Neocatastrophism? A further look

This paper takes further an inquiry (Dury, 1975) into the prospects of a powerful growth of neocatastrophism, whether under the actual name or not. Coined for the purposes of palaeontology, the term has already escaped into geoscience in general. The concept of the significance, and in some connections the dominance, of events of great magnitude and low frequency is gaining ground among sedimentologists at least. But the words neocatastrophism and neocatastrophist carry strong emotional overtones, as has been revealed in the renewed debate about uniformitarianism. Still more emotionally charged are the words neodeterminism and neodeterminist: environmental determinism in geography has a history which many find distasteful. Nevertheless, some current work is dealing precisely with the impact on social systems of major changes in physical systems. Our sociocultural heritage and present setting seem likely to predispose us to think in catastrophic terms. The present-day context is, at least to some extent, one of increasing pessimism and rising hysteria, related largely to the prospects (or lack of prospects) of survival of part or any of the human species. Technical work on environmental hazards also leads our attention toward major, and sudden, disastrous events. This work is especially concerned with the effect on people of happenings in the physical world. Magnitude-frequency analysis is widely used, both in the specification of a particular disaster, and in the calculation of future probabilities. For the delivery of water and sediment by streams, the principle holds that fluvial action is dominated by events of modest magnitude and low frequency. That principle may, however, not apply universally to interfluves: there, mass movement can be dominated by events with recurrence intervals of a century or more; the transportation index of a single mass movement may be comparable to the annual delivery of sediment by a whole continent; and the ejection of tephra or extrusion of lava in a single eruption may also produce impressive totals. In respect of the channelled scabland of the Pacific Northwest, and of catastrophic debris streams, the earth displays landforms and experiences events comparable to some of those of the