Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

This dataset includes HROV/Nereus dive bottom navigation in the Kermadec Trench calculated from course, speed and distance from origin, April/May 2014. The dives were in the Southwest Pacific, 4000 to ~10,000m from the RV/ Thomas G. Thompson during cruise TN309 (HADES-K), April - May 2014.

The HROV Nereus was used to conduct exploration and characterization (including downloading video seafloor transects) of the Kermadec Trench region in May 2014.  Geo-referenced vehicle navigation was conducted using the R/V Thompson’s GPS launch position of the vehicle, the estimated initial on bottom position of the vehicle, the course over ground (determined by the Gyro heading, Doppler Velocity Profiler, and thruster speed).

Navigation processing was conducted Matlab (2011 Release; MathWorks, Inc.) and Microsoft Excel for Mac 14.7.3.

Summary of HADES-K Nereus dives:

BCO-DMO Processing Notes:
- added conventional header with dataset name, PI name, version date
- modified parameter names to conform with BCO-DMO naming conventions
- re-formatted date from m/d/yyyy to yyyy-mm-dd
- concatenated all the dive data into a single file
- added column for temp and altitude if not present in dive file
- reduced lat and lon digits from 7 to 5 to right of the decimal
- added date_start, obtained from PI submission, differs somewhat from HadesK_deploylog dataset

Extracted from the NSF award abstract:

Severe technical challenges associated with the extremes of hydrostatic pressure have prevented major advances in hadal ecological studies, and relegated hadal systems to among the most poorly investigated habitats on Earth. Through this project, Hadal Ecosystems Studies (HADES) program, PIs will determine the composition and distribution of hadal species, the role of hadal pressures (piezolyte concentrations, enzyme function under pressure), food supply (distribution of POC with the abundance and biomass of trench organisms, and metabolic rates/energetic demand), and depth/topography (genetic divergence and spatial connectivity of populations) have on impacting deep-ocean community structure. This project will examine these factors using the world's first full-ocean depth hybrid remotely operated vehicle (HROV) in conjunction with the only full-ocean depth imaging lander (Hadal-Lander). This project will provide the first seafloor data and samples in one of the world's best, yet little known trenches- the Kermadec Trench (SW Pacific Ocean).  Megafaunal community structure and the relationship between POC and benthic bacterial biomass will be examined as a function of depth and location by systematic high-definition imaging and sediment/faunal sampling transects from abyssal to full trench depths both along and perpendicular to the trench axis. Population genetic approaches will provide levels of genetic divergence and evolutionarily independent lineages to assess the role of depth and topography in trenches and their adjacent abyssal plain in promoting the formation of species. Physiological constraints will be investigated by examining in-situ respiration of selected fauna and tissue concentrations of such protein stabilizers as trimethylamine oxide (TMAO), and the structural adaptations of macromolecules. 

Image of NEREUS Deployment Sites. [click on the image to view a larger version]