A suite of 350 simulations were designed to explore the parameter space of model uncertainties and sensitivities, to yield a subset of experiments that showed close correspondence to offshore and onshore ice-directional indicators, broad BIIS chronology, and the relative sea-level record.
Similar regional till architectures will be manifest wherever the palaeogeography resulted in the onshore flow of ice and the concomitant production of glacitectonites from glacial lake sediments.
"In western Hudson Bay, during years when polar bears spend more time onshore and the ice-free period is longest, survival rates are lowest despite observed terrestrial feeding".
Unlike grizzly or black bears that require a real den on a hillside, polar bears on the other hand build their dens in temporary snow banks onshore or on sea ice offshore.
Opponents have argued that an oil spill would be virtually impossible to contain, given the region's remoteness, its severe weather and ice and limited onshore support.
The designated habitat includes three ecozones -- sea ice, barrier islands and onshore denning habitat.
"It appears they've reached a point where the earlier departure of the sea ice and their earlier appearance onshore is starting to affect their survival," he said.
On the other hand, numerical model simulations (e.g., Kusahara and Hasumi 2013) suggest that sea-ice production in the coastal polynyas controls the onshore intrusion of warm Circumpolar Deep Water and thus melting of the ice shelves.
This information is especially relevant to the Arctic, where responding to even a small spill would be complicated by ice, forbidding weather and a lack of onshore support.
Correlation with the onshore record suggests that the older of the two ice advances, which excavated the Mackenzie Trough, probably occurred during the Illinoian or Early Wisconsinan glaciations.
If you look across the range of polar bears there are many areas where there are grizzly bears that live onshore, adjacent to the polar bears that live on the sea ice offshore.
