The Woodstock Lineament: A Possible Surface Expression of the Seismogenic Fault of the 1886 Charleston, South Carolina, Earthquake

1992 ◽  
Vol 63 (2) ◽  
pp. 153-160
Author(s):  
Ronald T. Marple ◽  
Pradeep Talwani
Keyword(s):  
South Carolina ◽  
Satellite Image ◽  
Wide Band ◽  
Surface Expression ◽  
Geophysical Data ◽  
Tectonic Activity ◽  
East Side ◽  
Seismogenic Fault ◽  
Linear Feature ◽  
Spot Image

Abstract A SPOT satellite image of the Charleston, South Carolina, area revealed a linear feature, the Woodstock lineament, that may be the surface expression of a seismogenic fault of the 1886 Charleston earthquake. An enhancement of the SPOT image reveals a linear, 5 km wide band on the east side of the lineament that extends at least 65 km in a north-northeast direction and coincides with a part of the axis of the highest intensity isoseismal contours of the Charleston earthquake. Corroborative geologic, geodetic, and geophysical data suggest that the lineament and associated band may be the result of ongoing tectonic activity on the Woodstock fault inferred from seismicity.

Wave conversions from earthquakes and a new velocity model for the South Carolina coastal plain

1987 ◽  
Vol 77 (6) ◽  
pp. 2143-2151
Author(s):  
Susan Rhea
Keyword(s):  
Surface Layer ◽  
South Carolina ◽  
Coastal Plain ◽  
Velocity Structure ◽  
Velocity Model ◽  
Seismogenic Fault ◽  
Impedance Boundary ◽  
High Impedance ◽  
Hypocentral Parameters ◽  
Converted Phases

Abstract Phase conversions from P to SV and from SV to P occur at a high impedance boundary near the surface in Charleston, South Carolina. Four arrivals (P, converted P, converted S, and S) are observed on three-component records of earthquakes in this area. Using arrival-time differences between paired arrivals of direct and converted phases, a shallow surface layer Vp/Vs ratio of 2.9 was determined. Applying the Wadati method to travel times derived at the base of the surface layer yields a Vp/Vs ratio in deeper layers of 1.73. Relocating earthquakes using this more appropriate velocity structure for direct and converted shear waves alters hypocentral parameters such that epicenters diverge and depths converge. It is inferred that these relocated earthquakes are not exclusively associated with a single seismogenic fault.

Synthesizing Shallow-Water Geophysical Data for Shoreline Evolution Models: Shallow Coastal Stratigraphy Workshop; Conway, South Carolina, 9–10 July 2008

Eos ◽  
2008 ◽  
Vol 89 (41) ◽  
pp. 393
Author(s):  
Jennifer L. Miselis ◽  
Paul T. Gayes ◽  
Jesse McNinch ◽  
John Goff ◽  
Antonio Rodriguez
Keyword(s):  
South Carolina ◽  
Shallow Water ◽  
Geophysical Data ◽  
Shoreline Evolution

scholarly journals Investigation of a possible crevasse near the main airstrip on McMurdo Ice Shelf, Antarctica

1997 ◽  
Vol 24 ◽  
pp. 152-156 ◽  
Author(s):  
I. M. Whillans ◽  
C. J. Merry ◽  
G. S. Hamilton
Keyword(s):  
Global Positioning System ◽  
Sea Water ◽  
Satellite Image ◽  
Surface Expression ◽  
Surface Elevation ◽  
Positioning System ◽  
Ice Shelf ◽  
Dark Line ◽  
Global Positioning

A dark line appears on a recent satellite image of McMurdo Ice Shelf, Antarctica. It is parallel to the calving front. Initial thoughts were that the line marks an opening crevasse associated with an impending major calving event. The feature was studied by means of a strain and surface-elevation grid that was surveyed twice, 25 d apart, using global positioning system (GPS) techniques. Results show that the dark line is not due to an opening crevasse. The feature is probably the surface expression of firn collapse over sea water soaking horizontally into the ice shelf.

scholarly journals Late Quaternary Tectonic Activity of the Udine-Buttrio Thrust, Friulian Plain, NE Italy

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 84
Author(s):  
Andrea Viscolani ◽  
Christoph Grützner ◽  
Manuel Diercks ◽  
Klaus Reicherter ◽  
Kamil Ustaszewski
Keyword(s):  
Late Quaternary ◽  
Tectonic Setting ◽  
Surface Expression ◽  
Vertical Surface ◽  
Fault System ◽  
Tectonic Activity ◽  
Morphological Evidence ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Ne Italy

The NW-SE trending Udine-Buttrio Thrust is a partly blind fault that affects the Friulian plain southeast of Udine in NE Italy. It is part of a wider fault system that accommodates the northward motion of the Adriatic plate. Although seismic reflection data and morphological evidence show that the fault was active during the Quaternary, comparably little is known about its tectonic activity. We used high-resolution digital elevation models to investigate the surface expression of the fault. Measured vertical surface offsets show significant changes along strike with uplift rates varying between 0 and 0.5 mm/yr. We then analyze a topographic scarp near the village of Manzano in more detail. Field mapping and geophysical prospections (Georadar and Electrical Resistivity Tomography) were used to image the subsurface geometry of the fault. We found vertical offsets of 1–3 m in Natisone River terraces younger than 20 ka. The geophysical data allowed the identification of deformation of the fluvial sediments, supporting the idea that the topographic scarp is a tectonic feature and that the terraces have been uplifted systematically over time. Our findings fit the long-term behaviour of the Udine-Buttrio Thrust. We estimate a post-glacial vertical uplift rate of 0.08–0.17 mm/yr recorded by the offset terraces. Our results shed light on the Late Quaternary behaviour of this thrust fault in the complicated regional tectonic setting and inform about its hitherto overlooked possible seismic hazard.

scholarly journals TRANSTENSIVE ORIGIN OF THE ENCADENADAS-VALLIMANCA CORRIDOR (BUENOS AIRES, ARGENTINA): A REVISION AND A NEW PROPOSAL FROM SATELLITE IMAGES

2020 ◽  
Vol 39 (04) ◽  
pp. 965-976
Author(s):  
Eduardo A. ROSSELLO ◽  
Sergio A. LÓPEZ
Keyword(s):  
Buenos Aires ◽  
Average Length ◽  
Sedimentary Cover ◽  
Surface Expression ◽  
Gravity Potential ◽  
Buenos Aires Province ◽  
Fault Activity ◽  
Cross Sectional ◽  
Linear Feature ◽  
Lateral Flower

The Encadenadas-Vallimanca Corridor (EVC) corresponds to a morphostructural linear feature defining the northern boundary of the Sierra de la Ventana and Tandil hills in the Buenos Aires province. The scarcity of concluding geological studies has resulted in diverse tectonic and hydrographic interpretations regarding the genesis of the corridor. A new analysis of surface morphology, mainly derived from satellite imagery, led to the identification of a series of gentle and elongated en échelon left-stepping relief features or ridges with cross-sectional asymmetric flanks, having an average length of 20 km and oriented sub-latitudinally at 20° to the ENE strike of the corridor. The arrangement of these ridges reminds a tectonic scenario of right-lateral transcurrent faulting, for which, the limiting parallel faults fulfill the function of synthetic Riedel type shear. Besides, the cross-sectional asymmetry of the ridges suggests extensional normal faulting coherent with a transtensional right-lateral flower structure. Shallow seismicity of Mw 4.0 registered by the year 2016 in the proximities of the lineament could suggest recent fault activity. Also, previous gravity potential field mapping in the area seems to highlight basement anomalies underneath the sedimentary cover, coinciding with the main lineament of the Corridor. Based on all this information, the EVC is considered to be the surface expression of dextral transtensional fault activity.

Micro-bathymetric mapping of the North Alfeo strike-slip fault (offshore Catania Sicily): preliminary results from the FocusX1 expedition

2021 ◽  
Author(s):  
Arnaud Gaillot ◽  
Marc-André Gutscher ◽  
Shane Murphy ◽  
Frauke Klingelhoefer
Keyword(s):  
Fiber Optic ◽  
Video Camera ◽  
Surface Expression ◽  
Relative Displacement ◽  
Fault Scarp ◽  
Linear Feature ◽  
Navigation Data ◽  
Bathymetric Data ◽  
The North ◽  
Summit Region

<p>In October 2020, during the marine expedition FocusX1 onboard the research vessel PourquoiPas? microbathymetric mapping was performed using the ROV Victor6000. The main goal was to map the seafloor expression of the North Alfeo fault and select the best path for deployment of a 6-km long fiber optic strain cable designed to monitor movement along the fault and the deployment sites for 8 geodetic stations.</p><p>Bathymetric data were collected through a Reson Seabat 7125 multibeam echosounder (400 kHz). ROV navigation data were processed using DelphINS, resulting in an optimal merging of navigation sensors (GPS, USBL, DVL, pressure). The MBES data processing (GLOBE software) mainly consisted in estimating and correcting static angular offsets, applying actual in-situ sound speed profile, and finally performing an automatical and manual soundings filtering.</p><p>The resulting bathymetric grid spans a region of roughly 3 km x 1.5 km, with a 1m cell size, and allows  us to identify a variety of morphological features:</p><p>1 - a set of narrow, linear, E-W oriented gulleys, all parallel (not merging/branching) on a regional E dipping 5-15° slope</p><p>2 - a striking, continuous curvi-linear feature, which is interpreted as the primary surface expression of the fault.The fault morphology changes from a smooth less than 10 m depression in the NW to a up to 10-20m high scarp with slopes of 20-30°, and locally sub-vertical cliff faces.</p><p>3 - a local bathymetric plateau (mesa like feature) with a gently E-dipping summit region, showing signs of eastward sliding / rafting tectonics, indicated by N-S oriented gashes/depressions.</p><p>The 3-km long segment of the fault covered by our survey includes the mesa-like bathymetric high (at the NW extremity) interpreted as a transpressional pop-up feature and an elongated, fault bounded trough (at the SE extremity) interpreted as a transtensional pull-apart basin. Video-camera images recorded by ROV Victor6000 from the seafloor provide visual documentation of the fault scarp and seafloor morphology. Future surveys with a sub-bottom profiler and/or HR- seismics can help confirm these interpretations. The ongoing monitoring with the fiber-optic strain cable is being calibrated by a 3-4 year deployment of seafloor geodetic instruments (Canopus acoustic beacons manufactured by iXblue) which started in Oct. 2020, and will allow us to quantify relative displacement across the fault.</p>

Ant-Snake model for Linear Feature Extraction from Satellite Image

2014 ◽  
Vol 13 (6) ◽  
pp. 4574-4582
Author(s):  
Jalal Amini ◽  
Leila Mohammadnia
Keyword(s):  
Feature Extraction ◽  
Satellite Images ◽  
Satellite Image ◽  
Ant Colony ◽  
Superior Performance ◽  
Linear Features ◽  
Snake Model ◽  
Parametric Curve ◽  
Linear Feature ◽  
Linear Feature Extraction

This paper proposes an optimized mathematical model for linear feature extraction from satellite images. The model is based on a developed ant colony model combined with the snake model (called Ant-Snake model) to identify and extract the linear features like roads from satellite images. The process is started with the developed ant colony model to recognize and identify interest object and then with a snake model extract object. The developed ant model is able to establish a pheromone matrix that represents the object information at each pixel position of the image, according to the movements of a number of ants which are dispatch to move on the image. And the snake model is a parametric curve which is allowed to deform from some arbitrary initial locations from pheromone matrix toward the desired final location by minimizing an energy function. Experimental results are provided to demonstrate the superior performance of the proposed approach.

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