Descent of the ancient Farallon slab drives localized mantle flow below the New Madrid seismic zone
نویسندگان
چکیده
[1] The great earthquake sequence that occurred in the central Mississippi River Valley during the winter of 1811– 1812 is unprecedented in the historical record of seismicity within stable continental plate interiors. We show, using viscous flow models based on high resolution seismic tomography, that the descent of the ancient Farallon slab into the deep mantle beneath central North America induces a highly localized flow directly below the New Madrid seismic zone (NMSZ). This localization arises because of structural variability in the Farallon slab and the lowviscosity of the sub-lithospheric upper mantle, and it represents a heretofore unrecognized and possibly significant driving mechanism for the enigmatic intraplate seismicity. Citation: Forte, A. M., J. X. Mitrovica, R. Moucha, N. A. Simmons, and S. P. Grand (2007), Descent of the ancient Farallon slab drives localized mantle flow below the New Madrid seismic zone, Geophys. Res. Lett., 34, L04308, doi:10.1029/ 2006GL027895.
منابع مشابه
Adjoint models of mantle convection with seismic, plate motion, and stratigraphic constraints: North America since the Late Cretaceous
[1] We apply adjoint models of mantle convection to North America since the Late Cretaceous. The present-day mantle structure is constrained by seismic tomography and the time-dependent evolution by plate motions and stratigraphic data (paleoshorelines, borehole tectonic subsidence, and sediment isopachs). We infer values of average upper and lower mantle viscosities, provide a synthesis of Nor...
متن کاملReconstructing Farallon plate subduction beneath North America back to the Late Cretaceous.
Using an inverse mantle convection model that assimilates seismic structure and plate motions, we reconstruct Farallon plate subduction back to 100 million years ago. Models consistent with stratigraphy constrain the depth dependence of mantle viscosity and buoyancy, requiring that the Farallon slab was flat lying in the Late Cretaceous, consistent with geological reconstructions. The simulatio...
متن کاملDynamic subsidence and uplift of the Colorado Plateau
We use inverse models of mantle convection to explore the vertical evolution of the Colorado Plateau. By satisfying multiple constraints (seismic tomography, stratigraphy in the western United States and Great Plains, and other structural and volcanic data adjacent to the plateau), the model provides predictions on the continuous history of Colorado Plateau vertical motion since 100 Ma. With th...
متن کاملA dipping, thick segment of the Farallon Slab beneath Central US
It has been hypothesized that much of the crustal deformation attributed to the Laramide orogeny of the southwest North American Cordillera was caused by dynamic effects induced by the flat subduction of a large oceanic plateau that was embedded within the Farallon plate. Previous studies have identified within the North American mantle a seismic velocity anomaly that plausibly represents the r...
متن کاملMantle transition zone discontinuities beneath the contiguous United States
Using over 310,000 high-quality radial receiver functions recorded by the USArray and other seismic stations in the contiguous United States, the depths of the 410 km and 660 km discontinuities (d410 and d660) are mapped in over 1,000 consecutive overlapping circles with a radius of 1◦. The average mantle transition zone (MTZ) thickness for both the western and central/eastern U.S. is within 3 ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2007