Small-scale insights into seismic-scale slumps: a comparison of slump features from the Waitemata Basin, New Zealand, and the Møre Basin, off-shore Norway

The results of a comparison between two different submarine mass wasting events, using differing methods of investigation are presented in this study. Remotely sensed geophysical data types, such as 3D seismic, can be used to image and analyze large-scale examples. The strengths of such techniques lie in the ability to image large areas (i.e. 10’s of sq km), allowing consideration of the broad-scale architecture of the units. In contrast, field-outcrop studies allow more detailed analysis of geological features, down to a mm scale. Two slumps have been compared; one exposed in outcrop, the other imaged using 3D seismic data. The outcrop example comes from the Miocene of the Waitemata Basin, northern New Zealand, and the seismic example comes from the Pliocene of the Møre Basin, off-shore Norway, and occurs on a scale some 100 times greater that the field outcrop example. Despite this, the two examples exhibit similarities in their gross architecture, with each showing a bi-partite anatomy, well developed slump folds and geometrically similar basal shear surfaces. The results of the comparison emphasize the complexity of large-scale events, and illustrate the potential value of combining field outcrop data with geophysical data types.