Cumulative sediment volume and cumulative distance in Squamish River delta from 2011-04-27 to 2011-08-24 (NCEI Accession 0169399)

The data within this data file were produced by using bathymetric surveys and creating difference maps out of those surveys. Data were collected using an EM710 multibeam sonar with a vertical resolution of 0.2% of water depth, and a horizontal resolution of 3% of water depth. The sedimentologically active prodelta region was surveyed every weekday, and the distal delta region was surveyed every fortnight. The very shallow water region (< 5 m) of the delta top was surveyed on a semi-weekly basis.

We calculated the difference in seafloor elevation between consecutive bathymetric surveys, which are usually 1-day apart, but can be 3-days apart during weekends. We define an event when there is discernible change in seafloor morphology, and subdivide events that affected the southern, central and northern channels on the delta front. When there is change in more than one channel during the same period, these are counted as separate events.

The cumulative volume (in metres cubed) and corresponding distance (in metres) data used to produce the plots in Figure 2, Figure 3, and Supplemental Figure 5 of the publication entitled "Which triggers produce the most erosive, frequent and longest runout turbidity currents on deltas?" are provided. Filenames (e.g. ‘f_jd137138s’) are given based on the type of event (‘f’ = landslide and ‘m’ = plume event), the Julian day on which they occurred (‘137138’ means the event occurred between Julian Day 137 and 138). The letter at the end of the name corresponds to the channel in which the event occurred (‘n, c, s’ corresponds to north, central and south channel).

本数据集文件中的数据通过开展水深测量（bathymetric surveys），并基于测量结果生成差异地图而得到。数据采集采用EM710多波束声呐（EM710 multibeam sonar），其垂直分辨率为水深的0.2%，水平分辨率为水深的3%。其中，沉积活跃的前三角洲（prodelta）区域每个工作日开展测量，远端三角洲区域每两周开展一次测量；三角洲顶部的极浅水区（水深<5 m）以半周为周期开展测量。

我们计算了连续水深测量之间的海底高程差：常规测量间隔为1天，周末期间的测量间隔可延长至3天。我们将海底地貌出现可识别变化的情形定义为一次事件，并对影响三角洲前缘南、中、北水道的事件进行细分。若同一时期内多条水道出现地貌变化，则将其分别计为独立事件。

本数据集提供了用于刊载于《三角洲上何种触发因素可产生侵蚀性最强、发生最频繁且运移距离最远的浊流》（Which triggers produce the most erosive, frequent and longest runout turbidity currents on deltas?）的论文中图2、图3及补充图5的累积体积（单位：立方米）与对应距离（单位：米）数据。文件名（例如`f_jd137138s`）的命名规则基于事件类型、事件发生的儒略日（Julian day）：`f`代表滑坡事件，`m`代表羽状流事件；`137138`表示事件发生在儒略日137至138之间。文件名末尾的字母对应事件发生的水道：`n`、`c`、`s`分别对应北水道、中水道与南水道。