Rockall Helen's Reef (the latter was named in 1830). Notes Bibliography Rockall Rockall () is a British uninhabited granite islet located within the exclusive economic zone (EEZ) of the United Kingdom, situated in the North Atlantic Ocean. Its approximate distances from the closest large islands are: west of Scotland; northwest of Ireland; and 700 km (440 miles) south of Iceland. The nearest permanently inhabited place is North Uist, an island in the Outer Hebrides of Scotland, 370 km (230 miles) to the east. The United Kingdom claimed Rockall in 1955 and incorporated it as a part of Scotland in 1972. Ireland
Mariana Trough Iwo Jima), and Iwo Jima . Rifting and spreading are inferred to be propagating northward at a rate of 10 to 40 cm/year , so the variations in tectonic and magmatic style seen along-strike north of 18°N provide an example of the sequence of events that occur at any one section across the back-arc basin as the rift evolves from updoming through rifting to true spreading. Mariana Trough The Mariana Trough is an active back-arc basin in the western Pacific Ocean . It is an integral part of the Izu-Bonin-Mariana Arc system. The Mariana Trough stretches 1300 km from north