Day 21: Underwater discoveries
By Olivia Belshaw
During a Swath yesterday, the Geophysical Surveying and Mapping team of scientists on board the RV Investigator, including Amy Nau, Phil Vandenbossche and Rob Beaman, mapped a deep ocean trench located in the North Eastern Coral Sea – the South Rennell Trough. Whilst scientists were aware there was a trench in this area, they were unaware of the width, depth or geological features of this trench.
The mapping team was able to map a significant section of this trench and discovered that some sections were over 5500m deep – this is indicated by the very deep blue sections on the map. The data also indicated that the side of the trench dropped off dramatically from a plateau that was at a depth of approximately 3000m (the areas of yellow alongside the trench). Some of the data collected also indicates that the presence of ridges and faults are at right angles to each other, leading scientists to infer that this is an area of sea floor spreading. Due to time constraints and voyage demands, we were unable to map the entire trench; however, the scientists on board were very excited about this discovery, and it was a topic of conversation for much of the day.
A map of the ocean floor, showing swathed areas in colour. The white areas are sections of the surrounding sea floor that are still unmapped. The small green icon at the bottom left of the map denotes the current position of the RV Investigator.