Travel Reference
In-Depth Information
underwater, where he would almost certainly have been killed by those
intense compression waves.
Members of the crew soon discovered even more dramatic ef ects of the
earthquake. As they explored the coast by small boat they found that some
of the mussels, barnacles, and other animals that normally lived in the inter-
tidal zone along the shore were now rotting in the sun above the level of the
highest tide. In a period of minutes the earthquake had raised kilometers of
coastline more than two meters into the air.*
Darwin soon realized that this earthquake, violent as it was, must have
been only a small contributor to the much larger pattern of events that had
sculpted the geology of the entire western coast of South America.
Just inland from the Chilean coast the land slopes dramatically upward
towards the Andes, the second highest mountain range in the world. A month
after the earthquake, Darwin had the opportunity to traverse the mountains
through a high pass. At 4,000 meters he observed beds of marine sediments
that contained fossils of mollusk shells from species similar to those living
in the deep sea today. It was clear that these fossil beds, and indeed the entire
mountain range, had been lifted through the cumulative ef ect of many earth-
quakes, some of which had probably been far more violent than the one he had
experienced:
All the main valleys in the Cordillera are characterized by having, on both sides, a fringe or
terrace of shingle and sand, rudely stratifi ed, and generally of considerable thickness . . . No
one fact in the geology of South America, interested me more than these terraces of . . . shin-
gle. They precisely resemble in composition the matter which the torrents in each valley
would deposit, if they were checked in their course by any cause, such as entering a lake or
arm of the sea[.] . . . If this be so, and I cannot doubt it, the grand and broken chain of the
[Andean] Cordillera, instead of having been suddenly thrown up, as was till lately the univer-
sal, and still is the common opinion of geologists, has been slowly upheaved in mass, in the
same gradual manner as the coasts of the Atlantic and Pacifi c have risen within the recent
period.
* On February 27, 2010, a massive earthquake measuring 8.8 on the Richter Scale hit the
Chilean coast. It was centered near Darwin's earthquake of almost exactly 175 years earlier,
but the damage was far greater because Concepciòn is now Chile's second largest city. The
inexorable forces that are pushing the Andes upward continue to endanger people who live
along the Ring of Fire.
