Recent coastal submergence of the Maritime Provinces, Canada
Hydrographic, archeologic, and geologic evidence indicates that for the last 4000 y the Maritime Provinces have been submerging three to five times faster than the 6 cm/century rate of eustatic rise of sea level. After correcting for the eustatic change, the Bay of Fundy shows an anomalous submergen...
Published in: | Canadian Journal of Earth Sciences |
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Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
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Canadian Science Publishing
1970
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Online Access: | http://dx.doi.org/10.1139/e70-067 http://www.nrcresearchpress.com/doi/pdf/10.1139/e70-067 |
Summary: | Hydrographic, archeologic, and geologic evidence indicates that for the last 4000 y the Maritime Provinces have been submerging three to five times faster than the 6 cm/century rate of eustatic rise of sea level. After correcting for the eustatic change, the Bay of Fundy shows an anomalous submergence of 24 cm/century, of which at least 15 cm/century is probably due mainly to rise of high tide, or increase of tidal range, beginning 4000–6000 y ago as eustatic sea-level rise widened and deepened the entrance to the Gulf of Maine. Submergence of the Atlantic coast of Nova Scotia, on the other hand, exceeds the eustatic rate by 9 cm/century, which can be largely explained by new mathematical models as isostatic subsidence of the earth's crust as the sea deepened eustatically over the continental shelf. Only a small part of the residual anomalies of 9 cm and 4 cm/century for the Fundy and Atlantic coasts, respectively, can be attributed to a combination of additional subsidence due to geosynclinal downwarping and relaxation of a possible glacier-margin peripheral bulge, thereby implicating other modes of regional crustal lowering. |
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