Quantcast Historical Analyses (cont.)

Custom Search
 
  
 
Solana Beach Coastal Preservation Association
August 20, 1998
Project No. 1831
Page 31
methods and provide a useful baseline for evaluating coastal erosion during the last 30 to
40 years (County of San Diego, 1960, 1975, 1985).
Even comparison of contemporary maps is subject to error, especially when the maps are
produced only a few years apart. In general, successive high-resolution photographs
showing readily-identified coastal features provide the best record of progressive shoreline
change.
A review of aerial photographs flown since 1928, as well as oblique aerial and land
photographs of the Solana Beach coastline area dating back to 1954, indicates a general
lack of observable marine erosion prior to the January 1978 storms, with subsequent
erosion occurring in discreet events in response to major storms.
Although photographic evidence of marine erosion was apparent as early as 1978, no
quantifiable amounts could be discerned from the available aerial photographs. The first
obvious recognizable amount of marine erosion occurred during the 1982-83 storm
season, where numerous sea caves and notches developed, with upwards of 6 to 8 feet of
marine erosion locally scouring into the base of the seacliff, and possibly upwards of 1 to 2
feet of marine erosion occurring along the remaining portions of the Solana Beach
coastline.
The 1982-83 storms also completely removed the nearshore beach sands from the shore
platform for a period of time, exposing the nearshore shingle deposits and enabling storm
waves to break directly on the base of the sea cliff, contributing to both sea cave and notch
development.
The 1997-98 El Nio storm season caused extensive additional retreat of the sea cliff
throughout most of the study area, where significant sea caves and notches developed and
subsequently collapsed, resulting in upwards of 15 feet of sea cliff retreat, significantly
undermining the upper sloping terrace deposits and locally developing significant
additional caves and notches, some of which have been infilled under recent emergency
permits and some remain to this day.



 


Privacy Statement - Copyright Information. - Contact Us

Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business