  The science potential of a 10 kiloton deep-ocean liquid scintillation
detector for ~1 MeV energy scale electron anti-neutrinos has been studied. Such
an instrument, designed to be portable and function in the deep ocean (3-5 km)
can make unique measurements of the anti-neutrinos from radioactive decays in
the Earth'.s mantle. Ths information speaks to some of the most fundamental
questions in geology about the origin of the Earth, plat e tectonics, the
geomagnetic field and even somewhat indirectly to global warming. Measurements
in multiple locations will strengthen the potential insights. On the particle
physics side, we have identified a unique role in the study of anti-neutrinos
from a nuclear power complex, at a range of 55-60 km off shore. Not only can
precision measurements be made of most neutrino mixing parameters, including
$\theta_{13}$ (depending on magnitude), but the neutrino mass hierarchy can be
determined in a method not heretofore discussed, and one which does not rely
upon matter effects. This detector is under active study on paper, in the
laboratory, and at sea. An interdisciplinary and international collaboration is
in formation, and plans are in motion for a major proposal, to be followed by
construction over several years.
