Abstract:

Two video cameras collected many short videos of the seafloor near the Megaplume study site (naturally occurring hydrocarbon seep area) in the Bureau of Energy GC600 lease block in the Gulf of Mexico. The goal was to learn about the spatial and temporal variability of the output of a pre-selected oil/methane seep. The cameras were deployed on 2017-09-03 from the Oceaneering vessel Intervention II and were recovered from the contracted vessel, Connor Bordelon. The cameras collected video for (A) 2017-09-03 to 2017-09-28 (~25 days) and (B) 2017-09-03 - 2018-02-02 (~150 days). A Remotely Operated Vehicle (ROV) also collected footage in order to quantify the (buoyancy) velocity and flow rate (volume/time) of the oil/methane seep. Images were collected in front of an illuminated regular 1”x1” grid in order to estimate the rise velocity and bubble size by imaging the seep outflow against an illuminated 1”x1” regular grid. To estimate the flow rate, a funnel with a known volume of 3.75” x 4” x 9” inches (135 cubic inches volume) was placed over the top of the seep. The time needed to fill the funnel allows the estimation of the seep’s volume output. The funnel is marked with vertical grid lines separated by one inch, and the ROV imagery contains an embedded time stamp. Other related datasets are available under GRIIDC Unique Dataset Identifiers (UDIs): R5.x270.000:0001 (DOI: 10.7266/N76H4FSN), R5.x270.000:0003 (DOI: 10.7266/n7-aryv-9s10), and R5.x270.000:0004 (DOI: 10.7266/n7-qyn1-sx24).

Suggested Citation:

Daniela Di Iorio, Andreas Thurnherr, Mahdi Razaz, James Kelly. 2020. Video imaging of a naturally-occurring hydrocarbon seep in the GC600 block of the Gulf of Mexico from 2017-09-03 to 2018-02-02. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-3466-rn36

Publications:

Razaz, M., Di Iorio, D., Wang, B., & MacDonald, I. (2020). Temporal Variations of a Natural Hydrocarbon Seep Using a Deep-Sea Camera System. Journal of Atmospheric and Oceanic Technology, 37(9), 1737–1751. doi:10.1175/jtech-d-19-0137.1

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:

To assist in quantifying the volume outflow of a hydrocarbon seep in the GC600 block of Gulf of Mexico.

Data Parameters and Units:

The two stationary cameras, Cameras A and B, recorded files in .MOV format. The ROV-mounted camera recorded in .wmv format. The timestamps on the stationary camera image files are not reliable (please see methods section). Details of the study's objectives and cruises can be found in the metadata document, “DiIorio UGA GoMRI Bottom Boundary Study GOM 2017_2018_ReadMe.pdf.”

Methods:

Note that the timestamps within the files are not reliable. The filenames have been manually modified to reflect the logged time of the files. There likely is a time difference of up to one hour between cameras. In addition, the cameras experienced an issue of randomly not recording at the set time intervals.

Instruments:

Harbortronics cameras

Individual Files: