This Earth Cache is intended to teach you about the geology and natural geography of New York Harbor while taking you on a self-guided boat tour of the harbor! That’s right, find a boat and get on it! Unlike many American Harbors, NY’s is still bustling, filled with commuter ferries and recreational boats, along with cargo ships and all other types of sea going vessels. To reach the posted coordinates you can board any ferry or boat you want, but I recommend the Staten Island Ferry, it is Free and runs 24/7 every 10 to 30 mins. While you are on your voyage, use the waypoints to point out the features you are looking at and when you are out in the Harbor look for the answers to claim your find. You do not need to visit any of the way points, only the posted coordinate, the way points are to help point out the different items listed below while you tour the harbor from your boat.
Questions:
1- While out on the water, what color is the water when you look directly down into it, opposed to when you look at the water from a distance! What do you think is the reason for the difference in colors?
2- From the center of the harbor what is the tallest natural land formation you can see? (height above sea level, remember items far away may seem shorter than they really are)
3- Many modern Cities have a problem with smog but not NYC. What geological attribute can you see from the harbor that might help NYC stay smog free?
4- (Optional) Please post some photos from your voyage!
5- (Optional) Please post: What time of day did you attempt this cache? What boat are you on?
New York Harbor is one of the largest Natural Harbors in the world and the busiest harbor on the East Coast. Approximately 25 square miles and with a natural depth of 17 feet. Today the average depth is dredged and maintained to be deeper than 50 feet to allow the passage of the new Post-Panamax ships.
Upper New York Harbor (posted coordinates) is between the Narrows and Manhattan, and Lower New York Harbor is South-east of the Narrows extending out as far as Coney Island, Broohlyn and Sandy Hook, NJ.
Manhattan Island is surprisingly small, only about 22 square miles. From your water view most of Downtown Manhattan is built on landfill. All of Battery Park City, Bowling Green and everything south of Pearl St is landfill.
Bedrock is underlying most of Manhattan, known as Manhattan Schist. It is a Strong Competent metamorphic rock created when Pangea formed. It is this rock that made a great foundation for early tall buildings and todays skyscrapers. Today Manhattan seems to be a tall crystal formation shooting straight out of the water to a height up to 1,792' above sea level.
Brooklyn on Long Island, Geographically speaking Brooklyn is part of Long Island. This island consists of two glacial moraines, the North Shore and the South Shore. These moraines consist of gravel and loose rock left behind during the last push of the Wisconsin glacier.
Your view of Long Island from the Harbor is of the North Shore; this shore tends to be rockier with hills and drops at the water's edge. The South Shore has more flat lands and sand out-washes. Long Island was the most southern reach of the Wisconsin Glacier, the south half of the island was the small debris being pushed in front of it and the North Shore was larger debris stuck in the Ice
Staten Island is mostly a huge serpentine stratum, formed by colliding plate tectonics during the Paleozoic Era. This collision is what formed the center of the island raising it almost 400 feet above sea level making it the highest natural formation of the eastern seaboard south of Maine.
This Island’s West shore is also connected to the Palisades Sill running along the Hudson River and the West shore is part of the moraines of Long Island.
Bergen Neck, New Jersey is the peninsula to the west of the harbor. Newark Bay is on the other side. The towns of Bayonne and Jersey City both sit on this peninsula. This peninsula is the lowest to sea level section of the Palisades Sill. During the Triassic Period, the earth crust saw large rifts or cracks that would fill with magma and cool. After millions of yeas the overlying rock would erode away exposing the Sill, made of igneous diabase. So as Newark Bay and New York harbor eroded into bodies of water, Bergen Neck, made of a harder igneous rock became New Jersey as we know it today.
If you look past the flat-lands of northern New Jersey you can see the Appalachian Mountains in the far background. With no natural structures nearby taller than the skyscrapers of Manhattan, winds freely flow though the Harbor and City on a daily basis.
Ellis Island and Bedloe’s Island, These two islands were part of a series of smaller tidal flat Islands that once hosted vast oyster banks. Many of these original islands where submerged during high tides.
Ellis Island originally was about 3 acres, but today the island is mostly man-made and over 28 acres. In 1890 server natural islands where combined with landfill to form the rectangular Ellis Island we know now. Incoming ships were told to dump their ballast on the island and the construction debris from the drilling of the NYC subway system was shipped there to fill in the island. The immigration Inspection station opened in 1892.
Liberty Island or Bedloe’s Island or The Great Oyster Island is also much larger today due to landfill. The island was filled in and buildup to make the private estate of the Bedlow family. Later the 11-point Fort Wood was built in preparation for the War of 1812, this fort was then chosen to be the pedestal for the Stature of Liberty that was officially opened in 1886.
Governors Island is a 172-acre Island just south of Manhattan Island. Before Europeans arrived this island was called the nut island, for its Hickory, Oak and Chestnut trees. Originally only 69 acres the southern 2/3 of the island is landfill added in the early 1900s.
Lower Hudson River is sometimes mistaken as one of the biggest rivers in the United States, but from New York Harbor up to Troy NY, it is actually a tidal estuary. This means the water is a mixture of salt water and fresh water changing depending on the Tides of the Ocean. Only a small section of the “Hudson River” is actually a fresh water river.
The floor of both Upper and Lower NY Harbors are the result of erosion from the Hudson River. Over 10,000 years ago before the last Ice Age the Hudson River eroded the Hudson Canyon that passes through today's harbor and all the way out to the continental shelf, over 100 miles out past todays NY Harbor. This Massive Canyon now lies completely under water.
The Narrows were most likely formed about 6,000 years ago at the end of the last ice age. Previously, Staten Island and Long Island were connected, preventing the Hudson River from flowing out into the Ocean. A buildup of water in the Upper New York Bay eventually allowed the Hudson River to break through the land mass that was connecting Staten Island and Brooklyn to form The Narrows.
The East River is another NYC river that is not a river, it is a saltwater tidal straight. It separates Long Island, including Brooklyn and Queens from Manhattan. The tidal strait changes the direction of water flow frequently.
Buttermilk Channel is a small tidal straight, approximately 1 mile long separating Governors Island from Brooklyn.
The Kill Van Kull is a tidal straight between Staten Island, NY and Bayonne, NJ and connects Newark Bay with Upper New York Harbor. Here the water flows over the Palisades Sill as it goes underground under Staten Island. The Kill Van Kull is the most heavily traveled waterway in NY Harbor.
The Robbins Reef Light Station marks the beginning of the Kill Van Kull. It was operational until the early 2000’s
The Robbin Reef Sewer Outfall Tower , that is not a fort next to the Light house but instead a sewer discharge from New Jersey. During heavy rain when the sewerage system in NJ was at capacity, sewerage once poured out into the harbor from this tower. This Sewer Outfall is now shut off and abandoned.
The Water Pollution is cleaner today than at any time in the last 100 years. This has led to increased recreational opportunities such as kayaking, swimming and fishing. The New York City Department of Environmental Protection operates 14 sewage treatment plants that together treat around 1.3 billion gallons of sewage each day, and a fleet of boats that are used to monitor the waters and the shoreline for water quality and sources of pollution.
In Conclusion: even though New York Harbor might be one of the Largest Natural Harbors in the world, humans have changed almost every part of it. From the landfill islands to the water depth, tall buildings and the water quality, you have to look very hard to see what is still natural.