As part of the environmental assessment of the proposed Gravina Access Project, scientists have started looking at the sea floor of the Tongass Narrows.
On May 7, workers began taking core samples from the ocean floor on the east side of Pennock Island. Samples were in the area of one of the proposed bridge options that would link Revilla Island with Pennock Island, eventually extending to Gravina Island.
Shannon & Wilson, a geoscience consulting firm from Anchorage, also is scheduled to take core samples near other bridge options. The samples are crucial in deciding where to place a bridge across the narrows, said Mark Dalton, a consultant with HDR Alaska.
The state Department of Transportation is developing the federally required draft environmental impact statement for the project. DOT is considering five bridge options and three ferry routes.
Most of the bridge discussion has centered on a low bridge from Revilla to Pennock, with a high bridge extending to Gravina. The high bridge would offer clearance for vessels that transit the Tongass Narrows.