Previous work in Palm Beach County by Scientific Environmental Applications, Inc. (SEA) and others has shown the mixtures of quartz-rich terrigenous sand and fractions of carbonate form a graded texture of sand compatible with the beaches of Palm Beach County (Zarillo, 2010 and 2014).  Thus, the targeted ideal sand body to yield beach quality material is a mixture of inter-bedded, quartz sand and carbonate rich layers, which when composited in a beach fill, provides a larger mean and median grain size and sediment graded across coarse sand sizes.  In Phase I of the project (Zarillo, 2015), sub-bottom seismic reflection data was synthesized along with existing lithologic data to assess the potential for recovery of beach quality sand in the Juno area of North Palm Beach County waters.  Geotechnical data resources for Juno Beach Area A were assembled from geotechnical surveys conducted over the past 20 years by SEA (Zarillo, 1995, 1996, 2003, 2004, 2005, 2011, 2014 and 2015).  These data were combined with the sub-bottom survey data collected in June 2015.  The results of combining historical data with the seismic data are provided in the Phase I report and were drawn upon as necessary in this Phase II report.

In the Phase II analysis, additional cores were targeted in a refined borrow area identified in the Phase I work. Figure 1 outlines the borrow area and shows the locations of the additional 20 cores obtained in late February and early March  2016.  Collection sites of core borings were spaced among the existing distribution of historical cores to assure an inter-core spacing of 1000 feet or less. This report includes descriptions of the coring methods, analysis methods, and results with respect to lithology and volume of potential beach quality sand in the borrow area.

Data from sub-bottom acoustic profiles were combined with the sedimentology and sediment characteristics of existing cores to examine the potential beach quality sand within Florida State waters off north Palm Beach County. The core lithology previously described in Palm Beach County sand search studies of the Juno area has been re-interpreted for this project to clearly resolve the difference between the two main sediment types that define offshore sand resources. Graded shelly sand and well sorted finer grained sands are layered and inter-bedded within the Juno borrow area. Recognition of these two distinct types of lithology is applied to identify potential volumes of beach quality sand resources. Well graded shelly sands dominate the upper sediment units. Well sorted finer sands are more common in lower sediment units, whereas the shelly, size graded sands dominate the upper sediment layers. In some areas coarser shelly sands are inter-bedded with finer well sorted sand units.  Mixtures of these two sediment types are likely to provide beach quality sand having a broad size distribution having the ability to adjust to a natural beach profile.

Geotechnical software was used to visualize the stratigraphic relations among the sediment types.  In a series of three-dimensional models and panel diagrams, measured cross-sections are presented to characterize the arrangement of lithologic sediment types within the area. Also presented are volume data by sediment type and depth interval within the borrow area. The volume data are based on the 3D model data interpreted from approximately 50 core borings.

Interpretation of geophysical data indicates a continuous sub-bottom reflector in the borrow area corresponding to a transition between clean sand and silty sand or peat rich sediments.  In some areas the sub-bottom reflector correlates with a rock layer underlying unconsolidated sediments.

Based on the sub-bottom geophysical data in combination with lithologic data from existing cores an additional 20 core locations are recommended to define a borrow cut with in the overall Juno area. Once the 20 cores are acquired, this report will be updated to describe the borrow cut area at permit level detail using sediment textures, lithologic cross-sections in combination with sub-bottom and bathymetric data.

Lido Ostia is a popular beach resort and residential area to the west of  Rome, Italy and just to the south of the Tiber River Delta on the west coast of Italy. In recent years beach erosion has accelerated and threatened to impact the economy of this resort, which is a 20 minute train ride from the heart of Rome. Thus, local government and regional entities pooled resourced to complete a study to identify the optimal beach restoration and shore protection methods to return Lido Ostia to its full status as a beach resort.  Following a series of conceptual designs Coastal Modeling System (CMS) of the U.S. army Corps of Engineers was used to test alternatives.  The model computational grid for the Lido Ostia Project area consists of about 30,000 water cells varying in size from 30 meters to 10 meters on a side. Smaller cell sizes were required to resolve the shore protection structures in the model. Cells containing the structures were specified  as harbottom, non-erodible cells.  The topographic data in the model grid were set using  results of  a recent survey of the project area.  Forcing for the model was provided by a time series of measured directional wave data that were adjusted to shallow water topography present in the Lido Ostia area.  The directional wave data was input at three hour intervals and adjusted to a spectral spread of energy according to wave period.  The tides were represented at the boundary of the circulation model using 15cm semidiurnal (M2) tide amplitude.