Figure 6. Maximum methane concentration measured at stations where the methane concentration exceeded 20 nM. Acoustic anomalies attributed to gas bubbles from natural oil and gas seeps with features similar to those shown in figure 3 are seen as stars. Overlapping occurrences of high methane concentration and acoustic anomalies are likely areas of active oil and gas seepage.http://geopubs.wr.usgs.gov/open-file/of03-122/figures/figure6 |