Gunung laut Hòn Tro

The Ile des Cendres group of submarine volcanoes off the SE coast of Vietnam includes two submarine cones that built ephemeral islands during an eruption in 1923 and two submarine lava cones of uncertain age. The 1923 eruption produced two small islands, one about 30 m high and about 450 m long, and the other 30 m wide and 30 cm high. A third submarine cone reached to within 20 m of the surface. Additional submarine cones occur between Ile des Cendres and the Vietnam mainland (Bondarenko and Nadezhnyi, 1989). In 1880 there was a reef (named Veteran) reported about 36 km S, described as being 34 km SSE of Grand Catwick Rock (Round Island). It was not found in 1882, but was attributed to a possible volcanic eruption (Catalog of Active Volcanoes of the World), and discolored water was reported in 1928.