Valparaíso Region

The Valparaíso Region of Chile wraps the central Pacific coast around the working port of Valparaíso and its sister resort city Viña del Mar to the north, with the long Aconcagua and Maipo river mouths emptying into the Pacific south of the harbour and the offshore Juan Fernández archipelago and Easter Island administered from the regional government. The tide here is a small mixed semidiurnal signal characteristic of open Pacific coasts at this latitude. Mean range at the Valparaíso harbour gauge is about 1.1 metres, climbing past 1.5 metres on the largest spring tides and dropping near 0.6 on neaps. Two highs and two lows of unequal size each day, with the asymmetry between the higher high and the lower low varying through the lunar month. The defining oceanographic feature is the cold Humboldt Current that sweeps north along the Chilean coast from the Antarctic Circumpolar Current, with sea-surface temperatures staying between 12 and 18 degrees year-round despite the mid-latitude position and the cold-water upwelling driving the Chilean industrial fishing economy. The defining historical events are the tsunami impacts. The 11 November 1922 Vallenar earthquake (Mw 8.5) generated a Pacific-wide tsunami that struck Valparaíso harbour with run-up exceeding 9 metres in places and reshaped the early-twentieth-century waterfront engineering; the 22 May 1960 Valdivia earthquake (Mw 9.5, the largest ever recorded) generated the trans-Pacific tsunami that struck Valparaíso 11 hours after the rupture and was felt as a series of 1 to 2 metre water-level oscillations through the harbour over several hours. The cerros (hill quarters) of Valparaíso — Concepción, Alegre, Bellavista — climb the 45-degree slopes immediately above the working harbour, and the funicular ascensor system has connected port-level workers to the residential cerros since 1883. The working container terminal at the Puerto de Valparaíso and the cruise calls, the Vergara Pier at Viña del Mar, and the long sand at Reñaca and Concón read the table for different windows. The Chilean Navy Hydrographic and Oceanographic Service (SHOA) publishes the authoritative Chilean tide tables and operates the Pacific Tsunami Warning Center liaison station.