Seismic Reflection Images of Shallow Faulting, Northernmost Mississippi Embayment, North of the New Madrid Seismic Zone

2001 ◽  
Vol 91 (1) ◽  
pp. 128-139 ◽  
Author(s):  
J. H. McBride
Keyword(s):  
Seismic Reflection ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Mississippi Embayment ◽  
New Madrid

Mini-Sosie High Resolution Seismic Reflection Profiles Along the Bootheel Lineament in the New Madrid Seismic Zone

1992 ◽  
Vol 63 (3) ◽  
pp. 297-307 ◽  
Author(s):  
John L. Sexton ◽  
Harvey Henson ◽  
Paul Dial ◽  
K. Shedlock
Keyword(s):  
High Resolution ◽  
Seismic Reflection ◽  
Aerial Photographs ◽  
Source Zone ◽  
Small Scale ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Geological Structures ◽  
Linear Features ◽  
New Madrid

Abstract Results of geological and geophysical research conducted in the New Madrid seismic zone since the early 1970’s indicate that much of the seismicity of the area is associated with late Precambrian age rift-related geological structures that have been reactivated by contemporary stresses. Deep seismic reflection surveys have been used to detect and delineate deeply buried geological structures thought to be associated with the seismicity. Satellite imagery and aerial photographs have recently been used to detect a linear feature named the Bootheel lineament inferred to be the surface expression of one of the faults responsible for the 1811–1812 earthquakes. To assess the seismogenic potential of these deep structures and linear features, high resolution seismic reflection and geomorphic studies are required. In July and August, 1990, Mini-Sosie high resolution reflection surveys were conducted in the New Madrid seismic zone. A total of 23 line-kilometers of high resolution reflection data were collected at nine locations. Specific targets for the new surveys include several locations on the Bootheel lineament in the New Madrid area, its northern projection near Sikeston, Missouri, and its southern projection near Blytheville, Arkansas at locations related to the Blytheville arch. A location several kilometers south of Charleston, Missouri, was also selected. Data presented in this paper consist of 7 line-kilometers recorded at locations on or close to the Bootheel lineament near New Madrid, Missouri, Hayti, Missouri, and Blytheville, Arkansas. Numerous small-offset faults, channels and other structures in Tertiary, Cretaceous and Paleozoic age rocks have been interpreted from the Mini-Sosie seismic sections. These structures, although generally not major features themselves, may be associated with deep seated rift-related reactivated structures. Many of the small-offset faults appear to deform or offset Quaternary age sediments. The spatial correlation of the observed faulting with sandblows and lineaments identified from aerial photographs, suggests the possibility that the observed faulting, sandblows, and linear features may be genetically related. If this is the case, then, because the origin of the sandblows has generally been attributed to the 1811–1812 seismic activity, the observed faulting may have been active at that time. It is not possible to directly link a single correlatable seismic signature with the Bootheel lineament, and thus we cannot state unequivocally that the lineament is continuous from Blytheville, Arkansas to New Madrid, Missouri. However, each seismic line has imaged similar small-offset faulting and gentle folding. If the faults and deformation observed are directly caused by reactivated deep structures associated with the Bootheel lineament, then, due to its great length, the total of which is yet undefined, this structure may be a source zone for major earthquakes, and therefore requires further investigations. The possibility exists, however, that the small scale faulting and deformation are ubiquitous throughout the New Madrid seismic zone. Additional high resolution seismic data are required to resolve this question.

Overview of Research in The New Madrid Seismic Zone

1992 ◽  
Vol 63 (3) ◽  
pp. 193-208 ◽  
Author(s):  
Arch C. Johnston ◽  
Kaye M. Shedlock
Keyword(s):  
Field Investigation ◽  
Detailed Knowledge ◽  
New Madrid Seismic Zone ◽  
Research Front ◽  
Seismic Zone ◽  
Mississippi Embayment ◽  
Upper Mississippi Embayment ◽  
New Information ◽  
Seismogenic Faults ◽  
New Madrid

Abstract We review the development of understanding of the seismicity and tectonic structure of the New Madrid seismic zone and the upper Mississippi embayment. The broad framework of a failed intracontinental rift with reactivated seismogenic faults was not established until the mid-1970s. By the early 1990s a much more detailed knowledge of the rift and the current seismicity has been gained but fundamental questions remain. The 25 papers of this Special Issue of Seismological Research Letters convey the location of the most recent research front in such diverse fields as seismology, paleoseismology, seismic and potential-field investigation of rift structure, neotectonic deformation, and seismic hazard estimation and response. The new information content of these papers, considered ensemble, is enormous and highlights the tremendous progress made since the 1970s. These current studies, in turn, sharpen the focus on remaining outstanding problems of seismogenesis in the New Madrid seismic zone. We close with a discussion of what we believe will be the important foci of research in the 1990s.

Noise to signal: A microtremor study at liquefaction sites in the New Madrid Seismic Zone

Geophysics ◽  
2010 ◽  
Vol 75 (3) ◽  
pp. B83-B90 ◽  
Author(s):  
Kelli Hardesty ◽  
Lorraine W. Wolf ◽  
Paul Bodin
Keyword(s):  
Strong Motion ◽  
Sedimentary Basins ◽  
Large Earthquake ◽  
Sedimentary Facies ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Mississippi Embayment ◽  
Ground Failure ◽  
Liquefaction Susceptibility ◽  
New Madrid

Understanding how sedimentary basins respond to seismic-wave energy generated by large earthquake events is a significant concern for seismic-hazard estimation. This study explores the use of microtremors, or ambient noise, for evaluating strong-motion site effects. The study focuses on the Mississippi Embayment in the New Madrid Seismic Zone, where widespread liquefaction and ground failure occurred during the 1811–1812 earthquake sequence. Spectral analyses of microtremor data at sites representing different environments of deposition (and sedimentary facies), different embayment thicknesses, and varying liquefaction susceptibility show correlations between (1) calculated vulnerability indices and evidence of liquefaction, (2) sediment thickness and fundamental resonant frequency, and (3) subsurface stratigraphic boundaries and observed peaks in horizontal-to-vertical spectral ratios. Results of the study suggest that the microtremor method could be helpful in identifying those areas most vulnerable to ground amplification in intraplate sedimentary basins, where large earthquakes are infrequent but potentially damaging.

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