Postglacial rebound at the northern Cascadia subduction zone

摘要: Postglacial rebound is the response of Earth to decay ice-sheets. A postglacial model explains crustal tilting and rapid uplift at northern Cascadia subduction zone that occurred during retreat Cordilleran ice-sheet. Observations explained by include shoreline tilts two proglacial lakes formed 13.5}14 ka (14C yr ago) sea level fall (land uplift) 12}12.5 ka. Modelled mantle viscosity values range from 5]1018 5]1019 Pa s, are consistent with previous inferences observations deformation following earthquakes (1018}1019 s). No lower limit apparent our model, but equal or larger than 1020 s de"nitely ruled out. Our modelled smaller most upper-mantle estimates derived studies tectonically less-active regions (1020}1021 The observed 12 requires, in addition a low viscosity, unloading sudden collapse remaining coastal portions southern provides 0.18 m global eustatic rise, approximately 0.7% rise associated melt-water pulse IA. Predictions (ICE-3G) 1021 were previously applied geodetic data this region isolate signals earthquake cycle. Owing low-viscosity values, resulting recovery glacial deformation, predicts present-day rates least 10 times ICE-3G (less about 0.1 mm/yr). As adjustments substantial, indicates need for re-evaluation data. ( 2000 Elsevier Science Ltd. All rights reserved.