Reply to Comment on “Bathymetric survey images structure off Sumatra”



As we understand the comment by J. N. Murdock on our article “Bathymetric survey images structure off Sumatra,” he wishes to point out that in our ongoing studies of the western Sumatra margin, we should consider an unconventional “blind thrust model” instead of a “megathrust model.”

First, we would like to remark that we reported on new bathymetric data, which by itself does not allow for interpretation of deep-seated subsurface structures. A discussion on megathrusting or not at the plate interface is beyond the scope of our article. We would further like to point out that in what Murdock calls a “conventional plate model of convergence,” blind thrusts are actually common features and known from accretionary prisms worldwide. In fact, many of the folds visible in the bathymetry offshore Sumatra will have developed above blind thrusts, especially the younger ones where the thrusts have not yet propagated through the core of the anticline up to the seafloor.