 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.
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Diagram Showing a Spit
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Diagram Showing Longshore Drift
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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.
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- 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.
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Congratulations to
HavelTrio for their First FTF WAY TO
GO!
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