An NMR system was developed to detect the presence of leaked or spilled oil trapped under persistent sea ice in the arctic regions. The system uses the extremely uniform earth's magnetic field and the constructed hardware consists of a 6-meter diameter pre-polarization and rf coil that is placed on the ice surface by a helicopter. The detection takes place while the helicopter hovers nearby for ~3–4 minutes after which the coil is moved to a new location. The system is able to detect small amounts of oil in the presence of large amounts of water under one meter of ice.
S. A. Altobelli, M. S. Conradi, E. Fukushima, J. Hodgson, T. J. Nedwed, D. A. Palandro, A. Peach, N. J. Sowko, and H. Thomann, "Helicopter-borne NMR for detection of oil under sea-ice," Marine Pollution Bulletin 144, 160-166 (2019).
M. S. Conradi, S. A. Altobelli, N. J. Sowko, S. H. Conradi, and E. Fukushima, "Earth's field NMR detection of oil under arctic ice-water suppression" J. Magn. Reson. 288, 95--99 (2018).
M. S. Conradi, S. A. Altobelli, N. J. Sowko, S. H. Conradi, and E. Fukushima, "Adiabatic sweep pulses for earth's field NMR with a surface coil," J. Magn. Reson. 288, 23--27 (2018).
M. S. Conradi, S. A. Altobelli, N. J. Sowko, S. H. Conradi, and E. Fukushima, "Pre-polarization fields for earth's field NMR: Fast discharge for use with short T1 and large coils," J. Magn. Reson. 281, 241--245 (2017).