Wave pounding is the '

sledge hammer A sledgehammer is a tool with a large, flat, often metal head, attached to a long handle. The long handle combined with a heavy head allows the sledgehammer to gather momentum during a swing and apply a large force compared to hammers designed t ...

' effect of tonnes of

water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...

crashing against

cliffs In geography and geology, a cliff is an area of rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by the processes of weathering and erosion, with the effect of gravity. Cliffs are common on co ...

. It shakes and weakens the rocks leaving them open to attack from

hydraulic action Hydraulic action, most generally, is the ability of moving water (flowing or waves) to dislodge and transport rock particles. This includes a number of specific erosional processes, including abrasion, at facilitated erosion, such as ''static eros ...

and abrasion. Eroded material gets carried away by the

wave In physics, mathematics, and related fields, a wave is a propagating dynamic disturbance (change from equilibrium) of one or more quantities. Waves can be periodic, in which case those quantities oscillate repeatedly about an equilibrium (re ...

. Wave pounding is particularly fierce in a

storm A storm is any disturbed state of the natural environment or the atmosphere of an astronomical body. It may be marked by significant disruptions to normal conditions such as strong wind, tornadoes, hail, thunder and lightning (a thunderstorm), ...

, where the waves are exceptionally large, and have a lot of

energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of hea ...

. It is an important engineering consideration in the construction of structures such as seawalls and dams. Wave pounding is a force of erosion along coast lines. The effects of wave pounding are influenced by wave shape,

ocean chemistry Marine chemistry, also known as ocean chemistry or chemical oceanography, is influenced by plate tectonics and seafloor spreading, turbidity currents, sediments, pH levels, atmospheric constituents, metamorphic activity, and ecology. The fie ...

, rock type, and morphology of the coastal landscape. There are three different types of waves to consider in this process: spilling, plunging, and surging waves. Spilling waves have the least amount of energy associated with them due to their shallow ocean floor. Plunging and surging waves contain the energy associated with wave pounding. Plunging and surging waves occur on moderate to steep angled beach plains. Along with energy, the water chemistry will also affect the rock exposed to the erosion. Salt, calcium, and acid levels in the ocean have adverse effects on specific rock types. The chemical weathering due to wave processes is part of why wave pounding is so damaging. Wave pounding is not primarily caused by tectonic margins. Wave pounding will occur any place around the world as long as the angle of the beach plain is steep enough to generate the plunging and surging waves. The action of wave pounding is the kinetic energy delivered by waves fracturing or removing rock and or sand from land sea margins. Any solid material not fully removed by this action will be hydraulically fractured as well. The surging water fills the existing cracks and physically wedges the rock apart. One specific rock is particularly susceptible to the hydraulic action. Chert rock, or any other rock which has fractured and has had siliceous material fill in the cracks, seems to be very weak to wave action. The water can get into the bubbles and voids in the quartz fracture lines. Some beaches in northern California have broken cliff side with these same fracture patterns on the break line. Some shorelines with wave pounding have large sand deposits and loosely consolidated sand cliffs. Waves in these areas can be extra damaging due to the suspended sand material in the water. These sand cliff faces do not fracture in the same way that solid rock will. Examples on the northern California coast line suggest that the water erodes the weakest veins of sand on the cliff face. This effectively carves out notches and weak points of the cliff leaving a large scale of sandstone ready to fall. A sandy cliff with wave pounding action present will appear as a large sand cliff with deep grooves carved laterally and slumped scales of sand mounding on the bottom edge of the cliff. Wave pounding can be a seasonal event or even a daily event depending on the beach. Specific beaches around the world have seasonal changes in the beach angle due to long shore sand drift patterns. These phenomena will affect the strength that a wave will hit the cliff face. The rise and fall of tides also can mean the difference between a wave spilling onto the beach surface rather than into the cliff face. Wave pounding will affect most jetties and man made outcrops as well. The title of the wave will be different due to the depth of the water at the specific location. The waves do possess the power to damage or move stone on jetties. The steep edges of the jetties allow the waves to crash onto the rock.

References

* {{DEFAULTSORT:Wave Pounding Geological processes