Gravitational Evidence for a Low-Density Mass beneath the Galápagos Islands

Science  14 Sep 1973:
Vol. 181, Issue 4104, pp. 1040-1042
DOI: 10.1126/science.181.4104.1040


A residual negative free-air and Bouguer anomaly of at least 80 milligals, superimposed on a broader high, occurs over the Galápagos Islands The axis of the anomaly trends roughly east and plunges eastward. Thus, a low-density mass in the crust or upper mantle must underlie the archipelago. This anomaly may be caused by thermal expansion over a crust-mantle " hot spot".