Supplementary material to “Rationale for a Permanent Seismic Network in the U.S. Central Plains Utilizing USArray”
Stephen S. Gao, Missouri University of Science and Technology, Rolla; Tina M. Niemi, University of Missouri at Kansas City; Ross A. Black, University of Kansas, Lawrence; Kelly H. Liu, Missouri University of Science and Technology, Rolla; Raymond R. Anderson, Iowa Geological Survey, Iowa City; Robert M. Joeckel, Nebraska Geological Survey, Lincoln; Robert W. Busby and John Taber, Incorporated Research Institutions for Seismology, Washington, D. C.
Citation:
Gao, S. S., T. M. Niemi, R. A. Black, K. H. Liu, R. R. Anderson, R. M. Joeckel, R. W. Busby, and J. Taber (2008), Rationale for a permanent seismic network in the U.S. Central Plains utilizing USArray, Eos Trans. AGU, 89(9), 85.
Fig. 1. Bouguer gravity map and major tectonic features of the Central Plains and adjacent areas. Triangles represent planned transportable array (TA) stations in the four-state area of Nebraska, Kansas, Iowa, and Missouri; stars are existing broadband seismic stations; and dots are earthquakes. Some of the TA stations will be converted into permanent stations, as described in the article. THO stands for Trans-Hudson Orogen. Blue lines separate crustal blocks with different ages, which become progressively younger toward the south. Bouguer gravity anomalies are measures of spatial variations of the density of underground rocks. High gravity values (warm colors; see the scale bar at the bottom of the figure) correspond to geologic features with dense rocks (such as the Midcontinent Rift, which is filled with heavy igneous rocks buried by younger sedimentary rocks), and low values (cool colors) in the study area correspond mostly to sedimentary basins. Although most of the pre-Cambrian crystalline basement rocks beneath the Central Plains are covered by younger sedimentary rocks and thus cannot be studied directly, major tectonic features can be observed from the gravity anomalies. The permanent seismic network advocated in the article would enable a significantly improved understanding about the formation, evolution, and structure of these tectonic features and their roles in the formation and distribution of earthquakes in the Central Plains.
