Multibeam bathymetry from Fifång Deep and Asköfjärden, southern Stockholm archipelago

Martin Jakobsson

Multibeam bathymetry collected from Asköfjärden and Fifång Deep, east of Askö Island in southern Stockholm archipelago. Detailed information about the depth and shape of the seafloor is provided by the acquired multibeam bathymetry. This information is commonly used to study, for example, general seafloor geology, glacial morphology, bottom habitats, and bottom current activities.

The data were collected with Stockholm University research vessels (RV) Electra and Skidbladner between 2012 and 2018 for multiple purposes, including all of those mentioned above. Some of the data were collected as a part of a course in marine geophysical mapping at Stockholm University.

The multibeam bathymetry is here provided in the form of a compiled Digital Terrain Model with a cell-spacing of 1x1 m. The processing of the raw data was carried out using the Qimera software by QPS. The data have been cleared to be been granted public release by the Swedish Maritime Administration.

Citation

Martin Jakobsson (2020) Multibeam bathymetry from Fifång Deep and Asköfjärden, southern Stockholm archipelago. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/jakobsson-2020-asko-1

References

Jakobsson, M., O'Regan, M., Mörth, C.-M., Stranne, C., Weidner, E., Hansson, J., Gyllencreutz, R., Humborg, C., Elfwing, T., Norkko, A., Norkko, J., Nilsson, B., Sjöström, A. (2020). Potential links between Baltic Sea submarine terraces and groundwater seeping. Earth Surf. Dynam. 8, 1–15. https://doi.org/10.5194/esurf-8-1-2020

Data description

The bathymetric data is provided as a processed grid at a resolution of 1x1 m in reference to the SWEREF 99 18 00 projection. Data are available in one GeoTIFF (.tif) file (49.5 MB). The geoid model SWEN08_RH2000 has been used to convert the data to the vertical datum RH2000.

Comments

The multibeam bathymetric data available as a processed grid were acquired between 2012 and 2018 during multiple surveys with RV Electra (24.3 m long) and RV Skidbladner (6.4 m long). A Kongsberg EM2040 0.4°x0.7°, 200-400 kHz, multibeam echo-sounder is hull mounted in RV Electra and RV Skidbladner has a pole-mounted Kongsberg EM2040 0.7°x0.7°, 200-400 kHz multibeam. Both RV Electra and RV Skidbladner receive position, heading and attitude data from Kongsberg-Seatex Seapath 330+ navigation units (GPS and GLONASS) with attached MRU5+ motion and reference sensors. Real-Time Kinematic (RTK) corrections were received from SWEPOS over the internet. Positions have horizontal accuracies estimated to be better than ±5 cm and slightly coarser vertical accuracies. A Valeport MiniSVP sound velocity probe was used at discrete stations to acquire sound speed profiles. In addition, both RV Electra and RV Skidbladner have AML sound velocity probes mounted near the transducers for continuous reading of surface sound speed. The data were processed using QPS Qimera (version 1.7.2).