View source for Earth:Surf zone

{{Short description|Nearshore zone where wave water comes onto the shore}}
As ocean surface waves approach [[Earth:Shore|shore]], they [[Physics:Wave shoaling|get taller]] and break, forming the [[Earth:Sea foam|foamy]], bubbly surface called ''surf''. The region of [[Physics:Breaking wave|breaking wave]]s defines the '''surf zone''', or '''breaker zone'''. After breaking in the surf zone, the waves (now reduced in height) continue to move in, and they run up onto the sloping front of the [[Earth:Beach|beach]], forming an uprush of water called [[Earth:Swash|swash]].  The water then runs back again as [[Earth:Swash#Backwash current|backwash]]. The nearshore zone where wave water comes onto the beach is the surf zone. The water in the surf zone is shallow, usually between {{cvt|5 and 10|m|ft}} deep; this causes the waves to be unstable.

==Animal life==
The animals that often are found living in the surf zone are crabs, clams, and snails. Surf clams and [[Biology:Mole crabs|mole crabs]] are two species that stand out as inhabitants of the surf zone. Both of these animals are very fast burrowers. The surf clam, also known as the variable coquina, is a filter feeder that uses its gills to filter microalgae, tiny [[Earth:Zooplankton|zooplankton]], and small particulates out of seawater. The mole crab is a suspension feeder that eats by capturing zooplankton with its antennae. All of these creatures burrow down into the sand to escape from being pulled into the ocean from the tides and waves. They also burrow themselves in the sand to protect themselves from predators. The surf zone is full of nutrients, oxygen, and sunlight which leaves the zone very productive with animal life.

==Rip currents==

{{main|Earth:Rip current}}

[[File:Rip Current.jpg|thumb|Rip current in the ocean. Rip currents are often very difficult to spot with one's bare eyes, take caution in any body of water]]

The surf zone can contain dangerous rip currents: strong local currents which flow offshore and pose a threat to swimmers. Rip-current outlooks use the following set of qualifications:
# ''Low-risk rip currents'': Wind and/or wave conditions are not expected to support the development of rip currents; however, rip currents can sometimes occur, especially in the vicinity of jetties and [[Engineering:Pier|pier]]s. Know how to swim and heed the advice of lifeguards.
# ''Moderate-risk rip currents'': Wind and/or wave conditions support stronger or more frequent rip currents. Only experienced surf swimmers should enter the water.
# ''High-risk rip currents'': Wind and/or wave conditions support dangerous rip currents. Rip currents are life-threatening to anyone entering the surf.

==See also==
* [[Earth:Intertidal zone|Intertidal zone]]
* [[Earth:Littoral zone|Littoral zone]]
* Surf fishing

==References==
* Pinet, Paul R (2008) ''Invitation to Oceanography'', Chapter 11: The Dynamic Shoreline. Edition 5 revised. Jones & Bartlett Learning, {{ISBN|0-7637-5993-7}}
* "Breaker Zone." ''The Free Dictionary''. Farlex Inc, 2012. Web. 18 Apr. 2012. <http://www.thefreedictionary.com/breaker+zone>.

==External links==
* ''MetEd''  (2012) [http://www.meted.ucar.edu/marine/ripcurrents/NSF Rip currents: Nearshore fundamentals] University Corporation for Atmospheric Research. Retrieved 17 April 2012.

{{coastal geography|state=expand}}
{{physical oceanography|expanded=none}}

{{DEFAULTSORT:Surf zone}}
[[Category:Coastal geography]]
[[Category:Physical oceanography]]
[[Category:Oceanographical terminology]]

{{Sourceattribution|Surf zone}}