Combined Seismic Refraction and Geomagnetic Surveys on Hills of Industrial Wastes of Gypsum in Aqaba for Stability Hazards

Abstract

This article deals with engineering stability against subsidence in a geological context. The Fertilizers’ Factory in Aqaba/Jordan has been established in 1982. The factory disposes its industrial wastes of gypsum behind the factory since its establishment. 25 million tons of wastes had been accumulated and formed hills of gypsum which cover an area of about 1 km2. 20-25 % of produced wastes are moisture. In november 2005, about fifty thousand cubic meters of water flooded suddenly from the hills which overlook the factory from the eastern part. These alarming phenomena led to the current study. Accompanying seismic refraction and geomagnetic investigations revealed areas of possible collapse and also assisted in subdividing the area into risk zones, where the seismic refraction results allowed delineating thickness of gypsum all over the area, while geomagnetic surveys allowed delineating nature of cavities in the hills. On the other hand, the mentioned investigations have been used to deduce amounts of entrapped water inside hills, which were found to be around 2 million cubic meters that are still entrapped in the hills at a depth of 12 meters.