Survey of Historic Buildings Predating the 1811-1812 New Madrid Earthquakes and Magnitude Estimation Based on Structural Fragility

Wagon Loads of Sand Blows in White County, Illinois

“…Based on a reanalysis of original felt reports, Hough et al (2000) estimated M w values of 7.2-7.3, 7.0, and 7.4-7.5, respectively. These magnitude estimates are consistent with results from geomorphic investigations (e.g., Guccione et al, 2002), scaling relationships (e.g., Mueller and Pujol, 2001), forensic analysis of historic buildings that were and were not damaged during the sequence (Kochkin and Crandell, 2004), and comparisons of macroseismic effects with the 2001 M w 7.6 Bhuj, India earthquake . An additional large earthquake, the so-called "dawn aftershock", occurred near dawn on 16 December 1811 (hereinafter referred to as NM l-A; Johnston, 1996b; .;.…”

“…At a distance of 210 km, the predicted PGA value is 5-10% g. Assuming that hard-rock shaking is amplified by the factor of 2-4 that intensity observations suggest is typical for soft-sediment sites (e.g., Hough et al, 2000), this analysis yields shaking levels of 10-40% g. Although the shaking threshold for liquefaction depends on a number of variables (e.g., Todorovska and Trifunac, 1999), the upper half of this range is probably high enough to cause liquefaction in highly susceptible materials (e.g., Youd and Idriss, 2001). The results of Kochkin and Crandell (2004), which are based on established attenuation relationships, indicate that observed chimney damage in St. Louis (at a distance of approximately 250 km from New Madrid) is most consistent with peak hard-rock ground motions of about 0.03 g. Considering this as well as our modeling results, we conclude that shaking at sediment sites at 210 kin would have likely been no higher than 0.1 g.…”

A technical note on seismic microzonation in the central United States

“…In most cases, the quantitative values calculated for these maps would be superior to a qualitative estimate based solely on lithology or nonsite-specific information. For example, the soil classification map based solely on geology by Bauer et al (2001) was used in a site-specific evaluation of ground motion amplification (Kochkin and Crandell 2004). This may not be appropriate (Street et al 2004).…”

Seismic‐Hazard Map of Southeast Missouri and Likely Magnitude of the February 1812 New Madrid Earthquake

“…We noted that the effect of various site responses on estimating magnitude based on MMIs has historically been ignored or oversimplified (e.g., uniform thickness of alluvium over infinitely large areas) by previous studies (Hough et al, 2000;Kochkin and Crandell, 2004;Street et al, 2004). Historic records suggest that most settlements of the early 1800s were situated along the major watercourses on lowland alluvium, where seismic site response would significantly elevate MMIs.…”

“…Most structures constructed prior to 1811 in the central United States were one to two-and-a-half stories high (Kochkin and Crandell, 2004), which are sensitive to ∼0:2 s SA. This suggests that the fundamental period of buildings damaged during NM3 is likely close to ∼0:2 s. For this reason, 0.2 s SA would appear to be an appropriate ground-motion parameter for estimating MMIs during NM3.…”