Metadata Report for BODC Series Reference Number 2225494

• Metadata Summary

• Problem Reports

• Data Access Policy

• Narrative Documents

• Project Information

• Data Activity or Cruise Information

• Fixed Station Information

• BODC Quality Flags

• SeaDataNet Quality Flags

Metadata Summary

Problem Reports

No Problem Report Found in the Database

Data Access Policy

Open Data

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."

Narrative Documents

Kongsberg EM122 12kHz Multibeam Echosounder

The EM122 is designed to perform seabed mapping to full ocean depth with a high resolution, coverage and accuracy. Beam focusing is applied both during reception and transmission. The system has up to 288 beams/432 soundings per swath with pointing angles, which are automatically adjusted according to achievable coverage or operator defined limits.

This model uses both Continuous Wave and Frequency Modulated sweep pulses with pulse compression on reception, in order to increase the maximum useful swath width. The transmit fan is split in several individual sectors, with independent active steering, in order to compensate for the vessel movements.

In multiplying mode, two swaths per ping cycle are generated, with up to 864 soundings. The beam spacing is equidistant or equiangular and the transmit fan is duplicated and transmitted with a small difference in along track tilt, which takes into account depth coverage and vessel speed, to give a constant sounding separation along track. In high density mode, more than one sounding per beam can be produced, such that horizontal resolution is increased and is almost constant over the whole swath.

The EM122 transducers are modular linear arrays in a Mills cross configuration with separate units for transmit and receive. If used to deliver sub-bottom profiling capabilities with a very narrow beamwidth, this system is known as SBP120 Sub-Bottom Profiler.

The specification sheet can be accessed here Kongsberg EM122.

Specifications

EM122 versions

JC237 PAP-SO and Whittard Canyon Bathymetry: Originator's Data Processing

Sampling Strategy

Kongsberg EM122 multibeam bathymetry data were collected on board RRS James Cook JC237 between 6th August to 4th September 2022 as part of the ongoing timeseries to the Porcupine Abyssal Plain Sustained Observatory (PAP-SO), a fixed-point, open-ocean, scientific observatory. A survey was also conducted over the Whittard Canyon, a deep ocean canyon in the Bay of Biscay, in order to obtain a better insight in the biodiversity patterns, benthic habitat distributions and sediment transport processes of submarine canyons. For dedicated surveys, a speed of 6-8kn was used and lines were occasionally surveyed in only one direction, to account for weather and poor data. All other transits were carried out at full speed (~10kn). The system was kept in 'AUTO' mode with varying expected depths to account for the quickly varying canyon terrain. Depth forcing was also frequently used in areas where bottom tracking had difficulties. Swath width was adjusted between 60 and 70deg on either side to account for weather and terrain, with equidistant spacing.

Data Processing

The data were edited using Caris HIPS software by Catherine Wardell and gridded at 50m spacing (EM122) in a WGS84 UTM Zone 28N (PAP-SO) and 29N (Whittard Canyon) projection. The vertical datum of the data is matched to mean sea level (MSL). They were exported as longitude-latitude-depth triples.

Further information is available in the cruise report.

JC237 PAP-SO and Whittard Canyon Bathymetry: Processing by BODC

The multibeam bathymetry grids from JC237 at the Porcupine Abyssal Plain Sustained Observatory (PAP-SO) and the Whittard Canyon were supplied to BODC as .txt ASCII files at 50 m resolution. Data were transferred into a common format, a netCDF subset. The following table shows how the variables within the files were mapped to the appropriate BODC parameter codes:

Following transfer, the data are screened visually using BODC's in-house visualisation software and Globe V2.6.0, and any spikes or instrument malfunctions are clearly labelled with quality control flags.

References

Poncelet Cyrille, Billant Gael, Corre Marie-Paule, Saunier Anthony (2025). Globe (GLobal Oceanographic Bathymetry Explorer) Software. SEANOE https://doi.org/10.17882/70460.

Project Information

Marine LTSS: CLASS (Climate Linked Atlantic Sector Science)

Introduction

CLASS is a five year (2018 to 2023) programme, funded by the Natural Environment Research Council (NERC) and extended until March 2024.

Scientific Rationale

The ocean plays a vital role in sustaining life on planet Earth, providing us with both living resources and climate regulation. The trajectory of anthropogenically driven climate change will be substantially controlled by the ocean due to its absorption of excess heat and carbon from the atmosphere, with consequent impacts on ocean resources that remain poorly understood. In an era of rapid planetary change, expanding global population and intense resource exploitation, it is vital that there are internationally coordinated ocean observing and prediction systems so policy makers can make sound evidence-based decisions about how to manage our interaction with the ocean. CLASS will underpin the UK contribution to these systems, documenting and understanding change in the marine environment, evaluating the impact of climate change and effectiveness of conservation measures and predicting the future evolution of marine environments. Over the five-year period CLASS will enhance the cost-effectiveness of observing systems by migrating them towards cutting edge autonomous technologies and developing new sensors. Finally, CLASS will create effective engagement activities ensuring academic partners have transparent access to NERC marine science capability through graduate training partnerships and access to shipborne, lab based and autonomous facilities, and modelling capabilities.

Data Activity or Cruise Information

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

Fixed Station - Whittard Canyon - The Canyons Marine Conservation Zone

The Canyons MCZ is located in the far south-west corner of the UK continental shelf, more than 330 km from Land's End, Cornwall. It encompasses the steep part of the shelf break where the seabed drops from a depth of 100 m to the oceanic abyssal plain at 2000 m. It is unique within the context of England's largely shallow seas due to its depth, sea-bed topography and the coral features it contains.

There are two large canyons within the site, which add to its topographic complexity: the Explorer Canyon to the north and the Dangaard Canyon below it. The wider Whittard Canyon area encapsulates the Canyons MCZ and also includes a network of submarine canyons to the West. The MCZ, also known as a Marine Protected Area (MPA), was designated in November 2013 under the Marine and Coastal Access Act (2009). The Canyons MCZ covers an area of 661 km², which extends to approximately 5200 km² when Whittard Canyon is included.

On the northernmost wall of the Explorer Canyon is a patch of live Cold-water coral reef (Lophelia pertusa) and Coral gardens, both of which are a OSPAR threatened and/or declining habitat. This is the only known example of living Cold-water coral reef recorded within England's seas, making it unique in these waters.

Cold-water corals and Coral gardens typically support a range of other organisms. The coral provides a three-dimensional structure and a variety of microhabitats that provide shelter and an attachment surface for other species. Both Cold-water corals and Coral gardens can be long-lived but are extremely slow growing (at about 6 mm a year), making protection important for their conservation. Another reef-forming cold-water coral, Madrepora oculata, is also present in the site.

The variety of deep-sea bed communities present are indicative of the range of substrates found in and around the canyons, including bedrock, biogenic reef, coral rubble, coarse sediment, mud and sand. These biological communities include cold-water coral communities (Lophelia pertusa and Madrepora oculata), Coral gardens, feather star (Leptometra celtica) assemblages and Sea-pen and burrowing megafauna communities (including, burrowing anemone fields, squat lobster (Munida sp.) assemblages, barnacle assemblages and deep-sea sea-pen (Kophobelemnon sp.) fields).

Sampling History

Related Fixed Station activities are detailed in Appendix 1

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Appendix 1: Whittard Canyon - The Canyons Marine Conservation Zone

Related series for this Fixed Station are presented in the table below. Further information can be found by following the appropriate links.

If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.