BY PETER J. SMITH
Department of Earth Sciences
Milton Keynes, U.K.
" On 1 August 1986, a seismic disturbance occurred near the Novaya Zemlya, USSR, nuclear test sites at a time when the Soviet Union claimed to be observing a unilateral moratorium on nuclear testing. This caused some concern, because the area is relatively aseismic. Regional seismic data failed to answer the obvious question, but teleseismic data now show that the disturbance was indeed an earthquake.
P.D. Marshall, R.C. Stewart, R.C. Lilwall, “The seismic disturbanceof 1986 August I near Novaya Zemlya: a source of concern?” Geophysical Journal, 98, 565-73, September 1989. (Ministry of Defense, Reading, England)
Eight distinct lines of evidence suggest that the buried river valleys of the eastern Sahara, discovered by Shuttle Imaging Radar, are part of the ancestral Nile drainage system. This hypothesis is more consistent with the large-scale geomorphological evolution of...