stress tectonics recorded in this part of the European platform is similar to the present one with a NE-SW direction of extension.The discrepancy between the regional stress field and the local stress in the Rochefort cave can be the result of the inversion of the σ2 and σ3 axes of the stress ellipsoid due to its symmetry or of a local modification at the ground surface of the crustal stress field as it has been already observed in active zones.

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