Input of river-derived sediment to the New Zealand continental shelf: I. Mass

Abstract

The input of river-borne sediments to the New Zealand continental shelf has been calculated for all the major rivers and basins in New Zealand. South Island yields 284 ± 40 × 10 6 tonnes per year of sediment from a land area of 152 977 km 2 and North Island yields 105 ± 9·4 × 10 6 tonnes per year from a land area of 114 621 km 2. Particularly high discharges are noted off the west coast of South Island and east coast of North Island and result in higher offshore sedimentation there. The data are compatible with measured sedimentation rates on the New Zealand continental shelf. The specific sediment yield from South Island is amongst the highest previously recorded.