Structure of the Blytheville arch in the New Madrid seismic zone

Seismic-reflection profiles across part of the New Madrid seismic zone in northeastern Arkansas and southeastern Missouri show a faulted and structurally complex zone, originally known as Charlie's ridge but herein renamed Blytheville arch, which is about 10 to 15 km wide and about 110 km long. Most earthquakes in the northeast-trending segment of the New Madrid seismic zone along the axis of the Reelfoot rift occur along the arch. Focal mechanisms, hypocentral depths and spatial distribution are contrasted. The relationship between the structural boundaries of the arch and the seismicity may establish the extent of part of New Madrid seismicity and improve the basis for seismic hazard assessment. -after Authors