Alpha Ridge

ID: 1-4

Observations and comments:

An early study by Vogt and Ostenso (1970) suggested that the Alpha Ridge may be an extinct ridge,however there are a lack of observations to support this inference, and multiple origins have since been suggested for the ridge (Jackson et al., 1986). There is an absence of appropriately aligned magnetic anomalies or morphology distinctive of a former spreading center. Furthermore, the 500 km width of the Alpha Ridge is far in excess of any active spreading-centers. After extensive mapping of the Alpha Ridge and surrounding basins, Weber et al. (1987) and Weber (1990), inferred that the most likely origin of the ridge is hotspot related volcanism. A more recent study by Døssing et al. (2013) has further suggested that there may be attenuated continental crust within the Alpha Ridge, that has been obscured by extensive magmatism, similar to burial of the Elan Bank by Kerguelen plume volcanism in the southern Indian Ocean. Given the lack of any strong evidence that a spreading center had been located at this ridge, in addition to there being no suggested placements of the ridge axis the Alpha Ridge was not included in this study.

Ocean: Arctic
Spreading center type: Unlikely to be an extinct spreading center


Døssing, A., Jackson, H. R., Matzka, J., Einarsson, I., Rasmassen, T. M., Olesen, A. V. and Brozena, J. M. 2013, On the origin of the Amerasia Basin and the High Arctic Large Igneous Province - Results of new aeromagnetic data, Earth and Planetary Science Letters, v. 363, p. 219-230.

Jackson, H. R., Forsyth, D. A. and Johnson, G. L. 1986, Oceanic affinities of the Alpha Ridge, Arctic Ocean, Marine Geology, v. 73, p. 237-261.

Vogt, P. R. and Ostenso, N. A., 1970, Magnetic and gravity profiles across the Alpha Cordillera and their relation to the Arctic sea-floor spreading. Journal of Geophysical Research, v. 75, no. 26, p. 4925-4937.

Weber, J. R. 1987, Maps of the Arctic Basin sea floor. Part II: Bathymetry and gravity of the Alpha Ridge: The 1983 CESAR Expedition, Arctic, v. 40, no. 1, p. 1-15.

Weber, J. R. 1990, The structures of the Alpha Ridge, Arctic Ocean and Iceland-Faroe Ridge, North Atlantic: Comparisons and implications for the evolution of the Canada Basin, Marine Geology, v. 93, p. 43-68.