Misers Gold Event, a high explosive simulation of a 4 kiloton tactical nuclear weapon, was conducted at White Sands Missile Range, N.M., in 1989. The base surge phenomena was studied in the MISERS GOLD high-explosive test. One of the most impressive features of this ~5 kt-equivalent blast was the damage caused by shock waves accompanying the base surge. Within several hundred meters of the crater, trees were incinerated almost instantaneously as the leading shock wave passed. Although the surge left only several centimeters of deposit at distances over 100 m from the crater, the surge had completely removed the turf. Granulometric analyses of the surge deposits showed a very systematic behavior.
Perhaps one of the most widely cited books describing the base surge and related phenomena created by man-made explosion (Fig. 5) is that by Glasstone and Dolan (1977). These authors make a comprehensive assessment of damage phenomena related to the surge and show that propagation of shock waves (air blast) and their interaction with the ground surface are a primary component of base surge. In reading other literature on explosive testing and crater formation, one finds that explosive crater formation is almost always accompanied by base surge. For example, the SEDAN nuclear event in 1962 formed a crater 370 m wide and 100 m deep with base surge deposits extending out for over 1 km. The base surge deposits to be bedded and contain dune-like structures.
High explosives and nuclear cratering tests produce a base surge by (1) the ballistic overturn of rock/sediment near the surface (producing inverted stratigraphy), (2) the interaction of low-angle ejecta with the substrate, (3) column (stem) fallback, and (4) propagation of multiple shock waves. The ejecta blanket within one to two crater radii of the crater rim is dominated by surge ejecta and surge-reworked ballistic ejecta. Surge ejecta shows fine-scale (mm to cm) bedding planes, and for large explosions, surge deposits show dune bedding.
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