Spencer Spit EarthCache

Spencer Spit located on Lopez Island at the State Park. We decided to place this while our son was completing the park's Junior Ranger Program; we wanted to share what we learned about this beautiful area. To log this earthcache you must visit the coordinates and email the cache owner a photo and the answer to the following question:

According to the information boards, will Spencer Spit become a tombolo and Why or When?

The information on this cache page and the informative boards located at the neck and the head of the spit will help you answer the question. To Protect the natural environment: Visitors are strongly encouraged to use the established trail, please do not disturb the cabin at the end of the spit, and remove only garbage from the cache site. Enjoy!

A spit is a deposition landform. Deposition is the geological process where material is added to a landform. In this process, wind and water create a sediment deposit through the laying down of granular material that has been eroded and transported from another geographical location. Deposition occurs when the forces responsible for sediment transportation are no longer sufficient to carry the particle weight.

Spits are formed by the movement of sediment (typically sand) along a shore by a process known as longshore drift. In geography, longshore drift (shore drift or littoral drift) is a process by which sediments move along a beach shore. It occurs when waves striking the shore at an angle as opposed to straight on cause the wave swash to move up the beach at an angle. The swash moves the sediment particles up the beach at this angle, while the backwash brings them (solely under the influence of gravity) directly down the beach. This has the net effect of gradual movement of the particles along the shore. Since the water molecules are among the particles moved in the process, there is a net movement of water as well. This establishes a longshore current. In the area where the direction of the shore turns inland, the longshore current spreads out or dissipates. Then, no longer able to carry the full load, much of the sediment is dropped. This causes a bar to build out from the shore, eventually becoming a spit.

If the supply of sediment is interrupted, the sand at the neck (landward side) of the spit may be moved towards the head, eventually creating an island. If the supply isn't interrupted, and the spit isn't breached by the sea, the spit may become a bar, with both ends joined to land, and a lagoon behind the bar. If an island lies offshore near where the coast changes direction, and the spit continues to grow until it connects the island to the mainland, then it is then called a tombolo.

Longshore drift is one of the principal processes in the construction of spits, bars and tombolos, and in the overall sustainability of beach deposits. Longshore currents and longshore drift are generally considered to be constructive processes. Unlike storm waves, they are not normally regarded as significant in coastal erosion, though the sedimentary particles have to come from somewhere. They are the continuing processes that nourish the beach and carry sand along the shore or a barrier spit to deposit it at the end of the spit so that the spit grows in length and size.

Diagram Showing a Spit

Diagram Showing Longshore Drift

Works Cited

1. Spit (landform) http://www.answers.com/topic/spit-landform

2. Longshore drift: http://www.answers.com/topic/longshore-drift

3. Deposition http://en.wikipedia.org/wiki/Deposition_%28sediment%29

The following notice is required on all geocaches placed within Washington State Parks. The geocache may be placed on Washington State Parks and Recreation Commission managed property only by written permission from the Washington State Parks and Recreation Commission. The following items shall not be placed in the geocache: Food items; illegal substances; medications; personal hygiene products, pornographic materials; inappropriate, offensive, or hazardous materials or weapons of any type. Log books are required for each cache and are to be provided by the owner of the cache. It is the visitor’s responsibility to orient themselves with policies and rules pertaining to State Parks areas. Report any incident, problem, or violation to State Parks staff.

" align="center">Congratulations to HavelTrio for their First FTF  WAY TO GO!