## 1 Introduction  
Active submarine channels are the primary conduits for the transfer of sediment from the shelf to basin floor. They may become good hydrocarbon reservoirs when abandoned and infilled with sediment [1, 2, 3, 4]. Submarine channels are located at the end of a shelf canyon system, down to the slope and basin floor regions, with dominant gravity-driven processes of the sediment transport mechanism [3, 5, 6, 7]. Sediment delivery to submarine channels occurs when there is a connection between the canyon heads and the fluvial-delta system [8, 9, 10], longshore drift current in the shelf regions [9, 11], and sediment mass movements on the canyon walls and shelf edge [4]. For this reason, factors that control the type, supply, and deposition of sediments such as basin tectonics, climate, and sea-level changes have substantial control over the genesis and evolution of submarine channels [4, 8, 12].  
Recent advances in marine geophysical exploration have enabled the organization and comparison of architectural elements associated with submarine channels [4, 6, 13, 14, 15, 16]. In addition, high-resolution 3D marine seismic reflection data have allowed the morphometric study of submarine channels to understand the sedimentary processes and paleoenvironments [17, 18, 19, 20]. However, the interpretation of channel incision or channel isolated amplitude from the 3D marine seismic reflection data poses several challenges due to data artifacts, e.g., velocity push-downs issues [19; 21; 22]. Furthermore, statistical analysis of channel morphometry has become increasingly insightful in understanding sedimentary processes and the paleoenvironment [18; 19; 23; 24; 25; 26; 27]. A combination of the quantitative seismic geomorphology approach and a traditional seismic interpretation (seismic facies analysis, attribute analysis, and slicing technique) are used in this study to obtain a detailed 3D image of channel morphometric elements, which have implications for hydrocarbon prospectivity.  
The study area is located in the southwestern area (continental slope) of the Canterbury Basin (Figure 1a), incorporating the offshore Waka 3D seismic reflection survey and several exploration and ocean drilling wellbore datasets. A previous study documented that the submarine channel initiation began during the Early Oligocene on the post-rift thermal sag phase (tectonically quiescent) with marine transgression to the Miocene--a recent time when the regression phase and prograding fore-sets occurred [28; 29; 30]. Furthermore, [PERSON], [PERSON], [PERSON], and [PERSON] [29] focused their research on the Miocene channels and [PERSON], [PERSON], [PERSON], and [PERSON] [30] on the Early Oligocene channels. In addition, a recent study by [PERSON], et al. [31] revealed that pockmarks (circular depression in the seabed caused by fluid expulsion) occur in association with modern submarine anyons that were developed by turbidity currents, together with Southland current and regional tectonic. However, documentation and description of the Quaternary continental slope channel system in the study area are very limited. Thus, the study area's sedimentary process, paleoenvironment, and hydrocarbon implications are poorly understood. Therefore, the objectives of this study are as follows: (1) describe the morphology of several types of continental slope channel complexes and seismic facies of its filling deposits; (2) describe their morphometric elements and scaling relationship among them; (3) investigate their development and paleoenvironment; and (4) examine the impact of differential compaction, horizon interpretation pitfalls, and burial effect for petroleum prospectivity in the study area.