HIGH HEAT FLOW AND OCEAN ACIDIFICATION IN NASCENT SPREADING CENTERS IN THE NORTHERN GULF OF CALIFORNIA, MEXICO

• Main Authors: Rosa Ma. Prol-ledesma, Autónoma México, Marco Antonio Torres-vera, Carlos Lechuga Deveze, Centro Investigaciones, Biológicas Noroeste, Ruth Esther Villanueva-estrada, Carlos Robinson, Evgueni Shumilin, Carles Canet
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Kongsberg; Ocean acidification
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1030.2691; http://www.biblioteca.cicimar.ipn.mx/amonPro/archivos_pdf/4360P-023.pdf

Background and Aims: Active sea floor spreading phenomena has been documented only in three (Einsele et al., 1980; Lizarralde et al., 2007) of the 8 tectonically active basins located in the Gulf of California (GoC), they define the tectonic setting prevailing in the region, and are determinant for major and minor elements balances (Edmond et al., 1982). No geophysical or geochemical evidence has been reported about active seafloor spreading in the northern GoC and the northernmost Wagner and Consag basins have been considered as unlikely to contain active seafloor spreading processes (Persaud et al., 2003); however, seismic modelling might indicate mantle upwelling under the Wagner Basin (Wang et al., 2009). We present heat flow and pH measurements, seismicity data, detailed bathymetry, gas composition, profiler sections and organic matter maturation data that provide supporting evidence to infer the occurrence of active spreading at the Wagner and Consag basins. Objective: Here, we show that the flares reported in the Wagner and Consag basins may be related to the occurrence of active seafloor spreading in the northern Gulf of California. Methods: The data presented were collected during two cruises: WAG-01 in 2007 (25 stations) and WAG-02 in 2010 (22 heat flow stations and 39 water and sediment samples) in the R/V El Puma. Two echosounders were used, an 18 kHz Simrad ES-60 and a 120 kHz Simrad EY-60 to map the bathymetry and to identify gas bubbles, data were processed using Fledermouse software. A Kongsberg TOPAS sub-bottom profiler was used to study sediment features and structure, including blanking due to gas