On feasibility to detect volcanoes hidden under the ice of Antarctica via their “gravitational signal”

Abstract

Many undiscovered volcanoes may be hidden under the thick layers of the ice of Antarctica. Hypothetic volcanoes were sought by means of the best present-day gravitational data (gravity field model EIGEN 6C4) and bedrock topography data (Bedmap2). A new previously unused method was tested. The analogy with the “gravitational signal” typical for volcanoes and other structures in other parts of the Earth is used. Various functions (not only ordinary gravity anomalies) of the disturbing geopotential were employed: Marussi tensor of the second derivatives, geopotential invariants, the strike angle and the virtual deformations. We attempted to discover if the best present-day gravitational and topographic data are of sufficient precision and resolution and how fast is the attenuation of the “gravitational signal” of a volcano with increasing depth under the ice. It is shown that there is no principal obstacle to detect volcanoes by our method. However, it appeared very quickly that our present-day attempts to discover such volcanoes could hardly be successful, mainly due to a low resolution of the existing gravity data and also due to a low resolution of the best bedrock topography of Antarctica currently available. Nevertheless, some examples of hypothetical volcanoes under the ice are given, but they are uncertain. However, the method, the main goal of this feasibility study, is ready and working.

Keywords

• Gravity field model EIGEN 6C4
• Functions of disturbing potential
• Volcanoes
• Antarctica
• Bedmap2
• RET 14