This is an Earthcache – as such, there is no physical cache.

Instead, you will partake in a geology lesson by making observations and answering 6 questions about the beach located on Hart-Miller Island.

Hart-Miller Island State Park can only be reached by a personal boat and is open from 8 a.m. until sunset (Only Registered Campers can be on the island after sunset) from May 1st - September 30th. The North Cell of the island is still a construction site and is off limits. TRAIL MAP LINK of the island. The western shore of the island offers safe mooring, wading, and access to a 3,000-foot sandy beach.

The closest public kayak launch point is at Rocky Point Beach and Park, which has entrance fees. You can visit this LINK to see this parks hours of operation and list of fees. It is approximately a two mile long paddle to Hart-Miller Island from Rocky Point State Park. The route is across open water with strong currents, no shelter from wind, and heavy boat traffic.

The Maryland Environmental Service offers boat shuttled field trips to the island for small organized groups. You can visit this LINK to find information on booking. These field trips are FREE and are usually 2 - 3 hours in length.

HART-MILLER ISLAND BEACH

On many warm weekends, large numbers of pleasure boats can be seen anchored off Hart-Miller Island. The island lets boaters anchor in waist-deep water protected from the waves and wind from the Chesapeake Bay. Here after many years of dredging, boaters and wildlife watchers come to “get away from it all” at this “hidden beach,” which is considered one of the most secluded places in Maryland.

A beach is a landform made of very small loose particles that gather at the shore of a body of water. These particles are typically made from rock, such as sand, gravel, pebbles, or shingles. About 31% of the world’s beaches are sandy. Sand comes from erosion of rocks both far away from and near the water. These rocks can be remnants of old mountains, eroded under water rock beds, or even coral reefs can be even source of sand.

The color of the sand particles can tell you more about how a particular beach is formed and the minerals of the rocks of which they are composed. Beaches along the Chesapeake Bay have sand colors that run from a deep orange to nearly white. It all depends on the minerals from the rocks which they came. For instance, a deep orange sand originates from rock that was high in iron, while a whiter sand is made up of many grains of quartz.

The size of the sand particles can give important clues to its sedimentary history. Imagine a mass movement of rock from a rockslide happening over a stream. All that sediment was grabbed at once and quickly relocated into one place below. The big stuff stays put for longer amounts of time, while overtime, as the sediments break down into smaller bits they move further down the stream are deposited elsewhere.

The more uniformed the size and coarseness of the sand, the closer it is to its source. The more diverse and fine the particle size of ther sand telling us that it has been moved very far from its source. There are many natural processes that can break down the size of sand particles, but most of these are controlled by the local speed of water flow.

The way these particles shape a beach depends on how waves or currents move its sand and other loose sediments. Waves can move material up the beach or down the beach. On sandy beaches, the waves move sand away from the beach and make gentle slopes. If the waves are not strong enough to move the sand, the beaches tend to be steeper. The stronger the wave, the more sediments get washed away from the shoreline, which in turn leaves the beach sand starved and eroded.

Approximately 4,579 miles of Maryland’s 6,659 miles of shoreline are eroding each year. Even a “growing” island like Hart-Miller hasn’t escaped the problem of erosion and rising sea levels. This beach, which is on the remnants of the original Hart and Miller Islands, once faced an erosion rate of 10 feet a year. Besides the loss of the islands beach shoreline, its migrating sands were washing away and being deposited into local navigational channels causing problems for boaters.

In the long run it was predicted to be costlier to continue to replenish the beach rather than stabilize it. In 1997 Maryland installed fifteen breakwaters at Hart-Miller Island. These breakwaters are 100 feet long, protrude about 2 to 3 feet above the water line, and were placed 150 feet offshore. These breakwaters now stabilize the beach by dissipating wave energy before it reaches the shore.

Breakwaters are structures, made of various materials, that are placed offshore to reflect or decrease wave energy. This creates a low energy zone between the structure and the existing beach. Decreasing a waves strength heading towards a shoreline significantly affects the transport of its sands. Sand moving along the shoreline may be slowed or just be deposited on the beach side of the breakwater.

LOGGING REQUIREMENTS:

To log this Earthcache: Read the geology lesson above. Answer all six questions posted below. Answers can be sent via e-mail or messenger contacts on my Geocaching profile within a reasonable time. Group answers are fine, but do not post the answers to the questions in your logs.

QUESTION 1. Grab a handful of sand. Does the color of the sand appear to be more quartz based, more iron based, or a good mixture of the two?

QUESTION 2. There are larger rocks mixed in with the beach sand here. Do these appear to be the same color as the beach sand?

QUESTION 3. Using the PRIMARY SAND PARTICAL SIZES chart in the write-up, how would you classify the size these sand particles?

QUESTION 4. Would you say that these particles are closer or further from their original source?

QUESTION 5. Before the Breakwaters were installed, what was annual erosion rate of the beach?

QUESTION 6. Look at the breakwaters. Besides slowing the movement of sand, do they appear to be depositing sand on the beach side of the break water (as pictured above)?

POST PHOTO IN YOUR LOG: Posting a photo in your log readily indicates that you (and anyone else logging the find) are at the location. You do not have to show your face, but the photo should be personalized by you or a personal item on Hart-Miller Island. NOTE: Per newly published Earthcache guidelines, this requirement is REQUIRED to claim the find.

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