The Mississippi Valley earthquakes of 1811 and 1812: Intesities, ground motion and magnitudes

1973 ◽  
Vol 63 (1) ◽  
pp. 227-248 ◽  
Author(s):  
Otto W. Nuttli
Keyword(s):  
North America ◽  
Ground Motion ◽  
Body Wave ◽  
Vertical Component ◽  
The Body ◽  
Eastern North America ◽  
Mississippi Valley ◽  
Isoseismal Map ◽  
Geological Conditions ◽  
Recent Earthquakes

abstract Contemporary newspaper accounts of the 1811-1812 Mississippi Valley earthquake sequence are used to construct a generalized isoseismal map of the first of three principal shocks of the sequence, that of December 16, 1811. The map is characterized by an unusually large felt area, with MM intensities of V as far away as the southeast Atlantic coastal area. By correlating the isoseismal map with that of recent earthquakes for which ground motion data are available, the body-wave magnitude of the December 16, 1811 earthquake is estimated to be 7.2. The other principal shocks, on January 23, 1812 and February 7, 1812, had estimated mb values of 7.1 and 7.4, respectively. The total energy released by the principal shocks and their larger-magnitude aftershocks is estimated to be equivalent to that of an mb = 7.5 (or Ms = 8.0) earthquake. The anomalously large areas of damage and of perceptibility of the principal shocks result from both the surficial geological conditions of the Mississippi Valley and the relatively low attenuation of surface-wave energy in eastern North America. Estimates of the vertical component of ground motion, for an earthquake of mb = 7.2 occurring in eastern North America, are given. These include values for particle velocity, displacement, and acceleration at frequencies of about 3, 1 and 0.3 Hz.

Site effects of the Denis-Perron dam (SM-3): A case study in Eastern North America

2021 ◽  
pp. 875529302110194
Author(s):  
Daniel Verret ◽  
Denis LeBœuf ◽  
Éric Péloquin
Keyword(s):  
North America ◽  
Ground Motion ◽  
Site Effects ◽  
Transfer Functions ◽  
Ground Motions ◽  
Published Data ◽  
Eastern North America ◽  
Ground Acceleration ◽  
Large Dams ◽  
Moderate Seismicity

Eastern North America (ENA) is part of a region with low-to-moderate seismicity; nonetheless, some significant seismic events have occurred in the last few decades. Recent events have reemphasized the need to review ENA seismicity and ground motion models, along with continually reevaluating and updating procedures related to the seismic safety assessment of hydroelectric infrastructures, particularly large dams in Québec. Furthermore, recent researchers have shown that site-specific characteristics, topography, and valley shapes may significantly aggravate the severity of ground motions. To the best of our knowledge, very few instrumental data from actual earthquakes have been published for examining the site effects of hydroelectric dam structures located in eastern Canada. This article presents an analysis of three small earthquakes that occurred in 1999 and 2002 at the Denis-Perron (SM-3) dam. This dam, the highest in Québec, is a rockfill embankment structure with a height of 171 m and a length of 378 m; it is located in a narrow valley. The ground motion datasets of these earthquakes include the bedrock and dam crest three-component accelerometer recordings. Ground motions are analyzed both in the time and frequency domains. The spectral ratios and transfer functions obtained from these small earthquakes provide new insights into the directionality of resonant frequencies, vibration modes, and site effects for the Denis-Perron dam. The crest amplifications observed for this dam are also compared with previously published data for large dams. New statistical relationships are proposed to establish dam crest amplification on the basis of the peak ground acceleration (PGA) at the foundation.

On the mN, M Relation for Eastern North American Earthquakes

1987 ◽  
Vol 58 (4) ◽  
pp. 119-124 ◽  
Author(s):  
Gail M. Atkinson ◽  
David M. Boore
Keyword(s):  
North America ◽  
Stochastic Model ◽  
Ground Motion ◽  
Seismic Moment ◽  
The Other ◽  
Moment Magnitude ◽  
Scaling Relations ◽  
Eastern North America ◽  
Data Set ◽  
Meaningful Data

Abstract A stochastic model of ground motion has been used as a basis for comparison of data and theoretically-predicted relations between mN (commonly denoted by mbLg) and moment magnitude for eastern North America (ENA) earthquakes. mN magnitudes are recomputed for several historical ENA earthquakes, to ensure consistency of definition and provide a meaningful data set. We show that by itself the magnitude relation cannot be used as a discriminant between two specific spectral scaling relations, one with constant stress and the other with stress increasing with seismic moment, that have been proposed for ENA earthquakes.

A comparison of earthquake damage areas as a function of magnitude across the United States

1993 ◽  
Vol 83 (4) ◽  
pp. 1064-1080 ◽  
Author(s):  
G. A. Bollinger ◽  
M. C. Chapman ◽  
M. S. Sibol
Keyword(s):  
United States ◽  
North America ◽  
Ground Motion ◽  
Epicentral Distance ◽  
The United States ◽  
Western United States ◽  
Eastern North America ◽  
Similar Response ◽  
Eastern United States ◽  
The West

Abstract This study investigates the relationship between earthquake magnitude and the size of damage areas in the eastern and western United States. To quantify damage area as a function of moment magnitude (M), 149 MMI VI and VII areas for 109 earthquakes (88 in the western United States, 21 in the eastern United States and Canada) were measured. Regression of isoseismal areas versus M indicated that areas in the East were larger than those in the West, at both intensity levels, by an average 5 × in the M 4.5 to 7.5 range. In terms of radii for circles of equivalent area, these results indicate that damaging ground motion from shocks of the same magnitude extend 2 × the epicentral distance in eastern North America compared to the West. To determine source and site parameters consistent with the above results, response spectral levels for eastern North America were stochastically simulated and compared with response spectral ordinates derived from recorded strong ground motion data in the western United States. Stress-drop values of 200 bars, combined with a surficial 2-km-thick low velocity “sedimentary” layer over rock basement, produced results that are compatible with the intensity observations, i.e., similar response spectral levels in the east at approximately twice their epicentral distance in the western U.S. distance. These results suggest that ground motion modeling in eastern North America may need to incorporate source and site parameters different from those presently in general use. The results are also of importance to eastern U.S. hazard assessments as they require allowance for the larger damage areas in preparedness and mitigation programs.

Revision of Boore (2018) Ground-Motion Predictions for Central and Eastern North America: Path and Offset Adjustments and Extension to 200  m/s≤VS30≤3000  m/s

2020 ◽  
Vol 91 (2A) ◽  
pp. 977-991
Author(s):  
David M. Boore
Keyword(s):  
North America ◽  
Stochastic Model ◽  
Point Source ◽  
Ground Motion ◽  
Hard Rock ◽  
Response Spectra ◽  
Site Amplification ◽  
Eastern North America ◽  
A Value ◽  
Stress Parameters

Abstract The three sets of ground-motion predictions (GMPs) of Boore (2018; hereafter, B18) are compared with a much larger dataset than was used in deriving the predictions. The B18 GMPs work well for response spectra at periods between ∼0.15 and 4.0 s after an adjustment accounting for a path bias at distances beyond 200 km—this was the maximum distance used to derive the stress parameters on which the simulations in B18 are based. An additional offset adjustment is needed in the B18 predictions for short and long periods. The adjustment at short periods may be because the κ0 of 0.006 s stipulated by the Next Generation Attenuation-East (NGA-East) project to be used in deriving the GMPs is inconsistent with the observations on rock sites. The explanation for the offset adjustment at long periods is not clear, but it could be a combination of limitations of the point-source stochastic model for longer period motions, as well as a decreasing number of observations at longer periods available to constrain the simulations on which the predictions are based. The predictions of B18, developed for very-hard-rock sites (VS30 of 2000 and 3000  m/s), have here been extended down to VS30 values as low as 200  m/s. I find, as have others, that for a given VS30, there is generally less site amplification for central and eastern North America (CENA) than for the active crustal region dataset used for the Boore, Stewart, et al. (2014; hereafter, BSSA14) GMP equations. This might have an impact on conclusions of several previous studies of CENA GMPs that used the site amplifications in BSSA14 in comparing data and predictions. An additional finding is that the κ0 implied by recordings on a subset of stations in the Charlevoix region located on rock (data from these stations were not used in the analysis described earlier) is more consistent with a value near 0.014 s than the 0.006 s value used in B18 and the NGA-East project.

Ground Motion Model for Small-to-Moderate Earthquakes in Texas, Oklahoma, and Kansas

2019 ◽  
Vol 35 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Georgios Zalachoris ◽  
Ellen M. Rathje
Keyword(s):  
North America ◽  
Ground Motion ◽  
Induced Seismicity ◽  
Ground Motions ◽  
Site Amplification ◽  
Eastern North America ◽  
Motion Model ◽  
Ground Motion Model ◽  
Magnitude Scaling ◽  
Proposed Model

A ground motion model (GMM) tuned to the characteristics of the observed, and potentially induced, seismicity in Texas, Oklahoma, and Kansas is developed using a database of 4,528 ground motions recorded during 376 events of Mw > 3.0 in the region. The GMM is derived using the referenced empirical approach with an existing Central and Eastern North America model as the reference GMM and is applicable for Mw = 3.0–5.8 and hypocentral distances less than 500 km. The proposed model incorporates weaker magnitude scaling than the reference GMM for periods less than about 1.0 s, resulting in smaller predicted ground motions at larger magnitudes. The proposed model predicts larger response spectral accelerations at short hypocentral distances (≤20 km), which is likely because of the shallow hypocenters of events in Texas, Oklahoma, and Kansas. Finally, the VS30 scaling for the newly developed model predicts less amplification at VS30 < 600 m/s than the reference GMM, which is likely because of the generally thinner sediments in the study area. This finding is consistent with recent studies regarding site amplification in Central and Eastern North America.

Empirical Linear Seismic Site Amplification in Central and Eastern North America

2019 ◽  
Vol 35 (2) ◽  
pp. 849-881 ◽  
Author(s):  
Grace A. Parker ◽  
Jonathan P. Stewart ◽  
Youssef M. A. Hashash ◽  
Ellen M. Rathje ◽  
Kenneth W. Campbell ◽  
...  
Keyword(s):  
North America ◽  
Ground Motion ◽  
Site Response ◽  
Site Amplification ◽  
Eastern North America ◽  
Resonance Effects ◽  
Bayesian Techniques ◽  
Motion Data ◽  
Motion Models ◽  
Scaling Models

We present empirical linear site amplification models conditioned on time-averaged shear wave velocity in the upper 30 m ( VS30) for central and eastern North America. The models are derived from ground motion data and site condition information from the NGA-East project and are intended for use with reference rock ground motion models. Site amplification is found to scale with VS30 for intermediate to stiff site conditions ( VS30 > 300 m/s) in a weaker manner than for active tectonic regions such as the western United States. For stiff sites ( >800 m/s), we find differences in site amplification for previously glaciated and nonglaciated regions, with nonglaciated sites having lower amplification. The models were developed using a combination of least-squares, mixed effects, and Bayesian techniques; the latter show that accounting for predictor uncertainty does not appreciably affect the median model but decreases model dispersion. Our VS30-scaling models are modular and additive to simulation-based models for the nonlinear components of site response. A limitation of the present models is that they do not account for site-specific resonance effects.

Updated GMICE for Central and Eastern North America Extending to Higher Intensities

2020 ◽  
Vol 91 (6) ◽  
pp. 3518-3527
Author(s):  
Chris H. Cramer
Keyword(s):  
North America ◽  
Linear Regression ◽  
Ground Motion ◽  
Ground Motions ◽  
Correlation Equation ◽  
Residual Analysis ◽  
Eastern North America ◽  
Intensity Correlation ◽  
Motion Range

Abstract Recent M 3–5 earthquakes near Cushing, Oklahoma, provide observations of intensity up to eight with accompanying ground motions due to close-in acceleration records at distances less than 30 km from the epicenters. Adding these observations to the existing Central and Eastern North America (CENA) ground-motion intensity correlation equation (GMICE) database allows the updating of a CENA GMICE from a linear (below intensity six) relationship to a more accurate bilinear relationship (up to intensity eight). The updating of the CENA GMICE is accomplished using linear regression and residual analysis. The analysis shows that the bilinear transition is fairly broad in the CENA covering one to two intensity units and one or more orders of magnitude in ground motion, depending on regression direction. The new CENA GMICE reduces the overprediction of ground motions from high intensities and the underprediction of intensities at both ends of the observed ground-motion range.

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