Indication of active Faults in the New Madrid Seismic Zone from Precise Location of Hypocenters

1988 ◽  
Vol 59 (4) ◽  
pp. 123-131 ◽  
Author(s):  
L. Himes ◽  
W. Stauder ◽  
R. B. Herrmann
Keyword(s):  
Active Faults ◽  
P Wave ◽  
New Madrid Seismic Zone ◽  
Supporting Evidence ◽  
Seismic Zone ◽  
Low Velocity ◽  
Focal Mechanism Solutions ◽  
Velocity Models ◽  
Planar Surfaces ◽  
New Madrid

Abstract The hypocenter locations of the larger and better recorded earthquakes of the New Madrid seismic zone are examined in order to determine how closely the hypocenters lie along planar surfaces, thus relating the foci to active fault surfaces. For this purpose more than 500 earthquakes of the region have been selected for study, based on the number (7 or more) of observing stations used in the initial hypocenter location and on the quality of the P-wave onset. These events are relocated using a joint hypocenter-velocity-depth (JHVD) algorithm. The relocated earthquakes are separated geographically into three trends: ARK, the southwest trending zone from Caruthersville, Missouri, to Marked Tree, Arkansas; DWM, the northeast trending zone from New Madrid to Charleston, Missouri; and CEN, the central, left-stepping offset zone from Ridgely, Tennessee, to New Madrid, Missouri. Vertical profiles taken along and across the ARK and DWM trends verify the strike and dip of dominantly strike slip motion on near vertical active faults along these trends. These results agree with previously determined composite focal mechanism solutions for these trends. No coherent picture has been obtained for the CEN trend. As a by-product of the study, velocity models from the JHVD inversion are found to be reasonably uniform throughout the New Madrid seismic zone, and to offer supporting evidence for the presence of a shallow low velocity zone in the central portion of the Mississippi embayment.

Imaging the Active Faults of the Central New Madrid Seismic Zone Using Panda Array Data

1992 ◽  
Vol 63 (3) ◽  
pp. 375-393 ◽  
Author(s):  
J.M. Chiu ◽  
A.C. Johnston ◽  
Y.T. Yang
Keyword(s):  
Hanging Wall ◽  
Active Faults ◽  
Velocity Model ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Thrust Faults ◽  
Secondary Phases ◽  
Low Velocity ◽  
Data Set ◽  
New Madrid

Abstract More than 700 earthquakes have been located in the central New Madrid seismic zone during a two-year deployment of the PANDA array. Magnitudes range from < 0.0 to the mblg 4.6 Risco, Missouri earthquake of 4 May 1991. The entire data set is digital, three-component and on-scale. These data were inverted to obtain a new shallow crustal velocity model of the upper Mississippi embayment for both P- and S-waves. Initially, inversion convergence was hindered by extreme velocity contrasts between the soft, low-velocity surficial alluvial sediments and the underlying Paleozoic carbonate and clastic high-velocity rock. However, constraints from extensive well log data for the embayment, secondary phases (Sp and Ps), and abundant, high-quality shear-wave data have yielded a relatively robust inversion. This in turn has led to a hypocentral data set of unprecedented quality for the central New Madrid seismic zone. Contrary to previous studies that utilized more restricted data, the PANDA data clearly delineate planar concentrations of hypocenters that compel an interpretation as active faults. Our results corroborate the vertical (strike-slip) faulting of the the southwest (axial), north-northeast, and western arms and define two new dipping planes in the central segment. The seismicity of the left-step zone between the NE-trending vertical segments is concentrated about a plane that dips at ∼31°SW; a separate zone to the SE of the axial zone defines a plane that dips at ∼48°SW. The reason for this difference in dip, possibly defining segmentation of an active fault, is not dear. When these planes are projected up dip, they intersect the surface along the eastern boundary of the Lake County uplift (LCU) and the western portion of Reelfoot Lake. If these SW-dipping planes are thrust faults, then the LCU would be on the upthrown hanging wall and Reelfoot Lake on the downthrown footwall. If in turn these inferred thrust faults were involved in the 1811–12 and/or pre-1811 large earthquakes, they provide an internally consistent explanation for (1) the existence and location of the LCU, (2) the wide-to-the-north, narrow-to-the-south shape of the LCU, and (3) the subsidence and/or impoundment of Reelfoot Lake.

The June 13, 1975 earthquake and its relationship to the New Madrid seismic zone

1977 ◽  
Vol 67 (1) ◽  
pp. 209-218
Author(s):  
R. B. Herrmann ◽  
G. W. Fischer ◽  
J. E. Zollweg
Keyword(s):  
Parameter Estimation ◽  
Seismic Moment ◽  
Strong Motion ◽  
P Wave ◽  
Eastern North America ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Long Period ◽  
Consistent Solution ◽  
New Madrid

abstract The June 13, 1975 earthquake in the New Madrid seismic zone produced the first recorded strong-motion accelerograms for an event in the region, as well as the largest recorded accelerations to date for any event in eastern North America. The peak strong-motion values obtained from an analysis of the accelerograms are the following: amax = 43 cm/sec2, vmax = 1 cm/sec and dmax = 0.05 cm for the longitudinal S88°W component; amax = 31 cm/sec2, vmax = 0.6 cm/sec and dmax = 0.01 cm for the DOWN component; amax = 64 cm/sec2, vmax = 1.6 cm/sec2, and dmax = 0.09 cm for the tangential S02°E component. Source parameter estimation using long-period surface waves, Lg spectra, P-wave first motions and the integrated accelerograms leads to a consistent solution. The seismic moment is estimated to be 4E21 dyne-cm and the corner period 0.6 sec. The corner period-seismic moment pair for this event agrees with the regional scaling of these parameters observed by Street et al. (1975).

3D GEOLOGIC MAPPING IN AND ADJACENT TO THE NEW MADRID SEISMIC ZONE, CENTRAL UNITED STATES

2020 ◽  
Author(s):  
Renee M. Reichenbacher ◽  
◽  
Valarie Harrison ◽  
Taylor Andrew Weathers ◽  
Roy B. Van Arsdale ◽  
...  
Keyword(s):  
United States ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Geologic Mapping ◽  
Central United States ◽  
New Madrid

POSSIBLE SURFACE WARPING ALONG THE BOOTHEEL FAULT REVEALED FROM LIDAR, NEW MADRID SEISMIC ZONE, CENTRAL US

2020 ◽  
Author(s):  
Samia Noor ◽  
◽  
Randel Tom Cox ◽  
Robert Smalley ◽  
Md Rizwanul Hasan
Keyword(s):  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
New Madrid

Stream response to repeated coseismic folding, Tiptonville dome, New Madrid seismic zone

Geomorphology ◽  
2002 ◽  
Vol 43 (3-4) ◽  
pp. 313-349 ◽  
Author(s):  
M.J Guccione ◽  
K Mueller ◽  
J Champion ◽  
S Shepherd ◽  
S.D Carlson ◽  
...  
Keyword(s):  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Stream Response ◽  
New Madrid

scholarly journals Seismic Structure of Local Crustal Earthquakes beneath the Zipingpu Reservoir of Longmenshan Fault Zone

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Haiou Li ◽  
Xiwei Xu ◽  
Wentao Ma ◽  
Ronghua Xie ◽  
Jingli Yuan ◽  
...  
Keyword(s):  
Fault Zone ◽  
Three Dimensional ◽  
P Wave ◽  
The Tibetan Plateau ◽  
Seismic Structure ◽  
Infiltration Depth ◽  
Low Velocity ◽  
Longmenshan Fault Zone ◽  
Velocity Models ◽  
Longmenshan Fault

Three-dimensional P wave velocity models under the Zipingpu reservoir in Longmenshan fault zone are obtained with a resolution of 2 km in the horizontal direction and 1 km in depth. We used a total of 8589 P wave arrival times from 1014 local earthquakes recorded by both the Zipingpu reservoir network and temporary stations deployed in the area. The 3-D velocity images at shallow depth show the low-velocity regions have strong correlation with the surface trace of the Zipingpu reservoir. According to the extension of those low-velocity regions, the infiltration depth directly from the Zipingpu reservoir itself is limited to 3.5 km depth, while the infiltration depth downwards along the Beichuan-Yingxiu fault in the study area is about 5.5 km depth. Results show the low-velocity region in the east part of the study area is related to the Proterozoic sedimentary rocks. The Guanxian-Anxian fault is well delineated by obvious velocity contrast and may mark the border between the Tibetan Plateau in the west and the Sichuan basin in the east.

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