In late August, a NORC cruise was implemented onboard R/V TKK in the central SCS (NORC2021-06). It’s the fourth times that R/V TKK was set to implement a NORC cruises. This cruise was divided into two legs—the comprehensive biogeochemical leg and the geological and geophysical leg. Rui Zhang and Yihua Cai served as chief scientists for each leg.

A group photo of KK2102 cruise participants. Photo: Yihua Cai

This expedition supported 27 NSFC-funded projects, focused on marine geophysics, hydrodynamics processes, marine biogeochemical processes and their interactions with biodiversity, ocean-atmosphere, sea-bottom multi-interface processes, along with their environmental and climatic effects.

Operations of the deep tow of optics video surveillance. Photo: Jinwei Wang

In total there were more than 300 over-the-side operations implemented at 69 stations during the 47-day cruise, including CTD casts, plankton trawls, in situ LVPs, VPR operations, box cores, and operations of the deep tow of optics video surveillance. Moreover, a benthic survey was successfully completed utilizing the deep tow of optics video surveillance for the first time on R/V TKK during the geological and geophysical leg. Valuable data and samples were collected.

Cruise participants collected sediment samples. Photo: Yihua Cai

With the deep tow of optics video surveillance, anomalously high methane concentrations, and a large number of carbonate nodules were found in the SCS by Dr. Yanlin Wang from SCSIO, which will help the investigation of mud volcanoes and petroleum resources.