Upper shoreface

Upper shoreface

Upper Shoreface refers to the portion of the seafloor that is shallow enough to be agitated by everyday wave action (wave base).

Overview

Water is moved in a circular motion when a wave passes. The radius of the circle of motion for any given water molecule decreases with depth. The maximum depth of influence of a water wave is half the wavelength. Below that depth the water remains stationary as the wave passes. For instance, in a pool of water 1 foot deep, a wave with a 2-foot wavelength would barely be moving the water at the bottom. In the same pool, a wave with a wavelength of 1 foot would not be able to cause water movement on the bottom.

The continuous agitation of the sea floor in the upper shoreface environment results in sediments that are winnowed of the smallest grains, leaving only those grains heavy enough that the water cannot keep them suspended.


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • Lower shoreface — refers to the portion of the seafloor that lies below everyday wave base (see also upper shoreface). In this portion of the coastal environment, only the larger waves produced during storms have the power to agitate the sea bottom. Between storms …   Wikipedia

  • Shoal — Bar (landform) redirects here. For other uses, see Bar (disambiguation)#Landforms. Sandbank redirects here. For other uses, see Sandbank (disambiguation). For other uses, see Shoal (disambiguation). Sandbar between St. Agnes and Gugh on the Isles …   Wikipedia

  • Geologic modelling — is the applied science of creating computerized representations of portions of the Earth s crust, especially oil and gas fields and groundwater aquifers. In the oil and gas industry, realistic geologic models are required as input to reservoir… …   Wikipedia

  • Oseberg oil field — Oseberg …   Wikipedia

  • Milk River Formation — Stratigraphic range: Upper Cretaceous …   Wikipedia

  • Carolina Bay — Carolina bays are elliptical depressions concentrated along the Atlantic seaboard within coastal Delaware, Maryland, New Jersey, North Carolina, South Carolina, Virginia, Georgia, and northcentral Florida (Prouty 1952, Kaczorowski 1977). In… …   Wikipedia

  • Henry W. Posamentier — Henry William Posamentier (born December 4, 1948) is an American geologist. He helped pioneer and develop the modern approach to sequence stratigraphy, blending the disciplines of sedimentology, stratigraphy, and depositional systems analysis,… …   Wikipedia

  • beach — beachless, adj. /beech/, n. 1. an expanse of sand or pebbles along a shore. 2. the part of the shore of an ocean, sea, large river, lake, etc., washed by the tide or waves. 3. the area adjacent to a seashore: We re vacationing at the beach. v.t.… …   Universalium

  • Beach — /beech/, n. 1. Moses Yale, 1800 68, U.S. newspaper publisher. 2. Rex Ellingwood /el ing wood /, 1877 1949, U.S. novelist and short story writer. * * * I Sediments that accumulate along sea or lake shores. One type of beach occurs as a sediment… …   Universalium

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”