35 Recent advances in our understanding of the New Madrid seismic zone

Thorough understanding of the New Madrid seismic zone will require integration of observations relating to surface features, the crust and the upper mantle. All contributions are welcomed.

Wednesday, 11 March 2026
8:30 AM - 12:00 PM
RCC, 104

Advances in Strain Resolution of the New Madrid Seismic Zone using Enhanced GNSS and OPERA InSAR Time Series Data

Paper number: 35-7
Program: Technical Sessions
Time: 10:15 AM – 10:30 AM

Authors

Abstract

The New Madrid Seismic Zone (NMSZ) is one of the most significant intraplate seismic regions worldwide, yet quantifying present-day strain accumulation remains challenging due to low deformation rates, sparse geodetic coverage, and strong non-tectonic signals associated with the Mississippi Embayment. Recent advances in geodetic data quality and the emergence of new satellite-based products provide an opportunity to improve strain resolution in this region.

In this study, we present updated strain estimates for the NMSZ derived from enhanced processing of continuous GNSS time series. Advanced noise-mitigation techniques are applied to reduce the influence of seasonal hydrological loading, monument instability, and colored noise, resulting in more robust station velocity estimates. These improved GNSS velocities are used to compute regional strain rates and associated uncertainties, and to evaluate spatial variations in deformation across the NMSZ.

In addition, we discuss the potential integration of interferometric synthetic aperture radar (InSAR) observations from the OPERA (Observational Products for End-Users from Remote Sensing Analysis) project, which represent a new and emerging geodetic resource for the central United States. InSAR coverage in the NMSZ is currently limited because of dense vegetation, extensive agricultural activity, and the sedimentary basin characteristics of the region. However, OPERA InSAR data provide complementary displacement information in areas not well sampled by GNSS and offer the potential to enhance spatial resolution where coherent measurements are available.

We outline an integrated GNSS–InSAR framework designed to leverage improved spatial sampling from InSAR where available, while preserving the long-term stability of GNSS-derived velocity estimates. Results from enhanced GNSS processing demonstrate improved resolution of low-magnitude strain signals in the NMSZ. The anticipated incorporation of OPERA InSAR data is expected to further refine strain estimates and improve spatial characterization of deformation as data coverage and maturity increase. This work highlights recent advances in geodetic observations and methodologies and underscores their importance for understanding intraplate deformation and seismic hazard in the New Madrid Seismic Zone.

Geological Society of America Abstracts with Programs. Vol. 58, No. 1

doi: 10.1130/abs/2026SE-411653

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