Observations of beach gravel transport, Wellington Harbour entrance, New Zealand. Technical Report
- Author
- Matthews, E.R.
- Year
- 1980
- Journal / Source
- New Zealand Journal of Geology and Geophysics
- Volume
- 23
- Pages
- 209-222
- Keywords
- Beach, sediments, beach pebble tracer experiment, gravel front, waves, shorelines, Wellington Harbour
- Summary
- Two small embayment at the entrance of the Wellington harbour thoight that have been depleted by regional tectonic uplift in 1855 have shown a sudden and rapid accumulation of gravel since 1911. Pebble sized sediments moves northwards int o the harbour at an average rate of 1.66 km a year. Further north a sudden change in the nature of the beach. At the entrance gravel of fresh appearance occur. Pebbles are transported during high wave energy events in a zone near low water level. Loss of pebbles offshore and by abrasion is probably small. It is suggested that the sudden progradation at eh harbour entrance and the existence of the mobile gravel front are due to a large influx of gravel to the coast that occurred after landslides were induced by the earthquakes of the 1840's and 1850's when the base level of the Orongorongo River was raised.