Modeling and Monitoring Submerged Prehistoric Sites during Offshore Sand Dredging and Implications for the Study of Early Holocene Coastal Occupation of Southern California

Track lines plots for sub bottom profiling data are represented by files with names:

TracklineDATE.pdf  where DATE is either 1999 or 2008.

These files use a Lambert Conformal Conic projection with the North American Datum 1983, California Zone 6 in feet.  The location of individual seismic lines are designated with a number at the beginning of the line, and distance along the track is designated in meters by the location of the CMP (common-mid-point) stack of the seismic data.  

Seismic data files are represented by files with names:

SITE_LINE#-DATE.pdf where SITE refers to the survey area, LINE# is the line number within that area, DATE is either 1999 or 2008. Files from 1999 are scans from the original graphic recorder output with no additional processing. They show the 3.5 kHz chirp sonar record on top and the Geopulse record on the bottom. The locations of vibracores are shown as annotations (blue triangles with core number). The vertical depth is given at 5 m increments. Files from 2008 were digitally recorded, and are the result of stacking and FK migration using a 24 channel streamer, as described in the methods section. Distance along track is given in m, and depth is given as time (ms) which can be nominally converted to depth using a two-way travel time and assumption of ~1500 m/s (0.75 m/ms), so that major time marks (10 ms) give 7.5 m depth increments. 

Vibracore Logs are represented by files with names:

VibracoreDATE.pdf where DATE is the year of the data collection. These plots give the sediment classification as a function of depth within each core.  Locations of grain size measurements are indicated at the appropriate depth. For the 2008 cores, field photographs are included at the end of the files.

GrainSize1999.pdf gives grain size distribution plots for samples obtained from cores collected in 1999. 

Funding provided by: San Diego Association of Governments*
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