Two submarine volcanoes, Tafu and Maka, lie along a NE-SW-trending ridge segment in the southern part of the NE Lau Spreading Center (NELSC). The NELSC is a back-arc spreading center in the northeast part of the Lau Basin. Tafu (Tongan for "source of fire") rises to about 1,400 m below sea level at the NE end of the ridge segment, and Maka (Tongan for "rock") reaches 1,560 m below sea level at the SW end. A November 2008 NOAA Vents Program expedition discovered submarine hydrothermal plumes consistent with very recent (days to weeks?) lava effusion from Maka; a return visit in May 2009 documented the freshly emplaced lava flow.