San Diego lies directly on one of California’s most active
fault line. The Rose Canyon Fault Line is said to be San Diego’s largest threat
in terms of a large earthquake. If this were to occur thousands to millions of
people would lose their belongings, homes, and possibly their lives. This fault
line occurs from movement of two plates sliding and grinding past each other,
also know as a transform plate movement.
Image from: http://mvsdperiod4.wikispaces.com/Transform+Boundaries
The large amount of pressure that the two plates passing by
one another create is what causes broken ground. In addition, this pressure
along with heat from inside the Earth can create metamorphic rock. Over time
this metamorphic rock surfaces due to shifting plates.
Image from: http://dnowlan.ca/VM/science7/planetearth/rocks.htm
When the plates begin to shift, during an earthquake, the
movement of the sediments causes liquefaction, the process where the soil
begins to act as a liquid in response to a change in applied stress. This
liquefaction could also create problems for the people in the area because this
will cause their houses to sink.
Image from: http://cce.oregonstate.edu/geotech/research.html
The tectonic pressure and faulting cause San Diego counties
coastal mountains that occur around the San Andreas Fault system. The fault is
a right lateral strike slip fault, which causes the mountains. An example of
these transverse ranges would be the La Jolla canyon in San Diego County.
Image from:http://membercentral.aaas.org/multimedia/galleries/field-trip-san-diego-coastal-geology-and-hazards
Sources:
http://www.eeri.org/cds_publications/earthquake_basics_series/LIQ1.pdf
http://aese2006.geology-guy.com/sd_geology_marshall.htm
http://www.ce.washington.edu/~liquefaction/html/what/what1.html
Hi I am Chelsea Stewart and I found your blog interesting because I am from California and I had no idea that San Diego was located on one of the most active fault lines. I like how you describe the fault lines and that they create earthquakes which can destroy landscapes, but could also form mountains. I also like how you included pictures to illustrate what each process does and what is formed. When you state how the San Andreas Fault system creates mountains within San Diego I think it allows readers to visualize what can occur due to an extremely active fault line.
ReplyDeleteHello this is Rachel Dawkins speaking, I think that your blog was very well done. It was very nice to see that you incorporated the metamorphic rock type with the strike slip fault type. Also, I liked that you focused on more than one central concept. It was interesting to learn that San Diego is on a fault line because when many people thing of San Diego all they think about is the ocean and nice weather. By writing about the fault line it added to peoples general knowledge of the geography and how residents of the area can be greatly affected by the fault.
ReplyDeleteHi my name is Moses, and I find your blog very informative being that San Diego is my birth place. You made the information matter by mentioning its relevance to how the processes cause damage and loss to homeowners. Your description of the Rose canyon fault line along with the detailed photo made understanding alot easier. You made mention of metamorphic rock, the process of liquefication, and tetctonic pressures and faulting. Very informative blog.
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