Magnitudes and Locations of the 1811–1812 New Madrid, Missouri, and the 1886 Charleston, South Carolina, Earthquakes

We estimate locations and moment magnitudes M and their uncertainties for the three largest events in the 1811–1812 sequence near New Madrid, Missouri, and for the 1 September 1886 event near Charleston, South Carolina. The intensity magnitude M I, our preferred estimate of M , is 7.6 for the 16 December 1811 event that occurred in the New Madrid seismic zone (NMSZ) on the Bootheel lineament or on the Blytheville seismic zone. M I is 7.5 for the 23 January 1812 event for a location on the New Madrid north zone of the NMSZ and 7.8 for the 7 February 1812 event that occurred on the Reelfoot blind thrust of the NMSZ. Our preferred locations for these events are located on those NMSZ segments preferred by Johnston and Schweig (1996). Our estimates of M are 0.1–0.4 M units less than those of Johnston (1996b) and 0.3–0.5 M units greater than those of Hough et al. (2000). M I is 6.9 for the 1 September 1886 event for a location at the Summerville–Middleton Place cluster of recent small earthquakes located about 30 km northwest of Charleston.

[1]  R. Street A Contribution to the Documentation of the 1811–1812 Mississippi Valley Earthquake Sequence , 1982 .

[2]  W. Bakun Seismic activity of the San Francisco Bay region , 1999, Bulletin of the Seismological Society of America.

[3]  Walter H. F. Smith,et al.  Free software helps map and display data , 1991 .

[4]  B. Efron The jackknife, the bootstrap, and other resampling plans , 1987 .

[5]  S. F. Obermeier Liquefaction evidence for strong earthquakes of Holocene and latest Pleistocene ages in the states of Indiana and Illinois, USA , 1998 .

[6]  T. Toppozada Earthquake magnitude as a function of intensity data in California and Western Nevada , 1975 .

[7]  G. Bollinger,et al.  List of intensities for the 1886 Charleston, South Carolina earthquake , 1976 .

[8]  Navin Sharma,et al.  Reevaluation of the Magnitudes of Three Destructive Aftershocks of the 1886 Charleston Earthquake , 1999 .

[9]  C. W. Stover,et al.  Seismicity of the United States, 1568-1989 (revised) , 1993 .

[10]  O. Nuttli,et al.  The Mississippi Valley earthquakes of 1811 and 1812: Intesities, ground motion and magnitudes , 1973, Bulletin of the Seismological Society of America.

[11]  A. Johnston Seismic moment assessment of earthquakes in stable continental regions—III. New Madrid 1811–1812, Charleston 1886 and Lisbon 1755 , 1996 .

[12]  S. Hough,et al.  On the Modified Mercalli intensities and magnitudes of the 1811–1812 New Madrid earthquakes , 2000 .

[13]  S. Harmsen,et al.  Documentation for the 2002 update of the national seismic hazard maps , 2002 .

[14]  T. Hanks,et al.  Seismic Moments of the Larger Earthquakes of the Southern California Region , 1975 .

[15]  S. Harmsen,et al.  Deaggregation of probabilistic ground motions in the central and eastern United States , 1999 .

[16]  W. B. Joyner,et al.  Methods for regression analysis of strong-motion data , 1993, Bulletin of the Seismological Society of America.

[17]  T. Hildenbrand,et al.  Geophysical Setting of the Wabash Valley Fault System , 1997 .

[18]  W. Bakun Seismicity of California's north coast , 2000 .

[19]  Pradeep Talwani,et al.  Internally consistent pattern of seismicity near Charleston, South Carolina , 1982 .

[20]  H. Kanamori,et al.  A moment magnitude scale , 1979 .

[21]  W. H. Bakun,et al.  Differences in attenuation among the stable continental regions , 2002 .

[22]  Arch C. Johnston,et al.  Seismic moment assessment of earthquakes in stable continental regions—II. Historical seismicity , 1996 .

[23]  S. F. Obermeier,et al.  Liquefaction Evidence for Holocene and Latest Pleistocene Seismicity in the Southern Halves of Indiana and Illinois: A Preliminary Overview , 1997 .

[24]  Jose Pujol,et al.  Three-Dimensional Geometry of the Reelfoot Blind Thrust: Implications for Moment Release and Earthquake Magnitude in the New Madrid Seismic Zone , 2001 .

[25]  A. Johnston,et al.  Modified Mercalli Intensities (MMI) for large earthquakes near New Madrid, Missouri, in 1811-1812 and near Charleston, South Carolina, in 1886 , 2002 .

[26]  H. O. Wood,et al.  Modified Mercalli intensity scale of 1931 , 1931 .

[27]  Eugene S. Schweig,et al.  THE -ENIGMA OF THE NEW MADRID EARTHQUAKES OF 1811-1812 , 1996 .

[28]  W. H. Bakun,et al.  Estimating earthquake location and magnitude from seismic intensity data , 1997, Bulletin of the Seismological Society of America.

[29]  W. H. Bakun,et al.  Estimating Locations and Magnitudes of Earthquakes in Eastern North America from Modified Mercalli Intensities , 2003 .