STUDY ON NUMERICAL MODELS ABOUT BUBBLE PLUMES IN THE COLD SEEPAGE ACTIVE REGION

Bubble plume is an indirect indicator to gas hydrate. In order to study the seismic responses produced by bubble plumes in a cold seepage active region, a model well marching the characteristics of the actual plume needs to be established. Taking the actual occurrence of the bubble plume as a reference and taking bubble water characteristics into account, we improved the vertical distribution pattern of the plume bubbles and the appearance of plume for established models following the principles of vertical migration law. At last, three models are worked out. Testing shows that the Model Ⅲ is more accurate in presenting the actual occurrence characteristics of the plume rather than the Model Ⅰ and Model Ⅱ. Rational discussion is made by comparing the model with the real plume. And it is concluded that the model established well reflects the essential characteristics of the bubbles in plume, and contains more complex changes in bubble content. Therefore, it can be used to further study the seismic response characteristics of plume, and make it possible to identify bubble plumes for research and evaluation of natural gas hydrate deposits.