abstract
Postshot field investigations indicate that most of the visible geological effects produced by the CANNIKIN event are limited to an area of a 2-km radius from ground zero (GZ). Two stages of fracturing are recognized, one at shot time that induced a maximum of 0.6 m vertical displacement along the Teal Creek Fault located 1,070 m northwest of GZ, and one inferred to have occurred at collapse time (38 hr later). The three principal directions of fractures are east-northeast, northwest, and north and are related to pre-existing faults and lineaments. Major displacement along a fault located 760 m southeast of GZ is inferred to have occurred during collapse. Preliminary surveys indicate that the collapse sink is asymmetric with relation to GZ. The oval subsidence area is 1,270 by 915 m and the surface low, located 366 m southeast of GZ, subsided about 20 m. Several lakes are forming in the sink area.
A portion of the intertidal platform along the Bering coast was uplifted about 1 m and major rock slides occurred along the cliffs within this zone of uplift. Elsewhere, minor rockfalls, slides and tundra slumps occurred along cliffs or steep slopes.
Lake beds have been fractured and, in some cases, the lakes have drained.
Enzyme activity and morphological change in the spleens of crucian carp in the Yongcheng coal mine subsidence area, China
