Sea surface temperature monitor and predict the El Niño phenomenon. Weather satellites have been available to determine sea surface temperature information since 1967, with the first global composites created during 1970. Since 1982, satellites have been increasingly utilized to measure SST and have allowed its spatial and temporal variation to be viewed more fully. Satellite measurements of SST are in reasonable agreement with in situ temperature measurements. The satellite measurement is made by sensing the ocean radiation in two or more wavelengths within the infrared part of the electromagnetic spectrum or other parts of the spectrum which can then be empirically related to
Geology of the Pacific Ocean Plate in the north, the Cocos Plate off today's Central America, and the Nazca and Phoenix Plates in the southern Pacific. Charles Darwin had proposed a theory of the slow subsidence of the ocean floor based on his studies of Pacific oceanic islands, seamounts (underwater volcanoes) and guyots (flat-topped seamounts). His observations have been verified and expanded in the development of plate tectonic theory. The tectonic plates continue to move today. The slowest ridge spreading rate is across the Gakkel Ridge in the Arctic Ocean which separates at less than 2.5 cm/yr while the fastest, across the East Pacific Rise