Gathering information for the Earthcache requires walking approximately 100 yards on soft sand. Street parking is readily available, except on sunny summer weekends, when parking may be sparse. Access the beach from the parking coordinates for the shortest distance to the jetty.
Requirements to claim this Earthcache
Do not email me the information, instead put your answers in your log to help document the beach and wave conditions at the South Jetty.
Include in your log:
- How many people in your group?
- The date and time of your observations.
- Measure the distance in feet from the posted coordinates to the wet sand on the upcoast side of the jetty, the side toward Santa Barbara.
- Measure the distance in feet from the posted coordinates to the wet sand on the down-coast side of the jetty; on the Oxnard side.
- Walk 150 feet down-coast from the jetty.
- What is the approximate height of the waves? Are they breaking away from the jetty or toward the jetty?
- Throw a piece of wood into the water and watch it for one minute. Which direction does it travel and how far?
- EXTRA CREDIT: Repeat the two observations 150 feet upcoast from the jetty.
The South Beach Jetty in Ventura Harbor is unique. There are eight beach jetties in Ventura County. Seven are designed to slow the down-coast sand movement created by littoral drift. Littoral drift is the term used for transporting non-cohesive sediments, i.e. mainly sand, along the foreshore and the shoreface due to the action of the breaking waves and the longshore current. The littoral drift is also called the longshore transport or the littoral transport. In Ventura, and most of Southern California, this sand movement is down-coast, from north to south as the predominant western swell hits the beach. This is especially prominent in Ventura, where the beaches face southwest. One can see evidence of the effect of the jetties by observing that more sand accumulates on the upcoast side of most of the jetties.
However, when storms to the south create southerly swells, which temporarily reverse the direction of the littoral drift.
The Army Corps of Engineers constructed the South Beach Jetty in 1994 to reduce the amount of sand migrating into the mouth of Ventura Harbor during the southern swell events. This is especially important because the Santa Clara River, a major source of sand, discharges about three-fourths of a mile south of the Harbor entrance. Over time, more sand has accumulated on the downcoast side of the jetty. Let's measure the distance and make your observations about today's conditions.
Ref:
Coastal Wiki: Littoral Drift
Coastal Commission: Staff Report CD-168-97