scholarly journals A joint local and teleseismic tomography study of the Mississippi Embayment and New Madrid Seismic Zone

2016 ◽  
Vol 121 (5) ◽  
pp. 3570-3585 ◽  
Author(s):  
Cecilia A. Nyamwandha ◽  
Christine A. Powell ◽  
Charles A. Langston
Keyword(s):  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Mississippi Embayment ◽  
Teleseismic Tomography ◽  
New Madrid

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.

High-Resolution Aeromagnetic Study of the New Madrid Seismic Zone: A Preliminary Report

1992 ◽  
Vol 63 (3) ◽  
pp. 209-221 ◽  
Author(s):  
Thomas G. Hildenbrand ◽  
Joseph G. Rosenbaum ◽  
Richard L. Reynolds
Keyword(s):  
High Resolution ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Aeromagnetic Survey ◽  
Mississippi Embayment ◽  
Permissible Stress ◽  
Igneous Intrusions ◽  
Magnetic Features ◽  
Stress Models ◽  
New Madrid

Abstract A high-resolution aeromagnetic survey, flown over the northern part of the New Madrid seismic zone in the Mississippi embayment, reveals linear features that generally parallel active seismic zones. This parallelism suggests that the linear magnetic features are related to faults. Modeling of these anomalies indicates that the associated magnetic sources are shallow, steeply dipping (>80°) prism-like bodies. Their tops at depths of about 1 km are considerably shallower than the depth of crystalline basement (roughly 3 km). The bodies are typically 2 km wide. A plausible explanation for these bodies is that the magnetization within the sequence of generally nonmagnetic sedimentary rocks has been enhanced within and adjacent to fault zones. Such a magnetic enhancement could arise in several ways, including the emplacement of igneous intrusions, the authigenic growth of pyrrhotite, or the conversion of pyrite to magnetite. Whatever the cause of the magnetization contrast, the apparent relation between linear magnetic features and faults may lead to permissible stress models that accommodate the fault pattern inferred from the magnetic field.

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