Science of Tsunami Hazards (Jan 2012)
THE 2010 CHILEAN TSUNAMI: BEHAVIOR ON THE ECUADORIAN COAST AND THE GALAPAGOS ISLANDS
Abstract
Available mareograms from ports of Ecuador and the Galapagos Islands made possible analysis and understanding of the tsunami generated by the great Chile earthquake of 27 February 2010. In general, all tidal gauges along the coastal zones at these localities begun to record sea level changes minutes after the predicted low water tide near 08:30 in the morning of February 27. The mareographic records showed waves with amplitudes ranging from 20 to 70 cm and periods of up to 2 hours. From then on the records indicated lower amplitude waves and rather short periods perhaps due to local conditions at each port. At Caleta, Aeolian and Baltra Island in the Galapagos, sea level changes begun just before low tide. Recorded waves in Academy Bay of Puerto Ayora (Santa Cruz Island) ranged at about 35 cm in amplitude and boats sat on the rocky bottom at around 07:30 (local time). Initial periods were less than 60 minutes but later were shorter - possibly because of the port’s configuration. The water level fluctuations lasted for about 48 hours. Along the coast of Ecuador the tsunami wave amplitudes ranged between 20 and 70 cm the periods were longer but shorter in the Galapagos Islands. Based on initial sea level changes and the issuance of a tsunami warning at Puerto Ayora on Santa Cruz Island, there was evacuation of coastal inhabitants to safer, higher grounds.