Gravity measurements in the English Channel

In 1948 gravity measurements were made in a submarine, forty-three stations in the English Channel and at Portland, Devonport, Gosport and Cherbourg. There are also five stations in the area at which measurements were made in 1946. Tables are given of the details of the gravity measurements and of the free-air, Bouguer and isostatic anomalies (Airy-Heiskanen, crustal thickness 30 km). The accuracy of the results is estimated. The anomalies are shown to be compatible with an interpretation of existing knowledge of the Mesozoic geology of the Channel basin provided that reasonable assumptions are made. An area of strong negative anomalies off the French coast in the Cherbourg-Le Havre area extends about half-way across the Channel. These must be explained by intra-crustal masses. The anomalies show the same trend to positive values in the west as is found in the British Isles and northern France.