The Håkon Mosby Mud Volcano

Abstract

Fluid escape features such as mud volcanoes have been discovered along many active continental margins but rarely along passive continental margins. Seismic and sidescan sonar data are presented from a fluid escape system situated on the passive Norwegian-Barents Sea continental margin (Fig. 1). This fluid system supports bacterial communities (Fig. 2), causes rock alteration via fluids and gas flow (Fig. 2), drives eruptive processes at surface (Fig. 3) and in subsurface sediments (Fig. 4) and contributes to the development of gas hydrates (Fig. 5) (Mienert et al. 2001). To understand the complex dyn amics of such a fluid system we need to understand its history. The Håkon Mosby mud volcano (HMMV) provides an opportunity for long-term observations of the dynamics of a fluid system developed on a passive margin.Fig. 1.Location map of the Håkon Mosby Mud Volcano (HMMV) on the Norwegian-Barents Sea continental marginFig. 2.Seafloor photograph of the inner part (caldera) of the Håkon Mosby Mud Volcano showing white bacteria mats and a heatflow probe measurement