Stillstand

A useful exercise may be to calculate the basin-wide deglacial erosion rate for the Jakobshavn catchment area using the volume of glacimarine sediments deposited in front of the fjord-mouth sill (29.2 km3) during an 800 year stillstand (Hogan et al., 2012) and a glacial catchment area derived using the same procedures in this study (33 504 km2; Fig. S1b).

Repeated bathymetric measurements adjacent to the LeConte glacier terminus offer a rare view into the evolution of a morainal bank on interannual time scales during a stillstand, starting immediately after a rapid glacier retreat.

A relative stillstand of sea level is an apparently constant position of sea level with respect to the underlying initial surface of deposition, and is indicated by coastal toplap. It may result if both sea level and the underlying initial surface of deposition actually remain stationary, or if both rise or fall at the same rate.

More generally, regressive sedimentary episodes often correlate with widespread stratigraphic gaps implying erosion or non-deposition. Such facts imply a sea-level fall rather than a stillstand combined with sedimentary infill. Without such periodic falls it is difficult to understand why the successive phases of transgression did not extend much further than areal plots of marine deposits indicate.

The results show that shelf morphology in a far-field site, such as a South Atlantic continental margin, exhibits morphological evidences indicating a stillstand during YD, characterized by the configuration of distinct coastal systems (lagoons, estuaries, barrier islands and potential fringing reefs), followed by a rapid sea-level rise that drowned and preserved the morphology of these coastal features.

As with the tide, swell'd up unto its height , That makes a still-stand, running neither way

It is tempting in these circumstances to look for the 'smoking gun'-a mechanism whereby glaciers from both the local Cairngorm ice cap, and the much larger Scottish Ice Sheet could stillstand, or even readvance for a period of 1 kyr, during deglaciation.

The base of the stratigraphic successions consists of outwash fan deposits emplaced in the early deglaciation when ice margin stillstanded immediately beyond the depositional area.