Wednesday, February 3, 2016

Cliff erosion slow but sure, now what?


San Francisco Chronicle/Peter Fimrite, 1/29/16. "Perilous cliffhangers of Pacifica tell a cautionary tale."

Image result for Pacifica's crumbling cliffs picture
There goes the sound of the waves,
and the magnificent view
Image result for Pacifica's crumbling cliffs picture
Last house standing
"The Pacifica cliffs have been crumbling for decades, but experts say the sea’s creep inland accelerated due to a combination of natural and man-made factors, including an increase in El Niño storms and a drastic decrease in sediment flowing out of San Francisco Bay.

....  “That area south of San Francisco is the most rapidly retreating stretch of coastline in California,” said Patrick Barnard, a coastal geologist for the U.S. Geological Survey. “Cliffs do erode and they only go in one direction, so that situation is not likely to improve.”

....  Exacerbating the problem, said Barnard, is the fact that dredging, dam construction and water diversions have vastly reduced the silt flowing out of the Golden Gate and into coastal waters, where it has historically been deposited on beaches."  Read article.

Related, video.  How severe and how much damage? , view YouTube/Dave Kent, 1/24/16, 5:00 minutes, "Cliffside erosion Palmetto Avenue Pacifica, CA drone photography." More videos follow.

Related, article/photographs (not all open). San Francisco Chronicle/SF Gate/Peter Fimrite, 2/3/16, "Pacific Ocean devours Pacifica cliffs in aerial photos over decades." "Pacifica declared a state of emergency Jan. 22 after rain and big surf pounded the base of the cliffs, causing a huge chunk of dirt to separate and fall onto the beach. Forty apartment residents were ordered out by city officials who judged their homes to be too close to the vertical face of the cliff. As The Chronicle reported Sunday, the Pacifica cliffs have been crumbling for decades, but experts say the sea's creep inland accelerated due to a combination of natural and man-made factors, including an increase in El Niño storms and a drastic decrease in sediment flowing out of San Francisco Bay." Archives, San Francisco Chronicle archives/Peter Fimrite/Pacifica's crumbling cliffs, 2016.  

Note photographs.  Apartment buildings by John Edelson/Associated Press/Getty images from Los Angeles Times, 2/1/16.  House from Daily Mail/Associated Press, UK, 1/25/16. 

Posted by Kathy Meeh

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