Seismic Recordings of Large Explosions in South-Eastern Australia

Abstract

Three very large quarry explosions of between 50 and 100 tons of high explosive in the Snowy Mountains area were recorded by seismographs at distances up to 375 km. P and S wave velocities within the Earth's crust for this part of south-eastern Australia were formally determined to be 6·04 (±0'04) and 3·62 (±0·03) km/sec, respectively. The P n velocity was found to be 8· 03 km/sec, with an estimated error of O· 2 km/sec. Assuming a uniform layer above the Mohorovicic discontinuity with these velocities, the discontinuity was formally estimated to be at a depth of 37 km.