Tsunamis and the Galapagos Islands

A powerful 8.2 magnitude earthquake rocked northern Chile earlier this week, causing at least six deaths and a two-metre high tsunami that swept portions of the coast. In anticipation of further waves, the Pacific Tsunami Warning Centre issued warnings for Chile, Peru, Colombia, Panama and Ecuador, the last of which the Galapagos Islands belong to. All warnings, watches and alerts for Ecuador were fortunately lifted later, but this raises the question: What are the impacts of tsunamis on the Galapagos Islands?

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It may not be often remarked upon, but the Galapagos Islands are no strangers to natural disasters. Volcanic in origin and located near the conjunction of the Cocos and Nazca tectonic plates, the Archipelago witnesses eruptions and earthquakes to this day. It is also subjected to tsunamis, most recently in 2011 after the devastating Tohoku Earthquake in Japan. How well prepared are the Islands for these catastrophic events, especially for tsunamis, which can strike with deadly force thousands of kilometres from their source?

For the most part, the human impact is relatively minor. Thanks to efficient evacuation plans and disaster management, there have been no recorded fatalities from tsunamis in Galapagos’ history. In addition, damage to infrastructure on the Islands is generally not extensive; many affected businesses repairing and restarting operations quickly after the 2011 tsunami, where waves 1.77 metres in height coincided with a high tide to lash the shore.

Obviously, low-lying buildings were hit harder, including parts of the Charles Darwin Research Station (CDRS). The tsunami destroyed facilities, flooded workshops, laboratories and storage buildings while scattering equipment in a wide radius around the station. Highly buoyant scuba tanks were found scattered throughout the bay for weeks to come.

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Destroyed Pumphouse at the CDRS marine wet lab. Image (c)Volker Koch/GC

But what of the natural costs? The flora and fauna of the Galapagos Islands did suffer during the 2011 tsunami, though to varying extents. According to a rapid assessment carried out by the CDRS, wave height and penetration varied significantly between areas. Animals affected by the waves included the flightless cormorant (which suffered some nest destruction), sea turtles and marine iguanas. By all accounts the overall natural environment was not drastically disturbed, and critically endangered species, such as the mangrove finch, fortunately remained unharmed.

Still, it is too soon to say that the Galapagos Islands do not have much to fear from the sea. Despite escaping relatively unscathed from previous tsunamis, including Tuesday’s threat, this is no guarantee of future security. Geophysicist Mark Simons from the California Institute of Technology predicts that there will be an even larger earthquake to strike the region in the future, but nobody knows when that will be or the strength of the waves it may create. Eruptions can also generate tsunamis, and as an archipelago with active volcanoes, the threat of such waves is potentially very close to home.

As the human population continues to grow on the Islands, increasing competition and pressure upon the fragile ecosystem, there is also the heightened risk that the Galapagos as a whole will become more vulnerable to natural disasters. In this sense, this is but a reflection of a similar narrative that is playing out in the larger world. How we choose to manage our influence, and indeed our own responses to natural disasters, will play a progressively larger role in determining the impacts of such catastrophes on the environment – and us.

by Jose Hong