The Heating of Oceans by Volcanic Magma - Quantifying Global Warming by Submarine Volcanoes

Abstract

Recent observations are used to quantify the direct heating of the global ocean surface by submarine volcanism. These suggest a submarine magma budget substantially greater than the prevailing consensus.

The average ocean heating effect is estimated at c.0.034W/m2. This varies very significantly with the known variability of volcanic activity, whose long-term periodicities are also known to correlate strongly with the Milankovitch cycles, with the activity level close to the maximum during the interglacial optimum periods. The maximum emissions during the warm periods of the ice age cycles are estimated to be 4-5 time the average, in the 0.16W/m2 range, averaged across the entire Earth surface.

The quantification is derived on the basis of total heat loss from magma to the ocean and is expressed in terms of energy and also as radiative forcing, the average power per unit area as used by climate modelers.

The approach used here created some simple and direct metrics, which may assist others to refine their “better informed guesses“. The consequences for the causes of inter-glacial events are also reviewed.

The current consensus regarding the amount of volcanic emissions from volcanoes, now and on average, is clearly wrong. This requires updating using the better data geologists now have. Perhaps most interesting is the large and cyclic range of volcanic variability. THis paper suggests the cause is solid gravitational tides, powered by the orbital gravitational forcings of the solar system, with the main effects being those of the combined Milankovitch cycles on the Earth/Moon barycentric system. Insolation variation is not the only effect of the Milankovitch cycles on Earth systems.

Keywords: Climate, regional, global, volcanic emissions, submarine volcanoes, radiative forcing, El Nino, Interglacial, solid gravitational tides