Patterns of hot spot volcanism

The aim of this paper is to identify the characteristic features, in terms of geophysical measured parameters, of the hot spot sites over the Earth's surface. The hot spots, generally defined as volcanoes not obviously related to plate boundaries, are found to occur in sites characterized by either one of two main significant patterns: (1) positive values of geoid anomalies with harmonic degree between 2 and 10, (2) clustered volcanoes in slow moving plates. A third pattern, representative of isolated volcanoes anomalously close to mid-ocean ridges (distance from the ridge less than ~600 km) can also be tentatively identified. This result implies the existence of two main types of hot spot volcanism, the first one of sublithospheric origin, and the second one mainly due to a favorably "soft' lithosphere. -from Authors