Not logged in
PANGAEA.
Data Publisher for Earth & Environmental Science

Kulgemeyer, Tobias; von Dobeneck, Tilo; Müller, Hendrik; Bryan, Karin R; de Lange, Willem P; Battershill, Christopher N (2016): Lithofacies distribution in the western Bay of Plenty, New Zealand. PANGAEA, https://doi.org/10.1594/PANGAEA.861201, Supplement to: Kulgemeyer, T et al. (2016): Lithofacies distribution and sediment dynamics on a storm-dominated shelf from combined photographic, acoustic and sedimentological profiling methods (Bay of Plenty, New Zealand). Marine Geology, 376, 158-174, https://doi.org/10.1016/j.margeo.2016.03.005

Always quote citation above when using data! You can download the citation in several formats below.

RIS CitationBibTeX CitationShow MapGoogle Earth

Abstract:
Sediment dynamics on a storm-dominated shelf (western Bay of Plenty, New Zealand) were mapped and analyzed using the newly developed multi-sensor benthic profiler MARUM NERIDIS III. An area of 60 km × 7 km between 2 and 35 m water depth was surveyed with this bottom-towed sled equipped with a high-resolution camera for continuous close-up seafloor photography and a CTD with connected turbidity sensor. Here we introduce our approach of using this multi-parameter dataset combined with sidescan sonography and sedimentological analyses to create detailed lithofacies and bedform distribution maps and to derive regional sediment transport patterns.
For the assessment of sediment distribution, photographs were classified and their spatial distribution mapped out according to associated acoustic backscatter from a sidescan sonar. This provisional map was used to choose target locations for surficial sediment sampling and subsequent laboratory analysis of grain size distribution and mineralogical composition. Finally, photographic, granulometric and mineralogical facies were combined into a unified lithofacies map and corresponding stratigraphic model. Eight distinct types of lithofacies with seawards increasing grain size were discriminated and interpreted as reworked relict deposits overlain by post-transgressional fluvial sediments.
The dominant transport processes in different water depths were identified based on type and orientation of bedforms, as well as bottom water turbidity and lithofacies distribution. Observed bedforms include subaquatic dunes, coarse sand ribbons and sorted bedforms of varying dimensions, which were interpreted as being initially formed by erosion. Under fair weather conditions, sediment is transported from the northwest towards the southeast by littoral drift. During storm events, a current from the southeast to the northweast is induced which is transporting sediment along the shore in up to 35 m water depth. Shorewards oriented cross-shore transport is taking place in up to 60 m water depth and is likewise initiated by storm events.
Our study demonstrates how benthic photographic profiling delivers comprehensive compositional, structural and environmental information, which compares well with results obtained by traditional probing methods, but offers much higher spatial resolution while covering larger areas. Multi-sensor benthic profiling enhances the interpretability of acoustic seafloor mapping techniques and is a rapid and economic approach to seabed and habitat mapping especially in muddy to sandy facies.
Coverage:
Median Latitude: -37.576117 * Median Longitude: 176.236329 * South-bound Latitude: -37.748998 * West-bound Longitude: 175.945348 * North-bound Latitude: -37.379253 * East-bound Longitude: 176.549147
Comment:
Project: INTERCOAST - Integrated Coastal Zone and Shelf Sea Research
Size:
4 datasets

Download Data

Download ZIP file containing all datasets as tab-delimited text (use the following character encoding: )