Monsoon trough of the summertime Asian monsoon is in its normal orientation (oriented east-southeast to west-northwest), tropical cyclones along its periphery will move with a westward motion. If it reverses its orientation, orienting southwest to northeast, tropical cyclones will move more poleward. Tropical cyclone tracks with S-shapes tend to be associated with reverse-oriented monsoon troughs. The South Pacific convergence zone and South American convergence zones are generally reverse oriented. The failure of the monsoon trough, or the ITCZ, to move south of the equator in the eastern Pacific Ocean and Atlantic Ocean during the southern hemisphere summer, is considered one of the
Rockall Ledge, each secured by four 80-tonne rock-anchor bolts. Establishing that the rock is part of the United Kingdom and its development as a light beacon facilitated the incorporation of the island into the District of Harris in the County of Inverness in the Island of Rockall Act 1972 and reinforced the UK Government's position with regard to seabed rights in the area. In 1978, eight members of the Dangerous Sports Club, including David Kirke, one of its founders, held a cocktail party on the island. Former SAS member and survival expert (the Irish born) Tom McClean lived on the island