SURFICIAL AND SUB-SURFACE GEOLOGY OF A SMALL URBANIZED EMBAYMENT- SAVIN HILL COVE, BOSTON MA (PRE DREDGING)

Savin Hill Cove is dynamic anthropogenicly modified indentation along the Boston shoreline trending east-southeast. The Cove contains large fringing mudflats on the southwestern and western margins. The northeastern margin is armored and the southeastern-facing mouth is guarded by extensive mussel beds that uncover at low tide. The Cove serves as a source of cool seawater to supply the University of Massachusetts' cooling system and houses its many vessel and marine facilities. A navigation channel, used by both the University and Savin Hill Yacht Club, is located midway between the mouth and the landward margin. Due to sediment accumulation, the University's new research vessel can not transit the channel at spring low tides. A dredge project is scheduled to begin on December 15th 2006 to increase the depth of the channel and remove sediment from the cooling system intake. Previous studies by the Massachusetts Water Resources Authority during the 1990's have shown that there was an accumulation rate of about 10cm/yr in portions of the cove.

During the months of October and November a pre-dredge survey using a CHIRP subbottom system revealed the presence of modern channels, paleo-channels, mussel bars, and gas charged sediments. Future work prior to dredging will include a complete sidescan sonar mosaic and sediment sampling. With the combined data, we will determine the following: 1) currently active depocenters within the Cove; 2) the sediment source; 3) whether the mudflat is accreting vertically, bypassing or prograing; and 4) how the dredge has modified this pattern.