Abstract:

Multi-beam, side-scan sonar, and sub-bottom profiler data were obtained from 2017-06-18 to 2017-06-19 during a survey of the Green Canyon GC600 block in the region of the Megaplume natural hydrocarbon seep site (90.5710 W, 27.3698 N, water depth ~1186 m). The instruments were mounted on an autonomous underwater vehicle (AUV) deployed from Oceaneering International’s vessel Ocean Intervention II. The AUV was flown in a pre-determined grid pattern ~40m above the bottom to identify seep sites through the backscatter signature of buoyant gasses and oils.

Suggested Citation:

Di Iorio, Daniela. 2019. AUV based acoustic measurements: Multi-beam echosounder, sub-bottom profiler, and side-scan sonar data obtained in the vicinity of the Megaplume natural hydrocarbon seep site in the Gulf of Mexico from 2017-06-18 to 2017-06-19. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N76H4FSN

Publications:

Razaz, M., Di Iorio, D., Wang, B., Daneshgar Asl, S., & Thurnherr, A. M. (2020). Variability of a natural hydrocarbon seep and its connection to the ocean surface. Scientific Reports, 10(1). doi:10.1038/s41598-020-68807-4

Purpose:

The data collected from the autonomous underwater vehicle (AUV) was used to pin-point all hydrocarbon seep sites in the predetermined AUV survey grid.

Data Parameters and Units:

Topography-corrected sub-bottom profile data (constant and variable start times) are available for June 18, 2017 (1*.1.a.0.et.subb.e.sgy and 20*.1.a.0.et.subb.e.sgy) and June 19, 2017 (d*.1.a.0.et.subb.e.sgy). Multi-beam data are provided in .all files with naming conventions similar to the sub-bottom profile data ({1,2*,d*}.1.a.0.em2040-wc.all). Side-scan sonar data are available in for June 18 (1*.1.a.0.et..xtf and 2.1.a.0.et..xft) and June 19 (d.1.a.0.et.*.xtf) for high and low frequencies. Data are in binary format; preprocessing steps completed by Oceaneering are described in the files located in the "General Metadata" folder.

Instruments:

The C-Surveyor III AUV was operated by Oceaneering International. Sub-bottom profiles were obtained using an EdgeTech DW106 Chirp Subbottom Profiler, frequency band 1-6 kHz, 3Hz average ping rate. Side-scan sonar instrument was an EdgeTech 2200-M with dual frequencies centered at 120 kHz and 410 kHz. Multi-beam echosounder was a Kongsberg EM 2040 Multibeam Echosounder operating at 200 kHz with a maximum ping rate o 50 Hz.

Individual Files: