Significant Motions between GPS Sites in the New Madrid Region: Implications for Seismic Hazard

Frankel, Arthur; Smalley, Robert; Paul, J.

doi:10.1785/0120100219

Cited by 40 publications

(40 citation statements)

References 31 publications

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“…From the velocities, a first-order inference is whether there is detectable deformation within the network of GPS monuments. For instance, in the area straddling the Mississippi River in the central US, there is a debate about whether there is significant deformation associated with the New Madrid Seismic zone, where, on one hand, Calais and Stein (2009) argue that within the uncertainty of the data, there is no significant deformation; but, on the other hand, Frankel and Smalley (2011) detect some deformation that is consistent with creep at depth on the fault that last ruptured in the sequence of ∼M7 earthquakes in 1811-1812 (Hough and Page 2011). To understand the differences in the inference for detectable deformation, a critical examination of the ingredients and assumptions that go into estimating the uncertainty in rate is required.…”

Section: Introductionmentioning

confidence: 99%

Estimating rate uncertainty with maximum likelihood: differences between power-law and flicker–random-walk models

Langbein

2012

J Geod

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Recent studies have documented that global positioning system (GPS) time series of position estimates have temporal correlations which have been modeled as a combination of power-law and white noise processes. When estimating quantities such as a constant rate from GPS time series data, the estimated uncertainties on these quantities are more realistic when using a noise model that includes temporal correlations than simply assuming temporally uncorrelated noise. However, the choice of the specific representation of correlated noise can affect the estimate of uncertainty. For many GPS time series, the background noise can be represented by either: (1) a sum of flicker and random-walk noise or, (2) as a power-law noise model that represents an average of the flicker and random-walk noise. For instance, if the underlying noise model is a combination of flicker and random-walk noise, then incorrectly choosing the power-law model could underestimate the rate uncertainty by a factor of two. Distinguishing between the two alternate noise models is difficult since the flicker component can dominate the assessment of the noise properties because it is spread over a significant portion of the measurable frequency band. But, although not necessarily detectable, the random-walk component can be a major constituent of the estimated rate uncertainty. None the less, it is possible to determine the upper bound on the random-walk noise.

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Section: Introductionmentioning

confidence: 99%

Estimating rate uncertainty with maximum likelihood: differences between power-law and flicker–random-walk models

Langbein

2012

J Geod

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“…In any case, we expect that these other sources of stress do contribute to surface deformation, the long-term build up of stress, and the triggering of earthquake sequences. Frankel et al [2012] argue that the creep on the Reelfoot fault cannot be postseismic frictional afterslip because if it were, they would also infer creep on the Cottonwood Grove fault evidenced by northward motion of station ptgv relative to stle, which they do not see. Given the uncertainties in station velocities, we do not think that this conclusion can be made with a single pair of stations.…”

Section: Causes Of Creepmentioning

confidence: 92%

“…The processes modeled here include the following: (1) kinematically prescribed steady creep on dislocations residing along the downdip extensions of the Reelfoot fault [Frankel et al, 2012] and Cottonwood Grove fault; (2) dynamic models of postseismic viscoelastic relaxation and frictional afterslip from the 16 December 1811 earthquake on the Cottonwood Grove fault, the 17 February 1812 earthquake on the Reelfoot fault [Kenner and Segall, 2000;Li et al, 2005], and two of the~1450 AD earthquakes on the Cottonwood Grove and Reelfoot faults; and (3) kinematically prescribed large scale uniaxial compression and simple shearing of the region [Pratt, 2012]. Note that postseismic afterslip is one explanation for creep.…”

Section: Modeling the Gnss Velocitiesmentioning

confidence: 99%

“…Multiple models of kinematically prescribed steady creep on dislocations in a half-space are tested using an Okada [1992] formulation; models put forth by Frankel et al [2012] and Pratt [2012] are considered. In the former, they found that the regional geodetic signal could be explained by creep on a dislocation residing along a downdip extension of the Reelfoot fault between 12 to 20 km depth.…”

Section: Creep and Regional Strain Modelsmentioning

confidence: 99%

“…Calais and Stein [2009] and Craig and Calais [2014] argue that relative motion across the NMSZ from far-field strain accumulation, as determined from GNSS sites distributed across the region, is less than 0.2 mm/yr, implying a return period of at least 10,000 years for M7 events with 2 m of average slip. Frankel et al [2012] also analyzed the existing GNSS data in the region and found significant localized motion between several pairs of GAMA stations. They concluded that the motion could be explained by 4 mm/yr of creep on a 60 km long dislocation along the downdip extent of the Reelfoot fault at depths between 12 and 20 km.…”

Section: Introductionmentioning

confidence: 99%

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Crustal deformation in the New Madrid seismic zone and the role of postseismic processes

2015

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Global Navigation Satellite System data across the New Madrid seismic zone (NMSZ) in the central United States over the period from 2000 through 2014 are analyzed and modeled with several deformation mechanisms including the following: (1) creep on subsurface dislocations, (2) postseismic frictional afterslip and viscoelastic relaxation from the 1811–1812 and 1450 earthquakes in the NMSZ, and (3) regional strain. In agreement with previous studies, a dislocation creeping at about 4 mm/yr between 12 and 20 km depth along the downdip extension of the Reelfoot fault reproduces the observations well. We find that a dynamic model of postseismic frictional afterslip from the 1450 and February 1812 Reelfoot fault events can explain this creep. Kinematic and dynamic models involving the Cottonwood Grove fault provide minimal predictive power. This is likely due to the smaller size of the December 1811 event on the Cottonwood Grove fault and a distribution of stations better suited to constrain localized strain across the Reelfoot fault. Regional compressive strain across the NMSZ is found to be less than 3 × 10−9/yr. If much of the present‐day surface deformation results from afterslip, it is likely that many of the earthquakes we see today in the NMSZ are aftershocks from the 1811–1812 New Madrid earthquakes. Despite this conclusion, our results are consistent with observations and models of intraplate earthquake clustering. Given this and the recent paleoseismic history of the region, we suggest that seismic hazard is likely to remain significant.

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Strain accumulation in the New Madrid and Wabash Valley seismic zones from 14 years of continuous GPS observation

Craig

Calais

2014

JGR Solid Earth

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The mechanical behavior-and hence earthquake potential-of faults in continental interiors is an issue of critical importance for the resultant seismic hazard, but no consensus has yet been reached on this controversial topic. The debate has focused on the central and eastern United States, in particular, the New Madrid Seismic Zone, struck by four magnitude 7 or greater earthquakes in 1811-1812, and to a lesser extent the Wabash Valley Seismic Zone just to the north. A key aspect of this issue is the rate at which strain is currently accruing on those plate interior faults, a quantity that remains debated. Here we address this issue with an analysis of up to 14.6 years of continuous GPS data from a network of 200 sites in the central United States centered on the New Madrid and Wabash Valley seismic zones. We find that the high-quality sites in these regions show motions that are consistently within the 95% confidence limit of zero deformation. These results place an upper bound on strain accrual on faults of 0.2 mm/yr and 0.6 mm/yr in the New Madrid and Wabash Valley Seismic Zones, respectively. For the New Madrid region, where a paleoseismic record is available for the past ∼5000 years, we argue that strain accrual-if any-does not permit the 500-900 year repeat time of paleo-earthquakes observed in the Upper Mississippi Embayment. These results, together with increasing evidence for temporal clustering and spatial migration of earthquake sequences in continental interiors, indicate that either tectonic loading rates or fault properties vary with time in the New Madrid Seismic Zone and possibly plate wide.

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Significant Motions between GPS Sites in the New Madrid Region: Implications for Seismic Hazard

Cited by 40 publications

References 31 publications

Estimating rate uncertainty with maximum likelihood: differences between power-law and flicker–random-walk models

Estimating rate uncertainty with maximum likelihood: differences between power-law and flicker–random-walk models

Crustal deformation in the New Madrid seismic zone and the role of postseismic processes

Strain accumulation in the New Madrid and Wabash Valley seismic zones from 14 years of continuous GPS observation

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