Geoid anomalies over Gorringe Ridge, North Atlantic Ocean
In: Earth and Planetary Science Letters. Elsevier: Amsterdam. ISSN 0012-821X; e-ISSN 1385-013X, more
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| Keywords |
Anomalies > Geoid anomalies
Earth sciences > Geophysics > Geodesy
Forces (mechanics) > Gravity
Plate boundaries
Seismic activity
Gorringe Ridge [Marine Regions]
Marine/Coastal |
| Abstract |
Gorringe Ridge is a strong uplifted block of oceanic crust and upper mantle lying at the eastern end of the Azores-Gibraltar plate boundary. The geoid over this structure derived from SEASAT altimeter data exhibits a 9-m height anomaly with a north-south lateral extension smaller than 200 km. An attempt is made to interpret this geoid together with the gravity anomalies and with the seismicity, which has been compiled as a function of depth. It is first shown that the flexure of the oceanic lithosphere due to the ridge loading does not provide a good fit of the geoid anomalies and probably should be discarded, as it assumes a continuous unfractured elastic plate. Models involving local heterogeneities are then tested. The comparison of the observed geoid anomalies with the anomalies due to the uncompensated relief indicates that the topographic high has no shallow compensation. |
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