Thursday, October 6, 2011
In an Earthquake, the Ground Opens up and Swallows People: True or False? What everyone "knows" about earthquakes
In an earthquake, the ground opens up and swallows people: true or false?
I'm actually not sure how the crowd responded to this one at my lecture the other night, but they quickly appreciated my answer to the question:
True, but only in Hollywood....
does mention one instance where someone was killed in a fissure that opened up in a 1948 quake in Japan, but that hardly represents a pattern.
One other effect of large earthquakes is the production of slope failures and landslides, during which large fissures might open up. The Turnagain Heights liquefaction event during the Alaska earthquake of 1964 is a stunning example. Weak saturated sediments underneath the housing project were severely shaken, causing the whole landscape to break up and flow towards the adjacent bay, destroying the dwellings at the surface (I've included two pictures derived from my old slide collection, but I'm afraid I don't know who to attribute them to; I will add credit if someone can clue me in. They may be from a USGS collection).
famous tail/tale of Shafter's cow, which was swallowed up by the San Andreas fault. In the aftermath, only the poor bovine's tail could be seen at the surface. The story apparently became widespread, but in a letter from 1966, some locals recalled that the poor cow had actually died the night before. The earthquake produced a convenient fissure, the farmer tossed in the carcass, and when reporters showed up asking questions about the poor animal, farmer Shafter decided not to kill a "good story".