Abstract:

This dataset contains profiles of 226-radium measured during the R/V Endeavor cruise EN559 in the Gulf of Mexico from 2015-05-30 to 2015-06-19. It includes code to analyze the profiles and to determine the advective porewater velocities and corresponding confidence intervals, and a reaction-transport model to simulate the formation of gas hydrates and calcium carbonates in cold seeps with variable permeability. Radium was measured suing the Radium Delayed Coincidence Counter. The reaction-transport model was coded in R and C. The dataset also includes the location and date of the sampling collection sites. The cruise documentation was provided for the R/V Endeavor cruise EN559 led by chief scientist Dr. Joseph Montoya. This dataset supports the publication: Rooze, J., Peterson, L., Peterson, R. N., & Meile, C. (2020). Porewater flow patterns in surficial cold seep sediments inferred from conservative tracer profiles and early diagenetic modeling. Chemical Geology, 536, 119468. doi:10.1016/j.chemgeo.2020.11946800

Suggested Citation:

Jurjen Rooze. 2020. Porewater flow patterns in surficial cold seep sediments inferred from early diagenetic modeling and conservative tracer profiles in sediments collected during R/V Endeavor cruise EN559 in the Gulf of Mexico from 2015-05-30 to 2015-06-19. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-1wjm-1437

Publications:

Rooze, J., Peterson, L., Peterson, R. N., & Meile, C. (2020). Porewater flow patterns in surficial cold seep sediments inferred from conservative tracer profiles and early diagenetic modeling. Chemical Geology, 536, 119468. doi:10.1016/j.chemgeo.2020.119468

Purpose:

The radium profiles were used to determine the advective porewater velocities. The 1D model script was used to extract the porewater velocity by fitting the data. The multidimensional model was used to simulate the interaction between flow and solid formation, and to assess the effect of spatial variability in permeability on flow estimates.

Data Parameters and Units:

Main parameters: Sample collection depth range [centimeter below sediment-water interface (cm below SWI)]; Mid sample collection depth [centimeter below sediment-water interface (cm below SWI)]; 226 Ra Activity [radioactivity of 226-radium isotopes in disintegrations per minute per cubic meter (dpm/m3)]; 226Ra activity Unc [radioactivity of 226-radium isotopes uncertainty in disintegrations per minute per cubic meter (dpm/m3)]; Lat [degrees N]; Long [degrees W]; Date [Date of sample collection in dd/mm/yyyy]; Time [Local]; Time [Zulu]; Depth [meter]. There is a detailed Readme text file in the folder named “ColdSeep” that describes all the variables and abbreviations used in coding and details the steps required to install and compile the reaction-transport model. The data are organized in 4 sub-folders “ColdSeep”, “IdentifiabilityAnalysis”, “JurRTM”, “Radium_Profiles”, and also includes Readme file and cruise documentation. The contents of the each sub-folders are described below: The folder “ColdSeep” contains the code that was used to run the baseline model simulations. To run the model, SUNDIALS needs to be installed and the c-file in the main folder needs to be linked to sundials and compiled. The folder “JurRTM” contains the core code that runs the model. Please, see the doc folder within for a manual. The folder “Radium_Profiles” contains concentrations of radium in various depths of sediments at different locations in the Gulf of Mexico. The folder “IdentifiabilityAnalysis” contains scripts used for fitting and computing confidence intervals.

Methods:

For the method used to measure 226-radium please see Peterson et al., (2009; https://doi.org/10.4319/lom.2009.7.196). See the manuscript for methods used to retrieve and handle sediment cores. The reaction-transport model was coded in R and C. See the manuscript and included manual for a full description.

Provenance and Historical References:

Peterson, R. N., Burnett, W. C., Dimova, N., & Santos, I. R. (2009). Comparison of measurement methods for radium-226 on manganese-fiber. Limnology and Oceanography: Methods, 7(2), 196–205. doi:10.4319/lom.2009.7.196

Individual Files: