Somes Sound: Fjord or Fjard?
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The coordinates for this cache will bring you to a pull-off along the road where you will have a great view from the inland end of Somes Sound. The alternate waypoint will bring you to another pull-off along the road with an even better view, but with less space to pull off the road (suitable for cars, but not for campers, etc.).
Your goal will be to hypothesize whether Somes Sound is a fjord or a fjard. Whichever one it is, it is quite unique ... it is the only such geological feature on the eastern coast of the United States!
Description of Somes Sound
Somes Sound is a five-mile long embayment bordered by Norumbega Mountain to the east, and Acadia and St. Sauveur Mountains to the west. At its deepest point, the sound is slighter deeper than 40 m, and in several places it is between 30 and 40 m deep. The entrance to the sound, called "The Narrows," is 10-20 m deep and is bordered by boulder-strewn bluffs to either side.
Geological History of Somes Sound
Repeated glaciations during the past two million years have eroded and deepened Somes Sound more than the adjacent mountains. About 14,000 years ago, the edge of the melting glaciers stood at the mouth of Somes Sound, and the other ponds of Mt. Desert Island, long enough to build a morainal deposit of boulders, sand and mud up to 10 m high in The Narrows. Because of the enormous weight of the glacier, the crust of Maine was depressed under their load, and ocean water flooded Somes Sound after the ice retreated. Once the great ice sheet had melted, the land rebounded to its "normal" elevation, and the sound became a lake. By about 7,000 years ago, the ocean had risen to the elevation of the moraine in The Narrows and eroded shorelines into it. The ocean kept rising and eventually topped the moraines and the lake became marine.
Description of "Fjord"
A fjord, also spelled fiord is a long narrow arm of the sea, commonly extending far inland, that results from marine inundation of a glaciated valley. The great depth of these submerged valleys, extending thousands of feet below sea level, is compatible only with a glacial origin. It is assumed that the enormous, thick glaciers that formed in these valleys were so heavy that they could erode the bottom of the valley far below sea level before they floated in the ocean water. After the glaciers melted, the waters of the sea invaded the valleys. Fjords commonly are deeper in their middle and upper reaches than at the seaward end. This results from the greater erosive power of the glaciers closer to their source, where they are moving most actively and vigorously.
Description of "Fjard"
A fjard is a rocky inlet of the sea, usually found along relatively low-lying coasts. Formed by the submergence of a glacial valley, fjärds are characteristically more irregularly shaped than the fjords. Like fjords, they may be quite deep and may have thresholds at their mouths. Fjärds are often connected by mazes of channels but are not typically river-fed estuaries.
References
Maine Geological Survey: Somes Sound, Mount Desert Island, Maine {http://www.maine.gov/doc/nrimc/mgs/explore/marine/sites/nov98.htm}
Encyclopaedia Britannica Online {http://www.britannica.com}
Logging Requirement
Earthcaches are placed in order to give people an educational experience. For this earthcache, you must complete the following in an e-mail to me (not to be included as part of your log). After having read the description of Somes Sound above and the descriptions of fjord and fjard, you are to hypothesize whether Somes Sound is a fjord or a fjard. From the coordinates of this earthcache, you have a good view of Somes Sound. Use what you have learned and what you can observe from the earthcache coordinates to explain why you think that Somes Sound is either a fjord or a fjard. I am looking for connections between what you observe and what you have learned from the write-up of this earthcache. Please reference specifics that you observe from the earthcache coordinates and how they connect to your thinking about whether it is a fjord or a fjard. Please DO NOT post any photos of the view with your logs.
Thanks for visiting this earthcache, and I hope that you now enjoy and understand this unique area even more!
Additional Hints
(No hints available.)