  Models that envisage successful subduction channel transport of upper crustal
materials below 300 km depth, past a critical phase transition in buoyant
crustal lithologies, are capable of accumulating and assembling these materials
into so-called "second continents" that are gravitationally stabilized at the
base of the Transition Zone, at some 600 to 700 km depth. Global scale,
Pacific-type subduction (ocean-ocean and ocean-continent convergence), which
lead to super continent assembly, were hypothesized to produce second
continents that scale to about the size of Australia, with continental upper
crustal concentration levels of radiogenic power. Seismological techniques are
incapable of imaging these second continents because of their negligible
difference in seismic wave velocities with the surrounding mantle. We can image
the geoneutrino flux linked to the radioactive decays in these second
continents with land and/or ocean-based detectors. We present predictions of
the geoneutrino flux of second continents, assuming different scaled models and
we discuss the potential of current and future neutrino experiments to discover
or constrain second continents. The power emissions from second continents were
proposed to be drivers of super continental cycles. Thus, testing models for
the existence of second continents will place constraints on mantle and plate
dynamics when using land and ocean-based geoneutrino detectors deployed at
strategic locations.
