caa a22 4500 463216210 CHVBK 20180405153157.0 cr unu---uuuuu 170326e20070601xx s 000 0 eng 10.1007/s00367-007-0064-4 doi (NATIONALLICENCE)springer-10.1007/s00367-007-0064-4 Gas accumulations and their association with particle size distribution patterns in the Ría de Arousa seabed (Galicia, NW Spain): an application of discriminant analysis [Elektronische Daten] [R. Diez, S. García-Gil, R. Durán, F. Vilas] Gassy sediments in the Ría de Arousa are preferentially distributed in areas of muddy seabed sediments. The close relationship between seabed sediment parameters and gas distribution is here studied in detail to establish better constraints on the presence of gas. Discriminant analysis was applied to the textural and compositional characteristics of 303 seabed sediment samples to classify gas-related and gas-free areas in the Ría de Arousa. The parameters considered in the classification were: particle size data (percentages of clay, silt, sand and gravel), the total inorganic carbon and the total organic carbon contents of the samples. The samples were initially classified in two groups according to the presence or absence of acoustic turbidity in the seismic profiles, shallower than 150cm below seabed. Of the total known cases, 85.5% were correctly classified using these variables. Applying the Wilks' lambda criterion, the most influential textural discriminating variables were the percentage of clay and the percentage of coarse fraction (gravel and sand) in the sediment sample. Discriminant analysis has achieved good differentiation between gas-related and gas-free sediments using near-seabed sediment information. The application of the discriminant method has enabled the estimation of the total area covered by gassy sediments in the Ría de Arousa. The area calculated based on the seismic data (30km2) is a minimum estimate that is constrained by the limits of the existing seismic data. Based on the sediment information obtained from seabed samples, the statistical method estimates a total area of gassy sediments of 39km2. The new gassy areas recognized are located around the gas field at the inner ría, and the gas field west of Arousa Island, which increase in area by 8.3 and 0.4km2 respectively. Springer-Verlag, 2007 Diez R. Departamento de Geociencias Marinas y Ordenación del Territorio, Universidad de Vigo, 36310, Vigo, Spain aut García-Gil S. Departamento de Geociencias Marinas y Ordenación del Territorio, Universidad de Vigo, 36310, Vigo, Spain aut Durán R. Departamento de Geociencias Marinas y Ordenación del Territorio, Universidad de Vigo, 36310, Vigo, Spain aut Vilas F. Departamento de Geociencias Marinas y Ordenación del Territorio, Universidad de Vigo, 36310, Vigo, Spain aut Geo-Marine Letters Springer-Verlag 27/2-4(2007-06-01), 89-102 0276-0460 27:2-4<89 2007 27 367 https://doi.org/10.1007/s00367-007-0064-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00367-007-0064-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Diez R. Departamento de Geociencias Marinas y Ordenación del Territorio, Universidad de Vigo, 36310, Vigo, Spain aut NATIONALLICENCE 700 1- García-Gil S. Departamento de Geociencias Marinas y Ordenación del Territorio, Universidad de Vigo, 36310, Vigo, Spain aut NATIONALLICENCE 700 1- Durán R. Departamento de Geociencias Marinas y Ordenación del Territorio, Universidad de Vigo, 36310, Vigo, Spain aut NATIONALLICENCE 700 1- Vilas F. Departamento de Geociencias Marinas y Ordenación del Territorio, Universidad de Vigo, 36310, Vigo, Spain aut NATIONALLICENCE 773 0- Geo-Marine Letters Springer-Verlag 27/2-4(2007-06-01), 89-102 0276-0460 27:2-4<89 2007 27 367 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer