WEIRd Jetty at Perdido Pass EarthCache
WEIRd Jetty at Perdido Pass
-
Difficulty:
-
-
Terrain:
-
Size: 
(other)
Please note Use of geocaching.com services is subject to the terms and conditions
in our disclaimer.
To log this EarthCache, please email answers to the following questions (no answers in your log, please):
- Approximately how much of the weir section, if any, was above the water when you visited?
- Based on what you know about this weir jetty, can you surmise which way the coastal current runs on this stretch of the beach?
- In the spirit of recycle/reuse, the building near the parking coordinates is made from what?
- Although optional, this is a terrific picture spot and we love to see photos of the views in your Found It log.
The technical definition of a jetty is: any of a variety of engineering structures connected with river, harbor, and coastal works designed to influence the current or tide or to protect a harbor or beach from waves. If you have spent any time around the water then you have probably seen one, or even walked out onto one.
Jetties are built along coastal waters for one main reason: to interrupt the normal movement of sediments along the coast caused by waves, currents and tides. That being said, the two main practical applications are meant to perform this task to opposite ends. Jetties built perpendicular to the coast (i.e., those piles of rocks that stick straight out into the surf from the beach) are meant to catch the sediment in order to retain or widen the beach. On the other hand, jetties built on either side of an inlet are meant to reduce the amount of sediment deposited in the channel that could hamper navigation. What you see before you are the two converging jetties built in 1969 to stabilize the natural inlet at Perdido Pass. These are the latter type of jetty - meant to keep the inlet from being clogged by sand and sediment.
The cache coordinates will take you to a spot that has a great view of the east jetty - the one on the far side of the inlet. You will notice that, depending on the height of the tide, the first 1000' of the jetty may be completely under water. This is by design. This is known as a Weir jetty (hence the cache name). The Weir section, which is typically less than 1000' long, is a depressed region of the jetty that permits waves and currents to carry sediments to a deposit zone located in the lee of the weir. In other words, it allows the sand and sediment to settle in a particular spot - in this case, the area just to the west side (the near side when looking from your perspective) of the weir section - rather than wherever it wants to.
Since the east and west jetties were built in 1968-1969, the inlet channel has stabilized nicely and only requires dredging every 2-3 years.
Please email your answers to the questions above - no answers in your log please!
Additional Hints
(No hints available.)
Treasures
You'll collect a digital Treasure from one of these collections when you find and log this geocache:
Loading Treasures