Internal structure, active tectonics and dynamic topography of the eastern Nankai accretionary prism toe, Japan, and its tsunamigenic potential

2018 ◽  
Vol 158 (1) ◽  
pp. 30-38 ◽  
Author(s):  
Kiichiro Kawamura ◽  
Yujiro Ogawa
Keyword(s):  
Active Faults ◽  
Active Tectonics ◽  
Accretionary Prism ◽  
Fault Scarp ◽  
Burial Depth ◽  
Dynamic Topography ◽  
Slip Rates ◽  
Uplift Rates ◽  
Thrust Zone ◽  
Nankai Earthquake

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.

scholarly journals The active tectonic landscape of Lake Ohrid (FYR of Macedonia/Albania)

2014 ◽  
Vol 56 (6) ◽  
Author(s):  
Nadine Hoffmann
Keyword(s):  
Active Faults ◽  
Fault Scarp ◽  
Mass Wasting ◽  
Lake Ohrid ◽  
Slip Rates ◽  
Active Tectonic ◽  
Western Border ◽  
Wine Glass ◽  
Yugoslavian Republic ◽  
Fault Scarps

<p><span style="font-family: CMR10; font-size: medium;">The study area at the Lake Ohrid Basin is located on 693 m a.s.l. at the south-western border of the Former Yugoslavian Republic of Macedonia with Albania. It is a suitable location for neotectonic studies. It exhibits a large variety of morphological expressions associated with the seismic activity of the region. Linear bedrock fault scarps give the relief on both sides of the lake a staircase-like appearance; other features are wine-glass shaped valleys and triangular facets. These often short living features are used to identify active faults and to parameterise palaeoearthquakes (slip rates, subsidence and erosion). According to the results of fault scarp profiling a halfgraben shape of the basin is proposed with the west coast being dominated by mass wasting processes most likely triggered by seismic events.</span></p>

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

2017 ◽  
Author(s):  
Benoit Deffontaines ◽  
Kuo-Jen Chang ◽  
Johann Champenois ◽  
Kuan-Chuan Lin ◽  
Chyi-Tyi Lee ◽  
...  
Keyword(s):  
Time Series ◽  
Active Faults ◽  
Active Tectonics ◽  
Accretionary Prism ◽  
Point Of View ◽  
Gis Mapping ◽  
Geological Maps ◽  
Southern Taiwan ◽  
Very High ◽  
Chichi Earthquake

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 (

scholarly journals Fault-controlled geomorphic features in Ridi-Shantipur area of Gulmi District and their implications for active tectonics

2018 ◽  
Vol 55 (1) ◽  
pp. 157-165
Author(s):  
Kumar Timalsina ◽  
Kabi Raj Paudyal
Keyword(s):  
Active Faults ◽  
Active Tectonics ◽  
Shear Zones ◽  
Field Work ◽  
Fault Scarp ◽  
Left Bank ◽  
Aerial Photo ◽  
Aerial Photos ◽  
River Terraces ◽  
Geomorphic Features

The Lesser Himalaya is a fold-thrust belt in the Himalaya. In the Nepal Himalaya, several active faults, among which the Badi Gad Fault is one of them, are identified and mapped by many researchers in the past, However, very less study has been carried out on the existence of this fault and its extension. In the present study, an attempt was made to assess the fault and to map its extension in the region based on the geological as well as geomorphological criteria. For this purpose, a detailed geological map was prepared from Ridi to the Shantipur area in 1:25,000 scales. During the field work, several geological as well as geomorphic evidences of the existence of active fault were found, and some of them are also found under the aerial photo observation. These evidences include the presence of shear zones, clustering of large and several landslides along a confined linear zone, river course diversion, terrace tilting, fault scarps etc. In the present work, the Badi Gad Fault is traced out continuously from the Ridi to the Shantipur area and even extended far to the NW direction under aerial photo. The fault follows the moderate hills of the left bank of the present course of the Badi Gad River. Major shear zones found in the region are the Tal Khola, Aslewa, Eksingaun, Juhan, Gultung, and the Rupakot shear zones. These shear zones are represented by the wide zone of fault gauge, fault breccias, silickensides, striations and large landslides. Besides, other geomorphic evidences traced out are location of spring lines, tilted river terraces in Pul Camp and Wamitaksar area, river course diversion of the Lumdi Khola and fault scarp at Bhanjyangaun of Aslewa. Such types of fault-controlled geomorphic features are also found from the Rudrabeni-Wamitaksar areas under the aerial photos. Based on the fault controlled geomorphological study in the field and aerial photos interpretation, an attempt was made to map the Badi Gad Fault, an active strike slip fault in the region.

Constraining the regional uplift rate of the Corinth Isthmus area (Greece), through biostratigraphic and tectonic data

2019 ◽  
Vol 62 (2) ◽  
pp. 127-142 ◽  
Author(s):  
Aggelos Pallikarakis ◽  
Ioannis Papanikolaou ◽  
Klaus Reicherter ◽  
Maria Triantaphyllou ◽  
Margarita Dimiza ◽  
...  
Keyword(s):  
Active Faults ◽  
Middle Pleistocene ◽  
Published Data ◽  
Uplift Rate ◽  
Slip Rates ◽  
Corinth Gulf ◽  
Marine Sedimentation ◽  
Fault Slip Rates ◽  
Uplift Rates ◽  
Sedimentation Processes

The eastern Corinth Gulf is constantly uplifted at least since Middle Pleistocene. This uplift is the combined result of the regional uplift and the activity of major active faults which influence the area. These tectonic movements which control the sedimentation processes of the study area resulted in a complex stratigraphy, paleogeography and paleoenvironment of the Corinth Isthmus. Stratigraphy supported with nannofossil biozonation data, demonstrates that marine sedimentation processes occurred during MIS 7 and MIS 5, providing some important constraints regarding the uplift rate of the area. An 0.22 ± 0.12 mm/yr uplift rate is extracted through nannofossils biozonation which is in agreement with published data from U/Th coral dating in a neighboring setting, adding confidence to the measured uplift rates. In order to constrain the regional uplift of the area, the influence of the surrounding active faults has been extracted. The latter has been implemented by extracting the influence of each individual active fault to the study site (using the fault geometry, fault slip-rates, the fault dip and the fault footwall uplift/ hangingwall subsidence ratio), in order to calculate the regional uplift rate. By considering the stratigra- phy and the biostratigraphy of the eastern part of the Corinth Isthmus and by extracting the influence of the active faults, a~0.34 ± 0.04 mm/yr regional uplift is calculated.

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 ◽  
...  
Keyword(s):  
Active Faults ◽  
Active Tectonics ◽  
Accretionary Prism ◽  
Unmanned Aircraft ◽  
Point Of View ◽  
Surface Model ◽  
Surface Displacements ◽  
Persistent Scatterer ◽  
Southern Taiwan ◽  
Aircraft System

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.

scholarly journals Vertical slip rates of active faults of southern Albania inferred from river terraces

2014 ◽  
Vol 56 (6) ◽  
Author(s):  
Oswaldo Guzmán ◽  
Jean-Louis Mugnier ◽  
Riccardo Vassallo ◽  
Rexhep Koçi ◽  
François Jouanne
Keyword(s):  
Active Faults ◽  
Active Tectonics ◽  
Temporal Variations ◽  
Fold Belt ◽  
Quaternary Sediments ◽  
Slip Rates ◽  
Geomorphological Mapping ◽  
Fluvial Terraces ◽  
River Terraces ◽  
Northwestern Greece

Fluvial terraces of Shkumbin, Devoll, Osum and Vjosa rivers (southern Albania and northwestern Greece) are studied in order to quantify the vertical slip rates of the large active faults of the Dinaric-Albanic-Hellenic Alpine fold belt. The spatial and temporal variations of the incision rates along these rivers were estimated from the geomorphological mapping of the Quaternary sediments, the geometry and the dating of the terraces. Eleven terraces levels were identified in Albania from 68 geochronological ages already published or acquired for this work. The five lower terraces of the four studied rivers are well dated (10 new and 23 already published ages). These terraces are younger than 30 ka and their remnants are numerous. Their restoration allows estimating the regional trend of incision rate and the identification of local shifts. We argue that these shifts are linked to the active tectonics when they coincide with the faults already mapped by previous authors. Vertical slip rates for eight active faults in southern Albania are thus estimated for the last 19 ka and vary from ~0.1 to ~2 mm/a. The Lushnje Tepelene Thrust, that extends more than 120 kilometers, has a throw rate that varies from 0.2 to 0.8 mm/a, whereas the active faults of the extensional domain are segmented but are very active, with throw rates reaching locally 2 mm/a.

Slip rates along active faults estimated with cosmic-ray–exposure dates: Application to the Bogd fault, Gobi-Altaï, Mongolia

Geology ◽  
1995 ◽  
Vol 23 (11) ◽  
pp. 1019 ◽  
Author(s):  
J. F. Ritz ◽  
E. T. Brown ◽  
D. L. Bourlès ◽  
H. Philip ◽  
A. Schlupp ◽  
...  
Keyword(s):  
Active Faults ◽  
Cosmic Ray ◽  
Slip Rates

scholarly journals Active Fault Systems in the Inner Northwest Apennines, Italy: A Reappraisal One Century after the 1920 Mw ~6.5 Fivizzano Earthquake

Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 139
Author(s):  
Giancarlo Molli ◽  
Isabelle Manighetti ◽  
Rick Bennett ◽  
Jacques Malavieille ◽  
Enrico Serpelloni ◽  
...  
Keyword(s):  
Large Scale ◽  
Active Fault ◽  
Active Faults ◽  
Dense Network ◽  
Earthquake Fault ◽  
Slip Rates ◽  
Fault Systems ◽  
Seismological Data ◽  
Seismogenic Faults

Based on the review of the available stratigraphic, tectonic, morphological, geodetic, and seismological data, along with new structural observations, we present a reappraisal of the potential seismogenic faults and fault systems in the inner northwest Apennines, Italy, which was the site, one century ago, of the devastating Mw ~6.5, 1920 Fivizzano earthquake. Our updated fault catalog provides the fault locations, as well as the description of their architecture, large-scale segmentation, cumulative displacements, evidence for recent to present activity, and long-term slip rates. Our work documents that a dense network of active faults, and thus potential earthquake fault sources, exists in the region. We discuss the seismogenic potential of these faults, and propose a general tectonic scenario that might account for their development.

scholarly journals Tectonic Geomorphology and Paleoseismology of the Sharkhai fault: a new source of seismic hazard for Ulaanbaatar (Mongolia)

2021 ◽  
Author(s):  
Abeer Al-Ashkar ◽  
Antoine Schlupp ◽  
Matthieu Ferry ◽  
Ulziibat Munkhuu
Keyword(s):  
Seismic Hazard ◽  
Scaling Laws ◽  
Active Faults ◽  
Seismic Hazard Assessment ◽  
Capital City ◽  
Tectonic Geomorphology ◽  
Time Interval ◽  
Coseismic Slip ◽  
Slip Rates ◽  
Large Earthquakes

Abstract. We present new constraints from tectonic geomorphology and paleoseismology along the newly discovered Sharkhai fault near the capital city of Mongolia. Detailed observations from high resolution Pleiades satellite images and field investigations allowed us to map the fault in detail, describe its geometry and segmentation, characterize its kinematics, and document its recent activity and seismic behavior (cumulative displacements and paleoseismicity). The Sharkhai fault displays a surface length of ~40 km with a slightly arcuate geometry, and a strike ranging from N42° E to N72° E. It affects numerous drainages that show left-lateral cumulative displacements reaching 57 m. Paleoseismic investigations document the faulting and deposition record for the last ~3000 yr and reveal that the penultimate earthquake (PE) occurred between 1515 ± 90 BC and 945 ± 110 BC and the most recent event (MRE) occurred after 860 ± 85 AD. The resulting time interval of 2080 ± 470 years is the first constraint on the Sharkhai fault for large earthquakes. On the basis of our mapping of the surface rupture and the resulting segmentation analysis, we propose two possible scenarios for large earthquakes with likely magnitudes between 6.4 ± 0.2 and 7.1 ± 0.2. Furthermore, we apply scaling laws to infer coseismic slip values and derive preliminary estimates of long-term slip rates between 0.2 ± 0.2 and 1.0 ± 0.5 mm/y. Finally, we propose that these original observations and results from a newly discovered fault should be taken into account for the seismic hazard assessment for the city of Ulaanbaatar and help build a comprehensive model of active faults in that region.

scholarly journals Paleoearthquake history of the Spili fault

2017 ◽  
Vol 47 (2) ◽  
pp. 595
Author(s):  
V. Mouslopoulou ◽  
D. Moraetis ◽  
L. Benedetti ◽  
V. Guillou ◽  
D. Hristopulos
Keyword(s):  
Rare Earth ◽  
Active Faults ◽  
Fault Scarp ◽  
Large Magnitude ◽  
Earthquake Recurrence ◽  
Earthquake Parameters ◽  
History Of ◽  
Earthquake Recurrence Interval ◽  
Seismic Displacements

The paleoearthquake activity on the Spili Fault is examined using a novel methodology that combines measurements of Rare Earth Elements (REE) and of in situ cosmogenic 36Cl on the exhumed fault scarp. Data show that the Spili Fault is active and has generated a minimum of five large-magnitude earthquakes over the last ~16500 years. The timing and, to a lesser degree, the slip-size of the identified paleoearthquakes was highly variable. Specifically, the two most recent events occurred between 100 and 900 years BP producing a cumulative displacement of 3.5 meters. The timing of the three older paleoearthquakes is constraint at 7300, 16300 and 16500 years BP with slip sizes of 2.5, 1.2 and 1.8 meters, respectively. The magnitude of the earthquakes that produced the measured co-seismic displacements, ranges from M 6.3-7.3 while the average earthquake recurrence interval on the Spili Fault is about 4200 years. The above data suggest that the Spili is among the most active faults on Crete and its earthquake parameters may be incorporated into the National Seismic Hazard Model.

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