126:
28:
114:
121:
Although symmetrical ripples are also called bi-directional ripples there is a difference between them. Bi-directional ripples are rarely symmetrical due to the difference in force of the two directions, where as the wave formed or oscillation ripples form from the circular water movement pattern of
148:
Ripples are relatively small, elongated ridges that form on bed surfaces perpendicular to current flow. With continuous current flow in one direction, asymmetrical ripples form. Asymmetrical ripples contain a steeper slope downstream. With an alternation in current flow from one direction to the
157:
Symmetrical ripples form as water molecules oscillate in small circles. A particle of water within a wave does not move with the wave but rather it moves in a small circle between the wave crest and wave trough. This movement of water molecules is the same for all water molecules effected by the
158:
wave. The water molecules continue to do this to a depth equal to 1/2 the wavelength. The water molecule traveling in a circular pattern interacts with the sediment on the floor and moves the sediment into symmetrical ripples. These ripples can be either
90:
and long relatively straight crests, which may commonly bifurcate. Commonly, these crests can be truncated by subsequent flows. Their wavelength (periodicity) depends on the sediment grain size, water depth and water-particle orbits in the waves. On
255:
Hampton, Monty A., Torresan, Michael E., and Barber, Jr., John H., 1997, Sea-floor geology of a part of Mamala Bay, Hawaii: Pacific
Science, v. 51, n. 1, p. 54-75. Reproduced by permission of the University of Hawaii
102:
While wave-formed ripples are traditionally described as symmetrical, asymmetric wave ripples are common in shallow waters along sandy shores. They are produced by bottom oscillations generated by passing
283:
Atlantic coast beaches : a guide to ripples, dunes, and other natural features of the seashore / William J. Neal, Orrin H. Pilkey, Joseph T. Kelley. Publisher
Missoula, Mont. : Mountain Press,
265:
Department of Earth
Science, Preston Cloud Research Laboratory, University of California, Santa Barbara, CA 93106, United States Precambrian Research; Nov2009, Vol. 174 Issue 3/4, p215-240, 26p
274:
Marshak, Stephen. "Chapter 7: A Surface Veneer: Sediments, Soils and
Sedimentary Rocks." Earth Portrait of a Planet. 3rd ed. New York: W.W Norton & company, 2008. 211. Print.
238:
Monroe, James S., and Reed
Wicander. The Changing Earth: Exploring Geology and Evolution, 2nd ed. Belmont: West Publishing Company, 1997.
243:
207:
122:
water molecules. These ripples form parallel to the shore line. They usually display rounded troughs and rounded crests.
99:
directions. Symmetrical ripples are commonly found in shallow waters. Beaches are a good place to find these ripples.
110:
Wave-formed ripples indicate an environment with weak currents where water motion is dominated by wave oscillations.
149:
opposite symmetrical ripples form. Symmetrical ripples tend to have the same slope on both sides of the crest.
87:
300:
175:
159:
163:
95:
the pattern of wave-formed ripples may be complicated, as a product of changing depth and wind and
96:
227:
239:
203:
199:
223:
83:
294:
47:
104:
17:
79:
31:
125:
92:
71:
67:
63:
42:, Mongolia. Note "decapatation" of ripple crests due to change in current.
59:
180:
113:
35:
27:
39:
124:
112:
75:
218:
107:, which have unequal intensity in opposite directions.
82:
are often characterised (and thus distinguished from
133:B=Effect of oscillatory motion in shallow water
8:
131:A=Effect of oscillatory motion in deep water
228:10.1306/D42690DF-2B26-11D7-8648000102C1865D
26:
192:
7:
25:
220:Journal of Sedimentary Research
202:(2001) "Sedimentary Petrology",
1:
317:
34:or symmetric ripple, from
56:wave-formed ripple marks
246:pp. 114–15, 352.
176:Sedimentary structures
140:
118:
43:
135:1=Progression of wave
128:
116:
30:
222:, Volume 11 (1941),
52:wave-formed ripples
18:Wave-formed ripples
141:
119:
117:Symmetrical ripple
44:
200:Maurice E. Tucker
58:are a feature of
16:(Redirected from
308:
285:
281:
275:
272:
266:
263:
257:
253:
247:
236:
230:
216:
210:
197:
160:straight crested
129:Wave motion-i18n
21:
316:
315:
311:
310:
309:
307:
306:
305:
291:
290:
289:
288:
282:
278:
273:
269:
264:
260:
254:
250:
237:
233:
217:
213:
198:
194:
189:
172:
164:sinuous crested
155:
146:
138:
136:
134:
132:
130:
86:) by symmetric
84:current ripples
23:
22:
15:
12:
11:
5:
314:
312:
304:
303:
293:
292:
287:
286:
276:
267:
258:
248:
231:
211:
191:
190:
188:
185:
184:
183:
178:
171:
168:
154:
151:
145:
142:
139:3=Wave trough
88:cross sections
24:
14:
13:
10:
9:
6:
4:
3:
2:
313:
302:
301:Sedimentology
299:
298:
296:
280:
277:
271:
268:
262:
259:
252:
249:
245:
244:0-314-09577-2
241:
235:
232:
229:
225:
221:
215:
212:
209:
208:0-632-05735-1
205:
201:
196:
193:
186:
182:
179:
177:
174:
173:
169:
167:
165:
161:
152:
150:
143:
127:
123:
115:
111:
108:
106:
105:breaker waves
100:
98:
94:
89:
85:
81:
77:
73:
69:
65:
61:
57:
53:
49:
48:sedimentology
41:
37:
33:
29:
19:
279:
270:
261:
251:
234:
219:
214:
195:
156:
147:
137:2=Wave crest
120:
109:
101:
97:tidal runoff
80:ripple marks
55:
51:
45:
93:tidal flats
32:Wave ripple
187:References
72:siltstones
68:limestones
64:sandstones
166:ripples.
153:Formation
78:. These
60:sediments
38:rocks in
295:Category
170:See also
181:Bedform
144:Ripples
36:Permian
242:
206:
74:) and
40:Nomgon
256:Press
76:dunes
284:2007
240:ISBN
204:ISBN
224:doi
162:or
54:or
46:In
297::
70:,
66:,
50:,
226::
62:(
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
