In the South Island of New Zealand, the pattern of uplift is relatively simple, and the uplift and erosion rates are so high that man-accelerated erosion is a negligible part. In contrast, the pattern in the North Island is less simple, the rates lower, and man-accelerated erosion more significant. All available information relevant to the past 2 m.y. of uplift and erosion in the Southern Alps has been examined. The viewpoint taken is from geology (1,000 yr or more), not from engineering or culture (100 yr or less).
In New Zealand, early work on erosion rates was sporadic and done mainly by engineers. Cotton and other geomorphologists of the Davisian school considered that landforms took tens of millions of years to form. They assumed ample time was available and were not interested in rates. F. W. Furkert, an engineer concerned with harbour protection, made the first reasonable estimates. It is only within the last few years that the necessary regional data have become available. For the first time, uplift rates have been quantified, land retriangulations analyzed, river-flow records computerized, and the country has been mapped topographically at 1:63, 360 and mapped geologically.