M. G. Hopper
W. H. Bakun
2004
<p><span>We estimate locations and moment magnitudes </span><strong>M</strong><span> 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 </span><i>M</i><sub>I</sub><span>, our preferred estimate of </span><strong>M</strong><span>, 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. </span><i>M</i><sub>I</sub><span> 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 (</span><a class="link link-ref xref-bibr" data-modal-source-id="REF22">1996</a><span>). Our estimates of </span><strong>M</strong><span> are 0.1–0.4 </span><strong>M</strong><span> units less than those of Johnston (</span><a class="link link-ref xref-bibr" data-modal-source-id="REF21">1996b</a><span>) and 0.3–0.5 </span><strong>M</strong><span> units greater than those of Hough </span><i>et al.</i><span> (</span><a class="link link-ref xref-bibr" data-modal-source-id="REF19">2000</a><span>). </span><i>M</i><sub>I</sub><span> 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.</span></p>
application/pdf
10.1785/0120020122
en
Seismological Society of America
Magnitudes and locations of the 1811-1812 New Madrid, Missouri, and the 1886 Charleston, South Carolina, earthquakes
article