A possible in situ 3H and 3He source in Earth's interior: an alternative explanation of origin of 3He in deep Earth

Origin of He-3 in the Earth is a mystery. Lacking a production mechanism, scientists assume He-3 was trapped in the Earth, when the Earth was formed. In contrast to this assumption, we have found He-3 and H-3 concentrations in excess of the atmospheric values in the deep waters of the volcanic Lakes Pavin (France), Laacher (Germany) and Nemrut (Turkey). This paper reports the result of finding H-3 in these three volcanic lakes that appear to originate from the mantle. Because H-3 has a half-life of 12.3 years, this H-3 and the resulting He-3 must have formed recently in the mantle and not be part of a primordial reservoir. The nuclear reactions that generate tritium might be a source of "missing" energy in the interior of the Earth.